Air Bubbles in 14" Dagorgreenspun.com : LUSENET : Large format photography : One Thread
Hi, I just picked up a 14 Dagor and have notice about 10-12 tiny air bubbles in the front and rear elements. Is this common and does it have any significant effects on picture quality? I will be using it for 12x20.
-- James Christian (firstname.lastname@example.org), November 01, 2001
James - Not to worry (unless you have a BIG bubble right in the middle of an element!). This was common in older glass, and believe it or not was actually considered a sign of glass quality way back when (i.e. bubbles = high quality glass). Enjoy the lens - this is a wonderful piece of glass for that format.
-- Mark Parsons (email@example.com), November 01, 2001.
yeah , it means you got a piece of glass that is from the center of the pour... a lot of the old timers looked for bubbles because they thought the glass was more pure....
-- andrew smith (firstname.lastname@example.org), November 01, 2001.
It is common in lenses of that era, and as I understand it, bubbles were taken as a sign of high quality glass, because metals had to be added to the molten glass at a relatively low temperature to produce clear glass of a high refractive index. The bubbles were not considered desirable in themselves.
-- David Goldfarb (email@example.com), November 01, 2001.
Thank Goodness! That is good news.
It took me a while to find an affordable lens for my project, the shutter is right on and besides the air bubbles the glass is mint. And the bubbles are all on the outer half of the glass more or less.
Thanks for your input, can't wait to make my first images!!
-- James Christian (firstname.lastname@example.org), November 01, 2001.
Well now I'm really disappointed. I have a 14Ē Dagor with no bubbles. Apparently I have a crappy one ;). Seriously, I have other older lenses, like a 207mm Ektar with some bubbles. Let me tell you, there is no problem with sharpness there. Donít worry, just go shoot and enjoy.
-- Linas Kudzma (email@example.com), November 04, 2001.