FSU lenses for LF. Opinions and practical experiences anyone ??

Hello
I am looking for a lens that covers a 13 X 18 cm frame.
I have seen some sellers advertising the FSU Industar-51 FKD 210 mm f4,5 lens. Apertures from 4.5 to 32.
The price is surprisingly low !!!. (This may be a red flag, I know)
Does anyone have used this lens ? Any opinions ??
Thank you in advance
Joao

I sold my I-51. It was horribly soft at all apertures and distances. I understand that not all are like this.

Remember, the lens is in barrel and its cells can't be put in a standard shutter.

Decent 210/5.6 plasmat types (Symmar and Sironar, both with and without suffixes; Nikkor-W and Fujinon-W) will all serve you well.

Thank you Dan
Maybe that's why these lenses are not often mentioned...
Regfards
Joao

I use one on my Speed Graphic, it's a decent, Tessar-type lens.

Not FSU, but East German, Carl Zeiss Jena Tessar 210/4.5 that was fitted in Mentor or Globica cameras, is a cheap but good alternative, I believe.

Thank you
One more question, if I may:
I may have the chance of buying a Rodenstock Rotelar 270 mm f/5,6 (with a Synchro Compur shutter). The price is whithin my budget.
Is this too much for 13 x 18 plates ?? Or should I pick something around 210 - 250 mm ??
Joao

Bad idea. The VM says it barely covers 4x5. Telephoto lenses have less coverage than lenses of normal construction (neither telephoto nor retrofocus).

Thank you, Dan. You saved me from a wrong choice.
I will go for one of those you've mentioned before.
Regards
Joao

This lens is a classic Tessar retrofocus design.

Regarding sharpness this is a 24x16mm crop of the image circle:


https://lensbeam.com/obektivy/industar-51-obzor

If the sample cropped image is enlarged to some 25cm high in the monitor then it shows how the detail will be in a 2m high (187,5cm) print made from 13x18cm.

The calculation is 18cm x 25cm / 2.4cm = 187,5cm.

While sharpness is not stellar it would produce IMO perfect 80cm high portraits from 13x18cm format.

So IMO it is not a lens for ultra-sharp 2m printed landscapes but it anyway it may deliver a charm classic feel.

Bokeh is not is the soft side, those defocus discs with rings (also in a 16x24mm crop) shows that spherical aberration is overcorrected in the rear out of focus range, delivering a more detectable background.




So IMO not a glass for one wanting top performace and advanced coatings, but anyway it can be a great choice for an artist wanting to exploit its aesthetic nuances, at the end this kind of lenses has a footprint that has shaped the aesthetics of an era, specially in the eastern block.