wipe marks; what is the effect?

[raid]

I wonder what usually the negative effects are when a the front glass of a lens has heavy wipe marks. Will contrast be reduced? Will flare increase? Is it a major problem? Would a filter help? Is the lens worth far less from a user's point of view?

[Al Kaplan]

A filter won't help a damaged lens. You're likely to find a reduction in contrast and an increase in flare but it might not be enough to be a big problem in actual use. A lens is worth what a willing buyer and a willing seller agree on, but the damage most likely reduces the value.

[peterm1]

I think if you mean small scratches, from wiping, from what I have seen the optical impact is surprisingly small as especially if the scratches themselves are small and uniform. It will tend to produce flare when shot into the sun however. Apart from that it will seem to lower contrast to some extent. But relatively little seems to be lost in the way of inherent sharpness / resolving power of the lens. Unless a lens is old, (where it's not unreasonable to see some signs of long use) and otherwise in good condition, I dont think I would be happy buying such a lens myself - but thats just me and I like my kit to be in top notch condition form a personal aesthetics viewpoint Some people however, relish the chance to pick up a bargain knowing that these lenses will still function well and knowing also that most people will not be interested in such a lens - so the price will be less than a pristine model - fair enough, too!

[raid]

Is there are some circular shaped crystal like "things", is this fungus? Is this worse than wipe marks?

[Al Kaplan]

Google David Hamilton if you want to see the kind of effects you can get with "wipe marks" on your front element. He even uses sandpaper on his lenses, but he gets some beautiful effects. He's published a few books of his dreamy photos of mostly nude young girls. Some people consider his works pornographic, but it's great work non-the-less, and he's been widely exhibited.

[Sparrow]

The aperture will have a big effect too, more pronounced at wider apertures, if I’m remembering my soft focus faze correctly I put Vaseline, oil and even sweet wrappers on a UV filter then controlled the amount of softness using the aperture.

It’s surprising how little difference it makes on the neg even with a lot of grunge on the front

[Roger Hicks]

Originally Posted by peterm1

I think if you mean small scratches, from wiping, from what I have seen the optical impact is surprisingly small as especially if the scratches themselves are small and uniform. It will tend to produce flare when shot into the sun however. Apart from that it will seem to lower contrast to some extent. But relatively little seems to be lost in the way of inherent sharpness / resolving power of the lens. Unless a lens is old, (where it's not unreasonable to see some signs of long use) and otherwise in good condition, I dont think I would be happy buying such a lens myself - but thats just me and I like my kit to be in top notch condition form a personal aesthetics viewpoint Some people however, relish the chance to pick up a bargain knowing that these lenses will still function well and knowing also that most people will not be interested in such a lens - so the price will be less than a pristine model - fair enough, too!

I second every word.

Tashi delek,

R.

[Al Kaplan]

The condition of the exterior surfaces doesn't matter all that much. It's the interior surfaces that bounce all the light around.

It makes me want to go camera shopping at some thrift shops and yard sales this weekend, then pick up some various types of sand paper along with a one of those hardened steel things to set nails just below the surface. That and a small hammer should make some great cracks and chips.Don't forget to wear safety glasses!

Why waste money on expensive Rodenstock Imagons or collectable Leitz Thambars?

[furcafe]

Per Al Kaplan's & peterm1's posts, a lot depends on the # & depth of the scratches, the more & deeper they are, the greater the reduction in contrast & increase in flare. As the purchaser of many vintage lenses, I now have a pretty good ability to determine from inspection when a lens is too scratched up for my purposes (not that this helps much in eBay transactions), which would include shooting in bright &/or contrasty light & the occasional contre-jour shot. From the sound of it, a lens w/"heavy wipe marks" would be out of the running for me.

[feenej]

I have lots of lenses with swirls in the coating on the front element. I can just picture some previous owner giving the lens a "real good scrub to get it clean". It does not seem to be a big deal as far as I can tell.

[Roger Hicks]

(1) It degrades contrast and sharpness

(2) Less than you might expect. Often far less, but

(3) It is worst with lights shining into the front of the lens or even glancing across the front glass.

This is not quite the same as saying that manufacturers waste their time polishing lenses.

Tashi delek,

R.

[amin_sabet]

Marks in the center of the rear element will substantially affect performance when the lens is stopped down. I had this experience recently with a used 20mm lens. Marks on the front element, unless quite substantial, don't do much in my experience.

[Gumby]

an effective lens hood can reduce any potential problem associated with 'wipe marks', 'cleaning marks', and even scratches in many situations.

[Gumby]

Originally Posted by raid

There are some circular shaped crystal-like "things"; is this fungus? Is this worse than wipe marks?

Probably. Yes, worse... it grows; scratches don't..

[Sonnar2]

Originally Posted by Roger Hicks

(1) It degrades contrast and sharpness

(2) Less than you might expect. Often far less, but

(3) It is worst with lights shining into the front of the lens or even glancing across the front glass.

This is not quite the same as saying that manufacturers waste their time polishing lenses.

Tashi delek,

R.

True. Plus: one deep scratch, even cracks, has far less effects than some might expect, in terms of loss in value.

Obviously Ultra wide angles show defects more than fast telephotos. depends on depth-of-field
- same reason why flies very close to the lens appearing so often on 15mm Heliar pictures in summer.

It was said that one deep scratch on a front lens can be painted black and the effects will dissapear. Probably true.

I haven't fund out yet if it is better to buy used lenses without or with filters applied. More often than not lenses coverd by a filter are more damaged than naked ones.

[Gumby]

Originally Posted by Sonnar2

Plus: one deep scratch, even cracks, has far less effects than some might expect, in terms of loss in value.

I'd like to see the marketing study that supports this conclusion.

[Sonnar2]

You don't need a study you just need a seller serious about a lens with a "bad scratch"

[raid]

You have all given me valuable information here.
I have an inexpensive 35mm 1.8 Spiratone (By Mitake) lens in Nikon SLR F mount.
I decided to take the risk of buying a lens that was not perfect based on the description of it. There are small marks but no chipping and there are crystal like small areas on the front. I added a lens hood first.

I expect some occasional flaw to show up as I use it [based on your discussions above].

[JohnTF]

Originally Posted by Gumby

I'd like to see the marketing study that supports this conclusion.

Several informal "experiments", I have noted before that a very deep and large gouge in a Tamron Zoom, extending from the center out, could not be made to produce any noticeable effect in one test roll of film purpose shot and processed. I should have asked for the element back when the lens was serviced, it was the worst I have ever seen. I have a feeling it is in Tamron's museum of idiot things happening to their products.

Some of the best glass has bubbles in it.

I did have a lens from my Air Conditioned room fog up, and fog inside definitely was noticeable both visually and in the prints. Fortunately, it cleared up when the lens warmed up. Was in Florida, only woman with me was unwilling to go "David Hamilton" on me.

I used to apply cellophane tape, or finger nail polish to a UV filter to create "dreamy" effects in wedding portraits, and also there are commercial filters for the same thing, which never worked as well as the homemade ones. I had to open up the diaphragm one stop more than the size of the opening to obtain any effect visible in the print, and I had to increase the exposure to compensate for lost light. I experimented to get the most useful filter leaving an oval clear spot in the center and a mark on the ring to aid in mounting the filter on a TLR, plus the best stop to use marked on the case.

I have accidentally left cross star filters attached shooting some flash shots at normal distances, with a definite loss in contrast and some sharpness, but not enough to have to toss the images or do a lot of explaining. Client was not a photographer. ;-)

I had a cheap pre set M42 mount, (I seem to recall it as a Yashica) 60's era zoom, and a shot of a person in bright sun looked as if the person was aglow, -- I foolishly gave this lens away before I considered "signature". It certainly had that old time glow in the images. ;-)
But, the glass had no scratches and there was no dust inside of it, and probably no coatings?

These, perhaps, emulate real life damages to lenses, and that said, I know the first thing people buying lenses for a living do is to shine a flashlight through the lens and check the elements with a lens. They pay close attention to the rear elements.

They also know which lenses can be easily disassembled and reassembled at a reasonable cost to clean up minor dust, haze, and fungus. I hear many good lenses have the elements well mounted so that it is less necessary to have expensive equipment to realign the elements. I have also heard some lenses commonly have lots of interesting things found inside, like metal filings, dust, fungus, oil haze, hair.

Any visible damage or dust probably knocks off half the value of a lens, which may be terrible for the seller and acceptable for the buyer.

And, finally, a beautiful hard multicoating just looks great.

I recently shot a roll with my Avatar Leica I, and it does flare, glow, etc. a bit in bright sun, no visible scratches, but no coating, and I did not have a shade to fit with me. It was sharp and the shutter worked.

We are fortunate to have available to us many lenses that will quite normally shoot far better than we do. ;-)

Perhaps an "Ugly" lens contest should be held, photos taken of and with. I have a 90mm Elmarit with a separation, brassed lens ring, missing leather, missing red dot, well, you get the idea?

Regards, John

[raid]

Now that would be a new type of testing!
Let's find several fungus ridden, wipe marks infested, chipped lenses and let's compare them with lenses that are hardly used and that look like new.

[JohnTF]

Originally Posted by raid

You have all given me valuable information here.
I have an inexpensive 35mm 1.8 Spiratone (By Mitake) lens in Nikon SLR F mount.
I decided to take the risk of buying a lens that was not perfect based on the description of it. There are small marks but no chipping and there are crystal like small areas on the front. I added a lens hood first.

I expect some occasional flaw to show up as I use it [based on your discussions above].

I expect people to begin trying the late night marketed eyeglass scratch free stuff just before the lens goes on the table to sell. ;-) Best to sniff for solvents?

I will be looking for a book to come out soon. ;-)

John

[JohnTF]

Originally Posted by raid

Now that would be a new type of testing!
Let's find several fungus ridden, wipe marks infested, chipped lenses and let's compare them with lenses that are hardly used and that look like new.

Quick, before this drives up the prices? ;-)

[Gumby]

Originally Posted by JohnTF

Any visible damage or dust probably knocks off half the value of a lens, which may be terrible for the seller and acceptable for the buyer.

This is EXACTLY what I was implying, with the exception that you added 'dust' to the discussion which I find a bit extreme. Any argument to the contrary seems, umm... for lack of a better word, ignorant... or at least not well informed.

[Gumby]

Originally Posted by raid

Now that would be a new type of testing!
Let's find several fungus ridden, wipe marks infested, chipped lenses and let's compare them with lenses that are hardly used and that look like new.

This is probably a waste of time. I can't cite specific URLs or magazine articles or discussion forum threads... but it has been done time and time again.

[raid]

Originally Posted by Gumby

This is probably a waste of time. I can't cite specific URLs or magazine articles or discussion forum threads... but it has been done time and time again.

It was stated more as a joke than as a fact.
I certainly would not do such a lens comparison.

It would be a "waste of time".