A Tale of Two Ultrons

dexdog

dexdog

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I have a couple of CV 35/1.7 Ultron lenses in LTM, one is silver and one is black. I got the silver one about 15 years ago attached to a Bessa R4A, dont remember anything about the black one except that it was a good price on eBay. There is another active thread called "Weekend Photography Plans: What are you up to?" I am retired so weekends do not mean much to me, but given that it is really hot today at 90F, a good day to fart around with lenses, weekend or not.
 
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The cloudy lens group has less effect than I thought it would. I have an 85/3.5 in S-Mount with a fairly cloudy group. One day- I'll try to separate the group and get rid of the cement in between, use index matching oil to replace.
 
Tweaking the contrast a bit in photo software is pretty easy (even I can do it!). Another set at f4



What is harder to fix is the increased tendency to flare with the cloudy lens. Compare the two above pics, look to the right of the tallest pale purple blooms into the shadows of the evergreen (helps to look at bigger image using RFF as password). The flare starts to show up at f4, and by f5.6 is enough to be distracting. I took these pics about 315PM, so sun is still mostly overhead and not low in the sky at all. The first lens in each set is the silver one with the cloudy middle group. Sad to have such a lovely lens go bad. I have retired the silver one to be used as a parts lens in the event I ever damage the glass in the black one.

EDIT: Look closely at the mirror in the upper right corner of post #2, you can see the difference in the reflected image of a window, and increased diffusion of light at front door
 
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That's what I've found- a backlight, shining towards the lens will illuminate the cloudy element and ruin the picture.
Nikon had the same problem with whatever combination glass/cement was used in the AF-D 20mm F2.8.
 
I was looking at old threads from May 2022, I asked about which 35/1.7 Ultrons tended to go bad, and was advised that mine was one of the later versions in LTM that had a better track record. I stated at the time that the lens was pretty clear and had good contrast. Apparently something happened to the lens in the intervening 3 years, for it is a bit cloudy now, and contrast as shown in this test has dropped off. I hope that it does not occur on the black lens that I used in this test. Just to be sure, I disassembled and cleaned all available lens surfaces; yep, it is cloudy, not dirty or off-gassing of lubricants. Bummer
 
I have to say I am encouraged by this -- I have an older one of these and there's definitely haze on an interior surface. But I really don't see what you're talking about in the exterior photos -- nothing troubling to my eye. Yes, I see the flare in the interior shot, but again, I could live with that.

Your lens isn't my lens, of course, but this gives me hope that mine is usable. (As you can tell, I haven't had occasion to use it in some time. 🙂)
 
mapgraphs said:
I have a black Ultron with the flat knurling and a silver one with scalloped knurling as above. The black one has haze, the silver is clean.
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I have no idea if the presence of cloudiness can be tied to serial number, but serial on silver lens is 9050010, serial on black lens is 9960318.
 
I noticed the haze after one event where I ended up with some blown out frames due to veiling flare. Did the flashlight test and saw the culprit. I read one of Eric's missives in a thread about the Ultron's penchant for developing haze where he said his copy was clean and postulated that it was because it was a different version - the one with scalloped knurling. I found one. It was clean. Is still clean.

Obviously, a premise that different versions (flat vs. scalloped knurling) might be an explanation is just so much interwebs blather. We don't know what coatings, cements, glass were used, when, or in which production runs - or if there were differences, or if storage or location (humidity, heat etc) are contributing factors.

I actually like my hazy Ultron. In subdued light it is sharp and has a nice glow, a gentle rendering in out of focus areas... It's something like the Heliar 50/1.5 or a Summar/Summitar (both of which also have problems with veiling flare - as do a lot of Leica lenses...)

At any rate, it helps to know that they all may be susceptible to the cement degrading...

The hazy Ultron on a M240:

L1003881_cont6-shrp2_2048.jpg
 
Now, if there was a fix for Voigtländer lenses that have decentered (or "asymetrical") elements/groups (and don't have haze), I'd get in line for that. As it is, it seems, it's keep trying till you get a good one...
 
mapgraphs said:
Now, if there was a fix for Voigtländer lenses that have decentered (or "asymetrical") elements/groups (and don't have haze), I'd get in line for that. As it is, it seems, it's keep trying till you get a good one...
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I would send my silver lens out to have the cloudy element repaired or replaced, but I do not know of a company that provides such a service.
 
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Cosina should provide repairs. Those lenses are not really old.

If they will ignore it, some might start to think twice if it is worth to pay for brand with some questionable quality optics.

It is not just Cosina anymore which makes not Leica priced lenses.
 
Ko.Fe. said:
Cosina should provide repairs. Those lenses are not really old.

If they will ignore it, some might start to think twice if it is worth to pay for brand with some questionable quality optics.

It is not just Cosina anymore which makes not Leica priced lenses.
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I agree, they should offer a degree of service for their lenses, but it does not appear that they have a large (extant?) service department.

That being said, the separation issue is only present on their earliest lenses (and seemingly not all - my 28/1.9 is crystal clear). Perhaps they switched glues at some point? Or perhaps the rest of their lenses are destined for failure down-the-line. But, considering how much the overall build quality of their line-up has improved since 2000/2001, I am inclined to believe that the improvements are throughout.

Also, to your point, I'd argue that Cosina still makes the best 3rd party M-Mount lenses (when considering price, optics and ergonomics)...though, I do expect the competition to get there in short notice (the Thypoch m-mount lenses universally have a collection of bizarre ergonomics choices, but they could be a revision away from having something stellar).
 
I have the 35mm 1.7 LTM Ultron. It fell into my lap. I had not heard of it. And the reviews are not glowing. But it works well for me and works well at night around the harbor, better than some other lenses. I am posting here a couple of pics shot with this underappreciated lens on an underappreciated IMNSHO camera, the M240. The color, definition and image are pleasing to me. The pictures look nice. Subjective. I am advised that the M240 is weak above ISO 2500 but regard that the first photo was shot at ISO 3200 and still looks OK, for a photo of a derrick. ;o)

Yes, I am biased as it is my shot. But I do think that the color, definition and overall "feel" of these two is a nice one. As always, YMMV.

 
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Looks like you have a good copy, I like the 35/1.7 in LTM too. I also have the 35/1.7 Ultron Vintage series in M-mount, which is a completely different animal/lens altogether.
 
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