So really, How bad can a lens get?

I bought this little Retinette a while back in a box of other stuff.

Did a CLA, and then noticed the lens had a little stuff on it that

wouldn't come off. Just a "little" stuff, mind you. I had to try it

to see what the world would look like through crud colored glasses.

<p>

<a href="http://home.rmci.net/deanw/Dirty_lens_test.html">Dirty lens

test</a>

<p>

Dean

<p>

<a href="http://home.rmci.net/deanw/Old_Stuff.html">Old Stuff</a><div></div>

Holy Smokes, Dean! I wouldn't have believed it if I hadn't seen it! Who would have thought? I was expecting to see pictures with a snow storm on them! The wires in the distance were the real shocker! I'm going to have to rethink things.<p>Randy Jay

Amazin'

Dean, WOW, I think I might have to store one of my Retina's in a bucket in well to try and get that look. I would have thought it would have been much worst than that. I wonder what a backlit object would look like?

Very nice optics lesson. I've got a Tessar on my Ikonta 35 that isn't quite that dramatic, but you wouldn't guess looking at the white spots that it would produce outstandingly sharp images. My experience has been that the Tessars and Xenons are particularly prone to this kind of acquired - and mostly unimportant - defect.<br>     A worse case is a fine net of surface cleaning scratches. That produces flare which totally compromises the image. I'm attaching an image that demonstrates that from a Xenar on my Retina I. I experimented on that lens with some surface polishing, but that only produced some ho-hum results.<br><br><center><img src="http://d6d2h4gfvy8t8.cloudfront.net/3209263-lg.jpg"><br><i>Xenar + shirt-tail lens cleaning</i></center>

In survey optics; sometime the lens is almost completely obscured with concrete dust; and one barely read a close level rod in bright sun. Many times a lens like Dean showed is still performing well in an automatic level; and they only bring it for repair when really required. To clean out an internal lens requires recollimating the rig; so this is only done when actually required. They real workers setting forms; pouring concrete; using a bull float dont have time to worry about cosmetic dust; like a retired Leica collector does:) :). Some Leica board chaps and others here have chaps that really go into heart attack mode over one single piece of dust; or a bubble; and call it a defect. In many types of optical equipment; it is considered extremely bad practice to rip open a factory aligned precision piece of gear; to satisfy a customer who needs a really needs a shrink; who worries about non problems. <BR><BR><h3>Dean has a great test example here. </h3> I am not surprised in the results at all; and see many working lenses that appear far worse; that still perform OK. <BR><BR>Alot of folks worry here about false lens defects; and magnify in their brains the effects by billions of times. Many cannot fathom the their "piece of dust; some bubbles; crude; lens defect" cannot be measured; it is orders of magnitude less in performance drop that the scatter of a test. It is like worrying about gas mileage of a mack truck; when a 5 cent Nickle is glued to the frame. The math teachers will worry about the 5 gram increase in weight; to the mack trucks weight. The Leica crew here will magnify the loss/defect by a googleplex; and thus require XYZ to CLA it. <BR><BR>Dean; great work!

Hmm.

 

New version of a story the LF folk tell from time to time. Much of the time, we're much too prissy about our lenses' appearance. I have a couple of 135/4.8 Lustrars that look worse than your whatever-it-is. I shot the slightly better one to see how bad it was, it could be used in a pinch.

 

But not all lenses that look bad are basically ok. I once stole a 16/2.5 Luminar on a eBay auction. This is, unusually for lenses in that class, a five element lens. Basically a tessar, elements 3 and 4 are cemented, with a flat piece of glass at the back. It appeared to have been baked in an oven, face down. Most of the balsam that should have been between elements 3 and 4 was around the rim of element 1 and the space between 3 and 4 had some big very visible voids. Looked awful. At 30:1 this one could barely resolve 144 lp/mm in the target but a known good one beat 228 lp/mm. That's a difference big enough to matter.

 

Moral, if any? Give lenses that look bad a chance, don't reject 'em out of hand if the price is right enough.

 

Cheers,

 

Dan

The real puzzle here is this- it's always a surprise to me that a camera can be in beautiful cosmetic condition, with the viewfinder lenses front and back in great shape, but the only damaged part of the camera is the front element of the lens! It looks like it rattled around in a junk drawer for years, but the only damage was to the taking lens. Not the kind of damage Uncle Fred caused by cleaning the lens with his necktie in 1962.

 

And for Kelly- being retired from Leica and being a registered land surveyor, I would respectfully suggest that the guys who don't pay any attention to their optical equipment are not the surveyors on the job but the carpenters and masons who think they are.

 

As for Reomars, they have a poor reputation, just like a lot of other 3 element lenses. Proven incorrect here, time and again.

It does seem amazing. I've got an otherwise nice Ricoh Diacord that has what looks like a spray of oil droplets inside the lens, just in front of the shutter blades. It too does an incredibly nice job except... If there's any bright reflections, anything close to back lighting or harsh side lighting you can tell it. Looks like I'd held a piece of cellophane over the lens. And in this regard, you've used the optimum conditions to test your lens - overcast sky with even lighting. If the sun had been out and made a bright reflection on the windshield, I suspect you'd have a nice glow surrounding the bright spot.

 

But that's part of the deal, even with pristine new equipment. Knowing what your camera or lens will do and what it's limitations are. Then concentrate on what it will do and don't worry too much about things that you know are beyond its limitations.

"dont have time to worry about cosmetic dust; like a retired Leica collector does"

 

Thank you for my laugh for the day, Kelly.

 

Like Michael Linn, I wonder how the front element gets this kind of mottling. I also have a half dozen Silette/Memars waiting for me to rebuild. All but two have a similar pattern of spots on the front glass. The interior elements are all ok. I wonder if this is caused by skin oils, (finger prints) left to contaminate the front of the glass over the years. I have no idea how to get it off, in any case.

 

There are indeed, a lot of condesending remarks about three element lenses. The Reomar gets some and the Apotar seems to be some kind of optical pariah. I have no idea why. I've seen quite a few of them, and the ones I've used were all quite good.

 

I don't know how this lens will do with color film, but don't see why it would be any different from B&W, unless enough of the coating is missing that it will affect color corrections. I don't even know if the coating on the front element is what corrects for color. The camera has a roll of color in it right now, so I'll find out soon.

 

Flare will most likely be a problem. If I had to use this camera as my daily shooter, a lens shade is the first thing I'd get for it. As it is, it'll probably end up rattling around in the pick-up as an anywhere and everywhere rig. Or, I could sell it on ebay...

 

Just kidding.

Now we know - those are focusing bubbles!

Dean

 

An interesting read and results.

 

Are you going to attempt to "cure" it - leave the lens (element) in the sun for a while?

 

Paul

Obviously, you mistook a feature for a bug. Didn't you know that these ingenious German optical engineers added this special coating to enhance sharpness and contrast? It became too expensive for mass production so just a few lenses were upgraded this way. You've got a valuable collectors item!

It is a little hard to tell from your picture of the lens on which the surface the dusty marks reside. Did you disassemble the lens, and what solvents did you use to try to get rid of the problem? I've seen people recommend cold cream, but that always seems like a bad idea to me given that coatings are often very fragile. I've had some luck with alcohol and Ronsonol.<br>     My impression is that lens coatings primarily have an anti-glare function, and that color correction is mostly achieved through lens configuration and doping of the glass with rare earth elements.

Paul: I don't think this is the kind of thing sunlight will fix. I've seen fungus that will die, and can sometimes be cleaned off after having been left in the sun for a while. That kind looks like tiny worms to me. I don't know what this is.

 

Peter: Then maybe I should sell it on ebay after all! It really is RARE! Collectable! Pristine! then? ;}

 

Mike C: I only tried regular lens cleaning fluid, which is mostly alcohol as far as I know. Yes, I had all the elements out of the shutter. This stuff is on the outside of the front element. The other two elements are cherry. The inside surface of this front element is in good condition as far as I can tell. I'll give Rosonol a try, as it can't hurt at this point. If you know of anything else to try, I'd be glad to hear of it. I have a number of cameras with similar front element problems, though none of them are this bad. I won't sell them like this, so they are just waiting to get robbed of parts. I'd rather be able to get the stuff off the lens and have them be put back into circulation, though.

 

And thanks for the color correction info.

 

Dean

Years ago, I had this same thing happen with a Contaflex. The lens looked pretty horrible, but it generally took fine pictures. After I sold it (at a sacrifice), the new owner wrote me to say he never had a problem with it.

 

Jon

Say, Dean, if you ever do find out what that stuff is, let me know. I've got a Schneider Radionar that would obviously benefit by a liberal application of that kind of crud... ;)

An interesting test on certo6.com (Jergen's) web site:

 

http://www.certo6.com/gallery/planar.html

 

The lens (a Zeiss Planar) has all sorts of bits and pieces, including what looks like a cracked inner lens and a DEAD BUG inside!

 

Photos came out fine.

 

Go figure.

 

Jon

Todd Goodheart wrote: "If the sun had been out and made a bright reflection on the windshield, I suspect you'd have a nice glow surrounding the bright spot."

 

Is this the famous "Leica Glow"?

Dean,

 

I made a big blunder giving up an M3 in great shape with a 2/50 Summicron that had scratches on the front lens surface. I accepted the prevailing believe that these scratches would result in poor contrast and sharpness. I was surprised to see how well the photos taken with that camera came out. I thought it was a fluke and passed on the good price deal to the next person. This was back in the 80s when Leicas were still reasonably priced. I should have kept the camera and got another lens in better shape. It was my only experience with an M series Leica, and the appreciation of it had a delayed lag time. It took a long time to realize how much I liked the camera's feel, smooth operation and its finder with multi lens parallax compensation. Then I looked for another M3, but by that time its price went way out of my budget. Gave up a fine camera all because of a lens that really wasn't hurt by the few scratches on the lens front surface. It came with a hood that kept glare in check.

 

I'll rethink a lens'potential performance by trying it first, or if a super bargain, buy it on the spot.

Well I know I never had that type of problem with a "pinhole" camera. Just Kidding. I had an old post WWII Japonise Camera that had the same markings on it an old dood I worked with at the photo store told me it was the lens coating gon bad. I don't know if he was right but it took darn good pictures for me then it was a zone camera with top shutter speed of 1/125th of a second that would stop down to f/22. Damn I miss my Pan X. Larry