Glossary of terms and FAQ

GLOSSARY OF TERMS and FREQUENTLY ASKED QUESTIONS

Many times when we want to make a gift or we want to introduce ourselves in the world of astronomy, earth observation or microscopy, dozens of doubts arise. The most common resource is to go to an internet forum but many times the information is not correct or is so dense that it is of little help.

At Telescopiomania thanks to the knowledge of our team and being aware of the most common doubts that arise when choosing an equipment, we have written this brief glossary that we hope can be of help to any beginner who is immersed in a sea of doubts ;-)

We leave you a small index to make it easier for you to locate the points that may be of interest to you:

• Frequently asked questions about astronomical telescopes: .....................................1 - 11
• Frequently asked questions about eyepieces: .........................................................12 - 18
• Frequently asked questions about filters:..............................................................19 - 25
• Frequently asked questions about astrophotography: .................................................26 - 30
• Frequently asked questions about mounts:........................................................31 - 37
• Frequently asked questions about cCD cameras: ................................................38 - 45
• Frequently asked questions about binoculars: ....................................................46 - 53
• Frequently asked questions about solar telescopes: ...........................................54 - 56
• Frequently asked questions about terrestrial telescopes: .......................................57 - 66
• Frequently asked questions about microscopes: ...................................................67 - 73

Frequently asked questions about astronomical telescopes

1. What is a refracting telescope?

Refracting telescopes, designed by the astronomer Galileo Galilei, are constructed with a doublet lens as objective. They are telescopes with relatively small diameters, which therefore have low light-gathering power but offer high contrast. Apochromatic or low dispersion (ED) refractors offer sharper images than achromatic refractors because they have no chromaticity. This makes them ideal telescopes for observing the Moon and planets.

2. What can I see with a refracting telescope?

In general, a refracting telescope provides an excellent view of the Moon and planets. It will also offer a very good view of some star clusters if observed from a place without light pollution. Refractor telescopes, when used with a inverting prism also allow their use as terrestrial telescopes for general nature observation.

As an example, the following are images captured by an entry-level refractor telescope, the CELESTRON Astromaster 90EQ:

3. What is the difference between a telescope achromatic refractor and a apochromatic?
Achromatic refracting telescopes are the most basic telescopes that correspond to the entry-level or mid-level ranges of refracting telescopes. The objective (the front lens of the tube) is a two-element lens and always suffers a little from what are called chromatic aberrations (in the observation of very bright objects such as the Moon, a faint yellowish line appears in the profile). In apochromatic refractors, the lenses and their treatments are better and therefore, they do not present chromatic aberrations and the final image is sharper and better contrasted.

4. What is a reflecting telescope?
The reflecting telescopes, designed by the physicist Isaac Newton, capture the image through the use of mirrors. They are characterized by having a proportionally large diameter with respect to their focal length, which gives them an extraordinary luminosity. For this reason they are ideal for the observation of deep sky objects: galaxies, nebulae, planetary nebulae, emission nebulae, etc. Within the reflecting telescopes, also known as Newton telescopes, there is a variant famous for having an easy-to-mount mount and very economical prices dobson telescopes.

5. Is a Newton reflector telescope a variant of the reflector telescope?

No. The words reflector and Newton are used interchangeably to refer to the same type of telescopes. This is because Newton was the inventor of the design of reflecting telescopes and his name has been adopted in his honor.

6. What can I see with a reflecting telescope?
Thanks to their exceptional luminosity they are ideal for observing faint objects, therefore, where they perform best is observing deep sky objects, i.e. galaxies, nebulae, planetary nebulae, emission/reflection nebulae and Supernova remnants. However, the observation of these objects is subject to the quality of the night sky. If it is light polluted it will be difficult to observe these objects without a filter anti-light pollution UHC/LPR.

As an example, the following are images captured with an entry-level reflector telescope, the CELESTRON Astromaster 130EQ:

Celestron Images.com

7. What is a catadioptric telescope?
Catadioptric telescopes are very versatile devices that have been designed by combining the use of mirrors (as in Newton's) and a kind of corrector lens that allows the use of spherical geometry mirrors, which are easier to manufacture than those used, for example, in other types of reflecting telescopes. Catadioptric telescopes stand out for having already large diameters combined with relatively high focal lengths so that they offer a typical average brightness: brighter than refracting telescopes and considerably less bright than reflecting/Newton telescopes. Thanks to the double internal reflection between their mirrors, catadioptric telescopes have a much shorter length than expected for their focal length. This makes them an easily transportable telescope that will allow us to do remarkably well in the two main types of observation, planetary and deep sky.
There are several different catadioptric telescope designs, but the most popular ones are the Schmidt-Cassegrain and the Maksutov-Cassegrain. In the background are the Maksutov-Newton or Schmidt-Newton telescopes.

8. What are the differences between a Schmidt-Cassegrain and a Maksutov-Cassegrain telescope?
Both designs belong to the group of catadioptric telescopes. However, their differences are important and basically lie in the following points:

-The corrector plateCorrector plate: the corrector plate is a kind of lens that is placed at the front of the tube and whose function is not to converge the image to a point, as traditional lenses do, but to modify the path of the light in a suitable way to compensate for the spherical geometry of the primary mirror. As an optical element, the corrector plate causes light loss by absorption and reflection. In the case of Schmidt-Cassegrain the corrector plate is much thinner than in the Maksutov-Cassegrain and therefore allows much more light to pass through. In this sense, the Maksutov-Cassegrain are like a telescope with much higher contrast but with higher brightness losses.

-Focal points used: the Maksutov-Cassegrain, have proportionally very large focal lengths compared to their diameter. This means that they have a low light gathering power, with focal ratios such as f/12 or f/13, whereas the Schmidt-Cassegrain, in most cases, they are adjusted in diameter and focal length to present a higher luminosity, such as f/10. For this reason, the Maksutov-Cassegrain as ideal telescopes for the observation of Moon and Planets (they would be like a refractor but without the problem of chromatic aberrations) while the Schmidt-Cassegrain, the brightest, most luminous, would be true all-rounders, valid for both Moon and planet observation and deep sky observation.

-Thermal stability and diameterTelescopes Maksutov-Cassegrain usually have a limitation in diameter due to their extreme sensitivity to thermal stability (temperature difference between the inside of the telescope and the outside, which generates turbulence at the mouth of the tube making it impossible to perform a satisfactory observation). A Maksutov-Cassegrain, if it does, it should not exceed 130mm in diameter and if it does, it is essential that the manufacturer has integrated fans at the rear of the tube to assist in the air conditioning of the tube. The telescopes Schmidt-Cassegrain do not encounter this problem and can be manufactured in diameters up to 400mm without the need to integrate fans.

9. What characteristics should I take into account when selecting the right telescope?
Choosing your telescope is not an easy decision. Usually, we do not want to make a mistake and we want to buy a telescope that can serve us for a few years and that allows us to enjoy astronomy. Some people say that the worst telescope is not the cheapest one but the one that will serve us for years to come

NO USE!

Therefore, the decision must be a narrowing process in which we discard telescopes according to some basic criteria that we must be clear about.

These are the basic criteria that must be met before purchasing a telescope:

-Type of optics I wantFirst we have to consider what kind of objects we want to observe, because it will not be the same to observe the Moon than a galaxy, for example. If our objective is to observe the Moon and the Planets, in that case the most recommendable telescopes are the REFRACTORS and catadioptrics MAKSUTOV-CASSEGRAIN. If we wish to observe galaxies, nebulae, planetary nebulae, supernova remnants, etc., in this case, as they are very faint objects, we need to work with a telescope REFLECTOR/NEWTON. And if our objective is to be able to observe a little bit of everything, including planets and deep sky objects, in that case the most recommendable are the catadioptrics SCHMIDT-CASSEGRAIN.

-DiameterThe diameter of the telescope is the key point. The larger the diameter of the optical tube, the better, because we will have more light gathering power (and therefore we will be able to see fainter objects), more resolving power (the ability to resolve two points at a certain distance) and more magnification capacity (the larger the diameter, the higher the theoretical limit of maximum magnification that we can achieve with a telescope).

-Frame typeThe mount is the support where the telescope is placed. The mounts are determinant because the more robust they are, the more stability they give to the system and this can be essential in certain occasions. There are mainly two types of mounts: the altacimutals and the german equatorial. The altazimuths work like a terrestrial tripod with the typical up-down and left-right movements. They are easy to use and transport but have the disadvantage that they cannot be used for deep sky astrophotography (long exposure times and equatorial tracking). For photography of the Moon and Planets, the altazimuth mounts will also be useful. The German equatorial mounts are considered astronomical mounts, since they require alignment with the polar star and work with axes that follow the spherical coordinates of the sky (right ascension and declination). In general terms, German equatorial mounts are the best for astronomical observation and are a must for deep sky photography.

Finally, the mounts, whether altazimuthal or German equatorial, can be manual, motorized or computerized... The manual ones imply that you have to carry them by hand to point them at the astronomical object you want to observe. The motorized ones are like the manual ones, only that when you have the observed object centered in the field of view, the motor will follow the object to leave it more or less centered even if it is moving. And finally, there are the computerized ones that, apart from the motors, also have an extensive database with thousands of astronomical objects stored in memory, so that the computerized mounts are able to automatically locate the objects in the sky.

-PortabilityPortability is a determining factor if we will have to take the telescope to the field for observation. We have to take into account the boxes, their volume and the space we have in the car to go out observing. If we are lucky enough to observe from home, this factor is not so important.

-Place of observationOur place of observation can affect us a little depending on the degree of light pollution that we have there. It will not be the same to observe from the center of a city like Madrid or Barcelona than from a rural area. REFLECTOR/NEWTON telescopes are more sensitive to light pollution than other types of telescopes, therefore, a high presence of light pollution would be counterproductive to work with a REFLECTOR/NEWTON telescope unless you are using a light pollution filter (known as LPR filters).

-BrandThe manufacturers of astronomical telescopes have proliferated, but it is very important not to make a mistake and to work with serious, quality brands that are able to offer a good after-sales service. In this sense, at Telescopiomania we are strongly committed to the brands that provide us with all these advantages and we always put pressure, in the good sense of the word, on importers so that our customers benefit from purchasing through us. In this sense, we believe that brands such as CELESTRON, , SKY-WATCHER, , BAADER PLANETARIUM, , OPTICRON, , ATIK, , GEOPTIK, , TS, , KOWA, , VANGUARD among others are the ones we are most satisfied with and highly recommend.

-Warranty and technical serviceAfter-sales service as well as technical service assistance is another strong point that the manufacturer of the telescope we purchase must have. Here there are some brands that stand out notably above the rest. If you have any doubt about this, call us because it is very important to make sure that if you have any problem with the device, there will be a reliable warranty, valid for Spain (be careful with the purchase of telescopes in NON OFFICIAL distributors or NOT AUTHORIZED by the brand) and that there will be someone who will be able to solve the problem. In Telescopiomania we will make all the necessary arrangements to ensure that you get a solution to your problems.

-BudgetThe budget limit is obviously the one that will really limit the number of telescopes that are right for you. Anyway, as prices are becoming more and more competitive, it is interesting to leave this filtering criterion as the last one to be sure that we will buy the telescope that will meet our expectations.

10. How can I calculate the magnification of my telescope?
The calculation of the magnification is very simple to perform and will depend on two parameters: the focal length of your telescope (which we will call "F") and the focal length of the eyepiece we are using (which we will call "f"). The magnification is obtained by dividing F/f = Magnification.

The theoretical magnification limit of a telescope is usually calculated by multiplying the diameter in millimeters of the telescope by 2. Thus, a 130mm diameter telescope, for example, will have a maximum theoretical magnification limit of 260x. In practice, however, it is always advisable to stay within a safe distance of this maximum magnification.


11. How will I see galaxies or planets in my telescope?
First of all, it is necessary to break a myth that is sometimes very widespread. All astronomical objects, whether Moon, planets or galaxies, nebulae, etc., are seen in black and white. The human eye is not sensitive enough to appreciate colors in faint astronomical objects. At most, in the Moon and the Planets, certain shades can be appreciated; ocher, for example, in Jupiter, blue in Venus and reddish in Mars, but in general the sensation is of absence of color. In the photographs we see of various objects, the colors have been obtained by applying different filters and the images have been mounted after the fact, therefore, I will never see a color image in the telescope, no matter how much the manufacturers insist on putting color photographs on the packaging of the equipment.

Frequently asked questions about eyepieces


12. What is an eyepiece?
The ocular is the lens that we place on the telescope to be able to observe the image it shows us. Without an eyepiece we will not be able to see anything through the telescope because we will not be able to focus the image. There are eyepieces of different designs, depending on the number of lenses they have and the apparent field they capture, and they can be selected with different focal lengths.

13. What is the focal length of an eyepiece?
The focal of an eyepiece allows us to know what magnification it will give us once we place it in our telescope. The magnification is easily calculated by dividing the telescope focal by the eyepiece focal.

14. Why are there eyepieces with such different prices?
There are many different optical designs of eyepieces. Depending on these designs, there are many factors that influence the final price of the eyepiece such as the following:

-Number of internal lensesThe following is not the same for an eyepiece manufactured with three lenses as one that has 6 or 7 internal lenses.

-Quality of glass usedThe use of normal glass or low dispersion ED glass with special coatings will not be the same.

-Lens diameterIt will not be the same to manufacture a 1.25" eyepiece as a 2" diameter eyepiece.

- Apparent fieldNormal eyepieces usually offer apparent fields of 45 or 50º, but there are models that have been designed to offer fields of 68, 82 and even 100º of apparent field.

15. What is the apparent field of an eyepiece?
The apparent field of an eyepiece is a data given in degrees. It allows us to calculate what will be the real field that our eyepiece will capture once we place it in a telescope. The apparent field, let's say, is a generic value of the eyepiece and is a value that never changes. On the other hand, we have to calculate the real field based on the apparent field of the eyepiece and the magnification it will give us in our telescope.

16. Which eyepiece should I use for planetary and which for deep sky?
As noted above, since magnification is obtained by dividing the telescope focal length by the eyepiece focal length, we find that the smaller the eyepiece focal length, the more magnification we will get. Conversely, the larger the eyepiece focal, the less magnification we will get from our telescope.
To observe the Moon and the Planets, we are interested in working with high magnifications, therefore, we should use eyepieces with small focal lengths, i.e., those between 5 and 12mm approximately. Contrary to what intuition might suggest, to see deep sky objects (very distant and very faint) such as galaxies, nebulae, etc., what we are interested in is to have VERY LITTLE INCREASE to open the field and be able to capture much more light and thus have options to see these objects. So, to see deep sky, it is advisable to work with eyepieces with focal lengths between 30 and 50mm... If you can use an eyepiece with these focal lengths and also with a 2" diameter, even better.

17. How can I calculate the actual field I will see in my eyepiece?
All eyepieces on the market have two technical characteristics that are very important: the focal length (which will determine the magnification) and the apparent field (which will determine the actual field observed in the eyepiece). If F is the focal length of the telescope used, f is the focal length of the eyepiece and AFOV is the apparent field of the eyepiece, the real field that we will see captured in the image will be calculated with the following formula:

Actual Field (º) = AFOV / (F/f)

That is, dividing the apparent field of the eyepiece by the magnification that the eyepiece gives us for that telescope, we will obtain the REAL FIELD captured.

Thus, for example, for a telescope with F=1000mm and an eyepiece with f=10mm and AFOV= 50º we will obtain a REAL FIELD of 0.5º. Since the Moon has a size such that its diameter occupies precisely 0.5º we find that with this configuration, this eyepiece would fill its entire field of view with the image of the entire Moon. If it had given us a REAL FIELD of 0.25º, in that case, the entire field of view would be occupied by half of the Moon.

18. What is a barlow lens?
A barlow lens, strictly speaking, is not an eyepiece. It is simply a lens that multiplies the focal length of the telescope by 2 or 3 times. In this way, higher magnification can be easily achieved. However, it is necessary to look carefully at the use that is going to be given to it since it is just another optical element and therefore, if it is not of good quality, it can worsen the result of the final image.
If a good 2x barlow is desired, the barlow is recommended CELESTRON X-CEL LX 2x or the X-CEL LX 3x and the magnificent barlows of TeleVue.

Frequently asked questions about filters

19. What is a filter?
The filters are screwed on the lower part of the eyepiece so that the light reaching our eyes is not 100% of the light emitted by the observed object. That is, if we put a red filter, the light that will pass through the red filter and reach our eyes will only be light emitted by the observed object in the red spectral range. In this way, we sacrifice information, since we will only see the part that emits in the red channel, but in exchange, we get a higher contrast image.

20. What is a filter for?
Its main use is to achieve higher image contrast in order to resolve surface details on planets or to see deep sky objects more clearly.

21. What filters do I need for planetary observation?
For observing the Moon and Planets the recommended filters are color filters. Each filter can highlight or help resolve a different surface detail so there is no specific filter for each planet. What is recommended is to work with a varied set of color filters to be able to observe the Moon and planets with all of them. Each color filter will give us a different perspective. We recommend a set of 4 filters or, if eyepieces are also required, we recommend the optical kit with eyepieces and various filters.

22. What filters do I need for deep sky observation?
For deep sky, the filter that is considered as the nebular filter par excellence is the uHC/LPR filter. This filter lets through all light except that generated by streetlights and public lighting in general. In this way, it is possible to observe deep sky objects in places with a lot of light pollution. The effect is that the background sky becomes black again and in this way the galaxies and nebulae can be contrasted again and have options to see them.


23. What is an OIII filter for?
The filters OIII are filters that do not allow any type of light to pass through them except for the light emitted by ionized oxygen, known as OIII. In this way it is possible to see objects that otherwise could not be seen, or very specific regions of some deep sky objects. With the OIII filter, basically, we will be able to observe emission nebulae and some Supernova remnants.

24. What are narrowband filters?
The color filters commonly used for observing the Moon and planets are known as broadband filters. The reason is that although they filter in red, blue, green, etc., they allow a lot of light to pass through (many frequencies of light within the red range). On the other hand, when we talk about a narrow band filter, in this case, we are referring to very restrictive filters that only allow a very limited frequency of light to pass through. Therefore, they are very specific and have very specific applications, especially in photography, but on the other hand they offer high contrast images. Among the most common narrow-band filters, the most common are the Hydrogen Alpha (Ha), , Hydrogen Beta (Hb), , Ionized Oxygen (OIII) and the Sulfur Ionized (SII).

25. What is a polarization filter for?
The variable polarization filters are filters that by playing with the orientation of both filters allow to select the amount of light that we want to be transmitted through the filter. The amount of transmitted light can usually be selected between 20 and 85%. This is very useful for observing the Moon and double star systems where the main star eclipses the secondary star. By progressively reducing the transmitted light through the filter, we can easily reach the point where we eliminate the diffraction of light from the main star and that will allow us to see the secondary star perfectly.

Frequently asked questions about astrophotography

26. Can I do astrophotography with a refracting telescope?
Yes, but with most entry-level refractor telescopes, it is only possible to take pictures of the Moon and planets. We will not be able to take pictures of galaxies, nebulae, clusters, etc. In addition, we will need special adapters depending on the type of camera. It is best to photograph with a reflex camera and use the following adapters: Universal T-Adapter and the T-Ring according to the camera model.

27. Can I do astrophotography with a reflector telescope?
Yes, with the appropriate adapters. For most newton telescopes it is recommended to shoot with a DSLR camera using the following adapters: Universal T-Adapter with Barlow and the T-Ring according to the camera manufacturer. In any case, it must be taken into account that although a reflecting telescope performs best in photography of deep sky objects, as these are very faint, exposure times of several seconds or even a minute should be used. For this it is necessary that the telescope mount is at least motorized and ideally computerized. It is also necessary that the telescope mount is of German equatorial type.

28. Can I do astrophotography with a Schmidt-Cassegrain telescope?
Yes, the schmidt-Cassegrain telescopes can give an excellent result in photography of the Moon and planets. For deep sky photography, as they have an average focal ratio of f/10 it is highly recommended to acquire a focal reducer like the one offered by the manufacturer CELESTRON: f/6.3 focal reducer.

The coupling with the Schmidt-Cassegrain telescopes is simple and only two parts are needed to adapt DSLR cameras, the T-adapter for SC and the T-Ring according to the camera manufacturer.

29. What mount is the most suitable for astrophotography?
It will depend on the type of photography you want to do. If we are satisfied with taking images of the Moon and planets, we can say that almost any mount will do. In any case, both the altazimuth mounts such as the German equatorials. However, if we want to do deep sky (wide field) photography, i.e. galaxies, nebulae, planetary nebulae, clusters, etc., in that case we are required to have a german equatorial mount and that it is at least motorized, but if possible, it is much better if it is computerized.

30. Can I take pictures with my compact digital camera?
Yes, if you have a compact digital camera with a 3x or 4x optical lens at most, you can use the universal adapter for compact digital photo. If your digital camera has a lens between 8x and 12x in that case the coupling will only be possible if the lens has a thread in its front part that allows us to make a coupling with BAADER accessories. In any case, this adaptation will force you to work with an eyepiece BAADER Hyperion, of any focal point.

Frequently asked questions about frames


31. What is better: a altazimuth mount or a german equatorial?
It will depend on what we want to do. An altazimuth mount is easier and more intuitive to use and the software associated with them is usually designed with the neophyte in mind. Thus, altazimuth mounts, being also easier to transport and assemble, can be highly recommended. However, there is one limitation, which is deep sky photography. If we want to have the option of doing deep sky photography someday, this forces us to work with a German equatorial mount. German equatorial mounts, apart from being designed with photography in mind, are also usually sturdier and more stable mounts which makes for better observation. German equatorial mounts enjoy a better reputation than altazimuthal mounts for general quality.

32. Which is better: a manual, motorized or computerized mount?
It will depend on the time we have and the patience we have... A manual mount implies that we will have to locate all the objects we wish to observe, using our knowledge and skills. We will not have any kind of help other than a celestial chart or a constellation guide. This will mean that at the beginning we will be very slow and we may spend the night without having seen many objects. Also, with a manual mount, once we have the object we want to observe centered in the field of view, we must follow it by moving the right ascension axis by hand. Otherwise, the observed celestial body will disappear from the field of view.
If our mount is motorized, this means that we can steer it with the motors and that when we have the object centered in the field of view (and provided that we have correctly performed a polar alignment of the mount) the mount will follow by itself the movement of the planet, star or galaxy we have centered. Motorized mounts do not have a GOTO system, i.e. they cannot locate celestial objects by themselves. The GOTO system is only integrated in computerized mounts.

Computerized mounts, whether equatorial or altazimuthal, are capable of automatically locating astronomical objects, either based on the objects stored in the database or by means of coordinates entered by the users themselves. Computerized mounts are highly recommended for all users, since in the case of novice users, computerized mounts will greatly facilitate the location of objects and thus make the most of the observing session. For the advanced user, computerized mounts have a series of functions that will allow you to get the most out of the mount, especially in astrophotography applications.

33. Does a motorized mount automatically locate astronomical objects for me?
No, a motorized mount, the only thing it has is one, or two coupled motors so that the right ascension and declination axes can be moved without manual action. The movement of the axes is controlled by a simple control knob that allows setting one or two different speeds (fast and slow) and the direction of rotation of the axis. However, the motors are not connected to any database, so they are not able to find astronomical objects by themselves. This can only be done by the computerized frames with GOTO system.


34. What is the load capacity of a saddle?
The load capacity of a saddle is the maximum theoretical weight that a saddle can support without its performance being altered or its components being damaged by being forced. That is to say, if a saddle has a load capacity of 15Kg, it means that in no case we will be able to load on the saddle a weight that is superior to those 15Kg. In fact, the most advisable thing to do is to configure an optical system with a weight that is not too close to the load capacity of the mount. In the example of a 15Kg mount, it would be desirable not to load it with more than 12Kg maximum.

35. What is periodic error correction?
The accuracy of a mount's tracking of astronomical objects is closely linked to the manufacturing precision of its gears (crowns and bevel gears). The crowns linked to the right ascension and declination axes of motion have been manufactured with certain tolerances, so that they themselves are directly responsible for introducing certain errors in the tracking of astronomical objects. For example, suppose a mount has a crown on the right ascension axis that takes 8 minutes to make a complete turn on itself when tracking a star. If the crown, due to its quality, introduces a deviation of 25 seconds of arc, with respect to the position it should occupy, once those 8 minutes have passed, it means that at 16 minutes the error introduced would already be 50 seconds of arc, etc. This deviation caused by the precision of the crowns is called Periodic Error.

German computerized equatorial mounts, already of a certain performance, have a software function called Periodic Error Correction (PEC). With this function, the Periodic Error introduced by the mechanical components of the mount can be minimized as much as possible.
In Telescopiomania we have also tested some new devices for autoguiding eliminating the problems of periodic error. We are talking about the fantastic Explore ScientificTelescope Drive Master.

36. How can I feed my mount when I go to the field?
The most convenient way to power the mount on our field trips is to use a portable power supply or battery. A very practical example is the already popular PowerTanks.

37. Can I use the PowerTank to power the laptop and the mount at the same time?
You can, but it is not recommended. First we must make sure that our laptop works at 12V because there are some models that work with different voltages. But apart from that, the shared use of a PowerTank can introduce alterations in the performance of the mount, either because of lack of voltage (or voltage fluctuations) or because the output amperage is not stable enough. Therefore, our recommendation is to work with a single PowerTank to power the mount and another PowerTank unit to power other accessories such as electrical systems antidew, laptops, laptops, etc.

Frequently asked questions about CCD cameras


38. What cCD camera is it recommended for planetary photography?
To perform planetary photography, and thus be introduced into the wonderful world of astrophotography, it is recommended to use cameras with small CCD's that will give us a good magnification and obviously, with the highest sensitivity and resolution that may be possible ... In the case of planetary photography you can choose to work with both a color camera and a black and white camera. Normally, in deep sky photography we always opt for black and white (monochrome) as it takes more advantage of the resolving power of the sensor, but in planetary photography, we can afford, without sacrificing much, to work with color cameras and thus save having to take multiple exposures with different filters, work with filter holder wheels, etc.
The cameras that are currently producing the best results are the ZWO, the NexImage 5Mp from CELESTRON and the ATIK GP.


39. Which is better for astrophotography: monochrome or color camera?
The method used by CCD sensor manufacturers to provide direct color images implies that the CCD pixels are grouped 4 by 4, and in each group of 4 pixels, two are given a green microfilter, one a red microfilter and the other a blue microfilter. In this way, you get direct color images but at the cost of sacrificing the resolution power of the CCD because in the green color you only work with 50% of the CCD pixels and in the red and blue you only work with 25%. Therefore, with a color camera, the task of obtaining the color image is made much easier (because we do not use filters or filter-holder wheels) but we sacrifice resolution and, in addition, we will not be able to work with narrow band filters.
Therefore, for deep sky astrophotography in particular, we should recommend working with monochrome cameras as they allow us to take advantage of 100% of the CCD's resolving power and give us the freedom to work with the filters of our choice, whether they are color, narrow band or photometric.

40. What size of CCD is more convenient?
It will depend on the application for which you want to use the camera. If we are going to do planetary photography, a camera with a small CCD will suit us very well, since for this application we are not interested in capturing large fields. On the other hand, if we want to do deep sky astrophotography, we will be interested in capturing a larger field and in that case a large format CCD will be the most desirable.


41. What is the quantum efficiency of the CCD sensor?
The purpose of a cCD sensor is to convert each photon of light hitting its surface into an electron that can be digitally processed and reproduced on an output device such as a PC monitor. Quantum efficiency describes the sensor's ability to perform this conversion successfully. A quantum efficiency of 80% means that 80% of the photons that reach the CCD are successfully converted into electrons. Therefore, quantum efficiency is a very important property in a CCD that will be put to astronomical use.


42. Is it better to have a large pixel or a small pixel?
It will depend on the use we are going to give to the camera. A large pixel necessarily implies a lower resolving power, but on the contrary, having a larger surface area, it has a very large capacity to accumulate light. Therefore, in applications where the main goal is to capture the maximum amount of light (astrometry and photometry) we will be very interested in having a CCD with a large pixel size.
If, on the other hand, we wish to take photographs with maximum resolving power, then we are interested in cameras with a small pixel size but with the maximum possible number of pixels.


43. How can I take color photos if my camera is monochrome?
Most of the color images we see of objects in the sky have been obtained with monochrome cameras in order to take advantage of their maximum resolving power. The method used is as follows: a monochrome camera is placed on a filter holder wheel, between the camera and the telescope. A certain number of images are taken, but always in triplicate, using first a green, a blue and a red filter. The images obtained are superimposed and a single final color image is obtained.


44. What accessories can be interesting to use with a CCD camera?
If the camera is in color there is not so much need for accessories. Perhaps a off-axis radial guide can be very useful to be able to place another camera or an eyepiece on the side and thus be able to perform autoguiding successfully. If the camera is monochrome, we will certainly need a monochrome camera in the long run filter holder wheel (manual or electric), filters, which may be made of color, of narrow band o photometric as we are interested in and also the off-axis radial guide.


45. What is adaptive optics?
An adaptive optic is an accessory that is placed in front of the CCD sensor and through a series of internal reflections makes an estimation of the real position of the captured star, so that the distorting effect of "seeing" (quality of visibility of the night sky attributable only to atmospheric factors) is minimized or eliminated. In this way, since the star being used as a guide is much smaller and point-like, the system is able to improve the performance of the self-guided and obviously the photographic image captured by the CCD is also significantly improved.
Recently the manufacturer ZWO has designed a small, efficient device that can economically replace adaptive optics. It is the Atmospheric Dispersion Corrector. With this simple device you can also correct the negative effect of atmospheric dispersion and improve image sharpness to obtain better planetary photographs and improve guiding performance.

Frequently asked questions about binoculars


46. What does the numbering on the model mean? binoculars or binoculars?
Binoculars are called 8x42mm, 10x50mm, etc. according to their format. The first number (8 and 10 in the examples used) refers to the magnification of the binoculars. The second number, often followed by the unit mm, refers to the diameter of the objective lens of the binocular (the objective is the front lens).
Apart from the objective diameter and magnification, the other determining factor when selecting a binocular or binocular is the type of prime it uses. There are two types of prism (by design) those of porro prism and those of roof premiums:

-Joint prismBinoculars: these are the most traditional and often the most economical binoculars. They can be distinguished by their shape which makes the objectives of the binoculars farther apart than the eyepieces. That is, the eyepiece of the binocular is not aligned with the objective. These binoculars have larger prisms that are not fixed to the binocular body.

-Roof prismThese binoculars have a straight format. The eyepieces are aligned with the objectives and the prisms are small and fixed to the body of the binocular. This makes them more compact so that they take up less volume without sacrificing brightness and they are more resistant to shocks and therefore much more difficult to dislodge.


47. Where is the binocular focused?
There can be different formats, but the most common is that in the central axis of the binocular, located between the two eyepieces, there is a focusing wheel and by turning it we can focus at any distance. In some large format models, you have to focus individually for each eye, but this method is used in a small number of models.


48. What is diopter adjustment?
Generally, on the right eyepiece of the binocular, there is a knob that can be turned a little to either side. This is what is known as diopter adjustment and allows us to fine tune the focus to bridge the small differences that we may have between one eye and the other. The idea is that we should first focus the left eye using the central focusing wheel and once we have the left eye in perfect focus, we should use the diopter adjustment to bring the right eye also in perfect focus. If we know that our left and right eyes are identical (i.e. we have the same degree or absence of myopia or hyperopia) then we should leave the diopter adjustment in the "0" position.


49. What is the interpupillary distance?
The interpupillary distance is the distance between our eyes. Depending on the person, the eyes have one separation or another. For this reason, it is essential that binoculars are adjustable and allow the interpupillary distance to be adjusted. All binoculars can be adjusted and the adjustment is usually made by means of a hinge system located on the central axis where the focusing wheel is also located. The important thing is that this distance is well adjusted so that the user only sees a single image in a single central circle. If when looking through a binocular we see two independent circles, it means that we do not have the interpupillary distance properly adjusted.


50. What is the minimum focusing distance?
Binoculars, depending on their design, have a focusing path that allows focusing from infinity to a distance as close as possible to the observer. This is known as the minimum focusing distance. It is the closest distance at which it will be possible to focus. This minimum focusing distance is usually about 2 meters, depending on the format and design of the binocular.


51. What is the visual field?
The field of view can be given in degrees or in meters at a given distance. It is the portion of the horizon seen through the binocular. A binocular with a 6º field of view will show a larger portion of the horizon than one with only a 4º field of view. There are applications, especially astronomical ones, where having a large field of view is interesting, as it is also associated with having a higher brightness. However, having a large field of view can be at odds with having a high magnification. Therefore, it is good to evaluate which factor is more determinant for our type of observation, the magnification or the luminosity and the field of view.


52. What is eye relief?
The eyepieces of the binoculars are the ones that allow us to see the image. Although it is not visible from the side, the eyepieces project the image to the outside of the binoculars so that our eyes can capture the image. This outward projection of the image is called eye relief. Usually, an average value in binoculars of a certain level is an eye relief of about 20mm. That means that if you put your eye within the range of 20mm from the surface of the binocular you can see the image... The 20mm allows you to see even with glasses... But if you bought a binocular with an eye relief of only 10mm, maybe a user with glasses would not be able to see the image. Therefore, it is an important factor to take into account.


53. What type of observation is recommended for a binocular or binocular?
Binoculars are excellent for those nature lovers who want to have a portable and easy to handle optical device. They can be taken to the field, to the mountains, for hiking, for ornithological observation. The binoculars provide ideal magnification for general observation. In applications where high magnification is required, it will be better to work with a spotting scope.
For astronomical observation, binoculars are a good element to get started allowing the observation of deep sky objects. In the following link you can filter the binoculars according to the use you are going to give them:

- Binoculars classified by use in Telescopiomania

Frequently asked questions about solar telescopes


54. What can I see with a solar telescope?
With a dedicated solar telescope such as the LUNT SOLAR SYSTEMS, the H-alpha filters, which have what is called an H-alpha filter inside, allow the most complete observation of the sun that can be obtained. We will be able to observe eclipses, transits, sunspots, surface granulation, bulges, flares and filaments. This is much more than can be seen with a solar filter placed in a normal astronomical telescope. In the latter case, only eclipses and sunspots are visible.


55. Can I use a solar telescope for other types of observation?
No, dedicated solar telescopes have special filters that do not allow normal light to pass through... Therefore, they only allow observations of the Sun.


56. Can I see sun bumps with normal sunscreens?
No. The bumps and flares can only be seen with dedicated solar telescopes such as the ones from the brands CORONADO o LUNT.



Frequently Asked Questions about Terrestrial Telescopes


57. What can I see with a ground-based telescope?
Much will depend on the diameter of the telescope, the magnification power of the eyepiece and the visibility conditions on the day of the observation, but in general, the terrestrial telescopes are used when we already intend to make observations a few kilometers away. We could say that they are recommended for observations of objects that are between 1 and 12Km away. However, there are specific models, such as the Maksutov or the Schmidt-Cassegrain that allow the visualization of objects of considerable size but which are located at a distance of up to 30 km.


58. I'm an ornithologist and don't know which brands of spotting scopes are the best?
There are several very powerful brands, but without a doubt, the best for ornithological observation are Kowa, , Leica, , Swarovski y Zeiss. Lately, due to the technological improvements that have been introduced in their products, we could also include in this group Kite Optics. Then, in a second term and for those cases in which a good quality is sought but at a more affordable price we would have to highlight brands such as Celestron, , Opticron y Vanguard.


59. What is a Fluorite telescope?
A Fluorite telescope is said to be a Fluorite telescope because it has at least one Fluorite lens in the objective. Fluorite is a mineral (which can be natural or synthetic) that acts as a color corrector making Fluorite telescopes free of chromatic aberrations. Therefore, with Fluorite telescopes we would be talking about the best ground telescopes on the market. The fluorite telescopes, also use low dispersion lenses.


60. What is low dispersion?
Low dispersion is the ability of certain lenses (which constitute the objectives of ground-based telescopes) to minimize the dispersion of the light beam as it passes through the lens. In this way, the observation with the telescope gains in contrast and definition. Ground-based telescopes with low-dispersion optics are often labeled with the acronym ED o XED (Extra Low Dispersion). In this range of equipment, telescopes and binoculars stand out notably ENDEAVOR ED of the brand VANGUARD.


61. What diameter should I choose?
The ideal diameter will depend on what our priority or need is. Obviously, the larger the diameter of our telescope, the brighter it will be and the higher magnification it will be able to reach. In this sense, a 100mm diameter would seem ideal. However, we must also take into account the portability and stability of the system once we mount the telescope on a tripod. Taking these factors into account, we could say that the ideal is a telescope around 80mm in diameter. In fact, most spotting scopes sold, for any type of use, are 80mm diameter telescopes. That said, each application may have its particular needs and based on those needs other options can be looked at.


62. I participate in shooting competitions and need a portable telescope to see the target?
As there are different shooting modalities (bow, pistol, different distances, in the gallery or outdoors) each case would have to be studied in detail, but one of the equipment that is performing best in these applications is the following:

- Ultralight telescope Mighty Midget from OPTICRON
- Support light bipod and folding of OPTICRON

The most important thing for this application is that the telescope is very easily transportable, has a small footprint and has sufficient magnification to see the target perfectly. Other options that may be of interest are the following:

- Earth Telescope Vanguard Endeavor XF 60A
- Earth Telescope Pack Celestron Ultima 80 with tripod HAMA Star 63

In another more low-cost product line, we would recommend the following:

- Earth Telescope Celestron UpClose 60mm Zoom 20-60x 45º
- Terrestrial telescope Bresser 20-60x60 8820100


63. Which eyepiece is the most suitable for observing?
The most common, and for more general applications, is the Zoom eyepiece, which usually covers an approximate magnification range from 20x to 60x. The magnification range of the Zoom eyepiece will depend on the diameter and focal length of the telescope with which it is used. Other eyepieces that are often very successful are the 30x or 27x eyepieces but are designed to give a wide field of view. These eyepieces are very interesting in the case of photography through the eyepiece.


64. What is Digiscoping?
Digiscoping is the technique used to take photographs through a terrestrial telescope. In the world of ornithology, Digiscoping has evolved a lot and very fast in the last 10 years. To perform Digiscoping, apart from the telescope and the camera, several accessories are needed that have to allow a robust coupling between both and that does not cause secondary problems such as vignetting. Big brands such as KOWA, , LEICA, sWAROVSKI or ZEISS have a wide variety of accessories to allow almost all couplings to be possible.


65. Can I make Digiscoping with all telescopes?
In principle yes. There are brands that have the issue more carefully than others, but there is almost always one solution or another to attach our camera to a spotting scope. It is true that there will be more elegant solutions and others a little more rudimentary, but if our goal is to capture the image displayed through the eyepiece of our telescope, there will almost always be some alternative that will allow us to successfully perform this task. The best thing to do is to consult with our technicians if there is any doubt.


66. Can I buy more eyepieces for my spotting scope?
Normally, most manufacturers use bayonet eyepieces. This means that the eyepieces only fit into the eyepiece holder by means of a unique bayonet system, which is not universal. This means that if you want to expand the number of eyepieces you have for your spotting scope, you will almost certainly have to buy eyepieces from the same manufacturer and make sure that the eyepiece is compatible with your telescope model. However, there are models from manufacturers such as CELESTRON that work with a 1.25" eyepiece holder and this is a Universal standard. Therefore, with telescopes such as those in the REGAL F-ED from CELESTRON we can use eyepieces from other manufacturers, such as the Hyperion by BAADER PLANETARIUM.



Frequently Asked Questions about Microscopes

67. What is a microscope better biological or a stereoscopic?
They are two different microscope designs. It cannot be said that one is better than the other because they are designed for different applications. A biological microscope usually gives high magnifications of up to 400x or 1000x but implies having to work with samples prepared on a slide. It would be for viewing cells, studying blood, viewing organisms in pooled water, etc. A stereo microscope, on the other hand, works at a much lower magnification range, usually covering between 7x and 45x. They are called stereo microscopes because they have two objectives and offer a stereoscopic view of the observed object (with a feeling of depth of field). They are used to view minerals, stamps, plants, coins, circuit boards, insects, jewelry, etc.


68. What type of microscope is most suitable for a child?
Both types of microscopes may be suitable for a child. However, stereo microscopes offer the facility of being able to observe any object that falls into their hands, without the need to prepare the sample for observation. In this sense, stereo microscopes give a lot of play in the observation of insects, flowers and minerals in general, which are often the object of attention of children.


69. What is a magnifying glass?
Sometimes, to make it easier to identify, a magnifying glass is called a loupe stereo microscope.


70. What is the difference between a monocular and a binocular microscope?
This refers to the type of head the microscope uses. If the head has only one exit with one eyepiece, we will say that it is monocular. If it has two eyepieces, one for each eye, it is a binocular microscope. Binoculars are more comfortable if you spend a long time in front of the microscope. If the head is binocular and also has a third vertical exit (at the top of the head) we will say that it is a triocular head.


71. What is a triocular head used for?
It is used to make it easier to adapt a microscopy camera or reflex camera to the microscope and thus obtain photographs of the samples observed. Currently, specific CCD cameras for microscopy can be attached to almost all models of microscopes.


72. I want to see blood with a microscope, what do I need?
To observe blood in detail it will be necessary to work with a biological optical microscope with a minimum magnification of 1000x.


73. Do they digital microscopes are biological microscopes?
Most of them do. They are biological microscopes that have integrated an internal CCD camera and sometimes even have integrated screens to display the captured image. They are very practical microscopes and very oriented to educational and popularization tasks. The following digital microscopes stand out above others CELESTRON as the TetraView (with touch screen) or the LCD II.


In this document, elaborated entirely by Telescopiomania, you will find the answers to all the doubts that potential buyers of telescopes and binoculars may have. The technical but concise and clear answers will allow the reader to better choose the product he/she needs.