Has anyone used the German single-element teleconverters

[loccdor]

Made by JSCO, the ones I saw are 42mm push-on, which fits my 150mm Zeiss Jena Tessar f/4.5. I use this lens on 6x9.

One of them is a 1.4x teleconverter, the other is a 0.8x teleconverter, which would change the lens to 210mm and 120mm, respectively.

I'm not looking for optical perfection from these - but is the character they add to the image pleasing? For portraits or isolated central subject photography. Does it make something of a soft focus effect?

The names are
Veriangerungslinse 300/420 B
Verkurzungslinse 20/420 E

 

[Alexander6x6]

If you want to introduce more chromatic aberrations and in case of 0.8x reducer the distortion at the edges and corners, then this is the option for you.

 

[xkaes]

The first one 1.4X is a negative diopter INCREASING the apparent FL, while the other 0.8X is a positive diopter SHORTENING the FL.

The first turns a 150mm lens into a 210mm lens (additional bellows needed), while the other creates a 120mm lens (less bellows needed).

That's roughly equivalent to +/- 1.5 diopters -- not very strong. Results should be fine stopped down. Wide open they would be great for portraits, softer effects.

 

[loccdor]

Thanks. I can't find any example pictures anywhere online with these so I guess I'll have to post the first!

 

[lobitar]

Have used a couple of these lenses (in the Zeiss variant called Distar-lenses), but regret I cannot now say precisely how much sharpness declines towards the edges. But edge-sharpness definitively suffers. However there is one curious effect of using a Distar with a suitable (uncoated) Tessar: when used in contre-jour situations the ubiquitous inner reflections in the Tessar practically disappears!

 

[JensH]

Thanks. I can't find any example pictures anywhere online with these so I guess I'll have to post the first!

Hi,
I'd like to see pictures with the Verlängerungslinse (aka Distar if made by Zeiss...).
The Verkürzungslinse (aka Proxar) should work fine with a Tessar.
I use such for my Rolleiflexes - here the Proxar 1 works very well, the Proxar 2 (reduces fl to 0.9x) is good with less contrast and sharpness and a swirly bokeh.
Jens

 

[loccdor]

in contre-jour situations the ubiquitous inner reflections in the Tessar practically disappears!

Quite interesting!

I'd like to see pictures with the Verlängerungslinse

I'll must remember to post them here when I try them out. Since I'm using 6x9 on a 4x5 lens there will probably be less edge sharpness loss but I don't know yet.

 

[Alexander6x6]

the Proxar 2 (reduces fl to 0.9x) is good with less contrast and sharpness and a swirly bokeh.

Incidentally, swirly bokeh is a common issue with all reducers regardless how much you pay for it (see below).

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