Just wondering if others have had this experience as I have recently acquired a 90mm summicron asph. This is actually the second lens and looks like its going back to the shop also. What I have noticed are small bubble/spot inclusions on the inside surface of the lens. This is seen by shining a light directly on the lens. It does not look like a lighting artifact as it follows the lens around as I rotate and tilt it.

Any ideas whether this will affect overall performance of the lens or is even acceptable... Needless to say I don't want to address this issue ASAP. I have not noticed this on my other lenses.

many thanks

-- John (johnlktan@yahoo.com), April 15, 2002

Answers

This is why I never shine lights into my new lenses (when they're off the camera anyway). There's always a ton of schmutz in there that will get you all hot/bothered/depressed when you see it. None of this little stuff makes any difference whatsoever to the photographic image, just to your mental images. Unfortunately, once you've noticed it the only cure short of replacing the lens seems to be oral diazepam.

The only exception to this rule is for used Tele-Elmarits that might have some fungus problems due to the balsam glues, or very old lenses that might have accumulated a goodly layer of internal haze over the years.

-- Paul Chefurka (paul@chefurka.com), April 15, 2002.

Take some pictures with a slow (slide)film use all f stops go against the light. Look at the pictures are they sharp are there flare if you are satisfied the lens is fine! (this doesent count if the lens is old though then you should shine through it )

Kaj

-- Kaj Froling (kf@draupnir.dk), April 15, 2002.

Well, it helps to know that when you have a "basically" perfect Leica lens, you'd probably be served well by keeping it since the next one might have worse quality. I should know, I've been through a few 75 luxes, for various scratches on rear and inner elements, and for a weird shiny mark, etc. Finally ended up with a nice one, albeit not perfection, but good enough not to allow the possibility of image degradation.

-- James (snodoggydogg@hotmail.com), April 15, 2002.

Get used to it: nothing made by humans is perfect. All Leica lenses have defects, the question is: are these "defects" significant enough to affect the lens' function?

-- Albert Knapp MD (albertknappmd@mac.com), April 15, 2002.

I had the same "small dust spot" on the front 90 APO Cron I bought. Sent I back for another and recieved a perfect replacement . I would send it back if you can. Any time you take it out you'll be thinking about it. And that IMHO is a expensive thought. Happy day & good luck ------> Scott

-- Scott Evans (scottevans@attbi.com), April 15, 2002.

Small bubbles will not affect image quality. I had a 40 mm Zeiss/Hassy which had these also and took the most beautiful images. I agree with a previous post "That's why I don't shine light thru my lenses". Do you images show areas of question?

-- Don M (maldos@cox.net), April 16, 2002.