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Would it matter if the glass is marked or scratched?
Old 05-15-2010   #1
fixbones
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Would it matter if the glass is marked or scratched?

Hi,

Most people like things to be nice and pristine.... me included.

However, i am currently shooting with a lens which i really like from the 1960s with spots and light scratches on the front element. It does not bother me and i don't think it has any negative impact on the final picture either (at least I can't see it).

Also, i think it'll be pretty darn hard to keep a lens scratch and spot free for 50 years unless it sees very minimal use.

Am i the only one????

Are all of you out there shooting through mostly unmarked optics???
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Old 05-15-2010   #2
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Old 05-15-2010   #3
payasam
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I bought three lenses in 1975 and sold them, after much use, in 2005. No marks.
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Old 05-15-2010   #4
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backalley: Thats pretty amazing

My assumption is that surely there are still lenses out there which are less then perfect but still getting plenty of use.

Would you think less of your favourite lens if unfortunately it has picked up some marks here and there?
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Old 05-18-2010   #5
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It makes not a single bit of difference at all. I told this story on the Nikon cafe but I knew one of the staffers (Dean Bicknell was his name)that was using a Nikkor 300 2.8 IF ED AIS that a chip in in the sizes of a lonnie in the front element. He used that lens for years and made cover after cover of the newspaper. If you have a deep gouge the best thing to do is not look at it and keep shooting. you could also paint so india black ink to minimize reflections.

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Old 05-18-2010   #6
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If you are a user, then no, it wouldn't matter as it does not affect your images.

However, if you are a reseller, then yes, it matters as it will affect the len's resale value.



Many people forget that these lenses are 30-50 years old, and expect the condition to be like as if buying new. Cheers.
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Old 05-18-2010   #7
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It is damned certain that if a photographers work is no longer satisfactory, then it's not caused by a scratched front element. It's about the photographer - unless your work is strictly lens tests against rez charts. OH! And if it's about MTF - fugedaboudit! They are completely artificial, having nothing to do with real world work. Look into their refocus methods for each aperture.

Look to all the great work done with 'inadequate' lenses and be happy.
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Old 05-18-2010   #8
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Scratches and chips on the rear element are a far, far bigger problem than blemishes on the front.

But even with marks on the rear element it depends where they are located. A chip on the edge may pose no problem whatsoever, but a scratch smack in the center could spell trouble. Shooting a test roll under challenging lighting conditions is advisable.

A few scratches or wipe marks on the front element should not render a lens useless.

I've seen countless posts about people freaking out that their Summicron has a wipe mark on the front. Again, in my experience the internal haze that most of these lenses have accumulated over nearly 60 years in a far bigger problem.

Last edited by Harry Lime : 05-18-2010 at 13:17.
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Old 06-01-2010   #9
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Quote:
Originally Posted by Harry Lime View Post
[...] but a scratch smack in the center could spell trouble. Shooting a test roll under challenging lighting conditions is advisable.
Well, it could. But I've once borrowed my neighbor's Hassy, and the 80 mm had a big mother of a scratch right down the middle of the rear element. And guess what? Zero effect. Got me thinking...
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Old 06-01-2010   #10
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I can agree with Harry that defects on the rear element are more serious than ones on the front. I can also say that your (fixbones) experience is pretty typical. Some of us have a favorite lens or two with some scratches; yet we don't mind using it, and find nothing wrong with the images we get. Once I tried a DR Summicron that had separations and haze. It wasn't easy to find anything wrong with the images it produced.
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Old 06-01-2010   #11
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Originally Posted by back alley View Post
Would KEH consider that lens UGly? Or is there a category below that?
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Old 06-01-2010   #12
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A scratched front element usually has nothing to do w/ lens sharpness. If you have a sample that is not so good, then it doesn't matter if it's pristine, it won't take optimal photos. On the other hand, if you have a good sample, then it can tolerate a lot of scratches before seeing any image degradation. Cleaning wipes are another matter, as they are probably more responsible for lowered IQ.

In the end, the only way to see if a lens is sharp or suffers from flare (from scratches on the front element) is to shoot some film through it, or look at it's digital files, and compare them to another sample.

I long ago realized that if you get a good lens, keep it, because there is absolutely no guarantee that an identical one is going to perform as good. This is especially relevant when dealing w/ 50 year old glass.
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Old 06-01-2010   #13
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Quote:
Originally Posted by Harry Lime View Post
Scratches and chips on the rear element are a far, far bigger problem than blemishes on the front.
For the type of shooting I do, a lot of shots into the sun I find the opposite to be true. When the mark is in the rear element then it doesn't cause added flare or a less of contrast. Even minor marks on the front element have caused lots of extra flare for me in the past. My 18/2.8D was absolutely trashed on the rear element and it made great pictures. The gouge looked like someone had taken a screwdriver to it:
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