Cyan Vignetting Issue

[andybarton]

Originally Posted by wparsonsgisnet

Not to start any noise, but what we need in the States is some European vacation standards!

What we need in Europe is some European vacation standards...

[chetccox]

Leica must therefore have been open all week since people have spoken to them. The dealer here is a very nice man so I don't know why he told me that. Perhaps the person he deals directly with is not yet back from his vacation. In any event, how long does it take to publish a list of correct lens prices? Perhaps the person in charge of that is also still missing.

[marknorton]

My German business partner confirms most businesses have either been closed or running on skeletal staff this week, so while some people have been able to make contact, it's not clear that much real work is being done.

[marknorton]

The BJP review of the Leica and Zeiss lenses is interesting because apart from showing there is little to choose between them (apart from cost), the vignetting correction is clear to see when lens coding is enabled (sensor vignetting only, not any cyan correction due to IR filters).

My reading of the graphs is that the correction in the corners is largely independent of aperture setting and in one case, the 50mm Summicron, not the Summilux pictured, this actually leads to over-correction two stops down. You'd think that if Leica were able to figure out the working aperture using the blue dot method, they wouldn't allow the corners to appear brighter than the centre. OTOH, this might still be work in progress.

Specifically, the graphs plot "light value" according to where in the image you look - centre out to corner - on a logarithmic scale. The vertical correction in f-stops in the cormers is approximately the same wide open and two stops down.

[scott kirkpatrick]

Originally Posted by marknorton

The BJP review of the Leica and Zeiss lenses is interesting ...

Specifically, the graphs plot "light value" according to where in the image you look - centre out to corner - on a logarithmic scale. The vertical correction in f-stops in the cormers is approximately the same wide open and two stops down.

I looked at the article using a two week "trialist" subscription, and didn't see any graphs. Where do they appear?

scott

[marknorton]

Scott - did you see the Leica/Zeiss comparison? I'm wondering if the results are not shown in the trial subscription?

[scott kirkpatrick]

Originally Posted by marknorton

Scott - did you see the Leica/Zeiss comparison? I'm wondering if the results are not shown in the trial subscription?

I read the Leica/Zeiss article, but it seemed to be text only. Had to go to IE (rather than Firefox) to get past the login. I also tried to go back to an older article by the same author but that didn't seem to work for a trial sub.

scott