This some freaky stuff here. I have owned and used a H-alpha modified Nikon Z6 by Lifepixel for over a year now. I have never had a problem with the images this camera produces.
My girlfriend and I just came back from a four night extravaganza of shooting the Milky Way. 4 nights in a row of clear skies in upstate NY— crazy, right! Keep in mind she has the exact same camera, lenses, tracker, and adapter as I do. The only difference is hers is stock, not modified at all. What is happening in my camera is not happening with hers.
It seems several of my images contain this awful reddish gradient depending on where/what I am shooting. This is the first time I have ever seen such an anomaly, and I am completely baffled. I fear I am losing valuable data and many of my shots from our adventure are completely ruined…
I cannot seem to pinpoint the problem, but given the example shots I feel like it may be the Canon 24-70 2.8L II I am using in conjunction with a Fringer Canon EF to Nikon Z mount adapter. I have never seen this happen with any of the Sigma ART primes with the Nikon FTZ adapter I have used in the past, and I have yet to find it an issue with the Canon 70-200 f/2.8L II coupled with the Fringer adapter. But as you will later see the 24-70 is perfectly capable of producing no gradient shots when there is no light pollution (I am assuming this is a factor).
What I do know is that it is not amp glow. The gradient changes when I zoom, it is not in the same spot on the sensor. It is also not an internal sensor light polluter like on the Sony bodies, the Z6 sensor does not have such a thing. I can also add in that while I have tested for a light leak on the Fringer adapter, it does not appear to be the culprit given I did the same test for the Nikon FTZ and the results were the same.
The gradient does not show up in dark frames if taken in a dark area. If taken in a more well-lit area, there are some light leaks, but I believe it is just coming from the lens cap of the 24-70.
I am stumped, so hopefully someone on here can help me out! Let’s get to some samples:
Figure 1: this is the first ever shot I noticed the gradient in. It happened shortly after I swapped a memory card. I thought it was the card so I replaced it with another one and recomposed. It seemed to have fixed the problem for the night and I thought I had found the culprit. The next night of shooting I found out I was wrong… Note that the settins are different for each shot but regardless the gradient isn’t visible in the shot post card swap. What happened?
Figure 2: this was the last night of the extravaganza. I was preparing to shoot a pano. I had my UV/IR cut filter on for the shot on the right. The shot on the left it was off. Settings were exactly the same. Obviously, the shot with the filter on is well more controlled, but the gradient is STILL there!! There is even a friggen lens flare in BOTH of these shots albeit more subtle in the shot with the filter on. What in the world?????
Figure 3: 2 shots. Same exact settings and focal length, different composition (panned only). Gradient is in the exact same location.
Figure 4: 2 shots, same settings, slightly different composition, same focal length BUT different lens. On left is the Canon 70-200 f/2.8L II, on right is the 24-70 f/2.8L II. Only the 24-70 has the gradient.
Figure 5: a shot that I took at another location with the 24-70 and no immediate light pollution in the foreground, no gradient!
Figure 6: another shot with the 24-70 zoomed to 35mm taken from a different location. You can see the gradient in the bottom right.
So, what is going on here? Any help is much appreciated. Hopefully we can get to the bottom of this.
Edited by DanielJStein, 28 May 2020 - 10:18 AM.