Ron-Indy Loc: Indy

I've just begun experimenting with Milky Way shots and noticed that in many of these shots, my Nikon D750 seems to be capturing or creating odd color banding between the lower lighter sky and and the darker upper sky. In post production they become even more noticeable. I shoot RAW & JPG simultaneously and it is visible in both. ISO 5000 at 10 second exposures or ISO 800 at 30 seconds, doesn't seem to matter.

This is the untouched / as shot JPG as taken @ Crater Lake Oregon a few weeks ago:

D750
Nikon 20mm 1.8
ISO-800
f/1.8
30 seconds
auto white balance

My question is:
- What is the cause?
- What can I do to prevent?
- Is it possible to remove / minimize in Photoshop/Lightroom/OpticPro?

OK to modify if anyone would like.

Thank you

As shot JPG

(Download)

TucsonCoyote Loc: Tucson AZ

Not that I'm a knowledgeable astronomer or anything like that but I don't notice any abnormal "banding" .....unless you are talking about the greenish arboreal banding ......if that is the case you have to bitch to a higher power than a camera maker ! :)

Ron-Indy Loc: Indy

So that's a natural phenomenon? Shows what I know! Just to be sure, it's more visible here in what is probably considered a poorly photoshop'd file

(Download)

TucsonCoyote Loc: Tucson AZ

Yup! what the naked eye can't see is revealed by your 10-15 second exposure with a good camera ! :)
Fantastic shots BTW ! :thumbup:

Ron-Indy Loc: Indy

Thank you very much! I can sleep peacefully tonight now :)

TucsonCoyote Loc: Tucson AZ

Aurora Borealis or northern lights is what I meant ...Arboreal has to do with trees ! ....Anyway ! :)
(will teach me to believe auto correct ! ) :roll:

tusketwedge Loc: Nova Scotia Canada

If the 750 has no anti aliasing filter it could contribute to banding which first popped up when they took the filter out of the d7100. What I see is nothing like the banding that can show up in a low light image taken with the 7100. Where I find I get it is if I'm shooting a sunset and it has shadows.the shadow part will have severe banding.Have shot the milky way and none present.
By the way if you using PS or Lightroom for processing, drop in into raw converter and use the dehaze found in effects. does a bang up job on night shots
just read up on the d750 and unlike the 7100 it does have the anti aliasing filter.

jerryc41 Loc: Catskill Mts of NY

The camera can sometimes see what the eye can't. Read up on Blue Hour photography. When you take a picture of the sky within an hour before sunrise or after sunset, the sky will look black to the photographer, but deep blue to the camera. I think that's what's happening here. The camera is seeing variations in the lighting in the sky. Either that, or your camera is broken. :D

Pixelpixie88 Loc: Northern Minnesota

I don't see any banding or haloing. Could it be possible that there are some light clouds above the horizon? With your shutter open so long it has picked that up. That's what it looks like to me.

Armadillo Loc: Ventura, CA

Ron,

If what you are referring to is the faint changes of light and color between the horizon and the stat pattern, you are probably seeing atmospheric layering in the Stratosphere. Look at that area at 100% magnification, you will be sable to see the layers of the atmosphere.

It is natural, you are lucky to have captured it, this gives the night sky a 3-D effect.

Look at the stars at 100% and notice the slight blur. If you used a long exposure and a solid tripod you may want to look at a star tracking tripod. This is used for large telescopes to track the Moon, planets, and stars so there is no earth movement during the exposure.

Michael G

R.G. Loc: Scotland

Green and magenta appearing in long exposure night sky shots has been commented on before in UHH. Some put it down to peculiarities of the camera when capturing low levels of light. Personally I think it's more than just a coincidence that green and magenta are the main colours of the Aurora Borealis. As Jerry pointed out, the camera will reveal things that the eye can't see during a long exposure.

The other colours that you might see in shots like that are due to

a) atmospheric haze (at night it's predominantly blue, but may include purple/magenta).

b) light pollution (it's colour depends on the source - typically it's yellow and/or orange from street lights).

If you're lucky you might capture a variety of colours that are a natural part of the Milky Way.

If the green and magenta bother you, you could use an HSL tool to target those colours. You could either darken and desaturate them to minimise their presence or you could shift them towards a more typical sky colour like blue.

twowindsbear

Could you have captured the 'green flash?'

Wikipedia says:

http://en.wikipedia.org/wiki/Green_flash

Ron-Indy Loc: Indy

Thanks for all the comments - I participate in a few other forums and I have to say the quality and quantity of the responses here are far and away superior. Thank you again.

Hard to quote the variety of responses all in one post but I'll try this way, newest first:

"Could you have captured the 'green flash?'"

Possible but since both the Crater Lake Oregon and Hurricane Ridge Olympic National Park have the referred to colors and were taken at different times, perhaps not. Crater Lake was soon after sunset but the Hurricane Ridge was taken at about 2:00am.

"...If the green and magenta bother you, you could use an HSL tool to target those colours. You could either darken and desaturate them to minimise their presence or you could shift them towards a more typical sky colour like blue."

Knowing that they are in fact actually there makes them more appealing to me. Thank you for the suggestion though as I might play around with minimizing just to see.

"...If you used a long exposure and a solid tripod you may want to look at a star tracking tripod..."

I used a Benro A1682T with a V1 ball head. Seems quite stable and there wasn't any wind in either location. I'd love a tracking tripod but living in Indy there is a lot of light pollution so I do most of my night shots during work travel and have to pack light. Not early meeting friendly but my career has already peaked so different priorities. 15 second exposure on the HR shot and 30 seconds on the CL. Going forward, I'll stick to higher ISO and shorter exposure times.

"...Could it be possible that there are some light clouds above the horizon? ..."

I thought the same but the stars don't look obscured at all in that area so I'm more toward the Aurora Borealis.

"...Read up on Blue Hour photography..."

Thank you I will.

"...if you using PS or Lightroom for processing, drop in into raw converter and use the dehaze found in effects. does a bang up job on night shots..."

I'll try that. The HR shot was run through DxO OpticsPro and it's interesting. Long way to go to become proficient in all of them (PS/LR & OP).

nikon_jon Loc: Northeast Arkansas

Astronomers didn't know the heavenly bodies and formations had color until the advent of color film. The instantaneous nature of light allows for only a glimpse of it to the human eye. When color film began being used in the observatories, the light accumulated on the film after long exposures and they discovered a wonderful variety of colors in the universe.

Alby144 Loc: Northern Nevada

No odd banding here; just an awesome photo! Great job.