Plena?

[Birna Rørslett]

The old Bellows-Nikkor 135mm f/4 had beautiful bokeh balls ....

One has to pay a lot more to get the last degree of 'roundness' to the corner region

[Roland Vink]

The new TTArtisan 100mm f2.8 seems to show no cat-eye/lemon shape.  So, chances could be that the old Nikkor-T 105/4.0 would behave similarly, because they share the same simplistic triplet design.

Any lens with relatively long focal length, moderate-small aperture and compact optical unit should have low mechanical vignetting. It's like looking down a tube at a slight angle. If the tube is long, the rear opening will be greatly offset from the front opening, and the view through will be shaped like a cat's eye with strong mechanical vignetting. If the tube is short, the offset is much smaller resulting in low vignetting. That is why lenses like the old 105/4 micro, 135/4 bellows and Nikkor-T 10.5cm perform well in this area. The alternative is to increase the diameter of the tube, in other words a faster aperture lens. Even if mechanical vignetting is high at full aperture, it can be greatly reduced or eliminated by closing down a stop or two.

[Erik Lund]

The old Bellows-Nikkor 135mm f/4 had beautiful bokeh balls ....

One has to pay a lot more to get the last degree of 'roundness' to the corner region

Yes, very nice samples, not far off full circle...
BTW, I would guess also the UV-Micro Nikkor 105mm f/4.5 belong to this list of lenses with almost circular OOF


Next question is how is the front OOF I recall the 105mm f/1.4 AF-S is quite good.

[MILLIREHM]

BTW, I would guess also the UV-Micro Nikkor 105mm f/4.5 belong to this list of lenses with almost circular OOF

Would need to test that out

[Erik Lund]

Would need to test that out

Sure. It's purely based on the that the optical cell is relative compact and placed way to the front of the lens, away from the focus plane and the general superb performance of the lens regarding rendering and color transition.
Price is about 2x or 3x that of a Plena so the interest is maybe not there...

[MEPER]

What about lenses made for much larger formats?
E.g. 6x6, 6x9 etc.?
Often enlarger lenses are quite compact?

[Birna Rørslett]

Enlarger lenses are not designed for general photography, including subjects at distance. Some times, in particular with symmetric designs, they do passably outside their designated applications, but never better than standard lenses.

Large-format lenses typically have lower resolving power  -- and slower speeds -- than optics for smaller format.

[bressong]

personally I don't think the round disc is such important out of center(70%), and in real world it's a little complex of bokeh disc perfomance. with same lense but different angles and distance...

if the plena selling at 1500-2000USD that will make more sense

[bressong]

same scene but different engle

[bressong]

all f1.8

[bressong]

the new generation 135/1.8 are already good enough on sharpness, resolution, bokeh...
I mean sigma art, sunyang,RF, GM 135/1.8, no doubt Z135/1.8 will be one of the best for portait and landscope.

[MEPER]

I tried in total darkness to handhold an old Meyer-Optik 300/4 Orestegor. It was made to cover 6x6 and now I tried it on DX-sensor Z50.
I set iso to 40.000 and tried to handhold it with some defocused images of traffic signals to force blur circles. Not easy to handhold this heavy lens without VR.
But it gives an idea. Not bad I think?

[MEPER]

When I do not defocus the scene looks like this.......but at 1/13 sec with no VR and handhold it is difficult with a heavy 300mm lens.
Iso 40000 with DX sensor it also to push the limits a bit but sensor has better night view than I have.
For pure documentation purpose it is usable.

[Eddie Draaisma]

Link to downloadable raw files, shot with Plena 135/1.8 AND Nikon Zf... (found on Nikonrumors).

https://drive.google.com/drive/u/0/folders/1-49QU9PpMhZ2bbbLeP3CKfhMyY9fSysZ

[bressong]

cat eye

ai 105/2.5