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boris
20-Mar-2009, 17:55
could someone post a picture of the original 5x7 back for this camera?
costum made 5x7 backs are also welcome to the show.
my main format is 5x7 i would love to convert my toyo (4x5 :o ) to 5x7.
boris

Gene McCluney
20-Mar-2009, 18:26
I made a 5x7 back for mine out of an old wood 5x7 back screwed to a thin piece of sheet metal cut to fit the opening on the back of the camera. I got the sheet metal in a small sheet at a local hardware store, and rough-cut it to size with a pair of sheet metal nibbler shears. I then used a grinder to smooth out the rough edges and drilled holes to mount it with wood screws to the 5x7 back. After construction, I spray painted the back flat black, and used some self-adhesive felt around the edge where the adaptor mates up with the camera opening as a light seal. The backs for the Toyo half-plate camera (4 3/4 x 6 1/2) fit into a groove at the bottom and are retained at the top with 2 clips. Very easy to attach, or rotate for verticals. The opening of the camera is square.

This camera makes a GREAT 5x7 field camera. Extremely light, and takes standard Crown Graphic lensboards.

kv nguyen
20-Mar-2009, 18:50
i think this call Rittreck camera , John schneider had modified the back for it , here the link http://www.largeformatphotography.info/forum/showthread.php?t=25581&page=2&highlight=rittreck+camera

boris
20-Mar-2009, 18:51
i have two spare 5x7 backs (plaubel and linhof) but both are to big. unfortunately it is very difficult to adapt :(
gene, could you show your adaptation?
thanks,
boris

boris
20-Mar-2009, 19:35
i contacted john schneider.. unfortunately he sold his camera so no pics.
did somebody ever saw a original 5x7 back for the toyo ?

Oren Grad
20-Mar-2009, 20:31
Glenn Evans (glennview.com) claims he's had two or three of them over the years. (He also sold a whole plate back for the camera not too long ago.)

Ralph Barker
21-Mar-2009, 07:58
I have never seen one of the original Toyo 5x7 backs, but it would be relatively easy to construct one because of Toyo's modular design. The interface for the back assembly attachment is the same as the Toyo 158mm lens board. Thus a spare 158mm lens board can be used as the basis for the new adapter back. Ideally, the adapter back should be deep enough to focus the shortest 5x7 lens at infinity, with the main camera bellows at close to minimum extension, so as to avoid vignetting by the main camera body.

I made an extension back for my 45AX using two spare 158mm lens boards and part of a 45G rear standard.

Gene McCluney
21-Mar-2009, 08:27
I have never seen one of the original Toyo 5x7 backs, but it would be relatively easy to construct one because of Toyo's modular design. The interface for the back assembly attachment is the same as the Toyo 158mm lens board.


The Toyo half-plate folding field camera does not have a 158mm rear, nor does it use a 158mm lensboard.

boris
21-Mar-2009, 09:38
gene, could you show your back? i would like to see the connection between the toyo and your selfmade adapter.
thank you, boris

Gene McCluney
21-Mar-2009, 09:49
gene, could you show your back? i would like to see the connection between the toyo and your selfmade adapter.
thank you, boris

I'll try to shoot some digi-snaps this afternoon when I go to my studio. and post them here soon afterward.

boris
21-Mar-2009, 11:23
wow that was fast! :cool:
thank you.

Gene McCluney
21-Mar-2009, 11:58
This will take 3 posts to fully illustrate.

First photo shows the Toyo with the common 4x5 rotating back.
Second photo shows how the back is clipped at the top of the camera.
Third photo shows the bottom retainer for the back.
Fourth photo shows the back of the camera showing a 7 3/4 inch square opening.

Gene McCluney
21-Mar-2009, 12:02
First photo shows an old Korona 5x7 back that I have adapted to the Toyo
Second photo shows the back where I have attached a thin steel plate, painted plack and covered with felt for a light trap.
Third photo shows the back seat bottom of camera.
Forth photo shows the top of back before clipping shut.

Gene McCluney
21-Mar-2009, 12:05
Photo one shows the back clipped in at the top.
Photo two shows the back attached to the camera.

I did not shoot photos while I was making this back, and I have had hard use of this camera out in the field for a year now with no problems with this back. Hundreds of 5x7 negatives exposed. Perhaps as many as 600 negatives so far.

The key is finding an old 5x7 back that is "close" to the dimensions you need.

The particular back I used had enough of an "undercut" in the wood of the mating surfaces that all I needed to do was to cut and finish the flat steel piece and screw it to the back. There was enough clearance for the mounting clips to grip the metal, without modification to the wooden back.

In fact all the work I have done to the wood back is reversable. Only a few screw-holes would need to be filled with wood putty, and the back could be used on the original camera. I don't have the original camera, just the back.

boris
21-Mar-2009, 15:03
thank you so much! with the great photos no further questiones for the construction :)

when i started with the project to build a 5x7 back, i copied the dimensiones of the camera combined with a super angulon 8/120. i thought that the 5x7 back should have 1 inch clearence to the camera in order to avoid vignetting caused by the bellows? this is just theoty..
gene, did you use wide angel lenses with your 5x7 back? any problems?
boris

Gene McCluney
21-Mar-2009, 15:13
thank you so much! with the great photos no further questiones for the construction :)


gene, did you use wide angel lenses with your 5x7 back? any problems?
boris

I use as wide as 90mm Super Angulon with no problems, with this 5x7 back. The 120mm Super-Angulon works great also, BUT the 90mm Angulon (not Super) did have some bellows issues, with the bellows getting into the edge of some shots. The 90 and 120 Super-Angulons have lens elements that protrude back into the camera and this seems to eliminate the problem. In general I use focal lengths with this Camera and 5x7 back from 90mm Wide Angle to 300mm, and I also use a 360mm Xenar telephoto.

I have attached a 5x7 b/w photo using the 90mm f8 Super-Angulon lens.

Gene McCluney
21-Mar-2009, 15:22
Here is a shot using the 120mm Super-Angulon f8 lens with the Toyo and my 5x7 back.

There was some upward shift applied to the camera to optimize composition without tilting the camera upward.

Gene McCluney
21-Mar-2009, 15:32
On the other end of the focal-length spectrum, here attached is a shot with the Schneider Xenar 360mm Telephoto on the Toyo with my 5x7 back. The edges are a little soft, but that is the nature of this lens.

All of the photos, 90mm, 120mm and 360mm are totally uncropped, they were scanned with the maximum image area of the negative, just cropped enough to square things up. They show more negative image than you would get if you used an enlarger and negative carrier to print the negative. So, in conclusion you do not need to mount your 5x7 back an inch further back as you speculated, you can get full negative coverage with all modern lenses designed to cover 5x7 from 90mm to the limit of the bellows extension.

Gene McCluney
21-Mar-2009, 17:11
I should add, that if you are using the 4x5 back, you can use lenses much wider than 90mm, as the design of the camera with the very thin tapered bellows allows the front standard to compress quite close, and you can tilt the back and front standard back, thus giving the effect of dropping the bed, to allow for extreme wide angles with 4x5.

John Schneider
21-Mar-2009, 21:43
i think this call Rittreck camera , John schneider had modified the back for it , here the link http://www.largeformatphotography.info/forum/showthread.php?t=25581&page=2&highlight=rittreck+camera

That was a metal 5x7 back that I modified to fit the 5x7 Toyo. I didn't know the make of the back at that time, but it had notches along the sides, so in retrospect it was probably either a Cambo or a Plaubel. It took a fair bit of machining, most of the effort to make a thin flange all around so that you could turn the back vetically or horizontally, and still have the camera's mounting tabs retain the back.

I have an original 5x7 back on the Toyo that I kept, so I'll get some pics up tomorrow.

In the meantime, here are some more pics of the modified back:

bvstaples
21-Mar-2009, 22:05
Here's a link to a post from Photo.net of a guy who had a system of backs for this camera:

http://photo.net/large-format-photography-forum/007kiA

I recently acquired one of these cameras and have to just reaqttach the bellows for it to be complete.


BVStaples

boris
22-Mar-2009, 04:57
Here's a link to a post from Photo.net of a guy who had a system of backs for this camera:

http://photo.net/large-format-photography-forum/007kiA

I recently acquired one of these cameras and have to just reaqttach the bellows for it to be complete.


BVStaples

i tried to contact this guy because of the interesting collection of backs, unfortunately without a response:(

John Schneider
23-Mar-2009, 22:59
Here are some pictures of the original 5x7 back which I have. I bought the camera from Jim at Mpex (where else?) in 1999 or 2000. It's the only original 5x7 back I have ever seen for this camera, except for the one on Glennview's website.

Note that this back in effect has a spacer that in effect places the film back 1cm further from the camera. Based on my experiences making another 5x7 back for another 5x7 Toyo metal field, I can say that this spacer allows the side arms (that support the camera back from the camera bed) to swing freely when the camera is closed with the back attached. The back that I modified didn't have this spacer (a more compact back than the factory, I thought), and I had to do a bit of hand filing to make enough clearance for these arms. Whether intentional or not, Gene McCluney's adapted Korona back has about a 1cm spacer as well.

Also, I made the other 5x7 back just to sell a camera with no back, and I never shot with it. It's possible that this 1cm spacer is also important to position the film back a little farther away from the camera to avoid vignetting from the camera back. FWIW, my adapted 5x7 back looked just like the one in the link two posts above.

John Schneider
23-Mar-2009, 23:00
some more pics:

John Schneider
25-Mar-2009, 00:59
I have been asked about how to make a 5x7 back for this camera. I have prepared this sketch of how to adapt a B&J 5x7 wooden back, but any wooden or metal back can be used. The important thing is to cut a rabbet on two sides of the back to (1) give clearance for the back clasps and bottom channel on the camera, and (2) give clearance for the camera back-to-bed struts as they swing through an arc as the camera folds.

For the mating plate I have spec'd 0.063 aluminum sheet.

If the 5x7 back you choose to adapt doesn't have sufficient thickness to cut these rabbets, then you'll have to add a spacer to achieve the same effect. The original back also has a step in the mating plate to give a better light seal; this is not shown on the sketch. The lateral position of the back on the plate is not shown because this will depend on the back chosen; you will want to position the 5x7 back on the plate such that the center of the grounglass is centered on the metal plate.