Front teleconverter on LF lens?

[alpshiker]

Has anyone had success putting a teleconverter for professional video in front of a long lens to make it even longer? I remember a year ago, someone advertised one of these on Ebay saying it could be used on LF lenses. If it works, a X 1.6 could turn a 600 into a 960mm. To be honest, I have tried that with a small video converter and although the 4x5 format was well covered, the results were unacceptably soft. The pro converters are big pieces of glass, made for zooms with focal lengths ranging from 10 to 180 mm, but using a longer prime lens probably induces some additional aberration. In reality the Fujinon C 600 is sharp enough to produce images that can be cropped, still, my curiosity calls for feedback if there is any!

[paul_owen]

Don't know about video converters, but Horseman used to make

a teleconverter for LF lenses (for 150mm I seem to recall). I also

recall that these were not that good in terms of quality.

[wilhelmn]

No, but I tried it the other way, (A wide-angle converter taped on

the front of a 190mm Ektar on my 4x5 Super D Graflex). It didn't

work. I don't understand why not.

[neal_shields]

I tried putting a good Sony 1.5 (VCL 1558) converter on the front of

my 270mm Schneider Tele Xenar. I had high hopes when it screwed right

on. I made two identical photographs one with and w/o on 100 asa

Ilford B&W.

 

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If I croped the 270 mm negative to the same image as the 400, I had

more detail in the stright 270 negative.

 

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I had more success with a single front element and a yellow filter,

off of a 10" Protar that is about 100 years old.

 

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Neal

[alpshiker]

I could just test this 1 Kg x1.6 Fujinon converter in front of a Fujinon C 600 and the result was sharp! ...but on the size of a video CCD. Never mind, now we know. Not a big surprise really.