Distortion? in a 50??
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monochromejrnl
Well-known
was the film lying flat in the film bracket? looks like film curl to me...
sanmich
Veteran
I also thought so after the first scan, but this one is with the FH-3 gizmo on coolscan, so it should lie as flat as possible.
And the neg itself seems to show the distortion.
And the neg itself seems to show the distortion.
kermaier
Well-known
What about film curl on the camera?
Ari
Ari
ferider
Veteran
I never noticed that. But I'm browsing the M-mount group, and see it there, too, for instance:
http://www.flickr.com/photos/photokalia/4063441151/in/pool-m-mount
Not too strong, and worse at close distances, it seams.
The Canon 50/1.4 is a very special design - only 6 elements (true Xenon copy). Other fast 50s have usually 7. Apparently a compromise was made ....
All I can say - use your Summicron instead when it's critical 🙂
Roland.
http://www.flickr.com/photos/photokalia/4063441151/in/pool-m-mount
Not too strong, and worse at close distances, it seams.
The Canon 50/1.4 is a very special design - only 6 elements (true Xenon copy). Other fast 50s have usually 7. Apparently a compromise was made ....
All I can say - use your Summicron instead when it's critical 🙂
Roland.
sanmich
Veteran
Good idea to browse flickr...
but I don't see anything as bad as the sample I have posted.
Here:
http://www.flickr.com/photos/photokalia/4198129398/
I don't see anything, and I guess the distance is not much more important than in my case.
The camera was a IIIf, and just by the feeling, the pressure plate seems ok. stroger than on my III, weaker than on a Nikon SLR.
what is the common knowledge about 50's and distortion?
Am I wrong assuming there shouldn't be any?
but I don't see anything as bad as the sample I have posted.
Here:
http://www.flickr.com/photos/photokalia/4198129398/
I don't see anything, and I guess the distance is not much more important than in my case.
The camera was a IIIf, and just by the feeling, the pressure plate seems ok. stroger than on my III, weaker than on a Nikon SLR.
what is the common knowledge about 50's and distortion?
Am I wrong assuming there shouldn't be any?
sanmich
Veteran
jmkelly
rangefinder user
My understanding is that all lenses show some distortion, even Planars and Summicrons. In another thread we saw a post where a 50mm Summilux - a lens that I had thought very flat for a fast lens - appears to be showing barrel distortion. 50mm Sonnars show some interesting distortions - that's one of the things that gives them their "character"!
Keith
The best camera is one that still works!
I have lots of lenses 50mm and others that exhibit barrel distortion ... sometimes you notice it, sometimes you don't!
My Zuiko 50's are noticably the worst!
My Zuiko 50's are noticably the worst!
35mmdelux
Veni, vidi, vici
if youre scanning you can use software to distort-correct.
Sonnar Brian
Established
I've not "stringently" tested the Canon 50/1.4 in LTM, but will give it the brick wall test.
The example shown is worse than my old 43~86 Zoom-Nikkor-C.
The example shown is worse than my old 43~86 Zoom-Nikkor-C.
ferider
Veteran
OK, I read up on a few other M mount lenses:
- The ZM Planar distorts within 1% of image height.
- The ZM Sonnar within 0.5%
- The Elmar-M within 0.5% as well
- Summicron 50/2 distortion is basically 0, also for older versions.
- Summilux 50/1.4 v2 less than 0.5% (a bit less than Elmar and Sonnar, apparently).
- M-Hex 50/2 around 0.3%
Given your picture, Michael, I would say it's around 2% or so for the Canon ?
Roland.
- The ZM Planar distorts within 1% of image height.
- The ZM Sonnar within 0.5%
- The Elmar-M within 0.5% as well
- Summicron 50/2 distortion is basically 0, also for older versions.
- Summilux 50/1.4 v2 less than 0.5% (a bit less than Elmar and Sonnar, apparently).
- M-Hex 50/2 around 0.3%
Given your picture, Michael, I would say it's around 2% or so for the Canon ?
Roland.
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sanmich
Veteran
Roland, thanks for the numbers. it seems f/2 helps, over f/1.4...
It's hard for me to guess the number by eyeballing a picture, but here is another example from the canon, and I must say, from the same roll, that seems pretty bad distortion wise. These two samples are taken while the camera is sligtly pointing downwards, and apparently it worsens things.
The film is not very flat also, but the distortion is visible on the neg itself.
I wonder if it could be the camera...
The Canon 1.4 was one of my true loves, and I would hate to admit it has such a heavy barrel distortion. But let's assume it's innocent untill further testing.
It's hard for me to guess the number by eyeballing a picture, but here is another example from the canon, and I must say, from the same roll, that seems pretty bad distortion wise. These two samples are taken while the camera is sligtly pointing downwards, and apparently it worsens things.
The film is not very flat also, but the distortion is visible on the neg itself.
I wonder if it could be the camera...
The Canon 1.4 was one of my true loves, and I would hate to admit it has such a heavy barrel distortion. But let's assume it's innocent untill further testing.
Attachments
Phantomas
Well-known
... by the way, great photo in the original post. I see what you were trying to do there, mirroring the painting and the lady sitting there.
sanmich
Veteran
That's pretty strong curving over there at the right edge. How about checking all four sides against known straight lines... it could be done with a single shot of a window of approx 1:1.5 proportions. I'm surprised to see so much barrel distortion, but I can't figure any reasonable way it would be the camera. Maybe the scanner, but the lens must be contributing.
Edit: On the original post shot, I don't see any curvature at the left edge; it's all at the right. Same with the second but it's harder to dismiss any left-side curve there. Say it's just on the right -- Are those each the first frames in cut strips of negs? Is that end "falling off" the film holder in the scanner? I'd think there would be a scanner focus issue there too if that were the case.
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sanmich
Veteran
Doug, you are right about the first shot: end of roll. The second is middle-of-the-strip frame.
also, as I said, the film is pretty curled due to our wonderfull heating sytem.
For the first shot, I used the scanner film holder (the second is just fed in)
also, as I said, the film is pretty curled due to our wonderfull heating sytem.
For the first shot, I used the scanner film holder (the second is just fed in)
HenningW
Well-known
All the 50/1.4's that I've used have had noticeable distortion, except for the 50/1.4 ASPH. Not that it doesn't have any, but it's quite a small amount. A couple of Nikon 50/1.4's for reflex, Canon's, Konica's, Pentax's, Olympus' etc have all displayed that distortion.
The 50 Summicron has even less distortion, as do various macro lenses, especially the slower ones. Some f/2.8's show a bit more.
Really, only truly symmetrical designs show no distortion, and then only at 1:1 reproduction ratios.
For some stuff it's a big deal (the old Pentax 28mm/3.5 shift lens had noticeable distortion; on that lens it's a big deal) and on others it doesn't matter, like for most fast 50's or 85/90's because of the use they're put to.
The 50 Summicron has even less distortion, as do various macro lenses, especially the slower ones. Some f/2.8's show a bit more.
Really, only truly symmetrical designs show no distortion, and then only at 1:1 reproduction ratios.
For some stuff it's a big deal (the old Pentax 28mm/3.5 shift lens had noticeable distortion; on that lens it's a big deal) and on others it doesn't matter, like for most fast 50's or 85/90's because of the use they're put to.
gavinlg
Veteran
I'd rather barrel distortion than pincushion any day of the week. I can't handle a wide or normal lens with pincushion distortion - just looks unnatural. The olympus RC comes to mind...
