Horseman VH Fresnel / Shim Question

When I bought my Horseman VH, I bought it from a gentleman that installed a fresnel. It is installed underneath the ground glass. I've done a lot of research and have read the standard method is to install it above the ground glass. Even Horseman's own angle viewer has a fresnel which puts it outside of the ground glass. So those with a Horseman VH, where do you have yours installed?

Also, you can see my retaining clips. They are installed backwards because if I install them the normal way, the ground glass / fresnel are not secure. There is some play, so I'm thinking there should be shims installed.

How can I check to see if my ground glass is on the same plan as my film? Is there a way to do so without shooting film and having it developed? I have just sent in 2 test rolls to get developed, so I'm anxiously awaiting the results.

I've never heard of a fresnel on the user (outside) side of the GG. Does the camera have infinity stops like a Speed Graphic? Turn the fresnel so that the etched side is against the etched side of the GG. Install and readjust the infinity stops Match focus with a magnifier on the back of the GG. If the camera does not have movable infinity stops like a Speed Graphic, then set the camera on a tripod and point it to something far away and use a magnifier to focus on it. Then readjust the rangefinder and distance scales to match.

If you don't know whether the fresnel is specifically intended for placement between ground glass and lens (i.e. the fresnel is made specifically for that camera and that positioning), the arrangement above is the fool-proof option. Placing the fresnel between the ground glass and the lens has a few drawbacks/risks, including reflections and loss of contrast that make focusing more difficult, the risk of the fresnel scratching/marring the ground glass surface if they somehow rub against each other during transport, and breaking the proper alignment of the GG surface and the film surface if the mechanical assembly does not allow the fresnel to slide in without affecting the GG position.
On the cameras I use, the fresnel is always installed as indicated above. As said, it's a fool-proof option wit the fewest risks and it's the easiest to implement because the fresnel can quite literally be stuck to the ground glass by whatever means convenient.

I'm not familiar with the Horseman-specific fresnel options and whether there was a fresnel that was intended for installation on the matte side of the ground glass, and how to identify that specific ground glass. There may be a fresnel option that can be used that way, IDK. In all cases where it's not 100% certain that it's supposed to go there, I'd recommend the setup as described above.

HaroldC3P0 said:

How can I check to see if my ground glass is on the same plan as my film?

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If you can easily get it off, do a measurement of the distance from the face of the frame holding the glass (lens side) to the surface of the glass. It should match a film holder face to film plane.

The etched surface of the ground glass always has to be the same distance from the lens as the film plane in the holder for correct focus, no matter if there is a fresnel or not.

You can use a piece of film to check, if you can't easily do otherwise. Focus on a sheet of paper with writing on it very close, lens as open as it gets, and expose a piece of film. If the film is out of focus, you know the glass arrangement is wrong. You can tape a strip of 35mm film in the centre of a holder to do that if you don't want to waste a sheet.

HaroldC3P0 said:

When I bought my Horseman VH, I bought it from a gentleman that installed a fresnel. It is installed underneath the ground glass. I've done a lot of research and have read the standard method is to install it above the ground glass. Even Horseman's own angle viewer has a fresnel which puts it outside of the ground glass. So those with a Horseman VH, where do you have yours installed?

Also, you can see my retaining clips. They are installed backwards because if I install them the normal way, the ground glass / fresnel are not secure. There is some play, so I'm thinking there should be shims installed.

How can I check to see if my ground glass is on the same plan as my film? Is there a way to do so without shooting film and having it developed? I have just sent in 2 test rolls to get developed, so I'm anxiously awaiting the results.

Click to expand...

Yes, the Horseman VH and VH-R came with the fresnel behind the ground glass. Between the observer and the ground glass.

If you don't have access to an autocollimator, do a test with film at distant object (horizon is good). You can bracket the focus by attaching a small indicator to the focus knob.

You appear to have the second and latest variation of Horseman focusing hoods. For this, as mentioned above, from the factory, the fresnel goes on the outside, grooved face down. The ground glass below it is frosted side down. Your retaining clips need to be rotated 180 degrees. There were some tiny L-profile metal spacers between the edges of the two sheets, but they are not essential(optically). You should be able to make this change - your ground glass appears to be Horseman.

For my own education I checked focus with a 7X magnifier with the two different orders, and unfortunately there is a clear difference in sharp focus point between them. That is, they cannot both be correct. The original VH ground glass (ground side) is very close to the film plane distance of the Horseman backs that I own, so I think you should reverse yours to the factory orientation.

Thanks everyone for replying. I was looking for a way to make sure the GG and film were on the same without taking pictures on film. I've already taken two test rolls and sent them off to be developed last week, so I'll see how the sharpness looks on those.

I may breakdown and buy another GG back off of ebay but I'm not guaranteed it's installed correctly. So I'm kind of waiting to see what my photos look like before I take any action.

EHM2 said:

You appear to have the second and latest variation of Horseman focusing hoods. For this, as mentioned above, from the factory, the fresnel goes on the outside, grooved face down. The ground glass below it is frosted side down. Your retaining clips need to be rotated 180 degrees. There were some tiny L-profile metal spacers between the edges of the two sheets, but they are not essential(optically). You should be able to make this change - your ground glass appears to be Horseman.

For my own education I checked focus with a 7X magnifier with the two different orders, and unfortunately there is a clear difference in sharp focus point between them. That is, they cannot both be correct. The original VH ground glass (ground side) is very close to the film plane distance of the Horseman backs that I own, so I think you should reverse yours to the factory orientation.

Click to expand...

I can't rotate my retaining clips 180 degrees. If I do, there is a tiny gap between the GG and the clips. I also tried reversing the order (fresnel on the outside) and noticed a slight difference in focus. Waiting to get my test rolls back before doing anything.

Just wanted to close the loop on this thread. I got my 2 test rolls back and the focus was perfectly fine. Everything was sharp and I was pleased with that aspect of my images. Unfortunately, I have two pretty bad light leaks. I have read the orange/red one is behind the film and the blue one is in front of the film. So I'm pretty disappointed to see that.

Ah, yes, that's unfortunate. How does the blue fog look outside the image area? Does it extend to the edges of the film?
The magenta one is a little odd, but I'm not familiar with the film holder that goes into the VH. Apparently it has an opportunity to leak around the back of the film somehow. Do you notice any particular pattern to the fogging; i.e. is it present on some frames, but not others? Is it always in the same spot? Assuming there are differences in intensity, what conditions may have affected the differences?

koraks said:

Ah, yes, that's unfortunate. How does the blue fog look outside the image area? Does it extend to the edges of the film?
The magenta one is a little odd, but I'm not familiar with the film holder that goes into the VH. Apparently it has an opportunity to leak around the back of the film somehow. Do you notice any particular pattern to the fogging; i.e. is it present on some frames, but not others? Is it always in the same spot? Assuming there are differences in intensity, what conditions may have affected the differences?

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Yes, it does extend some into outside the image. The blue is present in all images as is the red. It's strange because I had a towel over the film back in many instances when I took the picture. I'm assuming direction of the sun (in relation to the film back) would play a role into the intensity. I'm not sure what to look for with the seals. It gave me an excuse to try a Horseman 45fa (with a 6x9 roll back) as I do not like the small and dim ground glass of the VH, but I do love the size. So we'll see how I like the 45fa.

HaroldC3P0 said:

Yes, it does extend some into outside the image.

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But judging by the example in the post above, not all the way to the edge of the film, so that's a clear clue.
The blue/white fog occurs from the top edge of the film (the image is projected /recorded upside-down, after all), which is consistent with a light trap/seal problem in the film holder. I'm not familiar with this particular holder; perhaps someone else could chime in on this.