Looking for Advise on Lens Maintenance

shicks5319 · Oct 8, 2004

I just purchased a Caltar II-N 1:5.6 f=210mm lens of eBay. It appears to be in great shape and the copal 1 shutter seems to be right on.

The lens coating appears to be intact and the glass looks fine, however, there was a lot of dust and crud on the front and rear lens. After a careful cleaning I notice there remains a lot of dust on the rear glass of each element.

Can anyone advise how best to take this lens apart for cleaning and what cleaning method is most effective while at the same time safe?

Thanks for your help on this.

Jim Moore · Oct 8, 2004

The front and rear elements can be easily unscrewed from the shutter.

Just be careful not to drop them

There also might be some "shims" installed so make sure to watch for them so they don't get lost.

Once removed you can clean and reinstall.

Very simple.

Jim

shicks5319 · Oct 8, 2004

Thanks Jim,

What promoted my question is that the rear element comes off with no problem. The front element, however, must be jammed as it will not unscrew from. I am assuming these are right hand threads. I hate to put too much force on the outside of the shutter trying to get the front off.

Any suggestions?

Jim Moore · Oct 8, 2004

shicks5319 said:
Thanks Jim,

What promoted my question is that the rear element comes off with no problem. The front element, however, must be jammed as it will not unscrew from. I am assuming these are right hand threads. I hate to put too much force on the outside of the shutter trying to get the front off.

Any suggestions?

Hmmm... I've never had one "stuck" before so I'll leave that answer to someone with more experience.

Jim

jimgalli · Oct 8, 2004

All right hand thread. I have 2 pieces of an old inner tube laying round that I use to "grip" pieces that think they don't want to come undone. My beautiful bride buys me the 4 packs of canned air from time to time at Costco. With the preview open and the aperture wide open you can give the front a spritz while it's still in place.

Dave Parker · Oct 9, 2004

The bottom of a rubber soled shoe has always come in handy with stuck eleliments and stuck filters, just push firmly and start un-screwing it, I have had older lenses take quite a bit of pressure befor they start to move, but have never broke or ruined any of them.

Dave Parker
Ground Glass Specialties
Satin Snow(TM) Ground Glass
www.satinsnowglass.com

dr bob · Oct 9, 2004

Another method I have used: find a plastic bottle cap of sufficient diameter to engage the outer rim of the lens element. Gentle pressure will often release stuck element. The rubber pad idea will work too - if the element is not recessed. Ignorant about Caltars.

John Kasaian · Oct 9, 2004

I had a Ysaron I bought for the shutter and had a nasty time trying to get elements off. I finally bought a set of rubber strap wrenches from Harbor Frieght and Salvage for a couple of bucks on sale----worked like a charm!

Looking for Advise on Lens Maintenance

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