'Cleaning marks' - how much effect on pix?

[scottgee1]

OK. I tried the archives for this one and didn't find much of anything, so . . . apologies if this has already been addressed ad nauseum and I'd appreciate it if you could direct me to any previous threads on the subject.

It's common knowledge here that a lot (most?) older Leica lenses have 'cleaning marks', i.e., areas of glass on which the coatings are worn off, ostensibly from cleaning.

Given that cleaning marks cannot be cleaned off the lens, I'm wondering what effect they have on pix.

I realize this is difficult to truly quantify/qualify unless one has two lenses of the same model in hand - one with and the other without - cleaning marks.

That said, I've got to believe some RFF-ers (hmmm, may not be the best abbreviation 😱 ) are shooting with lenses that have cleaning marks or used to and traded them in for ones that don't.

A logical question is, "How bad are the marks?" I've included a pic of one that seems average, but what do I know . . . ?

Of course, Dr. Sweeney has instructed us on the subject of haze via his now famous 'Hello Kitty' series of tests, but I'm thinking cleaning marks are different. But as asked before, what do I know . . . ? And as they answer on the radio program 'Wait, Wait! Don't Tell Me!', "Not much!!" 😉

TIA!/ScottGee1

 

[back alley]

i think it depends on things like if you're shooting into the sun etc.
might cause a general softness to the image but i would think there would have to lots of cleaning marks.
my 35/2.8 is my 'worst' lens for marks and it seems ok, but i try not to shoot towards the sun.
i wouldn't let cleaning marks stop me from buying a lens. (at a good price)

joe

 

[Sonnar Brian]

I got this lens, Culminar 8.5cm F2.8 for $15. It has more cleaning marks than anything I have ever seen in my life. CHeck out the photo's. I will have to get a picture of the lens, the inner surface of the front element looks like someone used fine sandpaper in circular motions to take off the coating. I scanned the prints, and posted. No Photoshop magic. The lens should be used with a shade. With sunlight striking the cleaning marks, it flares. So, use a shade or keep it out of direct sunlight. If 10 is perfect, yours is a 9.5 compared to my Steinheils "5".

http://www.rangefinderforum.com/forums/showthread.php?t=2523&highlight=culminar

 

[scottgee1]

Sandpaper? LOL!!

Is $200 a good price for one of these in 'M' mount? My original fishing expedition (prior to Frank's kind offer) is still bringing offers up to the edge of the boat.

BTW, in the deep dark recesses of my memory I recall reading a story about Edward Weston shooting some of his most famous images with a lens with a crack in the front element. Anyone else remember hearing that one? Or was I dreaming . . . ? Haven't been able to google that one up.

Thanks!/ScottGee1

 

[d30gaijin]

Scott,

It is my understanding that haze, cleaning marks, and other such damage is/are much more detrimental to image quality when they are in/on the rear elements. I'm no expert on such but that's what I've read in several places on the net, as well as somewhere in a Leica Historical Society of America magazine, by so-called "Optical Experts."

From the picture your lens looks pretty good.

Don

 

[scottgee1]

Continuing to dig . . . attached is a pic of the rear element of this same lens. In my experience, 'stuff' on the rear element has more impact on pix than does the more obvious front element.

 

[Pherdinand]

Just what i know, i thought to share:
Dirt/scratch: The closer to the film plane, the more effect it has. Ultimately, something on the film itself leaves the clearest shadow, that's how you should think - while something between the principal planes (like a leaf shutter or a diafragma blade) does not produce sharp shadow only loss of light intensity. (Principal planes are for a simple lens approximately in the physical middle of the lens; but it can be can be very different for tele- or retrofocus designed lenses.)
This thing reverses outwards, meaning the closer the dirt to the object in focus is, the clearer the effect (the shadow) of the dirt is, again. But its not a 1:1 ratio; if it's 5mm closer from the inner principal plane it is much worse than if it's 5mm further from the outer principal plane. And, it is imaged smaller than in reality is.

If it's only the coating rubbed off, you should not expect any degradation, except slight loss of contract and increase of flare in critical situations. Even if it's in a non-uniform shape. The remaining anti-reflection coating might seem to have clear edges but it will not show up on the photo.

Haze over a large surface, that's different story.

Also, in the fifties it was quite normal to have tiny bubbles in the glass. It does not affect the image at all; why should another tiny mark do it then, even if it's on the surface.

 

[aizan]

if they're actually fine scratches, lots and lots of them, it will soften the image. coating marks will only increase flare. i'd try bargaining lower than $200. just say the collapsible summicron is already the least contrasty.

 

[sockeyed]

I have bubbles in my 1960 Jupiter 9, and they don't affect image quality at all. In fact, they used to be considered a sign of quality.

See a discussion I started on the subject at photo.net
http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00ASQ2

 

[Sonnar Brian]

$200 is "a good price" for an M-Mount Collapsible Summicron with marks but no fungus or haze. My Summarits with haze and cleaning marks on the front element were $125 in M-Mount and $140 in LTM. Add $80 for a CLA, put the price AFTER CLA just over the $200 mark.

 

[pshinkaw]

Fine scratches on the back element will oftentimes give you a dreamy , sparkly look. Somewhat like having your pupils dilated at the doctor's office. Cute but not always desireable.

I do have lenses with actual gouges in the front element that seem to have no effect on their performance.

-Paul

 

[scottgee1]

Pherdinand, your explanation makes sense to me, i.e. the closer 'stuff' is to the point at which the image is formed and the more that 'stuff' affects the light, the more the image is affected. Purty logikal when you think about it. 😉

Interestingly, this is one of the reasons one of my favorite lenses is the Mamiya Soft Focus lens for the RB series. Diffusion disks are placed in the middle of the optical path to provide better control over desired diffraction. See:

http://www.mamiya.com/lensesNI.asp?id=1&id2=8&id3=10&id4=689&id5=1588


Brian, thanks for the comments on pricing. The lens is offered by a dealer who has a one week trial period. Sounds like it may be worth a go.

Best regards,

ScottGee1

 

[rover]

I was just going to ask this exact question.

Actually, pehaps someone can help me find a web page addressing this. It is titled something like "The Truth about Coating Marks" or something like that. I come across it 2 or 3 times a week and of course, today after searching for 30 minutes I can't find it. I know that Huck Finn and others have linked it in replys here in the past.

Does anyone know about the page I am talking about?

 

[rover]

I found one, KB Camera of course

http://www.kbcamera.com/scratchedlenses.htm

 

[taffer]

Thanks for the point Rover ! Did you see this ?

Small scratches, especially those on the back element of the lens, won't make much difference

Very interesting, that's exactly the opposite of the commonly accepted theory ! KB camera is proving to be a jewel 🙂

 

[mr roberts]

I just found a 35/2 Summicron though it appears to be a generation older than i was hoping for. One of the shop's technicians was kind enough to look it over for me as it's on a shelf a long way off.

Can anyone tell me which generation before the current asph this belongs to? (That's if i've attached the picture correctly.) Can you share opinions on this version beyond what i've seen on the CameraQuest site? Would I be better off with a new CV Ultron 1.7?

The tech told me that the flashlight test shows a slight ring of haze on the second element in from the front which is obscured when stopped down ~1/2 stop from wide open. No cleaning marks, hood not deformed with only a couple of dings in the anodized finish and the mount/cam surfaces are clean with liitle wear.

Is this haze likely to be an issue? What are the chances of a CLA taking care of this haze on the fringe and what would a fair price for a lens in this condition be?

Any help or feedback is appreciated greatly.

 

[mr roberts]

I had forgotten to write down the serial number from the fellow that I spoke with regarding the len's condition. He was kind enough to call me back with that information later on. The serial number places it as early 70's vintage.

Any info relative to the other questions? Anyone...

 

[Sonnar Brian]

O doubt that the slight haze will cause effects on the photo's. A CLA will likely take off the haze without damaging the coatings; they were hard coated in the 70's. I have had thoroughly hazed over Summarits cleaned with beautiful results afterwards.

 

[mr roberts]

Thanks Brian. I spoke further with the tech and he said that it doesn't look like this one's ever had a spanner on it. So a CLA might be a good idea after i get my hands on it. The hood looks like it might obscure a bit more of the viewfinder than is desireable. Can the newer hood be retrofitted to the earlier gen lenses? Has one hood design proven more effective than the other?

 

[rover]

The vented hoods aren't too bad to look through. If you are looking for a good user, this may be it. Save a little $ because of the haze and a CLA shouldn't be too much.

Our sponsor, KB Camera has a great site with loads of info. Here is their take on the 35 Summicron.

http://www.kbcamera.com/summicron35mm.htm

1970s vintage will make it a Type 2 or 3 lens, which they say are the same lenses, just different barrels.