I've been experimenting a little, and I see that I can easily attach my metric 4x5 171 conversion kit to the older-style, silver colored Arca function carriers.
Are there any short or long term problems with this arrangement?
I also note that it's not possible to attach my older style 6x9 camera to modern Arca (non-metric) function carriers. (Shucks.)
Hello, Neil !
None as far as I know. The Oschwald (pre-1984) dovetails are as similar to current F-line dovetails as it can be, to ensure a proper, perfectly safe fixation.Originally Posted by neil poulsen
This looks strange. Do you mean that the dovetails do not fit, in total contradiction with what I (carelessly) stated just above ?
What is precisely the problem ?
The dovetail that mates the rear U-frame to the rear function carrier for the models A/B/C 8x10 camera is noticeably wider than any other dovetails in the Arca system. I'm not aware of any peculiar sizing to the ABC 6x9 carriers.
This isn't quite your question, but for the sake of completeness: The profile of the rails was changed slightly at the time of move to the current high-profile rail; the earlier rails (both Oschwald and the newer low-profile rails, like the original folding rail) seem to be a tad narrower than the current high-profile rail. Consequently the earlier function carriers fit a bit too tightly and have too much friction on the current high-profile rails. This includes both the silver A/B/C carriers and the black carriers for the newer but low-profile rail (these carriers have protruding heads of button head cap screws in the lower section which mates to the rail; these were used for instance on the original 4x5 [110-171] Field).
They are ill discoverers that think there is no land, when they can see nothing but sea.
-Francis Bacon
Just saw your response. Thank you.
The difference is that the older-style function carriers have a knob to retract the dovetails sufficiently for the format frame tobe lifted out or inserted vertically.
With the new style function carriers, the format frames must slide in from the side. The "U" style format frames of the older 6x9 are a solid piece of metal that slopes up on either corner, and these sloping corners prevent the older frames from being inserted from the side. Nor do the dovetails of the later function carriers open wide enough for the older frame to be vertically inserted.
Thanks, Neil, for the details. I was not aware of this peculiar situation proper to the U-shaped Oschwald 6x9 format frames, I'll take good note, since we often have to give details to our forum members regarding the compatibility between Oschwald cameras and modern F-line or M-line.
Hence, older 6x9 Oschwald format frame dovetails cannot fit a modern function carrier dovetail since they cannot slide from the side. However if I understand well, a modern format frame can be attached to an Oschwad carrier, since you can open the clamp completely?
And from John Schneider:
The profile of the rails was changed slightly at the time of move to the current high-profile rail; the earlier rails (both Oschwald and the newer low-profile rails, like the original folding rail) seem to be a tad narrower than the current high-profile rail.
Yes, John, Martin Vogt has explained to me that this has to do with modern machining techniques which differ from older ones. In Oschwald times, there were slight variations in width for the rail, and slight variations from the beginning of the manufacture to the end in 1984 for silver-finish Oschwald rails.
This is a matter of a few 1/100-th of a millimeter. My understanding is that some fine-tuning is possible, depending on the function carrier in use. For example the front, non-geared misura function carrier is adjusted sllightly less tight than the geared one. This is really a very tiny change in width !!
Or wider.The profile of the rails was changed slightly at the time of move to the current high-profile rail; the earlier rails (both Oschwald and the newer low-profile rails, like the original folding rail) seem to be a tad narrower than the current high-profile rail.
Just this spring I've purchased a 150mm Arca Swiss rail for my 'old' (1984/1986) F-Line 6x9. It did fit perfectly into the base carrier (the U shaped profile), so I could fit the standard rail plus the extended rail. However, when I tried to move the front standard to the extension rail, I could feel some resistance. The standard doesn't move as smooth as on the standard rail, so I think the new extension is a bit wider (or higher). The gear fits perfectly into the extension rail. It's ok with me for the few times I need to mount the extension.
BTW, does anybody know where I can get new plastic frames for the bellows? Those with the small notch on top... and maybe even a standard bellows in a longer version? I'd like to use a 400mm lens on this nice camera :-)
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