The "look" of three 50mm

Don't forget - use a tripod and a timed or cable release. As I pointed out, there are problems in standardization. But still, how many times have you looked at "sample photos?" 🙂
 
ray_g said:
Don't forget - use a tripod and a timed or cable release. As I pointed out, there are problems in standardization. But still, how many times have you looked at "sample photos?" 🙂
Click to expand...


Yes, I just thought about these points too, Ray. I will use a Bessa T for its built-in meter or a Canon P and use a spotmeter to get the right exposure for the test, and ask my daughter to sit on a chair, being side-lit by the sun. Then I will place a piece of paper somewhere, with large letters to help me identify which lens at which aperture was used. Such as "Z-2.0" for Zeiss lens at aperture 2.0 or "S-C 8.0" for Summicron Collapsible at 8.0. I will take photos at apertures 2.0/4.0/8.0.

At 2.0, it is the ultimate test wide open, then the aperture of 4.0 is to see whether the lenses doing poorly wide open do much better when stopped down to 4.0 and then at 8.0 all should do well or something is wrong with the lens.
Brian Sweeney would most likely also suggest a test of close-up photos, but then this may be a test to see if the lens needs shimming or not. Right Brian?

I will use a lens hood too, which I always do anyways. Then to minimize scanning errors, I will have the entire film scanned directly from the negatives. It would helpif others here do a similar test. If I see a test of the same lens by someone else, then maybe I can identify if my lens is better or worse than the same lens of someone else.
 
In a lens test, it would also be useful to have a light source in the background, like a window off behind the subject to check for flare, and a busy/cluttered/detailed background to check on bokeh. I agree with the wide open for f1.5 lenses, f2, and f4 aperture test settings. By 5.6 and smaller, it will all be pretty darn good. It is at the wider apertures that things are interesting.

lens hood, tripod, cable release, all test shots on the same roll of film (therefore same camera body), incident light meter with identical exposure set for each lens at the apertures tested, all done to control the variables in an experiment, so that the results can be directly attributed to the variable (the lens) being tested.
 
I will try to take into account your suggestion to have a source for flare. Maybe a few window photos will do the job here.
 
Or place a desk lamp aimed slightly towards the lens in the background. It would at the same time illuminate an out of focus area that will demonstrate the lens' bokeh. Perhaps some shiny crystal objects on the desk in the background.
 
Yes and no. It is not a factor because it is a constant with all of the shots so differences seen cannot be attributed to different film types. It is a factor in that slower film with finer grain will demonstrate the sharpness capabilities of a lens better than a faster course grain film. As for colour or B+W, I'll do my tests with B+W because that is mainly (>95%) what I shoot.
 
Color film may show some faults with very old lenses. I'm not sure here. I was going to use Fuji 100 color film or Ilford XP2 film.
 
I will add other 50's to my unscientific test tomorrow. The Canon 50/1.2, canon 50/2.8, and the J3 50/1.5.
 
Brian Sweeney said:
> test?

Raid: on the Sonnar's and others "adapted to or adopted by" the Leica's, it is necessary to test close and far focus.

HOW DID THE J-3 DO ON YOUR CAMERA!!!

I've currently got five J-3's in posession. I am going to try to get some time to test them for variation in sharpness/focal length. One kicked my butt for a long time, until I noticed the rear lens group was not correctly mounted into its collar. It was off by less than 1mm, but it really messed things up. That was on the 1950 lens made with German parts. Some do betters than others with focus drift once shimmed for close-up work, ie distant shots are more blurred on some lenses than on others. It's got to be the spacing of the elements and actual focal length of each lens.
Click to expand...

Brian: I will try to take your point into account. So now we have the Bokeh factor, the flare factor, and the distance factor.
I am still waiting for the film back from the J3. By the way, the front of the lens barrel is crooked. Is this OK? When rotating the focusing barrel, the extension is not parallel to the camera body. As long as the lens can focus properly, this is unimportant to me. I will let you know how my scans look like when I get them.
 
Brian Sweeney said:
Raid: in the three rolls that I shot with the lens, the focus was good with my Canon IIf and Canon 7. The lens took a filter, and the ring holding the front element unscrewed properly. I had to remount the aperture ring and focus collar to new positions after adjusting, and can understand if I got those off. How are you judging the barrel being crooked?thing surprises me on these FSU lenses any more. I had one J-3 that gave different distance readings to the same fixed point when used with two different Canon 7 bodies. The Canon 7's agreed on the distance when used with a Nikkor, Summarit, and Summitar. I finally found the Helical would not tightly screw into the mounting collar, and was getting pushed slightly out when used on the cameras. The lens mounted to a slightly different position on the two bodies. I ended up gluing it into place in its collar. Same lens with the rear module mis-mounted and helical re-assembled incorrectly..
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Brian: When I rotate the focus barrel to focus closer, the lens extends. The extension coming out is not equal all around but looks crooked. This is what I tried to explain. Once I have some photod back I will be able to tell whether this unequal extension has any effect on the photos or not. Maybe I can take a photo of it and send you a pm with it.
 
Raid, the unequal extension is measured (by eye) from the aperture ring, right? What Brian was saying is that maybe the aperture ring was not installed perfectly parallel to the camera. The part of the lens that extends when you focus closer, is kept in place by the helical, which is part of the lens body, which cannot be crooked if it is seated on the camera body.
 
FrankS said:
Raid, the unequal extension is measured (by eye) from the aperture ring, right? What Brian was saying is that maybe the aperture ring was not installed perfectly parallel to the camera. The part of the lens that extends when you focus closer, is kept in place by the helical, which is part of the lens body, which cannot be crooked if it is seated on the camera body.
Click to expand...

Frank: I saw this "crookedness" when holding the lens in my hand and rotating the focusing barrel and not when mounting it on the camera body. I simply have not noticed this when on a camera.
 
I just finished my testing of eight 50mm lenses and will take the roll of film for developing and scanning this afternoon. If all goes well, I will post a link to the photos tonight after loading the images up on some website; maybe PN if my account allows it. I used XP2 Super film since I took the photos indoors beside a window. I included the window for flare check, and maybe even for Bokeh. The line-up was as follows:

1. Canon 50/1.8
2. Nikon 5cm2
3. Collapsible Summicron 5cm/2
4. Rigid Summicron (First Version) 50/2
5. Canon 50/1.2
6. Canon 50/2.8
7. Jupiter 3 50/1.5

I took two photos for each lens @f2.0 and f4.0 except for the Canon 50/2.8 for which I took photos @f2.8 and @4.0. I used a Gitzo tripod and a cable release cord to reduce vibrations and shake. The photos were taken at shutter speeds 1/60 and 1/15. I used a lens hood for each lens. Camera used was a Bessa T with external Leitz viewfinder. The main factor I am worried about is my eyes sharpness or lack of it, but I hope it went well. Next time, I will do a similar test handheld, because that's how I take photos with a rangefinder camera and not on a tripod.
 
I'm very much looking forward to these results!

Raid, even though you do normally shoot without a tripod, there is simply no point to conducting this test without one IMO, beccause you then introduce a second variable: camera shake. The results therefore cannot then be attributed solely to the lens tested.
 
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