Bosscreen?

[David van Dam]

Hi fellow enthousiasts!

I just received a second hand Bosscreen from ebay but I'm not sure if it's really a Bosscreen. It came in a Bosscreen box but it looks like a single piece of ground glass an not two pieces with wax in between. Is there anyway to determine if it's a Bosscreen or just a regular ground glass?

Thanks!

David

[Jason Greenberg Motamedi]

It should clearly be made of two pieces of glass, a smaller one and a larger one. Sounds like you received ground glass instead. That said, I can understand how this could happen, as I store all my original ground glass in the BosScreen boxes, and someone finding it may not know the difference.

[Jon Shiu]

Usually, it says BOSSCREEN on it.

Jon

[David van Dam]

Hi Jason,

Exactly what I Thought. Thanks for your quick response, I will contact the seller asap.

[David van Dam]

@Jon, ok, in that case it's just glas. Thanks for your reply!

[David van Dam]

ok, seller will have it back with total refund. Thanks again for the advice. I still would like to have a Bosscreen though, anybody got an unused Bosccreen up fo sale? I have a Linhof Technika 3.

[Bob Salomon]

ok, seller will have it back with total refund. Thanks again for the advice. I still would like to have a Bosscreen though, anybody got an unused Bosccreen up fo sale? I have a Linhof Technika 3.

You can't just use a Boss Screen. You have to get one made just for the III. Otherwise there will be a focus problem since the focus surface is between the two pieces of glass and not on the bottom of the glass like all other focusing screens.

This is because the Boss was originally designed to be a transfer screen that you would project slides or movies on to copy or transfer them to video. With the original application the position of the image layer didn't matter since you would just focus the lens on the camera to record a sharp image.

[frotog]

Bosscreens come up for auction on ebay from time to time. But the chances of finding one specific to your camera (especially a tech iii) will be slim.

"You can't just use a Boss Screen. You have to get one made just for the III. Otherwise there will be a focus problem since the focus surface is between the two pieces of glass and not on the bottom of the glass like all other focusing screens."

Bob, I have a bosscreen for my 5x7 sinar p2. Problem is that I'm missing a few of the thin rubber bumper spacers that lie between the glass and the lip on the back. Your comment has me wondering how critical it will be to replace those spacers with material of the same thickness. Am I correct in thinking that Bosscreen used the same thickness rubber material throughout their entire line? I suppose I'll have to get an accurate caliper reading on the thickness of that rubber inorder to find an adequate replacement.

[Bob Salomon]

When I was selling Sinar in the 70's the Boss screen did not exist so I am not familiar with what Boss did for Sinar cameras. If you can still find a Sinar distributor (if there still is one in the U.S.) you should ask them. Otherwise whoever was the Boss importer. I think they were out of Pittsburgh.

Due to the reticulating problem with the wax layer in the Boss screen we never recommended them except maybe for cameras that stayed inside a studio.