Help: Haze found on Schneider Symmar 5.6/210, 12/370 convertible lens

[FLC]

Just found a slight whitish haze apparently on the interior surfaces of both the front and rear objectives on a Schneider Symmar 5.6/210, 12/370 convertible lens for my 4X5 camera.

Question:

1) Will this affect contrast and resolution?

2) How do I clean off the haze? While the front and rear lenses of this convertible lens unscrew from the Synchro-Compur shutter on which they are mounted, I do not see a way to effectively open or separate the lens groups on either side of the shutter in such a way as to access the interior surfaces of the lenses for cleaning purposes.

Welcome your comments.

Thank you.

[Kevin Crisp]

This happens with these lenses, which are otherwise terrific. It looks like fog, a ring around the outside? Kind of like the opposite of a cataract? A modest ring of fog makes no difference that I can tell when the lens is stopped down to a taking aperture in the f:22 or smaller range.

Get the SK Grimes lens wrench with the flat tips. It is great for mounting lenses on lens boards too. I have the Microtools wrench too, and it does some things the Grimes one does not. But the Grimes one is all steel and strong and inflexible which is what you need for this job.

Angle the two tips outward instead of inward for this particular lens. Carefully adjust them for the two slots on the retaining ring that goes around the front element and holds the glass in. They really have to fit well so you won't hit the glass (too small a diameter) or scrape (too big a diameter). Lock the arms of the wrench down when you get it tight. You really don't want to strip those slots by being hasty and careless about this.

With the two tips in the slots, turn counter clockwise, starting off gently and increasing the force as necessary. It should budge at some point, then you can screw it off the rest of the way with your fingernail. Don't lean the wrench out of perpendicular, you want the contact between the slots and the tips of be as strong as possible when you break it loose, so keep it upright.

With the lens over a soft surface like a cotton diaper, turn the lens over and the front element should gently slide or fall out. the clearances are so tight the vacuum of its movement will dampen it. Take a note of the position of any spacers. The rear element is held in (you don't need to take it out) but now you can clean the inside two surfaces on the front and rear elements. On reassembly when you think you have the retaining ring all the way tight, gently work it back and forth a few times to be sure. It needs to be tight/snug but not terribly tight. When the cement separates in these, you get little bright snow flakes in between the elements. Don't overdo the tightening to avoid this. Repeat on the rear element.

If the filter threads are buggered up front or rear, or corroded, or the edge is bent, you are basically done for. You may loosen the retaining ring but you won't get it off. For this reason I would never buy one of the original convertibles without excellent threads. Another problem is that people way back when understandably painted the threads black since the bright chrome look could cause reflections. Again, if that happened you are done for and will probably never get it apart.

Repeat for the rear group.

Focal Point probably charges around $50 to do this if you are not comfortable doing it yourself.

Good luck.

[Kevin Crisp]

If the haze is around the edge, and slight as you say, use the lens, it will be fine. I had a 180mm with moderate fog in a ring. Mr. Grimes told me he could not get the ring off because it had been painted, but that he thought the lens would be fine. He was right.

If you open it up, the haze will clean off easily with lens cleaning fluid and the usual cleaning process.

[Frank Petronio]

In some ways the haze can be desirable, looks at how these guys spend $$$ on vintage brass lenses for a classic look.

If you want sharpness and absolute clarity, spend $200 on a more recent Symmar or Sironar, they sell for peanuts these days. Keep the hazey Symmar for portraits.

Just my two cents. My old Symmar has slight haze that I find just right, sharp yet smooth.

[Jason Greenberg Motamedi]

Good advice above. However, I have found that occasionally it is nearly impossible to remove the haze. This seems to be particularly the case with the massive 360mm f5.6 version, however I had a set of hazy 210mm elements which I ended up giving away because nothing--no solvent I could find--would remove haze.

[Kevin Crisp]

I have found that the lens pen will remove things a regular cleaning will not. Also Acetone can do it, but be careful to keep it from wicking into the cement on a glued element.

[Daniel Unkefer]

John at Focalpoint cleaned a convertible Sinar 360mm Symmar for me, which was pretty milky-looking between the elements. I bought it in Germany cheaply, and the dealer said it was "perfect". HAH. John disassembled it and cleaned everything, it's now good as new. I did want it to be the best it could be. By the way he says the glasses "de-gas" and the milky deposits are the results of that. I've heard here triethylene will work, but that is really nasty stuff. My lens needed relubrication badly, so having John do the glass was a no-brainer. I think it was $150, as I remember, including cleaning and recollimination.

[gbogatko]

just chiming in.

I have a symmar 300/500 that had the same haze problem. Got it for CHEAP because of the haze. Grimes made it like new. Well worth the $$ -- It's a fantastic lens. Sharp as hell wide open.

George