[W.j.christy]

OK so my LBA is firing up again and I found a lens I am working on winning at an auction site. Is an 80-400 however, there appear to be marks on the front element very close to dead center. At this point it hard to tell if they are scratches, rub marks, or chips.

I would like to know what experience people have with lenses that have marks, chips, scratches, etc in the center or close to the center of the lens, and what kind of results I can expect if i proceed to purchase the lens....

thanks in advance!

[edmundrt]

In my experience it takes a pretty big mark to have any effect on image quality. This article demonstrates it pretty well:

Dirty lens article

[bertwert]

Interesting articles:
Dirty lens article
Lens Rentals | Blog

[W.j.christy]

that is a very good article! And gave me some very good confdience......

[Ontarian50]

A tip for the penny-pinching photographer, back in the day, was to buy up used telephoto lenses with scratched front elements. Big beasts like 300mm 2.8's often get a bit beaten up by pros, and gouges in the front glass were common - so the lenses would sell for a fraction of one in good shape.

Then the trick is to fill in the scratch with matte black model paint - probably applying it with a pin or needle. This turns the scratch into a dead spot - but unlike in the dirty lens article - the black doesn't refract or scatter stray light.

Sure, in an image with a lot of out of focus highlights, the image of your blackened scratch will be in every highlight, but who would really notice? And for everything else, the darkened scratch would have no effect.

Have I ever done this, myself? No, my OCD wouldn't allow me to own a scratched lens

[vonBaloney]

On a telephoto lens, you can see the *effects* of scratches on the front element if they catch the light, but if you use the technique of filling-in the scratch as suggested above (and using a hood, which you should be anyway), you'll never know it was there. (You probably don't have to apply it with a pin or needle to surgically target the scratch -- you just dab it on the scratch and then immediately wipe it off the surface while wet -- scratch will be filled, the surface will be clean. Most people suggest just using a black marker, but those are usually actually purple so something black black is probably better.) I suspect a center scratch is actually preferable to an edge scratch because of the way the light travels -- you can block out the entire center and it won't have that much effect other than lowering contrast and overall exposure (and maybe donut bokeh like a mirror lens?). Block out the edges and you have visible vignetting.

On a wide-angle lens, you might be able to see the actual scratch because the focus distance can get so close to the front element.

[Na Horuk]

Good replies. Generally you have to worry about scratches on the back more than on the front. Wide angle, especially ultra wide and fisheye, can actually catch the scratch close enough to focus that it might be visible.
Just get a good lens hood and you should be fine

[W.j.christy]

I appreciate the help! I am on my way to winning the lens and will report back once I know the results!