Early Summitar - uncoated?

[LeicaFoReVer]

I recently bought a leica IIf with summitar with 50% separated front group with rainbow color pattern. I read over internet that heating can help in re-curing the cement, which is actually epoxy I suppose. I heated the front group on the stove and the epoxy started to liquidify. Then I quickly removed the lens from the stove and applied high pressure with a cloth. The separation was gone with remaining couple of bubbles. However I realized that there are now lots of cleaning marks on the inner side of the front group. I thought this lens is uncoated. It seems like coated on the inside. How much would that affect the image? There are also paint and epoxy smears now along the outer edges due to expelled epoxy and melted paint. Did I screw up the lens?

Under flashlight it looks nasty but it is not looking as this bad as you can see on the other photos.



Sent from my m2 note using Tapatalk

 

[newst]

Just put it on a camera and take a few photos. I have been amazed in the past with apparently 'destroyed' lenses taking excellent photographs. The bottom line is you won't know until you try it.

 

[lxmike]

please post some shots once you have used a roll with it

 

[LeicaFoReVer]

The thing is that I am out of my country so I dont have my reliable M6 and developing tanks with me. If I can find a lab for BW developing I can try it with leica iif. I will definitely post sample shots.

Sent from my m2 note using Tapatalk

 

[35photo]

hmm, could be uncoated... I believe coated ones have a blueish tint to them could be totally wrong... The one I have has a blueish tint excellent lens regardless mine is super clean.. Stopped down its super sharp.. more open its got what I call "mojo"..

 

[peterm1]

It is not epoxy, this stuff was not around till perhaps the 1980s. Besides, any glue used to cement lens elements needs to have very specific optical characteristics - to work it needs the same refraction index as the glass used.

To this end, in the era this lens was made, they used "Canada balsam" a natural substance from tree resin that is soluble in alcohol and just happen to have this property. I recall once buying a pair of old WW1 binoculars and the balsam in one cemented group was crazed and cracked making the binoculars unusable. At that time I didn't know about the heating trick but instead removed the crazed balsam using an alcohol bath to dissolve the balsam. This meant the cemented element pair was no longer cemented but, get this, the binoculars are still perfectly usable - although probably more flare prone than they might have been if still perfect.

Long story short, if you need to clean up expelled balsam on your elements, try pure alcohol on a cloth. Google "optics balsam" for more info on Canada balsam and its uses in optics. BTW, if you were to totally remove the balsam and need to re-cement the elements, you can buy modern optical cement which is indeed a kind of epoxy and which sets using UV light (try ebay to see if anyone has it listed).

 

[Larry H-L]

I have a pristine Summitar, and another one that has severe separation in the front group.
It makes a fairly interesting soft-focus or portrait lens. Here's a quick photo taken out the front door:

As Newst suggests, try it, you may like the results.

 

[LeicaFoReVer]

Thanks Peter for the info. Expelled Balsam cleared very nicely. How about the melted paint?

And how about coating and cleaning marks?

Sent from my m2 note using Tapatalk

 

[Ronald M]

for sure. However it was POS before you messed with the Canadian Balsam by heating.

 

[David Hughes]

Hi,

The lens number will give the year it was made.

Very roughly speaking they started coating them in mid 1946 but there were some uncoated ones coated in what seems to be a cottage industry at one time. Also they could be sent back to the factory for coating. And some blue for the military but I'm not so sure about that...

As for cleaning, uncoated ones are easy to clean, according to the technician who did mine. They can also check the alignment, meaning that the axis of each lens is properly lined up.

BTW, the technician said the Canadian Balsam has to be heated to about 200° but didn't say if it was C or F.

Regards, David

 

[peterm1]

Thanks Peter for the info. Expelled Balsam cleared very nicely. How about the melted paint?

And how about coating and cleaning marks?

Sent from my m2 note using Tapatalk

If there is black paint around the outer edges of the lens elements (ie not on any of the front or back surfaces of an element but rather on the "side" of the element where it bears against the wall of the lens barrel) this would in all probably be deliberate. It was common for the edges of lens elements to get this treatment to prevent stray light rays from hitting the edge of elements and reflecting or refracting back into the lens where it might end up in the image ruining it. (For the same reason the inner metal barrel of a lens is painted black in any spot where light might hit it.) Without seeing it though I cannot be sure. If this is the case and some of the paint has gone the best bet would be to use some flat black paint to repaint around the edge rather than removing what is there.

Having said that, I would not expect paint to "melt". Paint usually burns if heated too high and turns to something like carbon. But it is just possible (I am not familiar with Leica's specific techniques) that rosin could have been used in these lenses to help bed elements in place. Rosin can melt.Rosin also might be expected to dissolve in a solvent like turpentine. But there is a need to be careful obviously when using such solvents around your newly balsamed elements which might also react.

I am afraid you are stuck with cleaning marks deep enough to affect the glass - these are usually too deep to polish out without changing the surface enough to affect the optical results. It is however possible to polish the coating but this will remove it - early Leica coatings were notoriously soft too which does not help. This especially applies to the inner element surfaces that did not need to be hard as they were normally well away from anything that would damage them/ (Possibly someone got to the lens in order to remove haze or fungus in the past and in doing so removed part of the coating. This is not unusual and even my camera technician had removed coating from inner elements of my lenses when getting rid of haze - its hard not to do this.) Removal of the remainder of the coating on an element surface may not matter as it would mean the lens would end up being like a prewar uncoated sample and if its as rough as it appears in your image you may have lost little. I find that if part of the coating on an element is lost it is often more damaging to image quality than if all of it is gone from that element (with partial loss you can end up with flare spots that are impossible to correct in post processing).

 

[LeicaFoReVer]

Hi Ronald, what is POS?

Sent from my m2 note using Tapatalk

 

[LeicaFoReVer]

Peter, thanks. Paint is smeared little on the lens surface. That is what tried to remove. Can you please look at the last photo and say if you see it? Paint thinner didnt help. So I should remove all the coating?

Sent from my m2 note using Tapatalk

 

[peterm1]

Peter, thanks. Paint is smeared little on the lens surface. That is what tried to remove. Can you please look at the last photo and say if you see it? Paint thinner didnt help. So I should remove all the coating?

Sent from my m2 note using Tapatalk

I am hesitant to give any definite advice such as removing coating without seeing it - previously I was just raising it as something to consider. Also while I can see in your image a little black stuff that could be paint on a rear element I can't be sure. My advice is be conservative without doing anything irretrievable at this stage.

Reassemble the lens and try it, as someone else points out you may be surprised at how little effect the lens flaws have. Paint on a lens (if small enough) often will not be at all visible in any images you make with it. Light travels as a wave and if the light is blocked in one small location the surrounding light waves spread out and you very often can't see the blockage (although a rear element flaw does have more effect than one on an internal or front element.) In fact an old way of "fixing" a serious scratch in a lens is to fill it with black paint. This is less damaging to the image than allowing light to pass thru the scratch and end up where it should not be.

Similarly I would expect partial damage to coating to be more problematic than a little paint on the lens surface (if there is not too much paint of course). But as I can't see what you are seeing my best advice is reassemble it and try it by taking pictures in different circumstances including some with a bright light source in the image. That will show you more than anything if something more drastic is needed. Good luck.

 

[LeicaFoReVer]

I am taking some shot today. Thanks for the advices. Will let you know.

Sent from my m2 note using Tapatalk

 

[peterm1]

I am taking some shot today. Thanks for the advices. Will let you know.

Sent from my m2 note using Tapatalk

By the way it just now occurs to me that if you are seeing something inside the lens that looks like scratches you might actually not be seeing scratches but instead be seeing lens fungus which is caused by a mold growing on the surface of the internal lens elements because the lens has been stored in slightly damp and dark conditions. This is quite common especially in older lenses.

It can often be cleaned but sometimes it has gone too far and still leaves marks on the lens. Even so the lens can still be used in most cases. What makes me think this may be what you are looking at is that fungus can sometimes look like splotches inside the lens and sometimes like spiders webs inside. Spiders webs it occurs to me might be mistaken for scratches if you do not know what to look for.

If you do an internet search on "camera lens fungus" I am sure you will find examples in photos to compare. I had not thought about this possibility till just now.

https://www.google.com.au/search?q=...rlpNfNAhWHnpQKHeBuDaEQsAQIHA&biw=1920&bih=874

 

[Ronald M]

Hi Ronald, what is POS?

Sent from my m2 note using Tapatalk

Piece of - you fill in the rest.

 

[LeicaFoReVer]

Piece of - you fill in the rest.

🙂

Sent from my m2 note using Tapatalk

 

[LeicaFoReVer]

Here are some samples from leica iif and fp4 film. The lab used probably ****ty developer as the result is very contrasty and grainy with coarse grains.

Samples with early summitar,

This one has a ghost in the image at upper left shown by red arrow. Is it from the lens or the leica has a light leak?

This one is weird. It is out of focus mostly. I probably missed the focus?

This one is towards the sun so it is a good example.

This one is good.

What are your opinions?

Sent from my m2 note using Tapatalk

 

[LeicaFoReVer]

Sent from my m2 note using Tapatalk