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

shiftyonthemic wrote:

Jerry-astro wrote:

I've been pretty successful with starscapes and other astro work with the following basic settings:

ISO 3200
25s max exposure length (else you risk star trailing)
Wide open (f/2.8 in my case -- Zeiss Touit 12mm lens)
Shoot RAW for maximum post processing latitude

Even at those settings, your shots might appear somewhat underexposed. However, there's enough processing latitude to give you plenty of contrast and detail (one reason to shoot RAW in this case). NR at that ISO is still pretty manageable with minimal "star eating" issues.

Jerry-- Did you boost the EC to get a more neutral histogram?

There is nothing to be gained by increasing the EC, ETTR really only applies at base ISO. By setting your SS at 25 sec (or less) and whatever aperture you’ve chosen, you have set the exposure, increasing the EC (ISO, in this case) will only limit the dynamic range you have to work with later and will likely blow out some highlights unnecessarily. Your camera is ISO invariant at 800, so you won’t increase the noise (relative to boosting it in-camera, but by boosting the brightness in post, you will be able to preserve some highlights that would get away otherwise. It’s fine to increase the EC in-camera a bit to see what’s going on, but use the highlight warning (a far better way to judge sensor saturation than the histogram), and keep the EC below (or “at”) where you see any blinking on important (usually ground based) highlight detail. ISO 1600 is usually fine, if you’ve got a lighthouse or something in the foreground you’ll likely be better off at 800 (or better yet, take multiple exposures).