Arca Swiss Lensboard Question

[alan_b]

Hi,

I’m wondering about variations of Arca Swiss 110mm lens boards I’ve seen - if it’s an old/new difference, or maybe genuine Arca vs 3rd party.

The flat boards I have are anodized aluminum, with a simple step milled down at the perimeter for the light trap. They’re also milled thinner around the center hole.
198886

I also have a couple recessed lens boards that are stamped aluminum, with a (glued-on?) strip a few mm from the perimeter for the light trap, similar to how bellows frames are shaped. At the center, the aluminum is pressed to form a recess around the hole on the backside, and consequently raised on the front side. These boards seem lighter, don’t fit as well in my newish 110 standard, and are painted rather than anodized.

Looks like this:
198884

Are those recessed boards genuine Arca, knockoffs, old-style, what? I’d like to find a recessed board with better construction quality and fit.

This photo from B&H seems promising:
198885

Thanks for any help!

[Emmanuel BIGLER]

Hi!

I have been using Arca Swiss 110 mm F-line lens boards since 19 years now, I have a variety of such boards, flat and recessed, old and new.
I never had any problem with any of them.
Boards which are thinner around the centre hole are #1 only, this is due to #1 shutter specifications, I do not know why #1 are different.

All thicknesses in millimetres
Compur or Copal ; #0 : 1.5->4 #1 : 1.3 (Compur 1) or 1.5->3 #3 : 1,5->5
Prontor Professionnal ; #01S : 1.5->3 #1S : 1.5->3 #3 : 1,5->4
Copal Press ; #0 : 1.5->3 #1 : 1.5->2

#0 and #3 boards do not need to be thinned around the centre hole.

Regarding recessed boards, Oschwald (pre-1984) and first generation of Arca Swiss F-line models are made from a flat plate shaped by stamping.
Some later deeply recessed 110 mm F-line boards are simply milled by a CNC machine from a single alumin(i)um block.

The only thing to be aware of, is that pre-1984 Oschwald 6x9 boards, flat or recessed, are designed as 109x109 mm and need a black foam seal on the front standard. Those boards are grey-finished, old-style crinkle paint.
See below an example of an Oschwald board. This is a 171x171 mm recessed board, stamped from a flate plate. This is of course not for a 6x9 camera, but the grey finish and the old-style Arca Swiss logo is characteristic of Oschwald models.
https://s2.qwant.com/thumbr/0x380/6/8/00c5f2902e389ebab7c766e2604a79cf8e1c1934ee17a8f7e3939dee35c372/06918.jpg?u=https%3A%2F%2Fwww.camleyphotographic.com%2Fwp-content%2Fuploads%2F2016%2F07%2F06918.jpg&q=0&b=1&p=0&a=1

A 109 mm Oschwald board will not fit a F-line camera. Conversely a modern 110 mm F-line board does not fit at all a pre-1984 Oschwald 6x9 camera.
To the best of my knowledge, all post-1984 110 mm F-line lens boards are black finished, black-anodized alumin(i)um. Not all of them bears the modern Arca Swiss logo.

Hope this helps!

[alan_b]

Thanks Emmanuel, that's helpful. My recessed boards must be 3rd party, so I'll try to find an Arca milled one.

[Siber]

Toyo lens boards have a size of 110x110, they are not suitable for Arca Swiss 6x9.

[Emmanuel BIGLER]

Just for information, the current list of 110x110 mm F-line recessed lens board reads as follows:
[date 2020-01-02]
recessed 15mm, #0 hole, ref. 091001,2

recessed 7mm, #0 hole, ref. 091004,2

recessed 7mm, #1 hole, ref. 091004,3