Question about Ansco 5x7 bellows

[brian steinberger]

I just acquired an ansco 5x7. The camera is nice and well put together. The problem I'm having is the bellows getting in the way of movements. I'm using a 180mm lens, so just slightly wider than normal. When I focus at infinity the front and rear standard are only 1" apart, so when I go to use front rise the very stiff bellows don't allow very much front rise at all. I'm thinking my only solution may be bag bellows. And if so where can I purchase bag bellows for such an old camera?

Thoughts?

 

[brian steinberger]

Can't help you with a bag bellows - others may know how to get one or have one made.

Another thing to try would be a recessed lens board, which will allow you to keep the standards a little farther apart. You could still end up running into rise limitations particularly if the rear lens cell extends into the area surrounded by the rear standard frame. But it might be something worth trying.

Great suggestions Michael, thanks!! I had to fabricate a wooden lens board for my rodenstock as the lens boards for the ansco are about 7/16" and my rodenstock is obviously made for metal lens boards (thickness-wise). So I had to rout out from the back of the lens board around the hole down to 1/8" thickness. Works pretty good! I don't even know how I'd make a recessed lens board!

 

[mdarnton]

A recessed board is basically just a shallow box (without a top) that will fit within the inner hole in the front of the camera, with just a little extra space at the top edge to allow the board to tip out, and then a rim around it to keep it from falling into the camera. You can make the whole thing from 3mm birch plywood from The Art Store, held together with super glue, spray painted black. Assuming you can make something accurate from wood.

On my 5x7 Ansco I start getting a pretty good range of movement at 150mm glass-to-board front, so I'm surprised your 180 doesn't work. Front and rear an inch apart with the 180 focused is definitely wrong, and makes no sense to me! At it's most collapsed, mine is 105mm, board-to-glass,.

In any case, you won't get the wide range you can get with a modern camera, and these don't work well with wide angles, either. Bag bellows are not an option, since the bellows on the camera are permanent. I made a recessed board about 34mm deep for my 90mm. I can get about 12mm rise, and that's all, and the lens is uncomfortable to get at, but it works.

 

[John Koehrer]

Spacing of the lens? Shim missing or too thick?
Focus infinity(measure it) on GG & slightly loosen the front group to see if it improves. If not is there a shim installed? Remove it I check again without it.
As above you shouldn't have a problem with a 7" lens and infinity focus.

If the lens is new to you, I'd suggest that & consider returning the lens.

 

[brian steinberger]

Guys, when I say 1" I mean between the front of the rear standard and the back of the front standard. Between the film plane and center of lens is roughly 4 3/4".

I'm also having a problem focussing sharply on the GG. please see (there was a url link here which no longer exists) link. Could these problems both be related?? Could it be the lens? How would I really know? I do have a week to return it yet.

You guys are lots of help.

 

[mdarnton]

The approximate center of a 180mm focal length lens should be 180mm from the lens when the lens is focused at infinity--pllllllenty of room for movements. It sounds like something is wrong with your lens. You should be able to take the lens off the camera and form a sharp image of something outside on your white wall, and there should be about 7" between the lens and the wall. From what you've said above and in the other thread, it sounds like something is wrong with your lens. The first place to look always seems to be, if the lens is new to you, that the previous owner took it apart to clean it and got one of the elements back in flipped front to back. I'm surprised how often this seems to happen, based what I read on various forums.

 

[brian steinberger]

The approximate center of a 180mm focal length lens should be 180mm from the lens when the lens is focused at infinity--pllllllenty of room for movements. It sounds like something is wrong with your lens. You should be able to take the lens off the camera and form a sharp image of something outside on your white wall, and there should be about 7" between the lens and the wall. From what you've said above and in the other thread, it sounds like something is wrong with your lens. The first place to look always seems to be, if the lens is new to you, that the previous owner took it apart to clean it and got one of the elements back in flipped front to back. I'm surprised how often this seems to happen, based what I read on various forums.

Thanks. It is no where near 7". It's forming an image but it's not crisp and sharp. Is there anything I can do to fix the flipped elements or should I just return it?

 

[brian steinberger]

Here's a shot of the lens:

 

[shutterfinger]

This should be your lens construction. Unscrewing the cells will tell if one, the other, or both have been opened and reassembled incorrectly. If all looks correct return it.

 

[Ian C]

From the diagram in post #11, you can immediately determine whether the element facing the shutter has been flipped. The surface facing the shutter is concave (element #3 of front cell and element #4 of the rear cell). If either of these exposed surfaces is convex, then it’s been flipped—though this must be tough to accomplish, if it’s even possible.

Simply unscrew the cells from the shutter to examine these surfaces.

 

[shutterfinger]

The source for the diagram says the Sironar/Sironar-N is roughly a air spaced Dagor design so there may be air spaces between elements 1 - 2 and elements 5 - 6 but their orientation will be the same.

 

[brian steinberger]

I did examine rears of both front and rear groups. Both are concave.

 

[brian steinberger]

The approximate center of a 180mm focal length lens should be 180mm from the lens when the lens is focused at infinity--pllllllenty of room for movements. It sounds like something is wrong with your lens. You should be able to take the lens off the camera and form a sharp image of something outside on your white wall, and there should be about 7" between the lens and the wall. From what you've said above and in the other thread, it sounds like something is wrong with your lens. The first place to look always seems to be, if the lens is new to you, that the previous owner took it apart to clean it and got one of the elements back in flipped front to back. I'm surprised how often this seems to happen, based what I read on various forums.

So I tried the wall trick. Focussed at infinity puts the distance from wall to center of lens at approximately 5 3/8".

 

[shutterfinger]

The front can by used alone and will give a softer image wide open and a sharp one stopped down for about 3X nominal focal length. If you have enough rail length/bellows extension give it a try, the rear may do the same.
It is possible that the rear cell was swapped during cleaning with a different focal length Sironar by accident.

 

[Ian C]

I found the following data on the B&H site under “Specifications” for the lens:

Rodenstock Sironar N 180mm f/5.6

Optical Construction 6 elements in 4 groups

Aperture Range f/5.6-f/64

Covering Power 72°

Image Circle @ Infinity 262mm diameter @ f/22

Shutter Copal #1

Shutter Speed 1-1/400 sec., T,B

Flange Attachment Size 39mm dia. x 0.75mm - standard Copal #1 size

Slip-on Cap Sizes 60mm front, 51mm rear

Filter Size 58mm

Flange Focal Distance 173mm

Overall Length 57mm (2.25")

Weight 400g (14oz)

Maximum Format Size 5x7"

http://www.bhphotovideo.com/c/product/800663912-USE/Rodenstock_180mm_f_5_6_Sironar_N_Lens.html

Since the infinity flange distance is 173mm, the distance from the image plane to the rear of the attached flange (flange seated against the shoulder of the mounting thread of the shutter, and is the same as the front of the lens board) is 173mm at infinity focus. This is what you need to check. This varies with the distance focused. At closer focusing distances, the flange-to-image distance will increase (greater than 173mm).

173mm = 6.81”. That is the infinity-focus flange distance. If your lens doesn’t focus at infinity at that point, then something is wrong and you should return the lens to the seller pronto.

If the lens cells don’t look like they were tampered with, then they probably are unchanged from the original assembly. But, it is possible that someone swapped the rear cell from a different lens model—not a 180/5.6 Sironar N—into the rear of the shutter. This is the only thing that makes sense to me. That would certainly spoil the results in an unpredictable way. This COULD have happened, but isn’t likely. There wouldn’t necessarily be any visual clues if you didn’t have a complete lens side-by-side for comparison.

For reasonable accuracy, you should measure the flange distance on a camera, not simply hold the lens near a white surface as you observe the projection.

 

[brian steinberger]

Ian, I did this and measured about 5 1/2" on camera. Same as the wall test.

 

[Ian C]

Get rid of the lens. There's something wrong. A mismatched rear cell seems the most likely culprit.