Focus Shift Test Shots

[KenBPhotos]

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I took some focus shift test shots at .8 meter with the 3 lens I currently have - Summicron-C 40mm, Summicron 35mm V3 and Summilux 50mm pre-ASPH E46. I don't think this exists, but I was thinking it would be a good idea if everyone who felt willing could do the same so we could have a database of all M-mount lenses. It's really easy to do, you just print the test chart and setup a tripod. This would give us a good idea of which lenses are the worst offenders. What do you guys think?

[KenBPhotos]

Summicron-C 40mm @ 0.8m 100% crops (Only allowed 4 images, the rest are on my flickr...)

 

CONCLUSION: This lens is spot on at every aperture at any distance. Essentially 0 focus shift.

 

Summicron-C 40 f:2,0 by KenBPhotos, on Flickr

 

Summicron-C 40 f:2,8 by KenBPhotos, on Flickr

 

Summicron-C 40 f:4,0 by KenBPhotos, on Flickr

 

Summicron-C 40 f:5,6 by KenBPhotos, on Flickr

[KenBPhotos]

Summicron 35mm pre-ASPH V3 @ 0.8m 100% crops (Only allowed 4 images, the rest are on my flickr...)

 

CONCLUSION: Has extreme front focus at f/2 which essentially clears up at f/2.8 and up. Pretty bad focus shift on this lens. It's possible I have a bad copy, but either way I'm returning this and using the Summicron-C 40 (bought used online with return policy!)

 

Summicron 35 Pre-ASPH V3 f:2,0 by KenBPhotos, on Flickr

 

Summicron 35 Pre-ASPH V3 f:2,8 by KenBPhotos, on Flickr

 

Summicron 35 Pre-ASPH V3 f:4,0 by KenBPhotos, on Flickr

 

Summicron 35 Pre-ASPH V3 f:5,6 by KenBPhotos, on Flickr

[KenBPhotos]

Summilux 50mm pre-ASPH E46 @ 0.8m 100% crops (Only allowed 4 images, the rest are on my flickr...)

 

CONCLUSION: Focus looks accurate at f/1.4 although it could use more resolution and has some pretty prevalent chromatic aberration issues (I think that's sensor related but also has something to do with lens design from my understanding). At f/2 it's starting to back focus and continues that trend up the apertures. This lens is pretty damn good, but I think I'm going to return it and get the ASPH version as I like a sharp lens wide-open and this one (again, possibly just the copy I have) isn't fully cutting it for me in that department. I also have to focus ahead slightly at higher apertures to compensate for the back focus which, for a $3k lens, isn't acceptable to me.

 

Summilux Pre-ASPH E46 f:1,4 by KenBPhotos, on Flickr

 

Summilux Pre-ASPH E46 f:2,0 by KenBPhotos, on Flickr

 

Summilux Pre-ASPH E46 f:2,8 by KenBPhotos, on Flickr

 

Summilux Pre-ASPH E46 f:4,0 by KenBPhotos, on Flickr

[Ecar]

I took some focus shift test shots at .8 meter with the 3 lens I currently have - Summicron-C 40mm, Summicron 35mm V3 and Summilux 50mm pre-ASPH E46. I don't think this exists, but I was thinking it would be a good idea if everyone who felt willing could do the same so we could have a database of all M-mount lenses. It's really easy to do, you just print the test chart and setup a tripod. This would give us a good idea of which lenses are the worst offenders. What do you guys think?

 

Hi Ken - and welcome to the forum,

Unfortunately, a database would be pretty useless as you can't tell the amount of focus shift that's inherent to the lens design (eg, Sonnar) from that which is due to a specific copy of the lens - not to mention the tolerances of the camera itself.

In other words, focus shift appearing on one lens and one camera may not necessarily show - or to a different degree - for different copies of the same lens and the same camera.

[farnz]

How have you confirmed the calibration/accuracy of your camera's rangefinder coupling?

 

Pete.

[IWC Doppel]

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Do take a few pictures with the 50 pre asph before dismissing, my 1983 VII 43mm renders beautifully, a couple at f1.4 below.

 

I would only consider selling for the later 70cm focus version. If they had a 35 equivalent I'd buy it tomorrow.... The 75 equivalent is the 75 Summilux and that's sublime to. Both make a mess of the test charts

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[gyoung]

I took some focus shift test shots at .8 meter with the 3 lens I currently have - Summicron-C 40mm, Summicron 35mm V3 and Summilux 50mm pre-ASPH E46. I don't think this exists, but I was thinking it would be a good idea if everyone who felt willing could do the same so we could have a database of all M-mount lenses. It's really easy to do, you just print the test chart and setup a tripod. This would give us a good idea of which lenses are the worst offenders. What do you guys think?

 

I cant see the point of testing any lens for performance in a situation which you wouldn't encounter in 'normal' use. All three of these are the last lenses you should choose to photograph anything at 0.8 metres, just because you can do it doesn't mean you should. I would be interested how they perform at, say, 5 or 6 metres. If you must use an unsuitable lens (i.e. for work it was never designed to do) for the job if nothing else is available you must expect that the results will show some problems.

A reflex would be a lot easier, with a macro lens, if you must do such close up work with an M, a Summicron or Elmar 50mm, would be a better choice, I know personally that the 'old' 2.8/50 Elmar does very well as an enlarging lens, so would presumably do well at Macro, and my 90mm Elmarit does well at 1 metre.

 

Gerry

[brusby]

tests=knowledge=good