Graflex.org

Jim Hobson · Joined: 24 Sep 2009 Posts: 14 Location: Vernon, NJ

O.K.
I ordered a new GG. I have to start somewhere. And here's the thing...
The camera is a 1947. I noticed the GG does not have a scratch or mark anywhere. I think maybe it was replaced. Maybe with a poor quality one to sell it (the camera).

Once I get it and put it in, I'll get back and let everyone know how I made out. I hope it's the end of this thread.

See ya on another.

Thanks again to all.

troublemaker · Joined: 24 Nov 2003 Posts: 715 Location: So Cal

There are only a couple other issues that can be addressed regarding GG focussing and the actual film plane, but this does not relate to the image you actually see on the GG. And I am guessing you have the traditional Graphic Spring panel back, and not the later International Graflok type with a removable focussing panel.
I honestly don't know, but I don't think the Spring back came standard with fresnels, but the Graflocs came with and without fresnels. The ones that have a fresnel screen are machined to accommodate the screen in front of the GG and thus keep the GG on the exact film plane. Sometimes someone may have removed the fresnel screen and thereby moving the GG forward of the actual film plane and creating a discrepancy between what one sees focussing and what the film sees, and thus the film can be out of intended focussing plane.
The only other thing I can think of is that something can be out of alignment, but one should still be able to focus at some point on the GG.
It is also possible that the GG is mounted in the camera backwards. Don't laugh it happens. The ground side faces forward toward the lens, so check this just for S&G. If it is basackwards, this might exlpain the issue. I can't think of anything else, but it bothers me that you can't see a high quality image, and your film is then just so so. Not suggesting you don't know which way the GG should be installed, but just adding info just in case.
Bottom line is that if you can't focus your lens, you don't really know if it is focussed where you would want it on the film plane.

45PSS · Posted: Sun Jan 31, 2010 9:20 am Post subject:

Jim, I think you are on the right track replacing the GG. The 47 Pace came with a Graphic (spring) back from the factory and if it has a Graflok (international) back it is a retro fit done at a later date.

Not getting a sharp image on the ground glass suggests a defective lens, and trying 2 or 3 lens and getting unsharp images suggest the ground glass itself.

There are free to download and print yourself lens test targets that will be of help to anyone testing a lens, camera, or rangefinder. The USAF 1951 test target at http://www.darkroomagic.com/ (this sites home page has female nudes that automatically display) under the Library tab and the ones from http://www.normankoren.com/Tutorials/MTF5.html
Set your printer to black ink only and to its highest resolution setting and print on plain or inkjet paper. Use higher quality paper/printer for critical testing applications. There are other targets and charts available for $$$.

I print several copies of either of these targets, attach them to an artist canvas and focus on them from various distances to set up rangefinders, gather rail movement information for making new rangefinder cams, and verify that I can get a particular lens to sharply focus on the ground glass. For lens/ground glass testing they can be attached to a wall just as easily as a movable board. It is important when checking lens focusing to have the targets at the same height of the camera, the camera level and square to the target(s).

In the event that the ground glass is sharp and the negatives are not then first find two film holders that are in spec. Take a straight edge and lay across a film holder with the darkslide removed then measure from the straight edge to the film backing plate at several places across the holder and record. I divide the backing plate into thirds vertically and horizontally and measure in each resulting quadrant. Two holders or both sides of the same holder that measurements within 1% of each other should be assumed to be correct.
Remove the complete back from the camera. Pay close attention to what length/diameter screw comes out of each screw position for reassembly as Graflex used a variety of lengths and if inserted into the wrong hole they either will not hold or damage the camera. Insert the test film holder into the camera back and remove the darkslide. Lay a straight edge across the camera back and measure to the film holder backing plate making certain that the straight edge is not laying on a bump in the back frame that will cause it to teeter or be higher on one side than the other, some camera makes are a challenge. Check at several places and record as when testing the film holders. Now remove the film holder and check to the ground glass being careful not to scratch the ground glass. The ground glass should be at the same position as the film backing plate. If you are using one type of film only then put a sheet of that film in the film holder and measure to the film surface instead of the film holder backing plate. Different films have different thicknesses. If the ground glass is closer than the film holder backing plate/film in the holder then shim the glass equally on each side to bring it to the same measurement. If the glass is further away then remove shims or mill down the glass seating bosses/edge to bring the glass to the correct measurement. I have not had any problems with using the film holder backing plate then testing the setting using thick film. Focus error is less than a fine hair thickness movement of the focus knob.

I found my copy of film holder specs and it shows the depth of film holders to be .197 +/- .007 inch from the edge to the film emulsion for 2x3; 3x4; and 4x5 film holders. A sheet of TXP (TriX320), a thick base film, is .007 inch. I do not know how .007 inch at the film plane will translate into rail movement of the lens you, the reader, are using as each lens is different and the focused distance in use will play a part.

http://home.earthlink.net/~eahoo/page8/filmhold.html
_________________
The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

Jim Hobson · Joined: 24 Sep 2009 Posts: 14 Location: Vernon, NJ

The GG screen is ordered.
The back is a standard Graphic spring back, not the International Graflok back. It doesn't look like it was modified. All the paint is still there.

I also checked again how the GG was put in. Ground side towards the lens. Smooth side to me.

Thanks for the detailed info on how to check the back for proper placement. If the new GG doesn't do the trick I'll try that next. Seems tedious, but not difficult. I'm a Luthier by trade, so I can measure in thousands of an inch.

45PSS:

Dan Fromm · Joined: 14 May 2001 Posts: 2147 Location: New Jersey

Jim, I just got curious about where Vernon is, so looked it up. There are two. Are you up near the NY border or on Burlington County?

If Burlington County, I'm in Cherry Hill and could drop by.

Jim Hobson · Joined: 24 Sep 2009 Posts: 14 Location: Vernon, NJ

I'm the Vernon at the top NJ. I'm about 3 minutes from NY state.

I have a friend in Toms River. How far are you from there?

Dan Fromm · Joined: 14 May 2001 Posts: 2147 Location: New Jersey

Mapquest says Toms River is around 50 miles from Cherry Hill.

Jim Hobson · Joined: 24 Sep 2009 Posts: 14 Location: Vernon, NJ

O.K. I received the new GG today.

It doesn't look any different than the old one.

So I put it in, and BINGO!
Nice, sharp image on the GG. Tried focusing about 3 feet away. Nice!
Also tried focusing on trees in the woods behind my house. About 200 feet away. Nice sharp little branches.

I'm very happy! Can't wait for the temperature to go up so I can take it out.

What a difference the new GG made!

Thanks for all your help, everyone.

Henry · Posted: Sun Feb 07, 2010 2:44 pm Post subject:

Could you kindly disclose the source for your gg?

Jim Hobson · Joined: 24 Sep 2009 Posts: 14 Location: Vernon, NJ

troublemaker · Joined: 24 Nov 2003 Posts: 715 Location: So Cal

Hallelujah !!!

Jim Hobson · Joined: 24 Sep 2009 Posts: 14 Location: Vernon, NJ

troublemaker: I wasn't that bad, was I?

troublemaker · Joined: 24 Nov 2003 Posts: 715 Location: So Cal

Heck no. Just glad you got the machine working. I couldn't figure out what your problem was, and doubted it would be the lens.

jerry upchurch · Joined: 17 Apr 2010 Posts: 1 Location: kNOXVILLE TN

I recently bought a 4x5 graflex from ebay. I tried to wash the ground glass in the holder and was suprised to find that there was 2 pieces of glass not one as I had assumend. I took the glass out of the holder and cleaned it and dried it with a towell and put it back into the holder. I was again suprised to find that the ground side of the glass was not toward the lens (front) it was toward the back of the camera. The other piece of glass, I assume, was a fresnel lens. How is this supposed to be assembled. I always thought the ground side of the glass was supposed to go toward the lens and you looked at it from the smooth side. Does the fresnel lens do anything besides magnify the image? If not how would that affect the focus since it does not change the plane of the gg?
_________________
WHY OH WHY DID I BUY THIS CAMERA?

45PSS · Posted: Fri Apr 23, 2010 10:49 pm Post subject:

Assembly order:
Ektalite field screen (graflex speak for fresnel) smooth side toward the lens/front standard.
Ground glass with ground side facing the lens front standard.

The fresnel smooths out the light allowing one to see into the corners of the ground glass and eliminates bright (hot) spots allowing for easier focusing/ composing.
_________________
The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.