collapsible summicron unsharp after cleaning

[charles_wick]

I have a beautiful 50mm collapsible summicron ,recently cleaned professionally by one of the top people. I looks

perfect and crystal clear, but has never been sharp, before or after the cleaning. I am on the verge of discarding it, but

wonder if I am missing something that I can do to repair its performance. It was clearly hazed before, but cleaning

has not improved it. Comments?

[michael_a._shapiro]

Are you positive that you've locked it into place when you extend it?

[l_dasousa]

Haze will cause flare and loss of contrast, it will not cause loss of sharpness. Therefore cleaning of haze will not restore sharpness that was not present. If the lens is not more unsharp after cleaning, then it can assumed it was put back together correctly. Perhaps at some time before it came to your possession, one or more glasses inside has been replaced, not by Leica or someone with skill. I used to know a camera store where the owner would put together one good lens to sell at full price, from two bad lenses for which he paid almost nothing. I also remember speaking to one old guy who said in the 1950s he had to trial a few of the same Leitz lenses to find the one which was most sharp, there was much sample variance.

 

I commend you if you will discard this lens as you say. Many guys would just sell it on ebay as Mint.

[john_wayne4]

Additionally, check your M body. Have you tried other lens on your camera? At any rate, do a quick distance check with a tape measure to a fixed spot (you could also do the one meter to mirror trick). Make sure the collapsible lens distance is the same. If this isn't the case, your horizontal alignment is off, and the rangefinder arm will have be adjusted. Do the test and you'll know if it's the lens or your body. If it's the lens, send it back for adjustment (I'm sure whoever did the original work will gladly repair it). Good luck.

[Brian1664876441]

I've done work on my own Collapsible Summicrons, including replacing the front element on one, and pulling the internal optics to clean them. Took me a couple of "rounds" to get it all back together correctly. But I did.

 

The elements on the 1950's Summicrons are very tight compared to other lenses that I've worked on. The fittings seem to be custom fitted to each lens.

 

On my Collapsible Summicron, I had to use (almost) "excessive force" to get the first inner element, just under the front element, to snap correctly into place. On the first test roll, it was out of place and the focal length was wrong. Great focus at 4ft, and no where else. After getting it "right", it was close to my Rigid Summicron in sharpness. But with a nicer overall look.

 

Additionally, on other lenses I've had great luck replacing elements. Not so on the Summicron. I found the inner elements with their fittings could not be traded across lenses. I could swap the front element- but that was all. With a 50 year-old lens, you do not know its history, and if someone tinkered with it.

[john_shriver]

The spacing of the two closely spaced elements that form the "air lens" at front is very critical.

 

But, you may just have a lens with swapped elements, what I'd call a "mutt".

[Brian1664876441]

This is taken with the Summicron AFTER getting the second element to properly snap in place, and replacing the

front element with a really clean one. test roll with the element slightly out was a "mess". <p>

 

<img src="http://farm4.static.flickr.com/3008/2287586434_d9aa2807a2_o.jpg"> <p>

 

Wide-Open on the Leica M2. This lens became one of my best performers.

 

"Your Mileage Might Vary", but worked for me!

[ed_schwartzreich]

Try shooting a yardstick with the camera tripod-mounted. Is the lens focusing short or long, or just not sharp. Is the lens equally unsharp at all distances wide open, or are there only point in the focus range that are unsharp?

 

As prior posters have suggested, there are several difficulties possible. I have had collapsible Summicrons with OOF areas close up and at infinity, where I carefully reground the cam. I have had another lens which was worked on and the backfocus was off at all distances.

 

You need more diagnostic information.

[christopher_a._junker1]

There are so many variables that may be causing your problem, that a successful sorting to a definitive answer will be difficult. One way to eliminate the body issue is to mount the body and bad lens on a tripod, set for infinity and take images of the moon. Then swap out to a lens that you know is ok and make sure that the moon image using that lens is sharp. If both image sets are bad you either have two bad lenses or the body has a problem. I'd bet on the body. If the test standard lens comes out sharp and the suspect does not, its the lens, and a body problem is ruled out.