Schneider Xenotar 150mm f/2.8 redesigns/versions/variations?

[paulbarden]

Bokeh is not poor, especially around f/4.



Of course bokeh is somewhat subjective. For instance, Zeiss Tessars are lauded for bokeh but I find they are typically pretty busy at wider apertures. So IMO the Xenotar has much faster usable aperture with good bokeh at those wide apertures, while the Tessar smooths out at smaller stops (hence why I think the Tessar design is really good on 8x10 since it still gives thin DOF at f/11).

Honestly, I find this to be truly awful bokeh. Very distracting, busy OOF. Not nearly enough separation of subject from background.

[Corran]

Okay. I simply disagree, especially wrt separation.

[Roger Thoms]

Doesn’t the shape of the iris also have an affect on bokeh?

Roger

[Pere Casals]

Doesn’t the shape of the iris also have an affect on bokeh?

Roger

Of course...

If iris is a pentagon then you see pentagons instead discs in the OOF bright spots, and this has also an effect in the OOF nature, even a heart shape can me used in the iris or in the entrance:



Another factor is how spheric aberration gets corrected in the OOF: neutral, under or over, the highlighted rings in the discs are provocated by that, overcorrection deivers nice bubbles but also a harsh OOF would be rendered:



Another factor is circular/swirly bokeh, this is provocated if the entrance/exit pupils trim the aperture pupil in the image off-center:



And there are other factors which I don't know/understand...

... but a "good bokeh" in the smoothness sense is often wanted for portraiture, this is just the counter of the bubbles/rings in the second example.

Of course the "good" OOF rendering for our image may not be the good (smooth) bokeh. There is some confusion about that...

_______________________

Japanese artists have a dozen adjectives to describe bokeh. They have a refined aesthetic culture about that. IMHO westeners may learn a lot from them, me at least.


https://web.archive.org/web/20081230...ys/bokeh.shtml
https://theonlinephotographer.typepa...hrankings5.pdf

[Jim Galli]

Back to some of the OP's questions. When I came to work at a test laboratory for the gov't in the desert, I inherited about 8 150mm Xenotar's that were mounted in a proprietary hardened housing for use on cine cameras that we ran mostly at 100 frames per second, but occasionally up to 360 fps. They were famous for their shapness at f4 - f5 - ish, which you need at those speeds. Angle of coverage was quite small as we were looking at half frame cine Kodak 35mm chrome films. So we used the very sweet spot. For our purposes a 127mm f4.7 Kodak Ektar would have done about as well for a pittance of the cost. But uncle sam like Xenotar's. There is legend that some ranges like White Sands got their grubby's on 210mm Xenotar's. We saw a few at auction 20 years ago but couldn't afford to ever get one.

When we finished our move to digital cine's the Xenotar's sat on a shelf for a while and finally, it broke my heart to send them off to "re-app" where I'm quite sure someone bought a pallet of junk and found those in a box at the bottom of a yard box. I kept one for old time sake. #9021664 But I plan to retire soon and that one will go the way of the Do - Do's soon. When we sent all the cold war legends off to re-app the folks there scan stuff carefully for radioactive anything. Alarms went off! The world nearly came to an end, the SWAT team suited up in their tyvek storm-troopers suits and they promptly sent the aberrant lenses back to us! Banish those horrid lenses to hell! But to my surprise, it wasn't the Xenotar's, it was some high dollar cine Wollensak's that were the offenders.

So the stories of hot Xenotar's are over-rated. The one I kept has the Schneider pink-orange and yellow coatings very similar to what I see in G-Claron's and even more so in Repro-Claron's.

As to bokeh, first of all, ignore Dan, but beyond that, don't get me started. It's like a dago and wine. We know what we like. Foolish to even try to dissuade. And define, that's for aristocrats. The Japanese started with un-corked Kodak achromatic menisci.

[EdSawyer]

Jim, great stories, thanks for sharing. Those must have been some of the Xenotars from White Sands or wherever that were on Ebay a few years ago. Probably you used them in Photo-sonics cameras if I had to guess.

There were I think 5 210mm xenotars made, the only one that has changed hands a couple of times publicly has gone from a ~$2500 lens to an ~$8k lens the two times it was sold.

Schneider themselves stated the Xenotar was at it's optimal aperture by f/4, in their own literature. That's where I shoot mine, generally... though nailing focus at that aperture can be challenging.

Of the xenotars that I have, I don't think any of them show the typical radioactive browning that you see on the Aero Ektars.

-Ed

[Jim Galli]

Jim, great stories, thanks for sharing. Those must have been some of the Xenotars from White Sands or wherever that were on Ebay a few years ago. Probably you used them in Photo-sonics cameras if I had to guess.

There were I think 5 210mm xenotars made, the only one that has changed hands a couple of times publicly has gone from a ~$2500 lens to an ~$8k lens the two times it was sold.

Schneider themselves stated the Xenotar was at it's optimal aperture by f/4, in their own literature. That's where I shoot mine, generally... though nailing focus at that aperture can be challenging.

Of the xenotars that I have, I don't think any of them show the typical radioactive browning that you see on the Aero Ektars.

-Ed

Yes, the Ektars look like "weak coffee brown". Yes, Photosonic 4E's. Maybe I'll tell the little green men there'll be no more daylight trips unless they can find me that 210mm Xenotar. Also there was a legend that the resolution numbers were secret. Makes a good story.

[Daniel Unkefer]

My Xenotar is from that Ebay Photosonic selloff. I was lucky to get one with good glass. No color to speak of in the glass. I like to shoot mine wide open, as I really think that was intended to be the point of it. A super speed lens, pushing the envelope.

[Pere Casals]

Yes, Photosonic 4E's.

Jim, now it's clear how your shutter was inspired: Photosonics !!!

This is a rotating prism in conjunction with a disc shutter.

I use the single blade version of the Galli shutter for pinhole... and learning the two blades operation.

It should be mentioned that the 4C sports 2500 FPS. In the Inception movie (Nolan) the cinematographer (Pfister) used a top notch Phantom digital camera and the Photosonics film camera for the falling car scene high-speed work:

https://www.youtube.com/watch?v=k_4qc-JYZPo

Only the Photosonics footage was good.

[Greg]

When we finished our move to digital cine's the Xenotar's sat on a shelf for a while and finally, it broke my heart to send them off to "re-app" where I'm quite sure someone bought a pallet of junk and found those in a box at the bottom of a yard box.

My first boss in the late 1970s was in the Armed Forces in the early 1970s. He was part of a photo unit that tested prototype lenses. Told me that very, very few of them ended up in their warehouse (actually more like ware"room"). The rest were listed/documented in detail, since most of them didn't have serial numbers on them, and then once a year taken out to a parking lot. They then had a bulldozer run it's tracks over them. Told me a steamroller was requested, but never sent. Evidently bulldozers were a lot more common than steamrollers.