cleaning my lens, help!

back alley · 12-27-2005

much to my own amazement, i took apart my 35/3.5 lens tonight.
by myself...

i removed the front lens assembly by unscrewing the round plastic thingy that holds the front lens assembly to something...i did this by myself.

i cleaned the lens with lens cleaner and q-tips and then a micro cloth.
about 4 q-tips into it the lens must have been clean cause there was no more black stuff on the last q-tip.
i did this too by myself.

then it was time to clean the rear assembly, from the inside. this could be done cause the whole thing fell into my hand about the time that i discovered how to take that back part out.

anyway, there was no black stuff on any of the q-tips which i thought would be a good thing.
except for the back of that lens...it is still a bit opaque, like dried spilled coke.
the lens cleaner does nothing and alcohol does nothing also.

so the lens is waaay cleaner than when i started but it could be cleaner still if someone here can tell me what to try next...all i have on hand is ronsonal & goo gone.
should i try any of that???

joe

ChrisN · 12-27-2005

Sounds like you've gone as far as mere mortals can with that cleaning, Joe. I got about that far with my 50/1.2 element, that is badly etched, with the same approach. Beyond that it's probably a job for the experts. I'll be sending my lens off to Arax some time soon, to see if they can improve it.

And hey - good work on the strip-down! You're getting pretty brave!

back alley · 12-27-2005

i have a hard time seeing myself as brave when it comes to this stuff.

i just thought that since i got the lens at a good price and if i screwed it up i was likely gonna send it off anyway...lol!

now, i'm not too sure what i'll do.
shoot first and think about it later i guess.

joe

ChrisN · 12-27-2005

Sounds like a good plan. I'm just scanning some negs from the 35/2.8. I'll post them soon. Nice!

Kim Coxon · 12-27-2005

Hi Joe,
Ronsonal won't hurt. I woulsn't try goo gone myself. Foe really sticky lenses that need cleaning, I have had good results with Flitz as sold by microtools. (The usual disclaimers of course!!) It will depend on the value of the lens to you. A pro job is likely to cost a fair amount and may not be 100%. If the lens was cheap and you don't mind too much if it goes wrong, I would try it. If the lens is that important to you, leave it to the pros but you have already started so this probably isn't the case.

Kim

Quote:

Originally Posted by back alley

so the lens is waaay cleaner than when i started but it could be cleaner still if someone here can tell me what to try next...all i have on hand is ronsonal & goo gone.
should i try any of that???

joe

back alley · 12-27-2005

thaks kim.

i already tried goo gone and ronsonal. they each seemed to take a tiny bit off. (wishful thinking?)

i may try that flitz as i'm open to trying anything right now (1:30 a.m.)

the lens was only 130 u.s. but is in very nice shape so i would like it to work well.
i will shoot with it tomorrow and check for any changes in it's bahaviour from yesterday.
i can live with a low contrast lens so at this point it will depend on if there is an increase in apparent sharpness from the cleaning.

joe

laptoprob · 12-28-2005

Joe, is this the lens that produced the somewhat flarey tree shot you posted a few days ago? That would be a great improvement.
Remember how to put it together!!

Rob.

back alley · 12-28-2005

it is indeed the same lens.
and it fit back together like it wanted to, i was pleased with myself.

i hope to get out today or tomorrow to see if there is any improvement.

joe

bmattock · 12-28-2005

Joe,

Is the stuff on the lens surface or between two cemented elements that appear to be one element out of the lens barrel? If it is between elements, it takes a pro to dissolve the balsam-based cement, clean, and reglue. That's my understanding of it, anyway.

Best Regards,

Bill Mattocks

back alley · 12-28-2005

i'm not sure bill.
it might be between the 2 rear elements.

the inside rear element did clean up a bit last night but that could have seperate dirt and what i see remaining could be sandwiched in there.

that would explain why it refuses to be cleaned off.

perhaps if i really want a 35/3.5 lens as a user i'll have to find another sample.
that would likely be cheaper than sending this one off for a bath.

joe

bmattock · 12-28-2005

Quote:

Originally Posted by back alley

i'm not sure bill.
it might be between the 2 rear elements.

the inside rear element did clean up a bit last night but that could have seperate dirt and what i see remaining could be sandwiched in there.

that would explain why it refuses to be cleaned off.

perhaps if i really want a 35/3.5 lens as a user i'll have to find another sample.
that would likely be cheaper than sending this one off for a bath.

joe

I was also wondering about the 'black stuff' you got off the lens - could it have been black paint from the sides of the lens? I have found that many times, lens elements are painted black on the sides - I am guessing to prevent internal reflection back into the lens by stray light hitting the sides of the element from inside. I need to pick up a small bottle of craft black paint to redo that when I remove it with enthusiastic cleaning!

Best Regards,

Bill Mattocks

wlewisiii · 12-28-2005

Good work, joe. I'd drop an email to DAG and see what he'd charge; it might well be cheaper than you think.

William

back alley · 12-28-2005

Quote:

Originally Posted by bmattock

I was also wondering about the 'black stuff' you got off the lens - could it have been black paint from the sides of the lens? I have found that many times, lens elements are painted black on the sides - I am guessing to prevent internal reflection back into the lens by stray light hitting the sides of the element from inside. I need to pick up a small bottle of craft black paint to redo that when I remove it with enthusiastic cleaning!

Best Regards,

Bill Mattocks

i don't think it's the black paint bill. the glass was still in the tiny mount and i cleaned only the glass surface. i think the lens had not been cleaned in many years (if ever) and it was just an accumulation of years of use.

as for sending this sample off i need to ponder that.
this was never going to be my daily user lens and i am just not too sure what i would be comfortable investing in it.
i love the 35/2.8 i have and use it the most, i have the 1.8 & 2 if i need/want the sharpest more modern look.

still thinking...

joe

enochRoot · 12-28-2005

not sure if this helps joe, but i was quoted $55 for a cleaning and relube of a 40/2 summicron from DAG. i would assume that should give you a pretty good idea of a starting point. my lens was fine (just a bit stiff), and i opted not to have the service, but it couldn't hurt for you to get a quote. if it is just one element that seems to be the problem, you might not even be looking at more than that! that said...i know the predicament you are in. sometimes a service makes that "cheap" lens you buy not so cheap!

Brian Sweeney · 12-28-2005

Just reformateed Hard Drive, Re-installed OS, back from Digital Death...

If the effected spot is in between the rear elements, in the Balsam, it will be hard to get it cleaner than you have done.

You would need to separate the elements and then reglue or use my Oil trick.

enochRoot · 12-28-2005

and if that is the case, i would assume it costs a lot more than $55. sorry ;-)

back alley · 12-28-2005

and i'm thinking it IS in between the elements.

i was surprised at how simple/easy it is to take that lens apart and i'm thinking that a simple cleaning from a professional won't be much different from what i did.

taking that rear group apart, cleaning and re-cementing would be a bit pricey i would think.

joe

bmattock · 12-28-2005

LOL - you might try this:

http://www.skgrimes.com/popsci/pops/

These guys are known for this type of work:

http://www.focalpointlens.com/fp_intro.html

Anyway, just some thoughts. Not something I'd tackle myself, and I have no lenses that I think worthy of expensive repairs - they're just not that good to begin with. If I owned a really rare or high-end lens, that would be something else again.

Sorry for the frustration you must be feeling!

Best Regards,

Bill Mattocks

Brian Sweeney · 12-28-2005

I took the cemented pair on the 135/3.5 apart, cleaned the glass with isopropyl alchohol, and put it back together with index matching oil. The mount keeps it together, and almost two years later it looks fine.

Index Matching Oil, like that used for oil immersion microscope lenses.

http://www.rangefinderforum.com/phot...=2346&cat=3204

back alley · 12-28-2005

'Sorry for the frustration you must be feeling!'

actually not so frustrated.
taking that lens apart was a thrill for me (plus getting it back together) and if it had been a more expensive lens or in a little better shape i might not have tried.

also, i kinda liked the look of the flare...made the photo take on a 40's look.
i think it might be a great 'landscape' lens or maybe play with some infrared film with it.

and who knows, it might be an ok lens now that i did some clean up on it.

joe

Kim Coxon · 12-28-2005

Hi Joe,
Can you post a pic of the rear group. From your original description, it didn't sound like a balsam fault to me. Normally, any separation of the doublet will affect only a small area of the group. It will grow over a period of time but my understanding is that it would be rare for the whole group to separate. All of the balsam faults I have seen appear to look more like an "air bubble" in the middle of the glass. I would have thought it likely that if the balsam had gone right across the surface, the 2 elements would have come apart. A doublet is usually made such that the 2 faces that meet should be identical in a "perfect" lens and make a single element. This is never achieved in practice and you are likely to get newton rings where the 2 elements meet. The purpose of the balsm is mainly to fill the very small imperfections and the "glueing" is more of a useful by product.

Looking at Bill's links, it should be fairly easy to tell if it dissolves in xylene. You should be able to get some at a hobby store. Floquil paints used to be xylene based and I am sure there must be others.

Kim

bmattock · 12-28-2005

Quote:

Originally Posted by back alley

'Sorry for the frustration you must be feeling!'

actually not so frustrated.
taking that lens apart was a thrill for me (plus getting it back together) and if it had been a more expensive lens or in a little better shape i might not have tried.

also, i kinda liked the look of the flare...made the photo take on a 40's look.
i think it might be a great 'landscape' lens or maybe play with some infrared film with it.

and who knows, it might be an ok lens now that i did some clean up on it.

joe

Hey, you're doing better than I am! You don't know anyone else who takes apart the rear element of a Canon 35mm 2.8 LTM lens and puts the lens back together with the f-stops on the bottom, do you? I'm such a moron.

Best Regards,

Bill Mattocks

back alley · 12-28-2005

Quote:

Originally Posted by greyhoundman

The two parts of the lens can be separated by heating to 300F. Then the balsam can be wiped off with acetone after the two pieces have cooled slowly.

ya but, then i'd have to put them back together...

joe

Kim Coxon · 12-28-2005

That is the general idea

Kim

Quote:

Originally Posted by back alley

ya but, then i'd have to put them back together...

joe

taffer · 12-28-2005

Joe, why don't you take some different kind of shots with it as it's now, review the results and maybe talk to Ronnie (hoot) later ? He was looking for a very low contrast lens, that Canon could suit him...