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Step down filters holder and vignetting

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#1 Hilmi

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Posted 05 August 2013 - 02:11 AM

I just purchased myself the Canon 70-200 f2.8 IS II USM lens and I am thinking of getting a step down ring for my LPS filter. This should bring the lens down to around F4. Will this cause significant vignetting on an APS-C sensor such as on the 60Da? I don't plan on spending the significant amount of money required to buy the clip on filter if I can get away with the step down filter.

#2 Hilmi

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Posted 06 August 2013 - 01:20 AM

Anybody tried this? Any experience with the effects of step down rings with this much difference in aperture?

#3 Falcon-

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Posted 06 August 2013 - 02:50 AM

I did try a session with a step-down ring for one of my lenses with a damaged aperture iris - In my case the step-down was I think not large enough of a difference so I was not able to REALLY tell if it effected vignetting all that much. This is the thread showing the results of that experiment. I would not exactly call it a clear answer to your question though.

I would like to know the answer myself really!

#4 Hilmi

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Posted 06 August 2013 - 02:40 PM

Thanks I will read through that thread to get an idea. I got the 52 to 48 mm ring which I feel won't make much difference. Its the 72 to 48 that is of concern.

#5 WarrenS

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Posted 06 August 2013 - 04:28 PM

When using my Nikon 180mm ED and 300mm ED lenses, I've used a combination of 72mm to 58mm and 58mm to 48mm with and without my 48mm IDAS filter. I've only noticed vignetting on the stacked image if I did not shoot flats. Bottom line, yes you probably will get vignetting, but flats should definitely eliminate it. Secondly, by using step down rings instead of using the lens aperture ring, I don't get weird star shapes caused by stopping down the lens diaphragm blades.

#6 Samir Kharusi

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Posted 07 August 2013 - 06:33 AM

Probably very different behavior at the wide end and at the long end. Just cut a 48mm diameter hole in a sheet of paper and take photos of something lit flatly, sky or wall.






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