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[brimc76]

I have looked through the different message boards and done a search but couldn't find an answer to my question. I was wondering if someone could tell me what lens focal lengths can be used with my Crown Graphic? I know that the 90mm is favoured for wide angle but can you use a wider lens before running into trouble?
Also telephotos, what is the upper range for these? Would you use a 240mm or more without trouble? I'm not planning on buying all these lenses but I'm just curious as a new user.

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Brian Mc.

[Nick]

Take the lensboard off the camera. Rack the bellows out all the way. Then stick a tape measure/ruler whatever in there. Measure from the front of the ground glass to what would be the back of the lensboard. Okay you've got that number? That's the longest non-telephoto lens that could be focussed at infinity. Multiply by 0.75 to get the longest lens you could use over a wider range. Then you could check the focal flange measurement on various telephoto lens. See which ones have a design that would work.

Now move the bellows to the shortest they'll go. Measure again. Without a recessed board or a special lens this is the shortest you can go. Some lens designs allow you to use shorter focal length. Scheinder's 48mm Xl I think needs close to 60mm to focuss. If the lottery ever hits me I'd love one. But in the real world it's pretty expensive for a lens that I'd rarely use.

The same ideas work for all cameras. Just measure your bellows. Now the thing is do you want movements? Then you often can't use the very shortest or longest lens.

I'm ignoring things like recessed boards or the opposite. These can sometimes increase the focal range even more.

[RichS]

[Nick]

It's okay I'm used to being corrected-)))

What I meant was lets say you've got 10" of bellows. A 10" [non-telephoto] lens will just focuss at infinity. Now if you multiply that by .75 you get 7.5". That shorter lens will focus at infinity and closer. It's just a rule of thumb.

There are formulas that take into account bellows length. Focal length. final image size on the negative. But these are for non-telephoto lenses. I don't know if something similar exists for telephoto lens.

[ This Message was edited by: Nick on 2003-11-05 07:26 ]

[ This Message was edited by: Nick on 2003-11-05 07:27 ]

[RichS]

It's apparently not all your fault. I'm way behind in my coffee quota and had to read that three times before it sank in

You're right in what you said, both times. I misunderstood. Oddly(?) enough, the .75 is the figure used for tele lenses when figuring bellows draw (I think). So it works both ways. Although they must have done something special with that 20 inch to get it to work on a 12 inch bellows!


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"Ya just can't have too many GVIIs"
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[brimc76]

Thanks guys. I beleive the bellows extension on my camera (Crown Special) is roughly 12 inches but I'll measure it to make sure. I bought it with the Xenar 135mm but I'm also using a Schneider 90mm Super Angulon, and a Schneider Symmar 150mm/265mm convertible lens. I haven't tried the 150mm/265mm yet as I'm waiting for a lensboard, but the 90mm is great. I use these lenses on an Arca Swiss F Basic B as well, and it's nice to use the 90mm without the recessed board (on the Graphic).
I was thinking of getting a 240mm for the Arca Swiss (the convertible lens isn't great at the 265mm end) and I was just curious if I could use it on the Crown Graphic Special as well, without any modifications.
Thanks again for your help.

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Brian Mc.

[Les]

Like they say, it depends on the lens design. You'll get more range--closer min distance and better balance with a Tele design.

A long focus 240 will give you sharper images, but will be limited in close range and the camera will be a bit unweildy with the lens racked all the way out.