[LargeFormat] Re: Lensboards on the road, bellows in the bushes, tripod in the trees.

[Les Newcomer]

Yes!  It's a multifocal telefocal usually has a 3-8x "zoom"  they are made
by placing a negative element behind a relatively normal lens.  Mine is a 7"
dagor in a sector shutter.  so it works as a 21-56" lens,  now at 3x it
won't cover 4x5,  and at 8x it will cover the earth.

but there are drawbacks.  you end up with a 5 to 8 stop light loss, and you
best to put it on something very sturdy as a 56" lens is prone to the
slightlest vibration.

these were also available in tessars, and Protars.  Mine is small about 7"
long.  The others I've seen are more like 10-14" and the flange is not
balanced, so it won't work with on axis movements like a deardorf.

theres a Pic of mine somewere in the Lenses section of the
f32 website.


Les

> From: Frantisek Vlcek <sonnar@centrum.cz>
> Reply-To: largeformat@f32.net
> Date: Wed, 10 Apr 2002 00:15:07 +0200
> To: rstein <largeformat@f32.net>
> Subject: Re: [LargeFormat] Re: Lensboards on the road, bellows in the bushes,
> tripod in the trees.
> 
> r>     Let that be a lesson to you - do not set up your camera on the road
> just
> r> over the brow of a hill.
> 
> Such an interesting story! What happened to you? And the car? I hope
> you at least used some very heavy camera.
> 
> r>     But I digress - with consummate ease - what I really wanted to ask was
> r> whether any manufacturer has ever made a zoom large format lens. I know
> r> about the Schneiders for the MF and all of the SF stuff. I was also not
> r> thinking of multi lenses or convertibles.
> 
> r>      No, has there ever been a dialable focal length-changing view camera
> r> lens? It would save a lot of backpacking space and lensboard shuffling and
> r> studio juggling....
> 
> In fact, not a zoom lens in its sense (zoom=keeping focus at all focal
> lengths) but a transfocal lens was made for LF first! Yes, no cine,
> small format, etc but LF! It was IIRC a dallmeyer telephoto, a
> simple lens with couple of elements and a sliding element between them
> providing the change of focal length. Of course, the apertures changed
> too, so you had to compute them each time (or carry a table), and it
> was nowhere too sharp... and never much popular.
> 
> Best regards,
> Frantisek Vlcek
> 
> 
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