Does a scratch on front element affect IQ?

My 70-200 has some small scratches on the front element and it's not noticable at all, the only downside to getting one that does have scratches is that it can lower resale value, if you care about that, which I do not.

I wouldn't touch a scratched lens unless it was at an extremely advantageous price - like perhaps 25% of new. and even then, to be totally honest, I'd rather not accept damaged goods. I look after my gear obsessively. If this guy is so careless he SCRATCHED it, what else did he do to it?

Regarding the effect on IQ, it probably won't notice on the images at all. but it WILL increase the risk of flare.

But the damning thing from my extremely retentive perspective, is that the lens is no longer perfect - so i wouldn't want it.

Also consider if its not an EF-S lens and the scratch is close to the edge, then it may not be in the field of view when attached to a crop sensor... or am I talking a load of cobblers? Don't crop sensors only use a smaller area within the lens's field of view?

Simon

svpworld wrote in post #2749754
Also consider if its not an EF-S lens and the scratch is close to the edge, then it may not be in the field of view when attached to a crop sensor... or am I talking a load of cobblers? Don't crop sensors only use a smaller area within the lens's field of view?

Simon

Yes they do. I wonder if they use exactly 1.6x less? Due to the spherical nature of the lens this cannot be so.

steved110 wrote in post #2749664
I wouldn't touch a scratched lens unless it was at an extremely advantageous price - like perhaps 25% of new. and even then, to be totally honest, I'd rather not accept damaged goods. I look after my gear obsessively. If this guy is so careless he SCRATCHED it, what else did he do to it?

Regarding the effect on IQ, it probably won't notice on the images at all. but it WILL increase the risk of flare.

But the damning thing from my extremely retentive perspective, is that the lens is no longer perfect - so i wouldn't want it.

Beat up lenses aren't bad deals at all if they're cheap. I dunno, I baby my equipment, too. But you should see the kinds of abuse photojournalists will dish out on equipment. Most photo-J lenses look like they've spent half their life tumbling in a clothes-dryer. Lord knows the images that photojournalists shoot sell just fine.

Of course it will. if it didn't, Canon wouldn't hold the standards that they do.

Will it show up all the time?...depends on how big it is I guess. But it will show up somewhere...perhaps a line on that perfect sunset shot, flare from the lights or strobes.

I'd call and ask how much Canon would charge to replace the front element. And begin massive deductions from there during your purchase negotiations.

Me? if I ended up with it, I wouldn't even mount on my camera....I'd sent it straight to Canon.......

chakalakasp wrote in post #2750145
Beat up lenses aren't bad deals at all if they're cheap. I dunno, I baby my equipment, too. But you should see the kinds of abuse photojournalists will dish out on equipment. Most photo-J lenses look like they've spent half their life tumbling in a clothes-dryer. Lord knows the images that photojournalists shoot sell just fine.

Newsprint and web viewing is one thing. I doubt the SI guys have gear as beat up as the4 newpaper guys I have seen.

Tried that. Did you see my post showing the dialog that went on between Canon and myself? Here it is again -

That was my first ever dealing with Canon service and I'm not at all impressed.

Chris

I'll try and not ask that type of question again (about scratches and filters - the kind that end up in debate).

I'm afraid I unwittingly re-opened the filter versus no filter debate. My bad.

If you look at my bio, it might explain things - engineering is applied science.

GBRandy wrote in post #2750255
Newsprint and web viewing is one thing. I doubt the SI guys have gear as beat up as the4 newpaper guys I have seen.

Yeah, they do. Well, maybe not AS beat up, but definately heavily used. The 400 2.8 primes seem to fare better since they spend most of their lives on monopods, but the 70-200's tend to have all kinds of brassing.

Really -- the canon L telephotos and the 1 series cameras were designed to be beat all to hell. That's partly why they cost so much.

So it all comes down to what kind of person you are ... if you belong to the camp that obsessively babies their gear and can't stand to look at a lens again once it has acquired its first scratch, then I guess it is not for you.

Especially if you start trying to negotiate the price down starting at a ridiculously low number ... then most likely somebody else who doesn't care as much about optical appearance (as opposed to optical quality ) will come along and offer a price that's more acceptable to the seller.

And - quite honest - if it made economic sense to get that front element replaced (guess that figure you mentioned is composed from something like 200$ for the element and 200$ for the work involved), well, then the current owner would just do that and sell it as mint once it is done.

Best regards,
Andy

There's a fair chance that the "scratch" is not, in fact, a scratch (meaning material has been either reshaped or removed from the lens) but instead material deposited on the lens. I have seen that numerous times, and after mentioning it to a couple of people on the forum here who were fretting about a scratch they were able to clean the "scratch" off their lens.

A very close examination of the lens in question, using a 10X magnifier, could reveal that the lens is quite a deal after all.

The scratch in question turns out to be 4 scratches. The guy was nice enough to send me a pic taken with the 100 macro and I can see all 4 VERY well. I kinda want to post it here to see what you guys think, but is that breaking some kind of ethics rules? If you guys think it's ok I'll post it and we can talk about the actual scratches.

Chris

the amount if time ou've spent on this makes me wonder if you just can't spend the extra bucks and get a lens with no issues.

Seriously, if you take the scratch and the implications of said sratch so resolutely, then buy a better quality used or *gasp* new lens.

Shooting paintball? Boat racing? Then buy a cheaper "run it into the ground" lens.

The amount of time I've spent on it? What like 30 mins. total between calling Canon and typing a few messages here.

If 30 min. can educate me and ultimately save me $300-400 then, I think it's time well spent.

Thanks for the, um, input though

Chris