Front lens damage - maybe fungus??

[vicmortelmans]

Hi,

I purchased an Olympus 35RC and it shows quite severe damage to the front lens element. I see a large number of small spots and two rather large scratches. My first film has given acceptable results, but in bright sunlight, there's a soft area in the middle of the image, probably due to flare caused by the damage.

Here's a picture of the damage:

The scratches are obvious, but what could have caused the spots? I don't see how this could be caused mechanically, unless the previous owner carried the camera without cap in a bucket of steel balls?? (note that the body of the camera is---after cleaning---in excellent condition!).

My only remaining hope is that it could be fungus and thus maybe removable... I cleared fungus from a Jupiter 8 once using aceton... but it's always reassuring if someone else could back up on this suggestion...

What is the effect of aceton on the plastic of the 35RC lens mount? I don't want to end up with a clean lens and a dissolved camera!

Up till now, I only used lens cleaner on it and scratched it with my finger nail (you feel the spots), both without any success.

Groeten,

Vic

 

[greyhoundman]

It's not fungus. It is a spotting of the soft coating on the lens. Oly RF cameras are known for real soft coatings,. When they get a small scratch or nick they start to spot. You'll have to replace the lens.

BTW. The front lens of an Oly ECR is the exact same thing as in the 35RC.
You could pick up a cheap ECR and rob it of the front element.

 

[vicmortelmans]

Hmmm... seems like an interesting project, but there are no ECR's on ebay and I wonder if they're really that easy to find.

Could I consider to remove the coating as a start? I took a look through google and found advise to use soft abrasive body creams or cleaning products. Mostly US brands, so it's hard for me to find the right equivalent product. One suggestions is the 'Bon Ami' cleaning product. If this is the same bath and sink cleaning powder as what I'm familiar with, seems like a rough method. Another suggestion is oil-free suncream...

Any opinions about this?

These are the products that google came up with:

Flitz polish
Pond's Cold Cream
oil-free, SPF 45 sunscreen
Bon Ami kitchen and bath cleaner

Groeten,

VIc

 

[clintock]

the EC and EC2 also used the same lens and are more common than the ecr, many have died due to battery box corrosion. I've got a spare mashed one I can send if need be- where are you?

Edit- could someone verify that the EC and EC2 use the same lens as the RC? Aside from the barrel being a bit shorter on the EC, the glass looks just the same to me..

 

[greyhoundman]

The EC and EC2 use the same front lens element as the RC.

 

[Xmas]

Well before you do anything else try some water (faucet). Dampen a cotton bus (q tip) after teasing out its end to a thin filiment wiper, dab a spot with moist tip until it is damp keep dabbing, wiping gently on occassion, if it is a water soluble material it may soften and move.

But this looks like coating damage as has been said.

Noel

 

[mjflory]

These are the products that google came up with:

Flitz polish
Pond's Cold Cream
oil-free, SPF 45 sunscreen
Bon Ami kitchen and bath cleaner

I've never heard of Flitz polish, but the other products vary wildly in abrasiveness. Pond's cold cream is a simple facial creme, which would restore the missing natural oils in the skin of your lens if it had any 😀 Sunscreen should be relatively non-abrasive as well, but Bon Ami is an abrasive scouring powder and would result in a very soft-focus lens!

The accepted polish for glass seems to be cerium oxide. It's a very fine polish and is used in a slurry, so it may take quite a bit of polishing to get below the coating. That's probably a good thing. I used it with a small cotton buffing pad on a Dremel tool (a small high-speed drill) to remove severe damage to the coating of a Tele-Elmarit. (Had the lens element not been otherwise beyond hope I wouldn't have tried.) The lens now produces somewhat acceptable results, but one can see an irregularity in the reflections from the lens surface. (Some of these may result from other methods I tried before the cerium oxide.)

 

[vicmortelmans]

Disassembly of the 35RC optical unit: impossible?

Disassembly of the 35RC optical unit: impossible?

Hi,

here's a follow-up on my repair of the 35RC with damaged front lens element.

User Clintock was so friendly to send me the optical unit of a parts Olympus EC, which has identical optical elements.

Both the 35RC and EC use a single optical unit, becuase all lens elements are in front of the shutter/diaphragma. This unit is moved as a whole for focusing, so it can be quite easily disassembled from the camera.

But the mechanical parts of this unit are not compatible e.g. the EC has a smaller helicoid than the RC. So I cannot just assemble the EC optical unit in the RC and I'll have to disassemble the units to replace the individual lens elements.

Disassembly of the EC optical unit is working out fine, as it has the typical spanner wrench grips to unscrew rings etc. Only the back element seems to be attached some other way (glued??). But I probably won't need that.

The RC is a different story: I don't see any grips and haven't got a clue where to start. It looks like a monolithic block. I tried to unscrew the ring on the front (which also protrudes from the camera when the unit is assembled), but can't get it to move. I can't even tell if it's really a ring, or if it's part of the mould.

I'll have a second look at it soon, but before I break something, I'd rather check if someone can give me advise.

One of the next days, I'll try to make some pictures of the units.

Groeten,

Vic

 

[greyhoundman]

It is a ring on the front of the RC unit. It is glued in place with a laquer type stuff. I soak them for 20 minutes in nail polish remover. Then they usually will unscrew with a little effort.

 

[vicmortelmans]

It is a ring on the front of the RC unit. It is glued in place with a laquer type stuff. I soak them for 20 minutes in nail polish remover. Then they usually will unscrew with a little effort.

Greyhoundman, thanks for the advise: it worked out!

So here's my next follow-up:

😀 I succeeded in disassemblin the RC optical unit, only one element that's fit at the back of the unit didn't come out, but it's still in good condition

😎 some of the elements have a *very* close fit, so it's quite an adventure to get them out. One of the elements I only got removed after soaking the unit in hot water, reasoning that the metal frame would expand more than the glass.

😛 I cleaned all elements and replaced the front element of the RC by that of the EC

😡 Then I had some trouble re-assembling the optical unit.... I remember that when disassembling the helicoid was quite loose. Maybe I damaged it when trying to loosen the front ring (before soaking took place)... After some exercise, I got it in, but it's still a bit stiff.

😕 I positioned the unit such that it would focus for infinity (using the method with a SLR looking into the lens and focusing on a target in the film plane). I have the impression that because of the slight difference in front lens position (see 'remaining problems'), the total unit has to be more backwards positioned to get infinity focus.

😱 Finally I had to make quite some adjustment to the rangefinder (also set it for infinity).

I shot a first roll and it's currently drying. Looks quite all right at first sight. 🙂

Thanks for all who contributed to my quest!:angel:

Remaining problems or questions:

😕 about the front element: the EC element seems like a tiny bit wider (1/10mm, says my micrometer) and the front ring won't screw on as far as it did originally... see also my notes on focus adjustment

🙄 about the back element: on the EC the two back elements are cemented. On the RC they came apart (maybe because of the soaking in aceton?). I hope that this doesn't affect optical properties?

😕 I cleaned the lenses using vinegar (to remove grease) and aceton and finished with dry cloth.. still I have the impression that they're not as clear as they could be. What's the best way to get them factory clean?? (starting from the assumption that they have some nasty residu!)

😕 I only checked rangefinder and focus for infinity, so I have no clue how it behaves at other differences.

-

 

[vicmortelmans]

Hi,

next follow-up is the pictures that I shot (see bottom of this message).

I notice
- generally good result, even focusing seems quite all right
- some strange 'bokeh'-effects at the border of the image (kind of tunnel-effect)
- general unsharpness at the borders
- some amount of flare

The flare is probably due to my cleaning job not being perfect (btw, would alcohol be a better cleaning agent?)

About the other artefacts, I have three possible explainations:

- that's how the 35RC should work (no?)

- that's because my problem to fit in the front element properly: the distance of the front element to the rest of the elements is larger than it should be

- that's because I made some mistake in reassembling the unit and switched the order or orientation of some element (could I?)

What do you think?

Groeten,

Vic

Here are the pictures:

picture1
picture2


Note: here are also some pictures how it was before the replacement of the front element. Notice the flary area in the top middle of the frame.

picture1
picture2

 

[clintock]

Sorry the EC2 unit did not just fit right in.. There is no doubt something is wrong in the post-operation pictures. I think the most likely cause is the front element not fitting into the housing all the way. That can't be good anyway. Also the separated rear elements is cause for concern.. I just don't know if they are supposed to be grouped or not.

For me getting lens elements factory clean means fresh gloves, some new cotton pads and very careful thought about oils from my fingers getting onto anything that will be used to touch anything that will eventually touch the glass..
If for example my gloved hands are used to rip open the bag of cotton pads, then I need to change gloves, as the plastic on the outside of the cotton pad bag has been touched by human hands, therefore has oil on it.

Here's some ec2 bokeh..

 

[vicmortelmans]

Hi,

I picked this problem up again and I'm making progress.

WIth some fine sanding paper, I made Clintock's lens a bit smaller, so it would fit in the housing.

After reassembling and a test-roll, things seem to be better.

One of the results is here:

picture

Still got to make a final adjustment to the rangefinder, but that's for another run...

Groeten,

Vic

 

[clintock]

Wow, you sanded it into place! That looks much better, I'd never have known there was ever a problem.. from that one picture anyway..