Cyan Vignetting with CV15 using Milich Adapter

[photolandscape]

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The first time or two that I used my CV15 with the Milich adapter and IR filter, everything worked fine. But lately, I'm getting the cyan vignetting again. What could be causing this? Any suggestions? When prompted to select 16, 18, or 21mm focal length, I have tried all three but that doesn't seem to have an effect. Puzzled as to why this is happening.

[farnz]

Steve,

 

Have you tried taking the same shot with the filter on and removed to see if there's a difference? If not then it sounds like your M8 may be misbehaving.

 

Pete.

[marknorton]

Just to be clear, if you were getting cyan vignetting, the image would be red into the corners, is that's what happening?

 

The IR filters cause red vignetting which leads to cyan "drift" if not corrected by the camera.

[photolandscape]

OK, sorry, I stand corrected. I'm getting cyan drift in the corners, and I am using an IR filter.

[marknorton]

If you use the Info button, is it showing the focal length you have selected? It seems strange to be recognising the lens for you to select the focal length but not to apply the correction. Weird. Have you painted in the white marks as well as the black one?

[sean_reid]

If you're using a Leica UV/IR filter and the camera is detecting the lens as a WATE (and is set to detection "on + UV/IR) then you're just hitting the limitations of the system. The WATE corrections are designed for the 67 mm filter which (Leica tells me) is not quite the same as a 39 mm, 49 mm, etc. Moreover, the M8's in-camera corrections are only an approximation. They work well with most lens but even the current Leica 21 is not always perfectly corrected for cyan drift (cyan vignetting would show as reddish corners).

 

In short, if you're doing everything as you should and the results still seem off then I'd recommend Cornerfix.

 

Cheers,

 

Sean

[chazlin]

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I also use Milich adapters with my CV 12 and 15, and I have a question regarding this too...

I have read that the vignetting corrections are applied right after the shot and written directly to the DNG files. If this is the case, how come when I review the pictures on the camera it shows the corrections a couple seconds after showing me what seems to be an uncorrected picture? Does this mean the settings for vignetting corrections are saved in the original, uncorrected DNG file? I had thought the DNG recorded would already be a corrected image?

 

Thanks very much

 

Charles

[willemvelthoven]

sorry, but maybe it is very simple?

 

the camera also has a setting for lens detection only.

 

maybe you accidentally switched to that setting?

[jaapv]

I sometimes get a slight red or cyan shift in the corners of the CV 15 and the Biogon 21. Can it be that very large or small amounts of IR around when making the image influence this, especially with non-Leica lenses, where the correction cannot be the optimal one?

[sean_reid]

I sometimes get a slight red or cyan shift in the corners of the CV 15 and the Biogon 21. Can it be that very large or small amounts of IR around when making the image influence this, especially with non-Leica lenses, wher the correction cannot be the optimal one?

 

Hi Jaap,

 

It can happen with any wide-angle lens, Leica or not. It's not any more likely to happen with a Zeiss or CV than it is with a WATE, Leica 21, etc. The in-camera correction, of course, is based on an estimation and, as you suggest, actual subjects and subject lighting can vary.

 

Cheers,

 

Sean