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Spare parts for Crown Graphic camera



 
 
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  #1  
Old July 6th 04, 02:25 PM
Argon3
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Default Spare parts for Crown Graphic camera

As to your first question re a ground glass, there have been plenty of threads
by people who are making their own ground glass and polishing it down to a more
fine degree than the commercially available ones. I believe that there is a
lot of material on this at photo.net.

argon
  #2  
Old July 6th 04, 05:50 PM
RSD99
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Default Spare parts for Crown Graphic camera

As to your first question re a ground glass, the first thing is to clean it. Remove it
from the camera, and use mild soap and water.



  #3  
Old July 6th 04, 08:41 PM
William Schneider
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Default Spare parts for Crown Graphic camera

As to your first question re a ground glass, the first thing is to clean
it. Remove it
from the camera, and use mild soap and water.

Agreed.


One more thing to watch for upon disassembly is a fresnel lens + ground
glass combination. Because the fresnel is likely cast from acrylic, it is
very soft. Be careful not to damage the grooves.

When resassembling a Graflex camera that has a fresnel, the fresnel should
be placed on the lens side of the ground glass with its grooved surface in
contact with the ground glass surface.

If the fresnel is removed from a camera that previously had one installed,
there will be a focus error introduced. The error is a sum of the
displacement of the ground glass by the thickness of the missing fresnel
plus a focus shift caused by refraction of off-axis light by the fresnel
lens. Graflex cameras having fresnel lenses were configured to move the
gound glass away from the lens by a distance about 1/3 the thickness of the
fresnel lens to accomodate the rearward focus shift. (Source: What the
Camera Technician Should Know about Fresnel Screens, J. M. Harris, The
Camera Craftsman, July/Aug--Sept/Oct 1980)

Because some fresnels are replaced with thicker or thinner units, running
some careful focus tests would be wise after you reassemble the camera.

Bill Schneider


  #4  
Old July 10th 04, 12:10 AM
Richard Knoppow
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Default Spare parts for Crown Graphic camera


"Serge Korolev" wrote in message
m...
Hello,

I've been lucky to pick-up one of the late Crown Graphic

Special
models a few months ago and, though I am quite satisfied

with the
camera, I would have some things improved:

1) The ground grass' surface is not evenly coated in

sense that it
punctured with a lot of small transparent spots. And its

coated part
seems a bit old dirty. All this makes it quite difficult

to focus even
at infinity.
I've been thinking to replace it with a new one but I am

not sure if
I suppose to look for this particular model's groud glass

(framed in a
Grafloc holder) or those sizes are standardized.

2) The camera rails used to be a bit tough on movements

and I think
I figured the source of this disturbance - small back

rails (those
which are sliding under the guides) are not perfectly

flat.
The camera doesn't look to have any complicated

mechanics and so I
believe it should not be hard to disassembe it.. Would it

be possible
to straighten the rails to the working condition or I've

better look
for a spare part?
Do any sources of the parts for Graflex still exist? I'd

buy another
Copal #0 lens board as well but I don't know if the only

place to hunt
it is eBay.

I am in Europe (Italy) and so local sources of those

items would be
preferable.. Though I have a number of friends in the US

who could buy
and ship goods to me with no problem.

Thanks,

Serge

PS. If you answer to email please replace "usenet" part of

it with
"serge".


Unfortunately, the best source of parts (and service) is
no longer available. This was Fred Lustig, but Fred suffered
a stroke some time ago and I think is still out of action.
However, I think you can fix the back without much
trouble. The Crown Graphic Special is a fairly late version
of the camera. The "special" part is that it came with a
Schneider Xenar in Compur shutter rather than the Rodenstock
or Wollensak lenses generally supplied. It will have a
Graflok back. The Graflok back has both a ground glass and a
fresnel lens. The fresnel lens is under the ground glass
with the grooves facing the ground side of the glass.
They are held in place by clips facing toward you when
looking at the ground glass. Slip the ground glass panel out
of the camera and remove the ground glass and fresnel by
unscrewing the clips. Wash both in dishwashing detergent and
luke warm water. If necessary rub the surfaces very gently
with a soft cloth. Rinse well and blot dry with paper
towels. If there is something like glue on the ground glass
it can be cleaned with a solvent like Alcohol or Acetone
with no damage. The fresnel lens should NOT be cleaned with
anything other than detergent and water or window cleaner,
even alcohol may injure the plastic. Re-install the way the
sheets came out. That should brighten up the image
considerably.
Somtimes the fresnel lens is missing. I don't know a
ready source of replacments. It is necessary to have the
fresnel there because the ground glass will be the wrong
distance from the focal plane otherwise.
The focus rails can be lubricated by wiping them with
synthetic grease. If they are not lined up its possible the
bed braces are not aligned correctly or the bed has been
warped. All Graphic cameras are pretty rugged and are
usually repairable. There are reprint factory instruction
books available from John S. Craig at
http://www.craigcamera.com and from Petra Keller at:
http://www.camerabooks.com Not too expensive, both are very
reliable dealers.
A good source of general information on Graflex made
cameras is at: http://www.graflex.org


--
---
Richard Knoppow
Los Angeles, CA, USA



--
---
Richard Knoppow
Los Angeles, CA, USA



  #5  
Old July 10th 04, 12:10 AM
Richard Knoppow
external usenet poster
 
Posts: n/a
Default Spare parts for Crown Graphic camera


"Serge Korolev" wrote in message
m...
Hello,

I've been lucky to pick-up one of the late Crown Graphic

Special
models a few months ago and, though I am quite satisfied

with the
camera, I would have some things improved:

1) The ground grass' surface is not evenly coated in

sense that it
punctured with a lot of small transparent spots. And its

coated part
seems a bit old dirty. All this makes it quite difficult

to focus even
at infinity.
I've been thinking to replace it with a new one but I am

not sure if
I suppose to look for this particular model's groud glass

(framed in a
Grafloc holder) or those sizes are standardized.

2) The camera rails used to be a bit tough on movements

and I think
I figured the source of this disturbance - small back

rails (those
which are sliding under the guides) are not perfectly

flat.
The camera doesn't look to have any complicated

mechanics and so I
believe it should not be hard to disassembe it.. Would it

be possible
to straighten the rails to the working condition or I've

better look
for a spare part?
Do any sources of the parts for Graflex still exist? I'd

buy another
Copal #0 lens board as well but I don't know if the only

place to hunt
it is eBay.

I am in Europe (Italy) and so local sources of those

items would be
preferable.. Though I have a number of friends in the US

who could buy
and ship goods to me with no problem.

Thanks,

Serge

PS. If you answer to email please replace "usenet" part of

it with
"serge".


Unfortunately, the best source of parts (and service) is
no longer available. This was Fred Lustig, but Fred suffered
a stroke some time ago and I think is still out of action.
However, I think you can fix the back without much
trouble. The Crown Graphic Special is a fairly late version
of the camera. The "special" part is that it came with a
Schneider Xenar in Compur shutter rather than the Rodenstock
or Wollensak lenses generally supplied. It will have a
Graflok back. The Graflok back has both a ground glass and a
fresnel lens. The fresnel lens is under the ground glass
with the grooves facing the ground side of the glass.
They are held in place by clips facing toward you when
looking at the ground glass. Slip the ground glass panel out
of the camera and remove the ground glass and fresnel by
unscrewing the clips. Wash both in dishwashing detergent and
luke warm water. If necessary rub the surfaces very gently
with a soft cloth. Rinse well and blot dry with paper
towels. If there is something like glue on the ground glass
it can be cleaned with a solvent like Alcohol or Acetone
with no damage. The fresnel lens should NOT be cleaned with
anything other than detergent and water or window cleaner,
even alcohol may injure the plastic. Re-install the way the
sheets came out. That should brighten up the image
considerably.
Somtimes the fresnel lens is missing. I don't know a
ready source of replacments. It is necessary to have the
fresnel there because the ground glass will be the wrong
distance from the focal plane otherwise.
The focus rails can be lubricated by wiping them with
synthetic grease. If they are not lined up its possible the
bed braces are not aligned correctly or the bed has been
warped. All Graphic cameras are pretty rugged and are
usually repairable. There are reprint factory instruction
books available from John S. Craig at
http://www.craigcamera.com and from Petra Keller at:
http://www.camerabooks.com Not too expensive, both are very
reliable dealers.
A good source of general information on Graflex made
cameras is at: http://www.graflex.org


--
---
Richard Knoppow
Los Angeles, CA, USA



--
---
Richard Knoppow
Los Angeles, CA, USA



 




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