Is ISO 400 stretched in PP the same or better DR than ISO6400 not stretched?

Started Aug 10, 2013 | Discussions thread
Per Baekgaard
Contributing MemberPosts: 915Gear list
Like?
Re: Is ISO 400 stretched in PP the same or better DR than ISO6400 not stretched?
In reply to Astrophotographer 10, Aug 12, 2013

I think ISO1000-1600 is fairly safe.

I am now inclined to shoot lower ISO and boost in post processing for that little extra as rich colour and subtle faint details but keeping good shadow dark areas intact is what its all about in a night sky shot.

Yes, I think your conclusion is fairly healthy, as Marianne has already commented: If you need the sensitivity and can avoid clipping, ISO1600 (or just under) is a very reasonable compromise for these types of shots.

Obviously if you increase the exposure you can gain more DR by going down to e.g. ISO400, but it requires a solid tracker (which it looks like you have...) but it will also cause more foreground blur of the non-celestial objects, as you also point out yourself.

Just one additional comment: When pushing, not all raw converters appear to do so linearly. Some people have reported slight hue twists for large pushs, so you may get different results between, say, Capture NX2, Lightroom and RawTherapee. Probably +2 EV will not make a big difference, but if you push +4 EV you might also introduce twists to certain hues (Jack Hogan linked to this page in another thread on a related topic: http://dcptool.sourceforge.net/Hue%20Twists.html, where he also pointed to RawTherapee as a quite linear converter when using the "neutral" profile).

Glad you found value in the links/comments -- look forward to see more cool shots from you

- Per.

 Per Baekgaard's gear list:Per Baekgaard's gear list
Nikon D800 Nikon AF-S Nikkor 70-200mm f/2.8G ED VR Nikon AF-S Nikkor 14-24mm f/2.8G ED Nikon AF-S Nikkor 24-70mm f/2.8G ED Nikon AF-S Micro-Nikkor 105mm f/2.8G IF-ED VR +15 more
Reply   Reply with quote   Complain
Post (hide subjects)Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow