Ebony 45 lens board hole offset question

[Arne]

I have searched the forum and done a general online search, but can not find a clear answer to my question.

I am wondering how many millimeters offset down holes on the Ebony lens boards holes are drilled. I'm asking as I am looking for boards for Copal 0 and 1 shutters, and prefer plain black boards rather than the Ebony brand boards, which have an ebony laminate.

I have an Ebony RSW45. It has one set of alignment dots on the lens standard, a red, and plain engraved dot, which are for zeroing the standard. Zeroing the lens would require no guesswork with boards of proper spec.

There are many options for hole placement on Linhof style boards. Generic boards seem to come with centered holes, and 3 or 4mm offset holes. I have new Linhof Technika boards. I don't have an accurate way to measure, but the holes on these seem to be offset about 8mm. In a past thread someone mentioned their 57 Ebony had two sets of dots on the lens standard, and said they were 7mm apart.

Does anyone know the exact amount the holes on Ebony branded lens boards are offset down from center? If I can find that out, I can order the boards I need from Luland in China through Ebay. The person I have been in contact with has been very helpful and professional, and their products look well made.

I'll also try contacting a couple of retailers that sold Ebony cameras next week, such as Robert white, and Badger Graphics. I'm not sure if Ebony is still available for contact or not.

I'd appreciate any solid, accurate info on these specs, thanks!

[Keith Pitman]

How far apart are the two dots? I think that's your answer.

But, why does it matter. Put the image where you want it in the frame.

[Arne]

There are only two dots, and when they are aligned the lens standard is zeroed.

I'll try contacting Ebony or a knowledgeable Ebony retailer so I can get an answer.

[Jeff Keller]

I have 1 of each (ebony laminated). Measuring as accurately as I can from board edge to hole edge:

copal 0: 38.82mm from top, 25.19mm from bottom board 98.53mm tall
copal 1: 35.34mm from top, 21,57mm from bottom board 98.49mm tall
copal 3: 18.00mm from top, 15.52mm from bottom board 98.71mm tall

[Doremus Scudder]

It appears that Ebony designed their cameras for the standard Technika-type boards with an offset hole. I've not been able to easily find exactly what this offset is, but it seems to be about 7-8mm. Maybe Bob can chime in here with the exact specs for the offset?

Best,

Doremus

[Arne]

Jeff and Doremus, thank you for the info.

Jeff, thank you very much for the measurements. I was about to go out an buy a caliper to make measurements of the Linhof boards I have, but these measurements are plenty accurate.

Using hole sizes from SK Grimes, and using Jeff's measurements the offset is probably supposed to be spec 7mm for Copal #0 and Copal #1. The Copal #3 is essentially centered, which makes sense, given the large size of hole.

I did send a PM to Bob before I posted the question, and he didn't have official specs for Linhof Technika boards. I'm assuming Ebony must have used the Linhof measurements as the basis for their boards.

Thank you very much. I think this answers my questions.

[Sal Santamaura]

...offset is probably supposed to be spec 7mm for Copal #0 and Copal #1...That is consistent with the 7mm between red and green dots on the front standards of my SV57 and SV Wholeplate. Since one can use an adapter board (which was included with each camera) to mount smaller Technika-type boards, and those might have been Ebony-branded offset or other manufacturers' center-bored, Ebony provided two alignment dots instead of one on these larger cameras.

[Arne]

It does make sense that the 5x7 Ebony has the two dots on the front standard, as you mention the 5x7 and 8x10 were set to use either a Sinar size lens board with centered hole, or the Ebony adapter to use a Linhof Technika style board. The RSW45 only has one set of dots, as they figured people would be using their lens boards with a 7mm offset.

Problem solved. Thanks everyone.

And thank you again to Jeff for making the accurate measurements. That was a big help.