Info Required on Kenko Variable Tube/Auto Teleplus 2X-3X
Posted 12/06/2010 - 14:46 - Helpful Comment
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I splashed out on one of these thinking it was a helicoid.
Unfortunately, it's nothing so useful!
It appears to be a sprung loaded Converter element, so that when the extension tube is screwed on the converter is pushed closer to the lens, changing the magnification achieved from 2x to 3x.
I hadn't even noticed the spring loading till I found this:
http://forum.mflenses.com/viewtopic.php?t=29068
An interesting toy perhaps, but not what I'd consider truly variable (Implying a zoom like function). The only adjustment ring is actually a simple guide to the effective f.no (loose 2 stops at 2x and three at 3x).
If it had been a helicoid it would have been worth the hassle of M42 adapters, but at least it was cheap enough...
Mike
Unfortunately, it's nothing so useful!
It appears to be a sprung loaded Converter element, so that when the extension tube is screwed on the converter is pushed closer to the lens, changing the magnification achieved from 2x to 3x.
I hadn't even noticed the spring loading till I found this:
http://forum.mflenses.com/viewtopic.php?t=29068
An interesting toy perhaps, but not what I'd consider truly variable (Implying a zoom like function). The only adjustment ring is actually a simple guide to the effective f.no (loose 2 stops at 2x and three at 3x).
If it had been a helicoid it would have been worth the hassle of M42 adapters, but at least it was cheap enough...
Mike
Mike
.
Pentax:K5ii, K7, K100D, DA18-55, DA10-17, DA55-300, DA50-200, F100-300, F50, DA35 AL, 4* M50, 2* M135, Helicoid extension, Tak 300 f4 (& 6 film bodies)
3rd Party: Bigmos (Sigma 150-500mm OS HSM),2* 28mm, 100mm macro, 28-200 zoom, 35-80 zoom, 80-200 zoom, 80-210 zoom, 300mm M42, 600 mirror, 1000-4000 scope, 50mm M42, enlarger lenses, Sony & micro 4/3 cameras with various PK mounts, Zenit E...
Far to many tele-converters, adapters, project parts & extension tubes etc.
.[size=11:].Flickr• WPF• Panoramio
.
Pentax:K5ii, K7, K100D, DA18-55, DA10-17, DA55-300, DA50-200, F100-300, F50, DA35 AL, 4* M50, 2* M135, Helicoid extension, Tak 300 f4 (& 6 film bodies)
3rd Party: Bigmos (Sigma 150-500mm OS HSM),2* 28mm, 100mm macro, 28-200 zoom, 35-80 zoom, 80-200 zoom, 80-210 zoom, 300mm M42, 600 mirror, 1000-4000 scope, 50mm M42, enlarger lenses, Sony & micro 4/3 cameras with various PK mounts, Zenit E...
Far to many tele-converters, adapters, project parts & extension tubes etc.
.[size=11:].Flickr• WPF• Panoramio
Posted 13/06/2010 - 13:59
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Thanks Mike - will give it a miss in that case.
All the best
All the best
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9 posts
17 years
I've noticed on eBay, etc a Kenko Variable Auto Tube matched with an APS Variable Auto teleplus 2X-3X setup for M42 mount. Could someone please advise me if the "variable tube" is a true variable tube (giving different lenghts of extension) or simply variable only in conjunction with the converter - changing it from a 2X to a 3X.
The converter doesn't interest me but if the variable tube is similar to those rare helicon variable extension tubes it would be marvelous.
Thanks and all the best,
Col