Night Sky Shooting / Astrophotography on X-T2 : ETTR? ISO 1600?

MPg1 wrote:

Hello, great discussion thank you all! I'm also moving my first steps with astrophoto. I have a Vixen polarie and this evening I will try to shoot Andromeda with a fuji X-t1 and 300 mm Nikkor lens. In my previous efforts I used ISO 3200 and 25 seconds, shot a lot of images (95) and stacked with Deep Sky Stacker. And lost color, so much that I decided to convert to B/N for the final image - I will include one of the results. Now I learn I probably had overexposed stars, any I did not try any highlight recovery converting from raw to tiff before stacking. I am now debating what iso setting I will use tonight, the site Photons to Photons for the X-T1 shows a fairly flat curve, does this mean thay whatever ISO I choose it will really not matter? I was thinking about using ISO 400 and then I found this thread and I am starting to rethink all over again. Another question: last time I invested a lot of time shooting those 95 frames with the same settings. This time I could go for shorter series of maybe 15 frames and then change settings to experiment, seems a better way to learn and choose better settings next time. What do you think?

Thank you, Marco

M31

Surprisingly good result w/ 300 on the Vixen, well done.  Traveling now so don't have access to tools to give you an answer to your question.  Suggest you search this forum for a thread by Rudypohl who uses this lens w/ a D5300 that has same vintage sensor as the XT1.  As I recall, his exposure was around 30" w/  a stepdown ring to stop the lens to something like f5.6 w/o diffraction spikes.  I think he used ISO 400 but my memory could be way off.  As I recall he has a lengthy discussion of how he manages aberrations from this lens.

I own an XT10.  It has much lower thermal noise than the XT2 so you need not worry about increased noise w/ long exposure duration.  And the dynamic range of the T10 almost equals the T2.  The T10 is certainly capable of excellent color Astro.  Suggest you reprocess the subs for this image w/ highlight recovery.  Also, I've seen several discussion here about a specific DSS setting you need to use or your stack will lose most of it color.  Sorry I don't use it since I'm on Mac.

Lastly, do you use a polar scope on the Vixen?

Good luck.