How much can you see in a large city light polluted sky?
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The following lists contains all the instrumentation used to take all the photos on this website.



Telescopes
Orbitor 70mm F4.2 refractor
SkyWatcher 102 mm F5 refractor
SkyWatcher 114 mm F4 Newtonian Telescope
Meade 2080 8" SCT
Meade SN8 (schmidt Newtonian)

Imagers
Meade DSI-C
Meade DSI Pro
Meade DSI Pro II

Filters
Wideband Light polution Blocking filter (Nebular filter)
Meade Narrow band 908N
Lumicon LF3085 Hydrogen Alpha long pass filter

Equatorial Mount
LXD-75

Special equipment
Orion AccuFocus electric focuser.
Telescope Info
The Orbitor Telescope has focal lenght of 300mm making it ideal for obtaining the widest field of view.

The SkyWacher 114mm F4 Netwonian telescope is a favorite because it allows pictures to be taken without any IR filter, since it does not contain any lens that do not focus IR light at the same point as visible light. As a result increased sensitivity is seen because of the IR energy gets focused and added to the visible light. The SkyWatchers 114 mm Newtonian does not have enough backfocus to use with the DSI Pro filter bar. A special adaptor had to be made to use these imagers more info can be found here on the design of this adaptor. Also the focal length of this telescope (450 mm) results in a relatively wide field of view but makes this telescope of limited use for planetary imaging. A barlow lens is required to obtain more magnification and since lens are added the use of an IR filter is required eliminating the advantage of the Newtonian telescope.

 

The SkyWatcher 102 mm F5 refractor telescope provides foughly the same focal length as the SkyWatcher 114 mm Newtonina but needs an IR filter therefore is less sensitive to light. However since it has no central obstruction it provides a better image on planetary pictures.

 

The Meade 2080 SCT telescope is very flexible since it allows various focal reducers and barlows to be use to obtain focal length from 600 to 4000mm. However mirror shift and the stablility of the focus makes it more difficult to use. Also a a special electric focuser is required to work with an SCT, such focuser are expensive ($200).

 

The Meade SN8 telescope is an F4 telescope which provides 812 mm focal length without any focal reducer. Since it contains a corrector lens the use of the IR filter is required.

Electric focuser usefullness

 
A good focus is a must for good astro photography, no matter what instrument is used focusing always makes the difference between a poor picture and a good one. To achieve good focus very fine movement of the focuser is required and without an electric focuser vibration is caused everytime the focuser is touched manually resulting in a longer time to acheive focus having to wait for the vibration to stop to evaluate the quality of the focus achieved so far. Also it is also difficult to make small movement of the focuser knob and one sometimes does not know if the movement done is insuficient or too much due to backlash in the focuser (unless you have a crayford focuser).