[aprssig] Taking photos of sats

[Ray Wells]

Neville A. Cross wrote:
> On Mon, Sep 7, 2009 at 12:15 PM, Andrew Rich
> (Home)<vk4tec at tech-software.net> wrote:
>   
>> Hello
>>
>> I saw the ISS and also hubble go across the night sky
>>
>> Anyone into photography that could give me some pointers as to how to
>> capture the streaks across the sky
>>
>> ----------------------------------------------------------
>> Andrew Rich
>>     
>
>
> There are two ways of doing this. Easy and Difficult.
>
> Easy: You use a tripod, wide angle lens and long exposure. You
> estimate the general direction where the sat will show and you shoot
> for a couple of minutes. You will end up with a bright line across the
> stars on the background.
>
> Difficult: You use a motorized azimuth elevation following system that
> is fast and very very stable. Use a software that follows the sat and
> long exposure. If it is not an stable rotor, you will have shaking on
> your photo. Astronomical rotors are not that fast to follow a sat.
> Depending on the magnification of your equipment you will have a
> bright dot or a bright shape and starts like lines on the background.
> Not sure if you will like this outcome.
>
> I have only see pictures of Iridium Flares, when a Iridium sat
> reflects the sun on its solar array. Not sure if the ISS will be
> bright enough to leave the bright trail.
>
> Best regards
>
>   
I seem to recall reading about the use of computer controlled stepping 
motors for telescope tracking of Celestial bodies. I think a Polar mount 
is also used. I'd guess it's the same principle so a bit of Googling 
might produce meaningful results.

Ray vk2tv