mike_smith2 Posted June 23, 2005 Share Posted June 23, 2005 Some of you may be interested in a series of comparison lens tests I have been conducting. Basically I am trying to find some decent wide angle lenses for use on a Canon 1DsmkII. The tests were drawn up for extreme "pixel peeking" at centre, centre right edge and centre top right edge performance. They are not reallly trying to establish colour or contrast differences. My testing has not been completed yet as I want to track down a better Zuiko/EOS adapter (I think the cheap Chinese Ebay variety isn't allowing the Zuikos to perform at their best) Anyway, Canon EF/Zeiss C/Y T* and Zuiko comparisons here plus more planned for the summer http://www.bramblingphotos.com/Lens%20test%20home%20page.htm Mike Smith UK Link to comment Share on other sites More sharing options...
bruce_kapla Posted June 23, 2005 Share Posted June 23, 2005 Mike, Try the adapter from Cameraquest.com. I use one on my DRebel and it is superb. Link to comment Share on other sites More sharing options...
grahams Posted June 23, 2005 Share Posted June 23, 2005 Mike - while I appreciate the time and effort that these comparisons have taken, I have a problem with some of them where the lighting conditions or time of day are radically different. This affects the apparent contrast of the image, and makes a meaningful subjective comparison of one lens to another , or even the same lens at various apertures, very difficult. How to overcome this would obviously narrow the working "window" during which you could take the shots, and thus extend the overall time that it would take to complete the exercise (days or weeks) depending on weather, atmospheric conditions etc. The Zuiko 50mm f1.8 test is a case in point where the centre shots and the right centre shots are not comparable. The length of shadow is totally different, and Mrs Jones has even had the time to take her washing in. Link to comment Share on other sites More sharing options...
mike_smith2 Posted June 23, 2005 Author Share Posted June 23, 2005 Graham To expand a bit on the methodology detail - The shots were all taken in 2 sessions in the same 2 hour period from 8am to 10 am. Each lens was tested in a single session taking about 5 minutes per lens test, the shot sequence was allign target at centre, take all apertures shots, move target to centre right position, shoot all apertures, move target to upper right target position shoot all apertures, change lens. Lighting conditions were almost identical for the 2 sessions. The differences in lighting show how difficult it is to get consistant results due to manual focus lenses having to be stopped down and exposure compensation dialed-in - the image darkening affects teh light meter system accuracy. Darkening from edge vignetting all but make it impossible to get exact exposure matching as the aperture increases. The amount of sky in each picture from lens angle of view differences also dramatically alters the exposure results. Passing clouds did put shadow over some images and finally each lens has different coloration and contrast characteristics. Hence I am not trying to assess images on a colour and contrast basis. I am not too concerned at the image exposure variations, my main interest when conducting these tests was (i) Image sharpness and resolution (which, yes, is dictated by contrast as well) (ii) Edge distortions The main use that the lenses will be put to is landscape work, so I tried to replicate real use conditions with a standard set of 'targets'. Idealy indoor shots could probably produce more even exposure results, but I was more interested with infinity performance rather than 20' performance from the usual lens resolution chart tests. ;-) I am still not happy with some focus results eg the 21mm wide open and where the image results look out of line with other aperture settings and I will rerun the tests with a different adapter in due course - hence the 28 & 35mm Zuiko results are pending. Mike Link to comment Share on other sites More sharing options...
neild Posted June 23, 2005 Share Posted June 23, 2005 I use the adapter from Kindai corp., in Japan - no complaints on the quality of this one!! Link to comment Share on other sites More sharing options...
grahams Posted June 24, 2005 Share Posted June 24, 2005 Thanks for the info, Mike. I agree, there may be focus issues. The Kindai adapter has a very good reputation. Is this what you are waiting for? Link to comment Share on other sites More sharing options...
curt_sampson1 Posted June 30, 2005 Share Posted June 30, 2005 I'm not entirely clear on why you used autoexposure. Using manual exposure, you could have ensured consistent lighting across all of the lenses. Link to comment Share on other sites More sharing options...
grahams Posted June 30, 2005 Share Posted June 30, 2005 Curt - Mike said "All images shot in RAW format at AWB setting using EV metrering with manual exposure adjustment to prevent highlight clipping." Doesn't sound like auto exposure to me. Link to comment Share on other sites More sharing options...
curt_sampson1 Posted July 1, 2005 Share Posted July 1, 2005 I guess I really meant, why not meter the scene once, work out an exposure low enough to avoid clipping on all lenses, and then use that exact same exposure on every lens. Then you don't get it changing due to reading the light meter with different vignetting and so on. Link to comment Share on other sites More sharing options...
gwilburn Posted July 3, 2005 Share Posted July 3, 2005 I use the Kindai adapter as well -- and that's the one <a href="http://www.cameraquest.com/">Cameraquest</a> sells (I confirmed with Stephen Gandy). The Zuiko 90mm/2 macro lens works great on my Digital Rebel body. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now