Archived posting to the Leica Users Group, 2007/11/05
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 9:22 PM -0500 11/4/07, Leonard Taupier wrote: >Hi Mark, > >I'm kinda fussy with the glass I buy. I can't tolerate bad barrel >distortion. The biggest offenders of course are the wide range zooms >which have barrel at the wide end and pincushion at the narrow end. >I have been using Nikon lenses for many years and pretty much have >not had to worry about this distortion. I also have the Nikon AF >14mm f2.8 lens and find it to be pretty free of distortion. Just >like my Leica gear. > >I have been using a Canon 5D camera for the last few months >primarily for it's low noise and to utilize the full frame for my >Nikon and Leica wide angle lenses via adapters. Well I decided to >get a Canon zoom to carry around and I got the Canon 24-105mm L >zoom. This is one of Canon's so called L professional lenses. I >found this lens was very sharp but the barrel distortion was so bad >at 24mm that I would not use it. The distortion was very weird. The >upper half of the frame was fairly straight but the bottom half of >the frame bowed in like a fish hook. I took it back to my dealer and >tried another new one right off the shelf. Same exact performance. >The dealer is very good so he said get anything else you want. So I >tried the 24-70 L zoom. It was very good at 24mm but at 70mm it had >bad pincushion. Both of these lenses are Canon's L lenses and cost >over $1000. I think they're crap. I ended taking home a fixed focal >length lens. I won't buy another Canon zoom. I'm actually thinking >of getting rid of all my Canon gear, except for the 20D I use with >the 560 Telyt, when the Nikon D3 comes out. > >Len > Overall, the Nikon lenses have as much distortion as the Canon lenses. In a specific type/range one will be better. In another type/range the other. Many Nkon lenses are quite poor in this regard. If you want a sharp, fast super wide, something's got to give. Same for the zooms. Canon's 24-105 is reasonably speedy for such a long range zoom, quite sharp, decently compact for what it is, and some distortion was sacrificed to get this. On critical shots I use PT tools to fix this. It is fixable. Lack of sharpness, bulkiness etc aren't. Nikon's 20mm lenses have been so-so. Not great, but generally useable. This goes for the UD 20/3.5, 20/4, 20/3.5 and 20/2.8's. The 20/3.5 (second) was best. Nikon also made two 15's. The first was also decent, but not great. The second (the 3.5) was better, but still not great. We're talking in the order of 3% distortion here. In between the 20 and the 15 were the 18's; the f/4, f/3.5 and f/2.8. All are terrible, with distortion of the worst compound kind, with portions of the image having up to 6% distortion. As bad as any zooms, Nikon or Canon. The WATE has a little less than 2% distortion, but it's fairly benign and not generally intrusive. The C/V 15 has slightly less. The distortion of Leica lenses is well documented in their downloadable tech data, so anyone should be able to see what it is. It's in a graph form, which is the most useful. The Zeiss 15/2.8 ZM has nearly 4% distortion, and it's the compound kind, so quite nasty unless corrected. Stay away from it if distorion bothers you. An earlier Zeiss 15, namely the Hologon, has zero distortion, but it is slow and not as sharp. Same as the Zeiss 16. If you want a wideangle with extremely low distortion of overall high performance, look at the Biogon C 21/4.5. It has almost no distortion, and extremely good performance over the whole image area. But it's f/4.5 and not a 15. -- * Henning J. Wulff /|\ Wulff Photography & Design /###\ mailto:henningw@archiphoto.com |[ ]| http://www.archiphoto.com