07-29-2010, 06:38 PM
[quote name='Sylvain' timestamp='1280427085' post='1396']
Hmm ok, bokeh test confirms aperture is locking right at capture time too. The exposure shift seems to be mostly occuring from wide open (at all focal lengths) to 2/3,1 stop down.After that, exposure is stable. I thought at first that it was only the perception of less vignetting but there's still a slight exposure boost IMHO. But not so much to worry about.
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How much does it change from fully open to a stop down? Overall it seems you got a decent copy. I would still check for de-centering though by doing the famous "brick-wall". If it is severely de-centered this would show it.
I look forward to seeing your praxis report on this one.
Hmm ok, bokeh test confirms aperture is locking right at capture time too. The exposure shift seems to be mostly occuring from wide open (at all focal lengths) to 2/3,1 stop down.After that, exposure is stable. I thought at first that it was only the perception of less vignetting but there's still a slight exposure boost IMHO. But not so much to worry about.
[/quote]
How much does it change from fully open to a stop down? Overall it seems you got a decent copy. I would still check for de-centering though by doing the famous "brick-wall". If it is severely de-centered this would show it.
I look forward to seeing your praxis report on this one.
enjoy