Lawrence Akutagawa wrote:
wrote in message ...
Lawrence Akutagawa wrote:
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...
I see. Here is an article which addresses the situation from the factory
setting perspective:

http://reviews.ebay.co.uk/Medium-for...00000000915733
Again they are just talking about setting infinity to get it as good as it
can be. No doubt that should be checked if you shoot things at infinity.

The problem I'm talking about is at infinity, because the cell spacing
(instead of the lens to film distance) was moved to adjust focus, the
Spherical Abberation is overcorrected, which is helped by stopping down
the lens. At f16 no doubt they can take sharp images but this isn't a
problem with a camera that moves the whole lens/shutter assembly. And
ultimately these other types will produce even sharper images.

This is another discussion of this on a front cell focusing TLR.

http://photo.net/classic-cameras-forum/00CQPp

No doubt a front cell focusing tessar lensed camera can make great images,
but I've found a couple of older models that use a moving bed focusing
tessar to be even better. The only problem is these older ones have
uncoated lenses so you have to be careful to not have flare issues.

Stephanie -

hmm...my reading of the article that I cited does not talk about setting at
infinity, but at 10 feet. Are you and I reading the same article?




Again this issue I am talking about is NOT about adjusting focus. No
matter what procedure you use to "repair" an out of focus front cell
focusing camera or how perfectly the camera is focused, you still have
over and under corrected Spherical Abberations induced by changing the
cell spacing to focus at other that the "designed cell spacing focus"
the camera was manufactured to (which is usually the middle of the focus
range) which ALWAYS degrades image quality.

Stopping down the lens helps this problem which makes these types still
usable. But they are at their best in the middle of the focus range, a
moving bed camera will NOT have this limitation.


Stephanie