circular arc scratch/crack on 80mm zeiss planar

[evanmoly]

Hello forum! This is my first post but I've been enjoying the discussions on film development and other camera related chat on here for a while, so thanks to everybody for making this a good place to do research.

I discovered a uniform circular scratch (maybe crack?) that appears to gouge into the front element of my 80mm Zeiss 2.8 Planar. The mark goes halfway around the diameter of the front element, and seems to be a perfect circular arc while the severity of the mark varies.

I picked this up from KEH about 7 years ago and never noticed this, so I'm guessing it occurred while in my possession. I've never noticed any effect on image quality throughout many rolls. I've heard of cleaning scratches, but this seems pretty severe to come from a micro fiber cloth. The camera has definitely been shuffled around a lot while traveling, but always in a padded bag and never dropped hard.

Anybody seen a similar issue before? What might be the cause of this? Thanks in advance for any input!

 

[Sirius Glass]

Welcome to APUG

The news about your lens is not so welcome. I do not have experience with this type of problem although I have heard stories about such problems not causing a difference in photographs. Does it change the quality of the photographs? Could it be lens separation?

 

[Gerald C Koch]

Sounds like over zealous cleaning to me. I have a cheap enlarging lens that has a similar set of circular scratches. It was included in a group of Schneider lens that I purchased. A single scratch will not degrade the image that much. Particularly as it is on the periphery of the lens. Since you say the scratch is deep that would seem to preclude having it repolished. Optical glass is rather soft and must be handled gently..

A condition like this illustrates why you should always use lens tissue which is disposable. Clothes tend to pick up grit resulting in circular scratches. Microfiber cloths are the worst since it is very hard to clean them. They seem to retain particles of grit.

If a lens has just a bit of lint or dust on it then it is best to leave it alone. Reserve cleaning for finger prints or other things. More lenses are ruined by "tender loving care" than by benign neglect.

 

[nsurit]

Looks like a scratch to me. Only affect you will likely notice is if you ever decide to sell it. Oh, and if it were mine, it might make me a little crazy. My typical way of cleaning is to brush the element with a natural hair make-up brush. Lightly dampen a 100% cotton ball with denatured alcohol and gently and in a circular motion clean the lens, followed immediately by another clean and dry 100% cotton ball to finish the job. All the cotton balls are kept in a tightly sealed zip lock bag. I know this might make some crazy, however I've done it this way for many years and have never damaged a lens.

 

[railwayman3]

It really does look like a cleaning scratch rather than a crack, both from the appearance and the fact that it is concentric with the curved edge of the lens (caused by wiping with a circular motion?). Perhaps check with a magnifying glass that it is on the surface, rather than a crack deeper in the glass.

I'd go with the advice and comment from Gerald and from nsurit, above. I also keep a filter on my lenses at all times, and always clean that rather then the lens....purists may argue than any filter must degrade the image, but I'd chance that a good quality filter would have no more effect than minor marks on the lens itself.

 

[Sean Mac]

Fill it with indian ink and try and forget about it. Looks way too big to be a cleaning mark.

 

[evanmoly]

Thank you all for your replies. I got some pec pad non abrasive disposable wipes and took a closer look, very gently running the pad over it to note the texture. Its definitely a scratch/gouge on top of the front element, and the symptoms aren't really consistent with examples of separation I was looking at. I am baffled that the glass got so deeply etched, especially since I had a hasselblad haze filter on within a couple of days of first getting the lens. I dont remember ever taking the filter off to clean it, but the only explanation I have is that at some point, in ignorance of the softness of the glass, I used a cloth with debris in it and damaged the lens. Its possible I bought it in this condition, but no way of knowing that now.

I've always loved this camera/lens, but was considering selling it to fund a 4x5 setup, which is why I looked at it more closely. As Nsurit noted, the greatest effect is on resale value, so I'm going to keep shooting with it unless I notice an effect on the images.

 

[frank]

Use a lens hood and I really don't think this scratch will degrade the image to the extent that it's noticeable.

 

[bdial]

Consider that if it would cause a noticeable affect, you probably would have seen that already.
It probably will cause some flair, but will also likely be unnoticeable otherwise, except for someone who might be buying it.
As Frank said, use a lens hood and forget about it to the extent you can.

If it's something you can feel, it's not repairable. Focal Point Lens can do some amazing work recoating, but the cost would exceed the value for that lens.

 

[Sean Mac]

"In the worst of instances, a scratch may cause a loss of contrast because extraneous light rays are being refracted from the scratch and are bouncing around inside the lens. But even this isn't incurable. An old opticians trick is to fill scratches with india ink. Astronomers and telescope makers have known about this trick for years and it works beautifully."

Michael McBroom in McBrooms Camera Bluebook. 1994

Lens hoods are good too..

 

[lxdude]

A condition like this illustrates why you should always use lens tissue which is disposable. Clothes tend to pick up grit resulting in circular scratches. Microfiber cloths are the worst since it is very hard to clean them. They seem to retain particles of grit.

Those lens pens look like trouble too.

 

[Arvee]

When I first saw the scratch, I imagined that someone attempted to use a reversed 50mm lens (for an SLR) as a macro attachment and rotated it against the glass while holding it in place. The scratch looks awfully uniform/equidistant from the edge.

 

[Alan Gales]

When I first saw the scratch, I imagined that someone attempted to use a reversed 50mm lens (for an SLR) as a macro attachment and rotated it against the glass while holding it in place. The scratch looks awfully uniform/equidistant from the edge.

It looks like something rotated against the glass to me too. It looks too uniform to be a cleaning scratch.

 

[cramej]

Could be where a rubber cup was used to loosen/tighten the element for service.

 

[railwayman3]

It looks like something rotated against the glass to me too. It looks too uniform to be a cleaning scratch.

Good point....as I said above, I was thinking of a bit of grit in a cleaning cloth with a rotary action, but it is a very deep gouge and some kind of attachment being screwed onto or against the lens certainly looks even more likely. Has the lens ever been screwed onto something like a microscope or telescope eyepiece ?

 

[evanmoly]

Good point....as I said above, I was thinking of a bit of grit in a cleaning cloth with a rotary action, but it is a very deep gouge and some kind of attachment being screwed onto or against the lens certainly looks even more likely. Has the lens ever been screwed onto something like a microscope or telescope eyepiece ?

Not to my knowledge. Another cause could be if somebody jammed a small filter, like a 52mm behind the main bayonet filter and tried to use the front filter to keep it in place.

Unfortunately the damage is done, and like bdial said, the repair cost would probably exceed the value. Looks like im going to try the india ink trick to get some damage control.

Thinking back, it was definitely listed 'BGN' condition from KEH at $500 for lens, 500c body and a12 back, all cosmetically worn for sure. I know the price was low, but I thought the market was kind of soft for these cameras in 2008. Maybe that price reflected the damage to the glass?

 

[Sean Mac]

"Much misconception exists about the effect scratches have on photographs. Allow me to put it to rest here and now. Generally, a scratch on the rear element of a lens-especially a wide angle lens-will have a greater effect on photographs than a scratch on the front element. However, in all but the most severe instances, the only effect a scratch will have is on a lenses resale value. Try this; Take a piece of string and hold it to the front of a lens mounted on your camera. Look through the viewfinder and focus on whatever you want. Can't see the string can you? Neither will the photograph. Now, imagine how ugly the front element of that lens would look if it had a scratch the same size as that piece of string."

Michael McBroom in McBrooms Camera Bluebook 1994

 

[Arvee]

"Much misconception exists about the effect scratches have on photographs. Allow me to put it to rest here and now. Generally, a scratch on the rear element of a lens-especially a wide angle lens-will have a greater effect on photographs than a scratch on the front element. However, in all but the most severe instances, the only effect a scratch will have is on a lenses resale value. Try this; Take a piece of string and hold it to the front of a lens mounted on your camera. Look through the viewfinder and focus on whatever you want. Can't see the string can you? Neither will the photograph. Now, imagine how ugly the front element of that lens would look if it had a scratch the same size as that piece of string."

Michael McBroom in McBrooms Camera Bluebook 1994

+1. I picked up a collapsible Summicron that had been dropped and had sustained damage about the size of half a dime at the edge. I blacked out the area, the lens became an f2.5 and I never noticed any degradation in any prints in the years I continued to use it.

Black it out and use it. You won't see any difference in its results than if you were to repair/exchange it with another lens. The only change you will see is the serious depletion of the contents of your wallet!

 

[evanmoly]

Sean and Fred, thanks for the great feedback! Since im not going to spend the money to replace the lens with something that makes the same quality images, i think its going to stay put. Besides, its got 'character.'

 

[bdial]

The examples shown here are pretty interesting when talking about lens damage;

http://www.lensrentals.com/blog/2008/10/front-element-scratches

 

[evanmoly]

The examples shown here are pretty interesting when talking about lens damage;

http://www.lensrentals.com/blog/2008/10/front-element-scratches

Wow! Thats a serious flaw in the front element.