I'm new to LF lenses. Just acquired a used 90mm angulon for 4X5 use. There is a very small (1/3 size of pin head) bubble in front element. Any thoughts on whether this will adversely affect the images? Are these common in older lenses or is the lens seriously flawed? This may be impossible to tell without testing but any opinions would be appreciated. Thanks

-- Bill Howe (Howehoppe@aol.com), June 11, 2000

Answers

It won't have any effect other than perhaps on resale price.

-- John Hicks (jbh@magicnet.net), June 11, 2000.

Bill, I talk from experience here!! IMHO too much is made of marks and imperfections on or inside lenses. At one time the "clenliness" of a lens has cost me dearly, in either returning lenses or not buying lenses that were not "immaculate". I was probably obsessed with the whole thing!!! (Ask Robert White here in the U.K !!) But I am now cured!! Small marks, blemishes, discolourations, dust specks, coating and cleaning marks, even small scratches have NO SIGNIFICANT/RECORDABLE EFFECT ON IMAGE QUALITY !! There I've said it!! I whole heartedly agree with previous poster, the only effect will be on resale value. If you find a used lens that is not "perfect" then you can use the "defects" as a bargaining point with the seller, knowing that image quality will not be effected!! Relax and enjoy your hobby and leave lens testing to the manufacturers, be more concerned with vibration from dodgy tripods or processing methods as these will effect your work!! Regards Paul

-- paul owen (paulowen_2000@yahoo.com), June 11, 2000.

I agree with the above posts, but would like to add that many of the old-timers (one of which I am rapidly becoming) considered a small bubble such as this to be the sign of a superior lens-one not to be passed up.

Fred

-- fred (fdeaton@hiwaay.net), June 11, 2000.

As I understand it, it wasn't the bubbles in themselves that were considered beneficial, but that bubbles were an unavoidable artifact at the time in the manufacture of some of the better types of optical glass.

-- David Goldfarb (dgoldfarb@barnard.edu), June 11, 2000.

At last some sensible answers about lenses. Unless you are collecting mint lenses, minor scratches do no harm. Nor do bubbles. Scratches on lthe rear element can effect image quality if bad enough, but the front has to be pretty bad indeed to affect image quality to any extent. The previous post is correct...in the old days, photograhers looked for bubbles as a sign of quality. I can't help but wonder if many of the questions concerning tiny blemishes in lenses are from equipment freaks instead of photographers.

-- Doug Paramore (dougmary@alanet.com), June 12, 2000.