a7rii and Tamron "Holy Trinity" Uneven Exposure

I just started noticing some weird artifact on some of my photos, wherein the brightness and color is strangely-inconsistent across the sky. In the sample photos attached, you can see that in the first one, the sky has a weird purple area in the middle and in the second one, there's a muddy blob in the sky and the edges are inconsistently colored. The third one is converted to B&W in Lightroom and the blues brought down to accentuate the issue in the image. These were shot on an a7rii. The first with the Tamron 28-75 and the second with the Tamron 17-28. I didn't grab an example from the 70-180, but see the same artifact there as well. Sensor is clean and all lens compensations are off. Only applied lens correction in Lightroom with no vignetting applied. Any ideas?

If the lenses are brand new, could it be that they still have some protective film on the front element? Of course be very careful when checking

AltVanguard said:

If the lenses are brand new, could it be that they still have some protective film on the front element? Of course be very careful when checking

Click to expand...

+1

Have heard that halos and coronas are part of any 'holy trinity' of lenses.

Lens correction includes vignetting correction.

You really should include EXIF.

Here are the photos with EXIF data.

No protective film or anything...I've had each of these lenses since they've first come available, but hadn't really noticed any issues except occasionally...trying to narrow down what could be causing it.

Here's with EXIF

So I have vignetting correction turned off...should I turn it on? Good point on including exif...will upload new versions without exif stripped once I'm back home.

75Central said:

I just started noticing some weird artifact on some of my photos, wherein the brightness and color is strangely-inconsistent across the sky. In the sample photos attached, you can see that in the first one, the sky has a weird purple area in the middle and in the second one, there's a muddy blob in the sky and the edges are inconsistently colored. The third one is converted to B&W in Lightroom and the blues brought down to accentuate the issue in the image. These were shot on an a7rii. The first with the Tamron 28-75 and the second with the Tamron 17-28. I didn't grab an example from the 70-180, but see the same artifact there as well. Sensor is clean and all lens compensations are off. Only applied lens correction in Lightroom with no vignetting applied. Any ideas?

Click to expand...

Could be condensation on the sensor or in the lens. How were weather conditions and were was the camera before taking the shot?

Interesting -

All nicely half-round circles, but to a varying degree of edge hardness. All in about the same location of the picture / sensor. Different lenses...

Look inside of the camera body. Is there something hanging down in the sensor box ? Is there anything moving (sound) if the camera (body only) if the camera is shaken ?

Have you tried shooting in the silent mode ? The shutter doesn't move in this mode, might explain, or direct you to a place to look, if the pictures are clean in the silent mode, or even if not !

Mike

I think I would make sure the camera firmware is up to date and then try a comparison of a similar scene with lens corrections on and off

While these were all taken on the same day, I've seen it on multiple occasions regardless of weather.

75Central said:

So I have vignetting correction turned off...should I turn it on? Good point on including exif...will upload new versions without exif stripped once I'm back home.

Click to expand...

You had mentioned that you were only enabling Lens Correction in Lightroom. That includes vignetting and distortion correction, and optionally CA correction.

The last one is the only one where, to me, there's an obvious problem.

ISO 50 isn't a great idea either, because it doesn't do much but cost you a stop of headroom.

How reproducible are these effects. Can you get them by shooting a blank sky? Have you opened a support case with Tamron?