crown or speed graphic lenses

[felix5616]

what is the shortest focal length lens that can be used on a 4x5 crown or speed graphic and be rangefinder coupled?

[BrianShaw]

90, I believe.

[Walter Calahan]

90, so long as you get the rangefinder shim

[felix5616]

Thanks

[Neal Chaves]

Cams can be cut for the TRF Crown for range finder focusing with lenses as short as 58mm.

[IanG]

I have a modified (from new) pre-Anniversary Speed Graphic and the rangefinder's set for a lens less than 90mm, I've no idea what lens though

75mm is the widest I use on my Crown Grapjic but beacuse I use a 90mm, 150mm or 200'sh it's just not possible to set the rangefinder for anything other than my main lens a 150mm coated Tessar.

Ian

[BrianShaw]

At some point shortly after 90 the bed tends to obstruct the view, doesn't it?

[IanG]

At some point shortly after 90 the bed tends to obstruct the view, doesn't it?

On my Speed Graphic part of the top of the case is cut away to allow rise and the bed has been altered so th track goes right into the body.



On the Crown with a 75mm I drop the bed, the 75mm sits happily on the inner rail.

Ian

[Dan Fromm]

Hmm. We have three questions here. What range of focal lengths can be used with the rangefinders fitted to Graphics? What range of focal lengths can be used on Graphics? What's the shortest focal length that can be used on a 4x5 Graphic without dropping the bed?

I can't answer the first question. I can, though, point out that there two types of rangefinders were commonly fitted to Graphics. The Kalart ("side", an option that could be fitted to all Graphics) and Graflex Inc's own ("top", integral with the body).

Kalart rangefinders use a system of linkages to measure how far the bed is in front of the infinity position and to translate that distance, given the lens' focal length, into an indication of the focused distance. The linkage that reads the bed's position has limited travel; this limits the minimum distance, given the lens' focal length, that the RF can measure. The linkages that do the translating also have limited adjustability. I'm sorry, but I don't know their limits. What I do know is that a Kalart can be adjusted for just one lens. Readjusting a Kalart for a different lens is time-consuming and fiddly. AFAIK no one adjusts a Kalart in the field. The standard way to get around this limitation is to set the Kalart up for a lens and use it with a focusing scale attached to the bed to measure focused distance. If the bed has infinity stops and focusing scales for other focal lengths, the focused distance (measured using the lens for which the Kalart is adjused) can be transferred to the scale for any other lens. Given that a focusing scale (really two, a fixed scale and a vernier that slides by it) can be obtained for the desired focal length and that the camera can focus the desired focal length, this approach can be used to focus any focal length on a Graphic.

Graphics' top RFs use lens-specific cams and linkages to translate the bed's position to focused distance. I've never seen anything about focal length limits, have seen many discussions about where to get/how to make cams. Their practical implication is that nowadays using a Graphic's top RF for most lenses is more a fantasy than a reality.

The second question -- what focal lengths can make infinity on a 4x5 Graphic? -- has been answered many times. Since the internet in general and this forum in particular has no memory, I'll post the limits again. 4x5 Crown Graphics' minimum and maximum extensions are 52.4 and 317.5 mm. 4x5 Pacemaker Graphics' min and max extensions are 66.7 and 323.5 mm.

The third question is a little wrong-headed; a dropped bed will be out of the frame for the shortest lens that will focus to infinity. I'm sure that the people who designed Graphics had many faults, but they were thoughtful, intelligent, and made cameras to be used.

If the OP was asking which 4x5 camera can be used, presumably hand-held, with RF-coupled lenses of any focal length, well, the short answer is Linhof Technika. If I'm not mistaken, custom cams can be made for any lens that will work at all on any recent Technika.

[IanG]

Dan, some 5x4 Graphics hade Meyer rangefinders.

Ian