Adapted lenses with interesting bokeh shapes

I know that many people dislike very distinct (geometric) bokeh shapes and view them as a gimmick which is fun for a second and then more annoying than anything else. While I agree that bokeh like that can distract from the main subject and narrow the possibilities you have with a particular lens in certain instances, I think it can be used in creative and fun ways, particularly with adapted lenses, where you have a lot of opportunities to consider the options in your adaption process (like variation of FFD, rotation of the lens, using a lens normal or reversed, use tilt/shift adapters etc.)

So I'm very curious about some of the lenses you know which feature interesting and unusual bokeh shapes, and if you have tried them perhaps also seeing a couple of sample shots made with them.

EDIT: There has been a very interesting thread here which goes in depth on background blur and bokeh. As part of the interesting discussion there, @TomAxford (who has already shown some interesting triangle examples below) has provided an explanation and some nice looking examples of "Shaped bokeh", where you create your own bokeh shapes, and let your fantasy go wild. While that approach is different to using adapted lenses with certain bokeh shapes built into the lens, it is an interesting and significantly more versatile approach to getting creative with bokeh.

I highly recommend checking it out here:
dprevived.com/t/bokeh-how-much-background-blur-will-i-get/2398/post/38073/
and giving it a try yourself! Thanks to @TomAxford and to @TimoK and @nzmacro for recognizing the overlap!

I'll start with a simple, very cheap enlarging lens in two focal lengths with square bokeh:

Meopta Belar 50 & 75 mm f/4.5

Because the Belar lenses are slow you have to get quite close in order for them to work properly, or the background bokeh far enough away but keeping that in mind, I'm sure they can be used to great effect, even outside of macro stuff. I'm curious if there are some faster (taking) lenses which feature very square bokeh like that... If you are aware of some, I'd appreciate it, if you can let me know.

I get it... no fan of squares here! 😉

I'll just keep going then. What about triangular shapes?

The Meyer Optik Oreston 50 mm f/1.8 (aka Pentacon electric 50 mm f/1.8) has aperture blades which can be modified in a certain way to create nice triangles:

My favorite shape is that of the unassuming Steinheil V-Cassarit 50 mm f/3.5 enlarging lens though:

Some famous Zeiss cine lenses feature the same shape, or so I've heard.

And finally - the Zeiss/Docter Tevidon lenses offer some interesting options to play with triangles as well, particularly because of their smaller image circles, which mangles them up quite a bit:

Quite odd indeed !!

I did buy a couple of M42 Helios model 44 lenses for "the swirl". Came out quite well, even on my 1.7 crop Sigma SD9.

First test:

Swirl is more obvious when focused close at f/2.0.

Shaped bokeh with a modern lens Olympus 75mm f/1.8:

Thanks a lot! I like swirly lenses but I don't have too many and often struggle to use them to great effect to be honest. Some projection lenses seem excellent in that regard though.

I'm looking forward to some more of your shots with it, I'm sure it's fun trying to get it to swirl with something in (close) focus! I have a Helios-44M 58 mm f/2 but only used it once or twice. My copy doesn't seem to be great for macros in terms of sharpness, but the bokeh is wonderful of course:

That's very interesting - thanks for sharing! How recent are we talking? I wasn't aware any modern lens is still using that shape. It seems to have been used by machine lenses for the most part in the past, where bokeh wasn't important. Not sure, why Zeiss used it in a cine lens, but perhaps they were just big fans of rounded triangles, just like me! 😍

Sorry, I was cheating! It is easy to create your own shaped bokeh by putting a shaped cut-out in front of the lens. Just google "shaped bokeh" to see lots of examples.

Okay - thanks for clarifying! Yeah, I'm aware of that possibility and even though it looks like fun, it's not really what I'm looking for. I have done something (slightly) similar though with a lens without aperture and it's a great way to experiment and find out the limits of what's possible.

!

The weirdest shape I saw is probably Color-Yashinon DX 35mm f1.8. It changes with aperture change.

Great to see you here - welcome!

That's really cool - these shapes look like tiny ghosts who want to escape or handkerchiefs in the wind... 😅

Here's something completely different... I might call it 'brokeh' 😎 Because this lens is severly affected by separation, to a point where most people would just trash it. Instead of doing that I tried to incorporate it into the theme of the image:

What if circles are too boring for you... and squares too rectangular? Well - fortunately there's a solution. I present to you 'the circling of the square bokeh':

Will Wetzlar Wilon 75 mm f/4.5

Meopta Anaret 30 mm f/4.5

While I don't find it as interesting to experiment with as the regular squares, it certainly feels more appealing and less distracting in some instances.

Finally, here are some shots with star-shaped highlights:

Noritsu 45 mm f/4

Zeiss S-Sonnar 62 mm f/2.5

For whatever reason, I find this one very appealing - would look very cool in a metal print.

Your photographic brain sure works differently than mine! ... in a good way!

I really like this one, as well. Creative.
Cheers!
Jerry

Schneider Apo-Digitar M 120mm f/5,6 in Schneider's aperture mount.
I think the bokeh trick comes more from the five blade iris in that aperture mount than the lens itself.

Thanks a lot - glad you like those experiments! I actually would like to see how some of the shots look like as a print, but I wouldn't know where to put them honestly... 😅

Very nice shot! Thanks for the reminder. The Schneider pentagonal star-bokeh is actually somewhat infamous among many people, but I'm sure it can be used in interesting ways. Can't claim I managed to do that very effectively yet, but I tried with a Componon lens once:

Really superb work and examples here folks. Impressive and yes most modern lenses tend to be round.

Very clever work and excellent results thanks. I might try a few with the Canon FD lenses. My 300 F/2.8 has one aperture blade missing and that might show up.

Danny.