Fuji Cosina/Voigtländer MF Folding Camera due out in May

[david b]

The British Journal of Photography says the Fuji GF670 / Voigtlander 667 camera will hit Europe in May.

Details here.

 

[Ian Grant]

No prices but quite a small production run, which should ensure they all sell quickly.

Expect Robert White to be a major UK supplier.

Ian

 

[Chazzy]

I suppose there's not much chance that Cosina will wind up with a lot of unsold cameras on their hands and mark them down to $1000?

 

[Sal Santamaura]

I suppose there's not much chance that Cosina will wind up with a lot of unsold cameras on their hands and mark them down to $1000?

About as much chance as the rangefinder baselength being adequate.

 

[sanking]

Do you have any information to suggest that the rangefinder baselength will be inadequate for the 80mm lens?

Sandy King

About as much chance as the rangefinder baselength being adequate.

 

[Oren Grad]

If I'm reading the Japanese press release correctly, the physical base length is 37.0mm and the effective base length, at the specified viewfinder magnification of 0.7x, is 25.9mm. A Leica it's not. (Actually, it's very like the RF spec for the 35mm Bessas. Hmmm...)

 

[John W]

Oren: Since it's a fixed lens rangefinder, its design criteria need only satisfy that one lens. From the document referenced here (see the linked scan at the bottom of the opening post), it appears that at 25.9mm EBL provides sufficient accuracy for an 80mm f/3.5 lens. That same chart indicates that there might well have been an accuracy problem at that EBL for an 80mm f/2.8 lens, however.

 

[John W]

One more item; I assume by context (not reading German) that the chart in question is in reference to DOF values calculated for a 35mm frame. Effective DOF will be greater for a 6x6 or 6x7 frame, so there's additional leeway not graphically represented by that chart. (E.g. the f-stop curves would shift to the left if the chart were redrawn for a medium format frame size.)

 

[Oren Grad]

John - You can see the full mathematical analysis in English in Sidney Ray's "Applied Photographic Optics". It's on pp 394-5 of the 1988 first edition, which is the one I have. Of course, the result depends on one's assumptions about the visual acuity of the eye and the acceptable circle of confusion.

Ray has a chart corresponding to an assumed visual acuity of 1 arc-min and a CoC of 0.05mm; the latter is in the range commonly used for 6x6 cm negatives. Assuming those criteria and reading Ray's graph, I'd interpret the GF670 specs as a bit more than just adequate.

That assumes that there's no slop in manufacture of the RF mechanism or in its stability over time; it's not clear that Cosina is up to that standard. And even then, it alows for the RF slop to eat up almost all of your margin for focusing error at maximum aperture; so much for your narrow DOF being exactly where you want it to be.

We won't know for sure, of course, until the camera becomes available. And again, what degree of slop is acceptable will depend on how critical a viewer you are and how big you want to print. But just based on a simple theoretical analysis like this, full aperture with this camera may be marginal for really critical users. Of course, it might be for other reasons anyway.

 

[Sal Santamaura]

Do you have any information to suggest that the rangefinder baselength will be inadequate for the 80mm lens?

Sandy King

If I'm reading the Japanese press release correctly, the physical base length is 37.0mm and the effective base length, at the specified viewfinder magnification of 0.7x, is 25.9mm. A Leica it's not. (Actually, it's very like the RF spec for the 35mm Bessas. Hmmm...)

...it appears that at 25.9mm EBL provides sufficient accuracy for an 80mm f/3.5 lens...

I've had experience with two different Bronica RF645s, both purchased new and with rangefinders adjusted by the factory service center. In neither case did I find the effective base length of 33.0mm adequate even for the 65mm f/4 lens. My earlier post in this thread was predicated on that along with another of Oren's posts (don't recall where) in which he provided the same translation he did here.

 

[John W]

John - You can see the full mathematical analysis in English in Sidney Ray's "Applied Photographic Optics". It's on pp 394-5 of the 1988 first edition, which is the one I have.

Good to know, and thanks for the details and reference Oren. I suppose this will be an area to watch as these make their way into user's hands...

 

[Oren Grad]

I suppose this will be an area to watch as these make their way into user's hands...

You bet. Here's hoping Cosina goes all out on this one and delivers a product that surpasses expectations.

 

[rootberry]

I don't understand the price at all for this guy.. I've never had a camera I could use primarily for hand held shots and got really excited about this one. I think I'll just go a chammy 45-n1 instead =)

 

[Mick Fagan]

I owned the original Fuji GS645 folder with the 75mm lens many years ago.

If I focused correctly it was wonderfully accurate, but your margin for error when wide open and hand held, and generally using 100 ASA film, did make life interesting some times.

If all those years ago they managed to make something that worked as well as it did, I don't see why with the better controlled CNC equipment that is used today, they cannot make the new camera as accurate as the original folder.

I'm sure it should work quite well, although there will be people who will bemoan any perceived shortcomings, whether they be real or imagined.

I myself am seriously thinking of purchasing one of these cameras, especially as I sort of know what to expect.

Mick.

 

[sanking]

How does this compare to the base and effective base length of the Fuji GSW670 and 690 cameras, and Mamiya 7?

Sandy King

If I'm reading the Japanese press release correctly, the physical base length is 37.0mm and the effective base length, at the specified viewfinder magnification of 0.7x, is 25.9mm. A Leica it's not. (Actually, it's very like the RF spec for the 35mm Bessas. Hmmm...)

 

[Oren Grad]

How does this compare to the base and effective base length of the Fuji GSW670 and 690 cameras, and Mamiya 7?

Now there's a good question. The Mamiya 7II instruction book says 60mm baselength x 0.57 magnification = 34.2 mm effective baselength, which is distinctly more conservative than the GF670 spec, taking into account the f/4 maximum aperture of the 80mm standard lens for the 7 and the rigid construction of the 7.

I'll see if I can dig up the spec for the Fujis - stay tuned.

 

[Oren Grad]

Mamiya 6 RF spec

The RF specification for the Mamiya 6 / 6MF is 60mm baselength x 0.58 magnification = 34.8 mm effective baselength. Standard lens is a 75mm f/3.5.

 

[Oren Grad]

Fuji GS645S RF spec

The RF specification for the Fuji GS645S is 40mm baselength x 0.5 magnification = 20 mm effective baselength. Lens is 60mm f/4.

 

[Oren Grad]

Fuji GS645 RF spec

The RF specification for the Fuji GS645 folder is 39.5 mm baselength x 0.63 magnification = 24.9 mm effective baselength. Lens is 75mm f/3.4.

 

[Andy K]

My Bessa R3M has an rf baelength of 37mm with it's 1/1 finder. That isn't too bad for a 35mm rf from a company camera snobs like to look down on.

 

[Oren Grad]

Fuji GW/GSW III RF specs

The RF specification for the Fuji GW670/690 III is 59 mm baselength x 0.75 magnification = 44.3 mm effective baselength. Lens is 90mm f/3.5.

The RF specification for the Fuji GSW690 III is 59 mm baselength x 0.45 magnification = 26.6 mm effective baselength. Lens is 65mm f/5.6.

 

[Oren Grad]

Fuji GL690/GM670 RF spec

The RF specification for the Fuji GL690/GM670 is 67 mm baselength x 0.75 magnification = 50.3 mm effective baselength. Standard lens is 100mm f/3.5.

 

[Oren Grad]

Bronica RF645 RF spec

And following up on Sal's post, the spec for the Bronica RF645 is 53.5 mm baselength x 0.6 magnification = 32mm effective baselength (the manual says 33mm, maybe a rounding issue somewhere). Standard lens is 65mm f/4.

 

[Oren Grad]

Plaubel Makina 67 RF specs

Makina 67: 63 mm baselength x 0.67 magnification = 42.2 mm effective baselength. Lens is 80mm f/2.8.

 

[Oren Grad]

OK, there's a bunch of modern medium format rangefinder cameras for you. I wonder how these numbers correlate with user experience in trying to push these various cameras to the limit.