Sonnar test 2: close up handheld at f/1.5.

Stephanie Brim

Mental Experimental.
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I didn't have my tripod at work so I figure that these aren't a really good representation of the focusing, but at least they'll give an idea.

closetest001.jpg


Focus was on the calculator.

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Focus was on the text on the envelope.

closetest003.jpg


Focus was on the blue balloon.

closetest004.jpg


Focus was on the lettering on the sign.

I've drawn a few conclusions. The first is that my rangefinder may be misaligned vertically a bit. That's not really going to affect this as much, but it is mildly annoying for me. The second is that the lens is front focusing by a few centimeters. I'm going to stick it on the tripod soon to get some shots that way and to make it more of an accurate test, but these were taken with ISO 400 film at 1/250 speed.
 
I will check my Canon 1,5 on close focus front focussing. This Sonnar close-up effect has been discussed here recently.
 
Kievs did not stick to the Contax tolerances for back focus. One way to compensate (also for normal Sonnars collimated at infinity) when making portraits is to focus on ears.

Michael
 
I figure I'll use it for a bit as is since it seems okay at about 5 feet. I'll send it to you when I can get another Kiev body to use in the mean time.
 
One other thing I have to say, though, is that I really like this lens with color film. Looks like I may be shooting more color again. I'm very, very impressed regardless of the front focusing. Thanks to all who were involved in getting me this lens.
 
and let's face it - the depth of field at that point is so narrow that even if it never shifted at all, you'd still miss it occasionally between your rangefinder, handholding the camera, and living human subjects.
 
Stephanie Brim said:
Right. I'm going to test it with the camera on a tripod before I send it (and the camera) back Brian's way.

I guess my point is, with all the variables that come up in real-life usage, the lens is the least of the problems. Even if the lens was precisely where you think it should be, there is no guarantee that your ability to focus precisely and hold the subject exactly in that narrow zone of focus while shooting is up to the task for each and every shot.

On the one hand, knowing about any focus shift at wide open and close up, and how much it has shifted, will allow you to use the lens close up and wide open, with appropriate care. However, no less care would be needed if the zone of focus exactly agreed with the rangefinder. And I don't know about you, but the shots I most often miss the focus on are close up and wide open, because often the light isn't the best, the subject approaches the minimum close focus distance, and I am doing the best I can in difficult circumstances. Again, the lens is the least of my problems, and tellingly, I tend to find the lens is focused behind the subject, not in front.
 
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