Dynamic range and colors

If you would like to post, you'll need to register. Note that if you have a BCG store account, you'll need a new, separate account here (we keep the two sites separate for security purposes).

DavidT

DavidT

Well-known member
Supporting Member
Marketplace
Member's gallery
Little back story to my upcoming questions. I shot some astro photography a week ago and used my D850 with Nikon 12-24 f2.8 @14mm and a Z6 with 14-30 f4 @f4. A seasoned astro guy there was using a D800, Z6 and another body I believe a D7200 and he mentioned the Z6 has the best dynamic range.

Does the Z6 have more dynamic range than a D850? How does the D6 compare?

Interestingly I liked the images from the D850 a lot more. However the Z6 images seemed to have more color in the sky than the D850 did.

The D850 had an exposure of around 30 sec at iso 10K and the Z6 had an exposure of around 20 sec at ISO 8K.

Thoughts as to why?

I would need to downsize the images to be able to upload if anyone needs to see them.
 
Member's gallery
Check here: https://www.photonstophotos.net/Charts/PDR.htm

Screen Shot 2020-12-18 at 16.39.42.jpg
You can only see EXIF info for this image if you are logged in.
 
Member's gallery
Here's the data from DxOMark.com for the D850, Z6, and D7200. The D7200 DX camera does not perform quite as well as it's FF cousins, but the D850 and Z6 are pretty close in sensor performance, but you have to give the edge to the D850 as it's a 45.7mp sensor compared to the 24mp Z6 sensor. With the right glass the D850 can show more detail, but the Z6 has a slightly better SNR, DR, as well as tonal range. The Z6 advantage is probably due to the lower pixel density compared to the D850, so the sensor light buckets are bigger and can hold more photons. Difference in exposure could be due to the glass, the slightly better Z6 sensor performance or just a different choice of exposures. Usually lenses are sharper a stop or two up from the bottom, so if you were running both at f/4, the 12-24 f/2.8 probably had a sharpness advantage at f/4, but I would have to look at the lens measurements to confirm that.
SNR Comparison.JPG
You can only see EXIF info for this image if you are logged in.
DR Comparison.JPG
You can only see EXIF info for this image if you are logged in.
TR Comparison.JPG
You can only see EXIF info for this image if you are logged in.
 
Member's gallery
dtibbals said:
Interestingly I liked the images from the D850 a lot more. However the Z6 images seemed to have more color in the sky than the D850 did.

The D850 had an exposure of around 30 sec at iso 10K and the Z6 had an exposure of around 20 sec at ISO 8K.
Click to expand...

The higher the ISO the less dynamic range you get. This might have an influence. Have you looked at Steve's Astrophotography stuff to see if there is any mention of ISO? long time since I read them.

Astrophotography Archives - Backcountry Gallery

backcountrygallery.com backcountrygallery.com
 
Member's gallery
Your exposure seems a little arse about for me. I would have thought you would push the F4 lens higher in the ISO and time?

I've not done much astro but the couple of times I've tried I got great Milky Way results (for single shot, no tracker) with the D850/14-24 combo at ISO 3200-6400 and 20-30 secs.

One thing regards colour too is understanding what colour your dark frame goes when pushed, my D850 goes purple and my D500 goes green. So I know to push white balance away from those colours.
 
You must log in or register to reply here.
Back
Top