Effects of coating/cleaning marks - older lenses

[EdC]

I'm giving some serious consideration to a 135mm Kodak Wide Field Ektar that is up for sale. I'm normally pretty fussy about lens condition, but have noticed that the Wide Field Ektars are not super common. In addition, discussions of these lenses indicate that the coating was soft. With that in mind, I'm wondering if my fussiness is getting in the way of picking up a decent lens. The seller states: "smudge on front - barely visible. no effect on images. - rub on back seems like maybe from contact with the cap. might add some flare." While I've not asked for better close ups on the lens surfaces, there really isn't much visible from a few inches away, although the photos aren't that great. (I do plan on asking the seller for more info.) Assuming that any coating loss is as minor as he claims, my understanding is that the only real downside (besides cosmetic) would be a slight loss of contrast in really bright lighting.

Am I overlooking anything here?

Thanks,

Ed

[Dan Fromm]

This http://web.archive.org/web/201703212...-/122401100727 one?

The rear cell (see 3d and 4th pictures) looks odd but that could be an artifact. I'd ask the seller about that. Also ask the seller about returns.

FWIW, the seller posts here and seems a decent person.

Re coatings, I have an 80 WF Ektar that was made in 1948 (EI like the one you're looking at) for years, had another also made in '48. Neither's coatings seemed delicate.

[MultiFormat Shooter]

You could also have the lens recoated with modern coatings. That would take care any potential blemishes.

http://www.focalpointlens.com/ I have no affiliation with them, nor I have I used them; just giving a potential resource.

[mdarnton]

I think it takes quite a mess to be visible in photos, but photographers seem disproportionately disturbed by this, so it seems like an opportunity to get a good price. Marks at dead center seem to be the ones to avoid, since stopping down makes the bruise take a larger and larger percentage of the imaging fraction of the glass.

[Nodda Duma]

Defects in the coating (scratches, blemishes) can induce forward scatter out of proportion to their physical appearance, depending on the scene. This increases veiling glare and loss of contrast.

To what extent is very difficult to predict (even if I have the full lens assembly modeled), but it's easy enough to take some photos with it and evaluate the effect. If the previous owner says it's ok, then the effect is probably minimal (I'm a trust but verify guy).

Coatings for single lenses are rarely cost-effective to repair, especially in the consumer market and especially when you pay for the coating job yourself. The company mentioned above would be worth contacting to determine pricing...they probably coat lenses from many different customers at once to amortize the cost.

[EdC]

This http://web.archive.org/web/201703212...-/122401100727 one?

The rear cell (see 3d and 4th pictures) looks odd but that could be an artifact. I'd ask the seller about that. Also ask the seller about returns.

FWIW, the seller posts here and seems a decent person.

Re coatings, I have an 80 WF Ektar that was made in 1948 (EI like the one you're looking at) for years, had another also made in '48. Neither's coatings seemed delicate.

Thanks, Dan!

You're correct. That is the particular lens that I was looking at. The seller does have a return privilege, and he has submitted an additional photo with an arrow pointing to the area of the rear element which is supposed to show the spot where there is some wear to the coating. I tried to include photo, but was unable to do so, for some reason.

[domaz]

You could also have the lens recoated with modern coatings. That would take care any potential blemishes.

http://www.focalpointlens.com/ I have no affiliation with them, nor I have I used them; just giving a potential resource.

You'd be better off finding a lens in perfect condition and paying a premium for it then using this service. It's quite expensive. Having said that it would make sense for a rare or expensive lens in some cases.

[jim10219]

I have several old lenses with scratches, chips, and balsam separation. All of them have proven to be excellent performers despite their cosmetic flaws. In most cases, a lens hood or stopping down fixes any issues they might pose. In my experience, photographers tend to over estimate the negative effects that minor lens flaws can have on an image, which is understandable, given how much attention to detail everything else about this art form demands. But in my experience, 35mm lenses seem to be more picky when it comes to flaws (especially on the rear element) than large format. However, each situation is going to be different, and each photographer is going to have a different standard, so only you can say if the lens performs well enough or not. Since the seller offers returns, it might be worth the gamble. I've been happy every time I've made that gamble on a lens! I can't say the same thing about every camera though.

[Louis Pacilla]

I have several old lenses with scratches, chips, and balsam separation. All of them have proven to be excellent performers despite their cosmetic flaws. In most cases, a lens hood or stopping down fixes any issues they might pose. In my experience, photographers tend to over estimate the negative effects that minor lens flaws can have on an image, which is understandable, given how much attention to detail everything else about this art form demands. But in my experience, 35mm lenses seem to be more picky when it comes to flaws (especially on the rear element) than large format. However, each situation is going to be different, and each photographer is going to have a different standard, so only you can say if the lens performs well enough or not. Since the seller offers returns, it might be worth the gamble. I've been happy every time I've made that gamble on a lens! I can't say the same thing about every camera though.

I agree with most all of what Jim10219 has to say. If not all.

[LabRat]

The way I "visualize" what type of optical surface issues (that might effect viewing) is to wear old glasses/sunglasses, and after awhile one sees what happens when the surfaces get scuffed/dirty/smeared/hazed/pitted/scratched etc and the visual effect from it...

The worst effect to me is scuffed fine cleaning marks that form an overall lower contrast and sleeks that act like a bad star filter shooting into the light (like looking out an old scuffed bus or train window), but some spots, chips, even cracks, and light hazes sometimes don't show at all... Make sure these (and all) lenses are well shaded while shooting... And avoid shooting into the light or a lot of bright light/high contrast type images... If in doubt, try it out...

Steve K