How can a scratch on the glass not affect picture quality?

[annnewjerz]

I'm looking at some used lenses on E-bay and one seems to be a steal. The description of the lens says that there is a small mark (about the size of a pen tip) on the glass, but it doesn't affect the picture quality at all.

I've Google'd the question a million different ways and the general concensus seems to be that a mark on the glass won't affect picture quality, just resale value.

Is this the case? If so, explain to me---how is that possible? AND, if you got a good price on a lens because of a mark so small, would you jump on it, or buy one that's $200 more but free fo any scratches?

 

[Master Mason]

Because essentially the sensor doesn't see it. I can't expain the physics of it, but it is the same phenominum that allows you to open your apeture and shoot through a fence and not have the fence be visible in the picture.

To your other question, no, I personally wouldn't be happy with it, the scratch would bug the crap out of me. But it's an individual thing.

 

[dansamy]

There was some discussion of this sort on an astrnomy forum I visited while researching telescopes. I came across a picture of a terribly cracked lens and a photo shot with it. I wish I could find it for you. Yes, it will affect IQ, but not nearly as badly as you think it will.

 

[GrillMouster]

On the lens or in the lens is too close to focus, so the mark shouldn't be visible in images, especially if you shoot at larger apertures. However, if the lens has quality coatings that help reduce flare and increase contrast, then the scratch might make it little more susceptible to flare or reduced contrast, but only in those instances where flare would normally occur.

 

[DznyFan]

Ann, its funny you mention because I ran across one on ebay last week with the same problem - an older lens that has become a bit of a collector's item. It was dirt cheap comparatively but I steered clear of bidding because it was listed with a scratch. They made the same claim, but I had the exact same question as you. I'm glad I know now. (I still don't know if I would buy, though... but that's just me) I guess if it's a good enough steal, it doesn't matter.

 

[annnewjerz]

To your other question, no, I personally wouldn't be happy with it, the scratch would bug the crap out of me. But it's an individual thing.

I know, same here. I'm trying to get over that.

There was some discussion of this sort on an astrnomy forum I visited while researching telescopes. I came across a picture of a terribly cracked lens and a photo shot with it. I wish I could find it for you. Yes, it will affect IQ, but not nearly as badly as you think it will.

I was given this article on another board. Not about telescopes, but pretty brutal regardless.

http://www.lensrentals.com/news/2008.10.30/front-element-scratches

On the lens or in the lens is too close to focus, so the mark shouldn't be visible in images, especially if you shoot at larger apertures. However, if the lens has quality coatings that help reduce flare and increase contrast, then the scratch might make it little more susceptible to flare or reduced contrast, but only in those instances where flare would normally occur.

The lens is the Nikon 10.5mm fisheye. I've shot with it before and there seems to be a blue-ish coating on it, so I'm not even sure if the scratch is on the glass itself, or just a mark on the coating.

Brand new the lens is almost $700 and I can get this used for $400. Normally, I'd just save and buy new, but I just purchased a Nikon 70-200 f/2.8 and as a result, DH has alerted me that a large chunk of my photography related budget this year has already been consumed and purchases this year will be limited. Booo!!!

 

[handicap18]

Where the scratch/mark on the lens is will make a difference too. If it is near the edge it wont affect the image much at all. If its smack dab in the middle then you might run into issues, though if it is small enough you might not notice it at all.

 

[Groucho]

A scratch might also be fine in some photos and not so good in others - like if there's light coming from the side that hits the scratch. A good lens hood would help.

If you want a demonstration of just what a damaged lens can do, check out this thread - a Takumar 50mm F1.4 that has crazy amounts of fungus and is still taking amazing, sharp photos. Like someone said, "lenses are for looking through, not looking at."

As for would you buy it - the big question is, could you resell it for that amount? If so, then you have nothing to lose. Buy it and see if it works well for you. If so, terrific - if not, sell it and get your money back.

 

[Gdad]

I had one of those once- it hit the concrete during a wedding I was shooting for free for a family member. Funny thing was it worked just fine for a year after that- I sold it 'as-is' cheap with full disclosure when I went to FX because I was too lazy to get it fixed but I could never see anything in the images in produced. Here are some test shots I made when I sold it. No marks at all (except for my dirty sensor shooting at f22 I had to clean it after that.)

http://www.capturelifeinaction.com/Private/105mm-Fisheye-Test-Shots/7915394_YVdkG

 

[annnewjerz]

Where the scratch/mark on the lens is will make a difference too. If it is near the edge it wont affect the image much at all. If its smack dab in the middle then you might run into issues, though if it is small enough you might not notice it at all.

I'm hoping that even if it is noticable (like a mark showing up in my shots) that I may be able to just clone it out in PSE. Hmmmmm.

A scratch might also be fine in some photos and not so good in others - like if there's light coming from the side that hits the scratch. A good lens hood would help.

If you want a demonstration of just what a damaged lens can do, check out this thread - a Takumar 50mm F1.4 that has crazy amounts of fungus and is still taking amazing, sharp photos. Like someone said, "lenses are for looking through, not looking at."

As for would you buy it - the big question is, could you resell it for that amount? If so, then you have nothing to lose. Buy it and see if it works well for you. If so, terrific - if not, sell it and get your money back.

I'm pretty sure I could re-sell it for close to what I'd buy it for (maybe more) and if not, to be honest I really don't care. I've sold 4 lenses that I have purchased already for slightly more than what I paid for them, so if I took a $50 hit on this lens, no biggie to me (although maybe it would be to my DH )

It's going for $700 new and I can get this one for under $400, so worst case scenario is that it'll just be something fun to pull out every so often like the Lensbaby. Best case scenario is that I end up loving it and get a great deal on a much-used lens. I have had the pleasure of borrowing one for about 2 months and really had a blast using it, but just didn't have the money then to buy one.

I know I can't dethrone the master, but maybe I can have loads of fun trying!

I had one of those once- it hit the concrete during a wedding I was shooting for free for a family member. Funny thing was it worked just fine for a year after that- I sold it 'as-is' cheap with full disclosure when I went to FX because I was too lazy to get it fixed but I could never see anything in the images in produced. Here are some test shots I made when I sold it. No marks at all (except for my dirty sensor shooting at f22 I had to clean it after that.)

http://www.capturelifeinaction.com/Private/105mm-Fisheye-Test-Shots/7915394_YVdkG

O......M......G. Well I guess that settles it! I can't believe someone actually bought it like that. I know it's not all about how a lens looks and I own two used right now, but that's even a little much for me.

 

[Gdad]

O......M......G. Well I guess that settles it! I can't believe someone actually bought it like that. I know it's not all about how a lens looks and I own two used right now, but that's even a little much for me.

It was to a student who probably could not afford it otherwise. I think I sold it for around $200- figuring the repair would have probably cost the difference I could have sold it for fixed.

 

[WDWFigment]

Ann, for what it's worth, there are a lot of completed listings in the ~$450 range for this lens. $400 is a good price (especially if there's a buy-it-now, so you can get the cashback), but depending on how much it will effect resale value, you might be better off waiting.

 

[annnewjerz]

Ann, for what it's worth, there are a lot of completed listings in the ~$450 range for this lens. $400 is a good price (especially if there's a buy-it-now, so you can get the cashback), but depending on how much it will effect resale value, you might be better off waiting.

Oh believe me, I've been watching, but I know you are the E-Bay king!

I got a chance to borrow this lens for a few months from a fellow DISer and knew then that it'd be on my NAS list. $400 (luckily) is the Buy-It-Now price and I am a frequent cash-back'r through Bing, so I'd really get it for more like $385 or so after shipping. And, I'm not even planning to use the Buy-It-Now until the price of the auction gets up there.

For now, I have a bid in of in the 2 somethings. Considering the lens is scratched, I'm guessing this won't even get into the upper 3's but if it does, that's fine, I'm willing to pay that much for it.

 

[WDWFigment]

Oh believe me, I've been watching, but I know you are the E-Bay king!

I got a chance to borrow this lens for a few months from a fellow DISer and knew then that it'd be on my NAS list. $400 (luckily) is the Buy-It-Now price and I am a frequent cash-back'r through Bing, so I'd really get it for more like $385 or so after shipping. And, I'm not even planning to use the Buy-It-Now until the price of the auction gets up there.

For now, I have a bid in of in the 2 somethings. Considering the lens is scratched, I'm guessing this won't even get into the upper 3's but if it does, that's fine, I'm willing to pay that much for it.

Unless there is a reserve, the BIN disappears after the first bid is placed, so I'd be careful with that strategy. I just did a search, and I couldn't find the listing in question. I did find a recently listed lens with a scratch that is now up to $5.50. I won't post the link here because I don't want to alert any lurkers as to your potential deal...

 

[mom2rtk]

Unless there is a reserve, the BIN disappears after the first bid is placed, so I'd be careful with that strategy. I just did a search, and I couldn't find the listing in question. I did find a recently listed lens with a scratch that is now up to $5.50. I won't post the link here because I don't want to alert any lurkers as to your potential deal...

You know, I don't know if that is the case any more. I don't know when, but sometime a while back, the BIN's started staying even after the first bid was placed. I don't know if it disappears when it hits a certain point or not, even without a reserve. I noticed it on some of the things I was selling.

 

[WDWFigment]

You know, I don't know if that is the case any more. I don't know when, but sometime a while back, the BIN's started staying even after the first bid was placed. I don't know if it disappears when it hits a certain point or not, even without a reserve. I noticed it on some of the things I was selling.

It also remains it some select categories until (I believe) it hits 50%. I rarely sell or buy in those categories, but I'm sure eBay has that listed somewhere? That, or they could have changed policies. However, eBay usually only changes policies if it results in higher fees charged to the seller, so that would have to play in somehow.

 

[mom2rtk]

However, eBay usually only changes policies if it results in higher fees charged to the seller, so that would have to play in somehow.

Isn't that the truth! (says the person who is now broke after paying her monthly ebay bill.....)

 

[spinetnglr]

Good luck in your search Ann .... hope you find one .. but you know .... you are welcome to use mine anytime.