Coating scratches on rear element

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Sickening, positively sickening...

I just discovered some very light scratches on the rear element of my new Summilux M 35 ASPH. They weren't there when I received the lens, and how they got there I have no idea. My only guess is that I somehow banged the element against the silver wheel thing inside the bayonet mount of the body. (I don't know what that part is called.) Even then, I've been very careful when mounting and unmounting the lens, so I'm still mystified by these scratches. The good news is that they're right at the edge of the aspherical element and it appears that only the coating is scratched. The bad news is that I bought the lens out of Hong Kong, so no Passport Warranty on this one. Ouch!

So, my questions to the forum are:

How much image degradation can I expect? I know that the rear element is "the one that counts".

About how much will this cost to repair?

And how long will I be without my 35 Lux while it's being repaired?

The lens is covered by a separate insurance policy from my homeowner's, but I'm afraid if I make a claim so soon it will affect my overall standing with State Farm. Is this an accurate assumption?

Thanks in advance for all your advice and emotional support.

Luke

-- Luke Dunlap (luked@mail.utexas.edu), February 07, 2002

Answers

Luke. Whether and how much these scratches (or coating marks) affect the image is impossible for me to judge without seeing them. I don't know if they even need repair. I suggest just shooting with the lens in back lit or otherwise flare prone situations to see if there is excessive flaring and/or loss of image contrast.

Scratching an exposed Leica lens surface, whether by accident or improper cleaning (if indeed it wasn't there when you bought the lens) is a big no no for a leicaphile. We pride ourselves on being able to use Leica M cameras and lenses heavily for years and still maintain them in mint cosmetic condition.

Only kidding :-)

-- Eliot (erosen@lij.edu), February 07, 2002.


Hi Luke

I realise you may well have already tried this but it's just a thought. I once got a big shock when I thought that I had scratched the coating on the front element of my Nikkor 85mm F1.4. Breathing on it and wiping did not remove the apparent scratch. A small amount of lens cleaning fluid on a microfibre cloth did the trick though. It was a very fine line smear of something oily which wiped off. I hope your scratches may turn out to be the same.

Harold

-- Harold (harold@haroldgess.com), February 07, 2002.


Try using a little vinegar and water, this usually works for me. As it is acidic, DO NOT REGULARLY CLEAN YOUR LENS WITH VINEGAR. Once in a blue moon to get something stubborn off is fine.

-- John Collier (jbcollier@powersurfr.com), February 07, 2002.

Oouch! @#%#&^%!!! Might be that you banged it against those various things near the mount. That rear element is out there for exposure. I posted a question about the dangers of mounting the 35 lux, and sure enough some thought it's a possible hazard. I think so too, so I'm careful about mounting it. Ask your agent if the claim will increase your premiums. Seems like house insurance is less prone to that than car insurance.

I noticed a few time while mounting my 35 lux and clanging sound, like it was hitting against the M body. I also noticed that the black plastic around the rear element had a nice little superficial gouge where apparently I had knocked it against something in the body while mounting it. Good thing it didn't hit glass. So, maybe get it fixed and be careful?

-- James (snodoggydogg@hotmail.com), February 07, 2002.


Okay. I'm a State Farm agent. (Yes, for real, you can check it out... I'm in Los Altos, CA.) One claim will not affect your standing with the company. However, several claims, or an unusual pattern of claims, will. Assuming you have listed your gear on a "personal articles policy", the company will pay for the repair of damaged items. Of course, you need to confirm that your item is in fact "damaged" first.

Modern, external lens element coatings are very tough. Unless you've abused your lens by over-zealously cleaning it with a dirty cloth, or let it roll around uncapped in your bag, I suspect you have oil- smears. First, clean your lens carefully with John Collier's 50/50 vinegar-water mix or a good lens cleaner and a NEW (or at least perfectly clean) micro-fiber cloth. Oh yeah, and before you clean your lens, wash your hands well with detergent to remove excess body oils as they can leave very fine streaking on your lens.

Good luck,

-- Jack Flesher (jbflesher@msn.com), February 07, 2002.



Hello Luke. I know you would never rest until those very light scratches are removed, hopefully by cleaning. However, I'm sure you have already tried this.As others would suggest try some comparison test shots.That rear element, in comparison to the older double gaussian design,is so much more exposed. So much so that I prefer to keep the 35mm. asph.'Lux almost exclusively on one M body...My experience is that sometimes it is better to leave what has been done alone ..even if instinct tells you otherwise ..That rear element may come back from the factory looking nice and new, but can you be guarranteed the micro tolerances will match the original. Regards.

-- Sheridan Zantis (albada60@hotmail.com), February 08, 2002.

Hi Luke, I lately scratched the back element of my 35 summicron on a trip and I didn't really notice any evident difference in the quality of the pictures. As far as I know scratches on the back element are much less affecting picture quality than on the front element. So expose some frames and try to detect on the picture where the damage should be obvious. Regards Johannes

-- Johannes Fleischhauer (j.fleischhauer@vsao.ch), February 08, 2002.

Luke,

Before you start playing with withcraft, read what they say on www.KBCamera.com

A scratch will only show in very peculiar situation like Front light causing flare, etc.

My experience is that the film are too often scratched by the lab, having a perfect lens feels like hammering down a fly.

So? Unless you want to spend some $$$$, keep that money and buy a few packs of Provia.

I should not disclose that but I bought a battered Summicron R 35/2, a little scratched and it delivers some of best pix I ever made. A scratch is far less important a damage in the coating due to some chemical action (such as acid rain) or overcleaning.

Enjoy life! X.

-- Xavier d'Alfort (hot_billexf@hotmail.com), February 08, 2002.


I think johannes has it backwards, especially with a wide lens---The back element is much more likey to show scratches as blurry spots or spots of different contrast on the negative while scratches on the front, unless the are something like a GOUGE, may slightly affect the contrast of the lens, but luke, I don't think the scratches as you described them will be noticeable unless you're into looking at negs with a microscope.

My advice would be just to grin and bear it because the more you wipe that thing with tissue or a cloth or whatever, the more likely you are to cause more scratches.

-- Tom Nutter (tmnphotos@erols.com), February 08, 2002.


Hello Luke,

after your post I checked my 35 mm-SUMMILUX Aspherical and I also detected slight marks on the rear element which I couldnīt remove with just wiping it. From now on I will change my lenses with a lot more care !! Thanks for posting your experience here.

If simulating you can easily reach bayonnett corners and/ or the metalroll of the distance meter with the surface of the rear lenselement. So it is better not to change this lens in a hurry.

I will just leave things as they are: when I look into the mirror my face also shows traces of wear. Now my lens is aging with me.

Best wishes

-- K. G. Wolf (k.g.wolf@web.de), February 10, 2002.



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