So, are you interested in astronomy
,
purchased telescope and think about the different obvese to improve the quality and convenience of observation. Retrofit issues and is dedicated to this post - eyepieces, filters, and other gadgets.
A word of warning h4> In coterie of amateur astronomy theme eyepieces and other body kit very holivarnaya. Here I present my experience two years lazy hobby amateur visual astronomy. If you disagree with the written on, or do you tell the opposite opinion, please treat with calmness and understanding.
Eyepieces h4> 
Some theory h5> Eyepieces, like telescopes, long evolved from primitive devices with lots of distortion at the beginning to advanced-telescope complex optical systems with anti-glare and computer simulation in the design. An optical circuit eyepieces not make much sense, because many optical systems now, they are complex, their at different firms, and, in fact, become the most important properties of eyepieces:
The focal length
The field of view
Relocation pupil
Diameter
Weight
Also eyepieces with fixed focal length has a so-called zoom-eyepiece with variable focal length. Available focal lengths typically lie in the range 7-24 mm, the normal field of view of 40-60 degrees. But there are also unusual representatives, for example, 2-4 mm zoom.
Number of workers available eyepiece focal lengths can be doubled by using the so-called Barlow. This diverging lens, which is placed in front of the eyepiece, reducing its focal length is usually twice (there are 3 other lenses).
How object will look into the eyepiece h5> The easiest way to see how the object will be visible in the eyepiece with the parameter of interest - this plugin "eyepieces" to Stellarium. The plugin comes bundled and is included in the parameters:
Consider the effect of the field of view of the eyepiece on the visibility of the object as an example for a small increase Pleiades: telescope 900 mm focal length eyepieces all 20 mm field of view is changed in increments of 20 degrees - 40, 60, 80 and 100 degrees. Do not forget that many of the objects Stellarium draws prettier than they look in the telescope visually, such chic nebulae in reality you will not see.
Consider the effect of the focal length of the eyepiece on the visibility of the object on the example of the Pleiades. Telescope with a focal length of 900 mm, all the eyepieces with the field of view of 60 degrees, the focal distance varies with the pitch of 5 mm - 30, 25, 20, 15, 10, 5 mm.
If you want to buy an eyepiece, it is highly desirable to substitute its characteristics in this plug-in and walk through the object of interest.
Planning ocular management h5> Manufacturers usually completed with one or two telescopes and eyepieces sometimes Barlow. If you took the telescope in the "generous" configuration with two eyepieces and Barlow lens, you have four available increase, which is quite possible to spend the first months, slowly picking optional kit. Possible increase of the telescope can be divided into:
Small
High School
Large
My experience h5> 
My ocular economy as agriculture Telescopic other gadgets, obeys the Pareto principle - 20% of the eyepieces used 80% of the time. I would say 20% percent is used by almost 100% of the time. I have a 25mm eyepiece (complete), 10 mm (complete), zoom 8-24 mm, 4 mm, Barlow lens (complete). Almost always use the zoom 8-24 mm due to its versatility. Without changing the eyepiece can be infinitely closer to the moon or to choose a balance between increasing the money for other projects. Possibility of increasing the smooth change is extremely convenient - you can see the moon at maximum brightness and minimal increase, then place it entirely in the eyepiece, and finally move on to the maximum zoom eyepiece for observing craters. Very convenient. If necessary, put Barlow lens and I get the range of 4-12 mm for the planet. Unfortunately, Barlow lens significantly degrade the image quality, so is not used very often. If necessary, maximize, without long and severe ligament zoom + Barlow lens is used 4mm eyepiece - on planets or double stars. But this is quite rare, the reality is almost always more comfortable in the range 37-112h, which gives me a zoom eyepiece.
Not eyepieces h4>
Filters h5> Filters provide image enhancement by filtering out unnecessary light flux or unnecessary parts of the spectrum. By construction, the filters are divided into solar, hydrogen lines (H-Alpha) lunar, polarization, color, deep sky, other.
Solar filters are metallized film or special coated glass. They are placed on the inlet / telescope lens instead of the cover and allow to observe the Sun in the eyepiece is similar nocturnal objects. Using sunscreen can see sunspots, flares field granulation on the sun.
Filters hydrogen lines - a thin grating intercept virtually all of the light spectrum except for the hydrogen lines. It allows us to observe prominences on the sun. The market amateur astronomy is actually one manufacturer - Coronado. They produce solar telescopes with built-in filters and filters for conventional telescopes. Because of the complexity of the production of these filters are very expensive - from $ 600 telescopes, filters in the area of $ 1000.
Moon filters reduce the overall brightness of the moon, making it comfortable observation. At full moon, the moon is so bright that it can cause discomfort during observations.
polarizing - a subspecies of the lunar filter that allows to adjust the brightness decrease on the move, for example, reducing the brightness of from 5% to 25%.
Color filters filter out various portions of the visible area. There excellent article on color filter , a table from which I quote here:
deep sky filters - these are special filters for observing nebulae. There UHC (Ultra-High Contrast - ultra-high contrast), O-III (spectral lines of oxygen), H-beta (hydrogen lines). At the same resource with educational materials on astronomy have table test filters (partially shown):
Other filters - a filter to reduce the chromaticity at the achromatic (Fringe killer), filters to reduce urban glare, contrast enhancement, etc.
My experience with the use of filters h5> I have two color filters - # 21 and # 82A orange blue and UHC filter. Serious quality improvement is not observed, in my view, reducing the brightness is stronger image enhancement. Color filters were used on Jupiter, there is a noticeable improvement. UHC used by M57 and Big Orion Nebula - the loss of brightness outweighed any benefit from the filter. But my observations have a balcony, good extra-filters I have not tested, maybe there will be better. Color filters worth to check on Mars, it was so very plain this year, but alas, I forgot.
Not eyepieces h4>
Drive mount h5> 
On equatorial mount EQ1 and EQ2 of the Sky-Watcher can buy the drive mount - a small motor that will rotate the telescope with the speed of rotation of the Earth. Very handy thing to single observations and invaluable to astrovyezde with friends - you can point the telescope to the object and not to accompany his hand for the passage of all interests aiming to continue.
Accessories Alignment h5> Half kindersyurpriza - it belongs to the alignment. The fact that it has a bore diameter 1 25 & quot; and very well inserted into the focuser assembly. Curiously, adjustment already survived two astrovyezda probably little better retain its Newtons.
Bag h5> If you plan to leave the telescope outside the balcony, the bag would be very helpful. I have a home-made, thanks to his wife. In principle, nothing complicated, fabric, foam and something solid type of linoleum.
Flashlight h5> 
Very useful to think ahead and make astrofonarik of kopeck Chinese headlamp, adding to the glass of red plastic folder or something like that. Such lanterns are often removed the windshield and it will not be difficult.
Eyecup h5> 
Squeezes his eyes shut eyes, looking through the eyepiece the other is not very convenient. Over time you get used and filtered image from the second eye brain, but for the first time, you can make your life easier eyecup - from simple bandages to special handmade equipment, again thanks to his wife.
Conclusion h4> In conclusion, small astrosekret - comfortable and well organized place for observations increases the permeability of the telescope by half a magnitude you :) Good observation!
Source: habrahabr.ru/post/226219/
