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View Full Version here: : Reutn to Astorphotography Sombrero 2017


ehgore1978
28-02-2017, 01:06 PM
Its been a couple of years since ve done anything and then I was only a beginner. This is last nights Sombrero. 2.5 hours ISO6400 45 seconds on a Canon 5d Mark 3. I was hoping for more detail. Any suggestions please. I also have stacked tiff file available from DSS I can link from dropbox that is 200 ood meg though

traveller
28-02-2017, 01:55 PM
Great effort Scott.
Maybe the focus was a bit off, but the image looks a bit "soft" and the stars look a bit bloated :shrug:

doppler
28-02-2017, 03:11 PM
Welcome back to astro imaging. You're off to a good start, tracking / guiding looks good but focus is definitely soft. 6400 iso is also a bit high to be using especially during summer. I would be trying for 1600 iso (or lower) and longer subs. Are you still using the 10" newt on the NEQ6 ? With the right iso, good focus and guiding you will get some great images with that set up.

ehgore1978
28-02-2017, 03:46 PM
Hi yes i am. Same setup had a feeling i was off any recommendations on the time of subs. the camera was running at 32 - 34c and Im also wondering if i have some smudge on my coma corrector As you may see I have the galaxy high up on the frame but ii know I can do better from past sessions. I was hoping to get some detail on the dust lane

https://www.dropbox.com/s/te9ant5ttkzotlu/Autosave.tif?dl=0

here is the stack version unprocessed if anyones interested

(edit just looked at my iso settings half was 1600 and 3200)

doppler
01-03-2017, 11:44 AM
The ideal length of subs and iso speed combination can vary between equipment and locations so you need to experiment a bit. In light polluted areas sub length will be much shorter before the background will be over exposed. Faster f ratio scopes will also work better with either shorter exposures or lower iso's . Temp wise sensor temps in the low 30's is not too bad for summer, mine has been running high 30's here in the tropics.
I check individual subs for focus (live view 10x zoom, then take a pic and zoom in on the image), background exposure and to see if I am getting some data of the subject before I start a sequence of subs. I check the focus every half hour or so because that can and does shift as the equipment cools.

sil
01-03-2017, 12:37 PM
I can only suggest apart from focus is to underexpose your settings, so maybe just lower ISO or shorter subs. Once stacked a wavelet process should bring out clearer structure and bring exposure out (if your subs are well exposed its easy for processing the stack to overexpose to clipping structure, but underexposure a little and you can bring it out easily, typically I tackle exposure last in my workflow.)

ehgore1978
01-03-2017, 02:27 PM
Thanks and I never even thought of the focus changing through out the night. I might try 800 @ 60 or 1600@30. This picture is of my setup inside the shed so i should be able to tell if Im on point. Im on the Yorke Penninsula in Moonta Bay not much light pollution