Copal #3 mounting question

[wclavey]

My 4x5 camera is actually assembled from multiple junk box Graphics cameras, both Speeds and Crowns. The front standard takes the 4x4" wooden lens boards which I make myself out of 2 layers of wood: and 1/8" 4x4 board with another 1/4" thick, slightly smaller board glued to the back to strengthen it and form a light trap. (BTW, I make a similar wooden design, with rounded corners, to fit the newer Speeds and Crowns with the stamped aluminum plates...)

I want to mount a Copal #3 shutter on one of these boards and my question is whether the resulting hole will weaken the board too much. Since the actual mounting hole in the stiffening board has a 1/2" wider diameter than the required lens mounting hole (to provide room to get the flange and spanner in), it means that there will not be much of it on the edges to strengthen the front board, only about 3/4".

Would this be a problem? I'd like to determine this before I buy the new lens. Thanks.

[Nick_3536]

I bet it'll depend on the lens. Some #3 mounted lenses are much bigger then some others. You could look for a metal board if you wanted. I've got a 300mm f/5.6 mounted in a #3 on a Linhof 96mmx98mm board and it's just fine. But that's a metal board.

[justin mueller]

for what it's worth i use 4mm black perspex to make lens boards for my 8x10 and 4x5 cameras and find that it's easy to machine and strong enough to support my heaviest lenses...

[Paul Ewins]

Another important question is how big is the rear element of your desired lens. My 300/5.6 Symmar is too big to be taken on or off a Graphic without removing the rear element, which would then have to be put on from inside the camera. Not something I'd like to do outside or in a hurry. I don't think the 360/6.8 would fit at all, but a 240 should be OK.

[wclavey]

Paul:

That's a very good point I had not considered... the size of the rear cell. Even if it turns out that the board will support it, I need to be sure the cell will fit through the opening without going in through the back. I agree... that would not be convenient in the field.

[Ernest Purdum]

The beech plywood that model shops sell is particularly strong and might help in this application.

[ifer]

wclavey, can i hijack your post for a moment?

i recently got a shen hao and i thought i fancy something a tad longer than the usual 210mm lens. came across the 240 symmar s but the thing is it comes with a copal 3 shutter.

can my shen hao accommodate this lens?

[Gene McCluney]

As a side note, there are some nice 240-250mm lenses that come in a Copal 1, such as older Fuji 250mm f6.7. This would be a much smaller hole than Copal 3. Most people think that Fuji lenses are every bit as good as the other major brands. Also, since you are using 4x5 press type camera, you could use an older 250mm Telephoto such as a Tele-Xenar or Tele-Raptar which also come in shutters about the size of Copal 1.

[Nick_3536]

can my shen hao accommodate this lens?

Which Shen Hao? How are you intending on using it?

Odds are it'll be fine. I know I use longer heavier ones on my 5x7 Shen Hao.

[ifer]

Which Shen Hao? How are you intending on using it?

Odds are it'll be fine. I know I use longer heavier ones on my 5x7 Shen Hao.

oppsss... forgot to tell... mine is the 4x5 shen hao.