Photoclubalpha

Yes, I do recall the CA on the 24-85mm even with the KM5D. I have checked a few of my wide angle shots on the Tamron 17-35 which were shot at reasonably small apertures on the A900 for signs of blurring at one side, but so far all seem fine, I suppose it may be that I have a lens with some defect that corrects for a non parallel sensor!

I always suspected that some of my A700 shots were worse on one edge, but was not sure if it was lens or sensor problems. I must say I am very impressed by the Tamron 17-35mm, a joy to use and doesn't suffer from the amount of Red/Green CA that the Sony DT 11-18mm had at 11mm. I do notice a small amount of purple fringing on high contrast edges however.

You may have a perfectly aligned camera, or lens. There will always be small variations and the very smallest become visible with the A900.

I may check my A900 more closely for alignment but the 35-200mm, which has a rotating front group, stays slightly softer at the right side - with a rotating group, you could reasonably expect any lens decentering to shift round the pic, and it does not. The degree of difference I am talking about would hardly be noticed by anyone not trying to analyse the images technically. I used the 17-35 for the A2 reproduction in Photoworld and the CZ 16-35 is going to have to be remarkable to persuade me I need it!

David

Thanks David, I was going to comment on the Photoworld A2 photo that seemed excellent, my feelings towards the forthcoming 16-35 are similar, I just don't think I need it given the results from the 17-35. PTlens now supports the A900 and automatically only selects lenses that have been calibrated for FF. The Tamron 17-35 is already calibrated and I tried PTlens on some of my shots and it works very nicely, taking out the barrel distortion. There is very little CA to remove, but purple fringe is still a slight problem against bright skies.

David,the poster on DPR who thought his 24-105mm was better than his CZ 24-70mm, has now tested more thoroughly and has shown that clearly the Zeiss wins at the edges by a mile.

http://www.dboyd.com/Photos_08/3lenscomp/3Lens_test.htm" onclick="window.open(this.href);return false;

I thought his judgment was too rapid. You could get a good impression from some shots. I've just ordered a s/h RS 28-105mm to try out (keep it if it works well, sell it if not). I begin to think that the best way to tackle the A900 is to get hold of as many lenses as possible and try them.

David