Green band diagnosis

[whited3]

Good morning experts!

For some time now I've had an issue where a green band appears in some of my landscapes. After a lot of thinking and investigation I think I have diagnosed the cause but I'd really appreciate it if you would read the following and pick holes in my logic, or agree.

This green band will only appear (but not always) when I'm using my 5Ds as follows:
• EF 16-35mm f4 L @ < 24mm
• Low light…usually sunrise/sunset.
• Lee 1.2ND (4 stop) 100mm resin filter is use.
• Landscape orientation, never portrait.
• Always 33% up from the bottom of the frame.

Consider these two examples from the same recent morning shoot. Note that the time stamp is 2 hours behind as the camera was set at AEST and NZ was 2 hours ahead on that day.

In the image "Lake Moke 489" the line first appears and then features in most shots (< 24mm and landscape orientation)following that. If you look closely there's actually a 2nd fainter line above the first.



The line does not appear in the image "Lake Moke 488" that was taken 90s before the above, nor any of the preceding shots taken that morning.



I don't make field notes of when or what filter I have fitted so I surmise that the slower shutter speed in 489 implies that I fitted the 6 stop ND filter in the 90s between these shots. 0.5 to 30 is ~ 5 stops + 1 stop for the exp comp?

The Lee filter is 100mm square and so can be fitted into the holder in any orientation, and back to front which you'd think would make the green band very inconsistent shot to shot, but once fitted I seldom change it for a given shoot.

I think the issue is the 13yo, Lee resin ND filter, not that I can see any physical issues with it. I look after my gear and the filter looks pristine to me. Also, I don't expect to see a fault with it as there are 8 orientations (4 orientations + flipping it) I could use to fit it on a given shoot.

To my mind the above points to the filter but I'm still not sure.

I have a 3yo Nisi 10 stop and a 14yo Lee 3 stop soft GND. Never an issue.

Thoughts?

[Manfred M]

Given the age of your Lee filter, I suspect you might be right.

There was a period around 2012 where Lee had some serious production quality issues and it sounds like your filter would have been produced about then. My understanding is that they were selling a lot of products and their attempts to scale up production volumes had some serious "teething pain", resulting in some sub-par products leaving the factory.