Coated glass for 8x10 neg carrier?

I have a Durst 10x10 enlarger with an Omega colorhead. It's big, bulky,
hard to align, loud as a jet engine and bright as a searchlight: I love
it.

The only thing I don't love is that its weird hybrid head uses an
obscure Durst negative carrier system that is not the usual one found
on the Laborator 184. So I am pretty much limited to the negative
carrier which came with the beast, which is an 8x10 glass carrier with
one sheet of Anti-Newton and one sheet of clear glass (AN on top, clear
on the bottom, of course).

I have a small number of negatives which show newton rings with this
system no matter what I do. I've tried adjusting the humidity in the
room, adjusting the pressure on the negative carrier from the enlarger
head, shimming the carrier so the glass doesn't rest directly on the
negative; no luck.

In an old article on Ron Wisner's web site he recommends using coated
optical glass in contact printers instead of anti-newton glass. He
says that this reduces the amplitude of the newton ring reflections
so much that they are usually not detectable on the print. It seems
like this material would be *perfect* for the bottom sheet of glass
in my negative carrier.

I cannot, however, figure out where on earth he got his hands on even
an 8x10 sheet of anti-reflection coated plain glass. Docter Optic
used to sell 8x10 and 11x14 Zeiss optical glass but it was not coated,
and I can't find any other source. I actually need a 10x10 piece.

Does anyone know where to get this stuff?

--
Thor Lancelot Simon

"The inconsistency is startling, though admittedly, if consistency is to be
abandoned or transcended, there is no problem." - Noam Chomsky

Seller FE2000 was selling 8x10 AN glass on Ebay not long ago. She
doesn't have any listed now.Do a search on FE2000 and send he a note
asking if she has any more, and in any other sizes.

Seller FE2000 was selling 8x10 AN glass on Ebay not long ago. She
doesn't have any listed now.Do a search on FE2000 and send he a note
asking if she has any more, and in any other sizes.

In article .com,
RJM wrote:
Seller FE2000 was selling 8x10 AN glass on Ebay not long ago. She
doesn't have any listed now.Do a search on FE2000 and send he a note
asking if she has any more, and in any other sizes.

I don't need anti-newton glass, I need anti-reflection coated glass.

You can't use anti-newton glass under the negative; the texture of the
glass will show on the print.

--
Thor Lancelot Simon

"The inconsistency is startling, though admittedly, if consistency is to be
abandoned or transcended, there is no problem." - Noam Chomsky

In article .com,
RJM wrote:
Seller FE2000 was selling 8x10 AN glass on Ebay not long ago. She
doesn't have any listed now.Do a search on FE2000 and send he a note
asking if she has any more, and in any other sizes.

I don't need anti-newton glass, I need anti-reflection coated glass.

You can't use anti-newton glass under the negative; the texture of the
glass will show on the print.

--
Thor Lancelot Simon

"The inconsistency is startling, though admittedly, if consistency is to be
abandoned or transcended, there is no problem." - Noam Chomsky

"Thor Lancelot Simon" wrote

In an old article on Ron Wisner's web site he recommends using coated
optical glass in contact printers instead of anti-newton glass.
.... Does anyone know where to get this stuff?

I have seen anti-reflective coated glass used for picture framing.
You might try searching the framing supply shops.

FWIW, you don't need optical glass -- float glass (a.k.a. window glass)
will work fine.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
To reply, remove spaces: n o lindan at ix . netcom . com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/

In article . net,
Nicholas O. Lindan wrote:
"Thor Lancelot Simon" wrote

In an old article on Ron Wisner's web site he recommends using coated
optical glass in contact printers instead of anti-newton glass.
.... Does anyone know where to get this stuff?

I have seen anti-reflective coated glass used for picture framing.
You might try searching the framing supply shops.

I'd love to find that -- the common material used for framing around
here seems to be lightly textured, not coated with a smooth AR coating,
and if I could get framing-sized pieces, I'd swap out the glass in a
lot of the framed photos in my house, too.

Wisner claims that most "AN" glass is in fact the textured glass used
as anti-glare glass for framing. I'm not entirely sure I believe that,
but that's what he says.

FWIW, you don't need optical glass -- float glass (a.k.a. window glass)
will work fine.

I've actually had trouble with the quality of window glass in contact
printers. I regularly see sheets with small bubbles and the surface
is sometimes not as good as I'd like, either.

As it turns out, Edmund Optical sells float glass in sizes up to 10x12
with a multilayer antireflection coating on both sides. If the coating
is durable enough to stand up to darkroom use, this isn't even too pricy
at $55 -- I guess I'll buy a sheet and find out.

The Edmund product is 3.3mm which if I did my math right is a little
over 1/8", the standard window glass thickness.
--
Thor Lancelot Simon

"The inconsistency is startling, though admittedly, if consistency is to be
abandoned or transcended, there is no problem." - Noam Chomsky

Thor Lancelot Simon wrote:
In article . net,
Nicholas O. Lindan wrote:

"Thor Lancelot Simon" wrote


I've actually had trouble with the quality of window glass in contact
printers. I regularly see sheets with small bubbles and the surface
is sometimes not as good as I'd like, either.

As it turns out, Edmund Optical sells float glass in sizes up to 10x12
with a multilayer antireflection coating on both sides. If the coating
is durable enough to stand up to darkroom use, this isn't even too pricy
at $55 -- I guess I'll buy a sheet and find out.

The Edmund product is 3.3mm which if I did my math right is a little
over 1/8", the standard window glass thickness.


You might want to get it a little thicker if your carrier can hold it.
And heat resistant/tempered if you can. It will be a little "tougher"
and last longer than standard float glass.



--

J

www.urbanvoyeur.com

On Tue, 3 May 2005 17:56:06 +0000 (UTC), (Thor Lancelot
Simon) wrote:

In article .com,
RJM wrote:
Seller FE2000 was selling 8x10 AN glass on Ebay not long ago. She
doesn't have any listed now.Do a search on FE2000 and send he a note
asking if she has any more, and in any other sizes.

I don't need anti-newton glass, I need anti-reflection coated glass.

You can't use anti-newton glass under the negative; the texture of the
glass will show on the print.

I've already posted an answer on sci.optics. In short, if you can
afford the cost, there are a number of optical manufacturers which can
supply such components, such as Technical Optics on the Isle of Man,
which I have used in the past:
http://www.cvi-tol.co.uk/4598.html

Expect to pay a lot of money, though ...

--
- Helge Nareid
Nordmann i utlendighet, Aberdeen, Scotland
For e-mail, please use my initials with the same domain as the posted address
Website: http://www.nareid-web.me.uk/

In article ,
UrbanVoyeur wrote:

You might want to get it a little thicker if your carrier can hold it.
And heat resistant/tempered if you can. It will be a little "tougher"
and last longer than standard float glass.

If I could get thicker, tempered, *coated* glass, that would be perfect.

Now, do you know where I can get glass like that?

--
Thor Lancelot Simon

"The inconsistency is startling, though admittedly, if consistency is to be
abandoned or transcended, there is no problem." - Noam Chomsky