groth12345

4 hours ago, The Admiral said:

What mount are you using to track the heavens? The maximum exposure I've used with my NexStar Alt-Az is 30 seconds without getting too many streaky subs, though others have managed to use a little longer. At the end of the day though you will be limited by physics, in that you will get field rotation. Lowest towards the East and West, and worse as you increase altitude towards the zenith. I used to limit it to 60°.

Ian

That's pretty good with the Nexstar.  Mine would be good in the east/west for about 20-30 sec but I'd still have to toss about 50% of the subs out.  Now using an Evo mount and it's much better.  Probably 80% usable subs as long as close to the east/west horizons.

Taken in city lights of Rochester, NY last night.  

90 x 30 sec lights (no filters, no darks, no flats). 

Alt-Az (Celestron Evolution mount). 

Fujifilm X-a10 mirrorless DSLR @1600 ASA (75F), Celestron C6, @ f/4.  Used Starizona Night Owl .4x reducer.

M57 - More data (150 x 30 sec subs)

Updated M13 with Nexstar 6" Evolution Alt-Az.  @ f/6.3 and Fujifilm X-a10 camera.  97 subs at 30 seconds, combination of 1600 & 800 ISO. 

Some new pics taken with Nexstar6SE upgraded to Evo mount which has much better tracking.  Each 30 sec subs x 60.