Scratched lenses, coatings, etc.

[Eric in Vegas]

I have a 203mm Optar f7.5 lens in a Graflex #2 shutter. The shutter was completely inop but I got it working (and had a great time doing it). The lens elements, however, are quite scratched and I was hoping to clean them up a bit. I have two questions I was hoping to get help with.

First, I assume this is a coated lens, but honestly have no idea how to tell. Any advice on determining if an old lens is coated or not would be greatly appreciated.

Secondly, any advice on cleaning up scratches on lens? I've read that some people clean up scratches with a dremel tool and some polish. I'm sure there are all sorts of factors that come into play if you decide to do this such as removing any lens coating that may be there. But, I'm under the impression that a once-coated lens with no scratches is preferable to a coated lens with significant scratches. Any advice to better understand any factors would be greatly appreciated.

I'm a hobbyist who gets alot of joy out of keeping old cameras and lenses alive so pristine optics is not the highest concern.

Thanks, Eric

 

[4season]

I never got around to trying it myself, but in amateur telescope-making, a pitch lap + successively finer grades of optical grit are used to turn an unpolished piece of glass into a mirror. But I’d hesitate to attempt this on a lens which was otherwise usable or which still had value. Deep scratches might be best simply filled with black paint in hopes of reducing light scatter.

 

[Jim Jones]

As I said on another forum, using a Dremel tool on a lens is worse than using a chain saw for brain surgery.

 

[reddesert]

A uncoated lens will have fairly strong neutral colored reflections of a light source. A coated lens will have weaker, colored reflections - typically a blue/purple or orange color, for a single-coated lens, which is what a Graflex Optar would be. Also, lens coating and flash sync both became fairly standard at the end of WW II, so a lens in a sync'ed shutter is typically coated, but this is not 100% reliable.

With respect, it sounds like you don't have a lot of experience with optics (I mean fabrication or repair level experience) and in that case, your best option for the scratches is to do as little as possible. Do not under any circumstances use a dremel tool, if one uses a hand polish it has to be an optical polish (cerium oxide) not a hardware store or rock-shop polish, etc.

Scratches on the front element of a lens mostly scatter light, reducing contrast. If there are a lot of them it can rise to the level of haze, but if they're pretty small it might work well anyway, just use a lens shade. If you are really concerned about a scratch or pit it is better to black it out with a removable ink as 4season suggested. You might like to review this post from lensrentals.com blog about the effects of a marred front element: https://www.lensrentals.com/blog/2008/10/front-element-scratches/

 

[Eric in Vegas]

A uncoated lens will have fairly strong neutral colored reflections of a light source. A coated lens will have weaker, colored reflections - typically a blue/purple or orange color, for a single-coated lens, which is what a Graflex Optar would be. Also, lens coating and flash sync both became fairly standard at the end of WW II, so a lens in a sync'ed shutter is typically coated, but this is not 100% reliable.

With respect, it sounds like you don't have a lot of experience with optics (I mean fabrication or repair level experience) and in that case, your best option for the scratches is to do as little as possible. Do not under any circumstances use a dremel tool, if one uses a hand polish it has to be an optical polish (cerium oxide) not a hardware store or rock-shop polish, etc.

Scratches on the front element of a lens mostly scatter light, reducing contrast. If there are a lot of them it can rise to the level of haze, but if they're pretty small it might work well anyway, just use a lens shade. If you are really concerned about a scratch or pit it is better to black it out with a removable ink as 4season suggested. You might like to review this post from lensrentals.com blog about the effects of a marred front element: https://www.lensrentals.com/blog/2008/10/front-element-scratches/

Thank you for the info as well as the link. I'm definitely going to try using the lens for awhile rather than attempting to remove the scratches.

 

[David Lindquist]

As a side note, it's my understanding that the Wolllensak 203 mm f/7.5 Optar replaced the Kodak 203 mm f/7.7 Ektar which by that time Kodak had been supplying to Graflex for use on the Graphic View II. Typically these f/7.7 Ektars were mounted in a number 1 Compur which was engraved "Graphic" on the front.

Given the vintage of your lens, I'd say it must be coated.

I have a 1967 Graflex price list, it shows this lens was $158.50. By this time Graflex was owned by the Singer Corporation, who of course started out making sewing machines.

David

 

[Dan Fromm]

Given the vintage of your lens, I'd say it must be coated.

David, there's a simple test. Coated Wolly lenses have a C around a W on the trim ring. This is parallel to EKCo's L in circle on the trim ring.

Cheers,

Dan

 

[albada]

A few years ago, I tested a 45mm lens with many scratches on the front. I shot a scene with sunlit white objects and some black objects and shade. The result looked great, with no evidence of haze or reduced contrast. My theory is that though the scratches were numerous, they ruined such a tiny percentage of the glass area that the photographic harm was not perceivable.
Thus, I agree with your decision to try shooting with the lens.

Mark