!Help! lens glass stuck

Srdjan · Joined: 11 Apr 2012 Posts: 316 Location: Nis

Anyone have any idea please i will appreciate. I started to clean one of my Carl Zeiss lens. There is a dust in rear lens group. I take of metal ring that holds rear glass but there is no way glass came out.
Usually I have just to turn over the lens and hit couple of times but, this glass dot't go out this time.
Next stage I took vacuum toy (that goes on glass) use it ti try to take of lens but nothing. Actually lens moves maybe couple of microns and then nothing. I know it moved because it clicks when I pees it (but only microns).
Is there some way to take it out, please help!!!!!!!!!!!!!!

Lloydy · Expire: 2022-01-01

I cleaned an old Tessar yesterday and the rear glass is very thick and small in diameter, and it would not come out of the body, although like yours, it was moving slightly. In the end I had to open the aperture and push the glass out with my finger, and it slid out very easily. Being thick the lens had to be dead straight to remove, and replace.

Srdjan · Joined: 11 Apr 2012 Posts: 316 Location: Nis

Jes thats a good way but I m cleaning flektogon and the rear group have 3 glasses so there is no way to push it from other side. There is only one way they coming out.

themoleman342 · Expire: 2013-01-24

Putting a tiny tiny bit of fluid around the element will reduce the friction and allow it to slide out. Just a drip of distilled water usually works.

Layer-cake · Joined: 18 Mar 2013 Posts: 560 Location: Cape Town

agreed with themoleman342, you could also use heat to expand the outer ring a bit and it might come out like that

RSalles · Posted: Thu Mar 27, 2014 2:35 pm Post subject:

... or use both: heath the metal with a hair dryer - for instance - and put a tiny drop of fluid around the lens element then tap gently,

Renato

themoleman342 · Expire: 2013-01-24

That's a lot of heat to put to the glass. I personally would not recommend that. I also don't fully understand it. Even if you could heat it enough where the metal would expand, wouldn't doing that actually pinch the glass tighter?

Layer-cake · Joined: 18 Mar 2013 Posts: 560 Location: Cape Town

generaly if you cool the whole item first and then heat the outer ring you can create enough space to allow for some movement, bear in mind when you heat a ring even though it is expanding in all directions the particles next to each other in the ring formation expand on each other, creating a gap.

RSalles · Posted: Thu Mar 27, 2014 4:08 pm Post subject:

SXR_Mark · Joined: 12 Jun 2010 Posts: 506 Location: England

I always use isopropyl alcohol for shifting anything stuck on a lens. It is a great lubricant, has just the right volatility so it hangs around long enough but eventually evaporates cleanly and is gentle so it won't attack paint and plastic. I also use it as a cutting fluid on the lathe and for tapping, drilling etc. A real wonder fluid in my opinion. A few drops on the lens edge should help free it.

Mark

Srdjan · Joined: 11 Apr 2012 Posts: 316 Location: Nis

Thank you friends for advises. I finally menage to take it out. I didn't wanted to use heat and I was afraid of using lighter fluid because glass was coted (I didn't wont some chemical reaction).
In the end i used the same oil that I use for lubricating lens (synthetic oil) and put just on the border. I wait 5 min and then I start to move back and forth until oil got inside and then glass went out easy. Later i have to clean glass of oil, but the most important it get out.