Is it possible to have scratches ....

[Mike V]

as above...

is it possible to have scratches on a lens, even minor ones and they wont affect the image at all?

Not sure whether I can believe it or not.

I see a lot of lenses on ebay with slight marks but the sellers consider them in perfect working order.

What do we think guys?

[Gem Singer]

Minor scratches will not effect the image, noticeably.

Major scratches will effect the image to some extent.

Both types of scratches will effect the resale price of a lens.

[Mike V]

Thanks, is there any kind of rule of thumb to adhere to?

i.e. anything bigger than a hair will be noticeable or scratches closer to the centre will show more than those to the edge.

[Bruce Watson]

Is it possible to have scratches on a lens, even minor ones and they wont affect the image at all?

Absolutely. The reason this works is that all points on the lens reproduce the full image. If you have a scratch, all the rest of the lens is unaffected. There is of course *some* degradation -- like 0.0001 %. Nothing is perfect. But it's impossible to see it in your final print.

People even fill in chips in the glass with India Ink. Big honking black spot (so it won't generate any reflections or flare). No visible effect on the final print.

Old lenses are known for having bubbles in the glass. Likewise, no visible effect in the final print.

This leaves you with the question of "how much is too much" and that's something you'll have to decide on your own.

[Kevin Crisp]

My test is to look through the wide open lens at a bright light in a dark room. (Say, a Tensor lamp.) Alternatively, hold it in your hand and hold a BRIGHT LED light on the other side. Does the light smear and diffuse (fuzz) due to the scratches beyond the boundary of the light? If so, you're going to see it on film, especially when not stopped down. If the light looks like a bright light with nothing more than a little wisp here and there spilling over then it will be fine. But these severely affect value and if you don't have the lens in your hand before you decide to purchase, and/or can't return it, you are taking a chance.

Localized dings and single scratches, even if pretty deep, are unlikely to affect the image. If they catch light you can fill them in with a marker. What gets you is the damage from dry/abusive cleaning that causes widespread damage.

[Mike V]

Thanks for your replies guys. Much appreciated!

[bspeed]

this is....interesting...:

http://www.lensrentals.com/news/2008...ment-scratches

[cblurton]

Take a look at this lens and the picture taken with it. Cracked and with a bug in between the lens elements, it still makes a nice image:

http://www.certo6.com/gallery/planar.html

[Mike V]

Both amazing links, really interesting! :O:O

[Jim Galli]

The scary ones are the ones that got cleaned with a brillo pad and just have microscopic swirls everywhere. Contrast with one of those really does suffer noticeably but you've at that point damaged a huge percentage of the original surface.