Identity Crisis

[RichL]

Picked up a camera and misc. today. The camera was a Hasselblad 1000F the misc. was a "BUSHNELL TELEVAR VARIABLE MOUNT 'LV'"
It is an extension tube with 39mm threads. The tube extends from 41mm closed to 56mm fully extended. The part that has me baffled is that the barrel extension points are marked 400-f/9, 450-f/10 etc. to 650-f/16.

Web check comes up blank, anybody here have the slightest idea of what it is?

Thanks
RichL

 

[farlymac]

Methinks that is for a telescope. Canon had an adapter for the FT/FTb that used M39 threads to attach the camera to scopes and other apparatus using M39. But not to mount a Leica lens on the FT/FTb

PF

 

[quejai]

I'm not too sure about the first part of the markings, but as you extend the tube with the lens set at constant settings, the F/number will reduce, because the f/number is a ratio of the aperture and the distance from the film plane. I guess that's to help with record keeping and non-TTL metering systems. It sounds interesting

 

[RichL]

farlymac and quejai Thanks, makes sense. If it were a particular Bushnell scope then each mark would indicate the 'new' lens size.

 

[JustPlainBill]

Hi,
Once upon a time I owned a Bushnell Televar but did not have a camera to mount it on. i thought it was a variable power (or variable focal length) monocular then. Eventually I traded it for a Canon FX body.
JustPlainBill

 

[RichL]

Hi,
Once upon a time I owned a Bushnell Televar but did not have a camera to mount it on. i thought it was a variable power (or variable focal length) monocular then. Eventually I traded it for a Canon FX body.
JustPlainBill

Thanks all
It is indeed a telescope adapter. Found a similar (updated) 'Vixen' adapter http://images2.opticsplanet.com/365-240-ffffff/opplanet-vixen-camera-adapter-1836.jpg