Tessar Coating Question

wrote in message
...
[...] And I don't for one believe Tessars are "turds".

Terssars are strange - kinda-sharp at the edges, sharp in the center, and
the rest is soft.

wrote in message
...

[...] Did
you consider that these Tessars are on a unusual body that has special
features, like rise and waterhouse stops for better bokeh?

Rise is no big deal. Now Waterhouse (Cap that W) stops and bokeh - that
might be interesting.

Malcolm Stewart wrote:

I've certainly noticed low
contrast when scanning Fuji transparencies taken with the f3.5 Xenar on my
Rolleicord Vb.


That's a coated lens..

--

Stacey

wrote:

wrote in message
ps.com...

wrote:
I recently got a quote to coat a Tessar - $700 if I'm figuring right.
My

I hope that was that a typo!
No typo, in fact I might have under-estimated. The quote was for two
Tessars and it added up to $1400 based on my calculation. But they made
it sound like there might be extra charges too.

Talk to the guys at www.arax.com. Lower labor rate, MUCH cheaper at
multicoating old optics and the people who have had them do this sort of
work have been happy.



--

Stacey

wrote:

waterhouse stops for better bokeh?

That's not going to help the bokeh of a tessar much, sure isn't going to
make it "magical". I have some old tessars with 30+blade fstops that are
for all purposes round and they still look "lumpy" like any tessar is going
to.

--

Stacey

"Stacey" wrote in message
...
Malcolm Stewart wrote:

I've certainly noticed low
contrast when scanning Fuji transparencies taken with the f3.5 Xenar on
my
Rolleicord Vb.

That's a coated lens..

Exactly...
Think what an uncoated lens would do.
--
M Stewart
Milton Keynes, UK

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Etaoin Shurdlu wrote:
wrote:
I recently got a quote to coat a Tessar - $700 if I'm figuring right.

Isn't that like gold-plating a turd? What's the point?

Well stated!

Bearing in mind that the Tessar is a fairly simple lens and better
lenses have since been made then it makes more sense to buy a camera
with a better lens. If contrast is the problem then bump it up using a
photo editor if scanning or use slide film which has more contrast.

If this person pays $700 to get a Tessar coated then the value of the
lens will only have increased by a few dollars.

Did I say I was looking to increase the value of the camera? What collector
would have lenses coated? Yes there are better lenses than Tessars. Did
you consider that these Tessars are on a unusual body that has special
features, like rise and waterhouse stops for better bokeh?

Are you sure it isn't "Waterhouse stops" because it's got no iris? I
have some very old English folding cameras that use holes for the iris
that are moved into place. It's done so that the camera was cheaper to
make.

I haven't read anywhere that Tessars have good bokeh.

wrote:
wrote:
wrote in message
oups.com...

Etaoin Shurdlu wrote:
wrote:
I recently got a quote to coat a Tessar - $700 if I'm figuring right.

Isn't that like gold-plating a turd? What's the point?

Well stated!

Bearing in mind that the Tessar is a fairly simple lens and better
lenses have since been made then it makes more sense to buy a camera
with a better lens. If contrast is the problem then bump it up using a
photo editor if scanning or use slide film which has more contrast.

If this person pays $700 to get a Tessar coated then the value of the
lens will only have increased by a few dollars.

Did I say I was looking to increase the value of the camera? What collector
would have lenses coated? Yes there are better lenses than Tessars. Did
you consider that these Tessars are on a unusual body that has special
features, like rise and waterhouse stops for better bokeh?

Are you sure it isn't "Waterhouse stops" because it's got no iris? I
have some very old English folding cameras that use holes for the iris
that are moved into place. It's done so that the camera was cheaper to
make.

I haven't read anywhere that Tessars have good bokeh.

There is a bokeh test on a Tessar example on this page and the results
for this particular lens are seen not to be good:
http://www.rickdenney.com/bokeh_test.htm There is a pronounced outer
ring and an inner bright spot with the aperture shape not playing a
part. If this is typical for Tessars and applies to your own Tessar
then the Waterhouse stops will give you no improvement.

In article ,
Malcolm Stewart wrote:
"Stacey" wrote in message
...
Malcolm Stewart wrote:

I've certainly noticed low
contrast when scanning Fuji transparencies taken with the f3.5 Xenar on
my
Rolleicord Vb.

That's a coated lens..

Exactly...
Think what an uncoated lens would do.

I've got some lovely results, with good contrast with an uncoated Tessar on
Provia 100F. It's only got 6 air/glass interfaces after all.

Sarah Brown wrote:
snip

I've got some lovely results, with good contrast with an uncoated Tessar on
Provia 100F. It's only got 6 air/glass interfaces after all.

Sarah, I'm with you. I've been trying out a couple of f/6.3 B&L IIbs,
one pre-WWI, the other apparently from the '20s. They're not the
sharpest lenses I have in their focal lengths, but they're not bad and
they make very satisfactory EPN transparencies. Flare is not a problem
with them.

But then, I'm not very sensitive to the fine points of lens
performance.

Cheers,

Dan