[Lowell Goudge]

You posted after I edited my post to add that the FA 77mm has 9 blades. The pre-sets have 2 key things, and those are that they usually have 9 to 20-something blades and the location of the diaphragm.

Edit: The reason the above images were shot wide-open was in part due to it being just after dark.

I personally think the Bokeh the presets have is really dependant on the location of the blades.

Regardless the presets make for an interesting alternative to some of the newer lenses, and even the super tak's.

Although I controlled LBA for a long time, my M42 kit is an example, it started out as a collection of lenses at focal lengths I did not have and only lenses faster than any of my zooms, i have found myself looking lately for lenses with different optical qualities. As a result, although I have a nice collection of K mount primes, I have put together a collection of M42 primes that are all a little unique. I have (or when the mail arrives in a few days) 3 presets with round apertures at all Fstops, and an 8 element super tak 50mmF1.4 plus a few other super tak's and SMC taks, etc, and all my lenses except for my 200mmF3.5 are F2.8 or faster and everything between 35 and 85 is F2 or faster with 24 and 28mm at F2.5.

[Nesster]

Another factor is what aberrations are corrected and how. Often the good-bokeh lenses seem to have spherical aberrations, which correct in-focus but remain oof. This contributes to the separation and -with a round aperture- pleasantly round and even bokeh.

Vintage fast aperture lenses especially seem to have this - traditionally they achieve speed at the cost of softness, and their slower brothers tend to out perform them sharpness/contrast wise throughout. The Takumar 50/1.4 is a notable exception, as it measures better than the 55/1.8 throughout.

[Lowell Goudge]

Another factor is what aberrations are corrected and how. Often the good-bokeh lenses seem to have spherical aberrations, which correct in-focus but remain oof. This contributes to the separation and -with a round aperture- pleasantly round and even bokeh.

yes you can see this in my 200 F3.5

Vintage fast aperture lenses especially seem to have this - traditionally they achieve speed at the cost of softness, and their slower brothers tend to out perform them sharpness/contrast wise throughout. The Takumar 50/1.4 is a notable exception, as it measures better than the 55/1.8 throughout.

not really a fair comparison, the 50mmF1.4 (version 1 - 8 elements) is one of the sharpest 50mm lenses ever.

[Nesster]

Yes, the 50/1.4 is an exception to the old rule

[Arjay Bee]

A pre-set that your mentioning presets reminded me about is the Schneider Kreuznach 360 F5.5 preset. It has 16 blades rather deep in from either end but below are two pics of the blades taken with the help of a LED light. The aperture is nicely circular of course wide open but goes chrysanthemum at F11 and then cicular again asit closes further. See examples below, f11 on the left and f22 on the right



Example image but don't recall aperture, f6 or so I would think:



As far as the slightly imperfect blade action of the Isco 135 mentioned above is concerned it is a completely manually apertured lens with no auto stop down. Like a pre-set without the pre-set ring so there is no issue with the blades' action.

[Lowell Goudge]

A pre-set that your mentioning presets reminded me about is the Schneider Kreuznach 360 F5.5 preset. It has 16 blades rather deep in from either end but below are two pics of the blades taken with the help of a LED light. The aperture is nicely circular of course wide open but goes chrysanthemum at F11 and then cicular again asit closes further. See examples below, f11 on the left and f22 on the right



Example image but don't recall aperture, f6 or so I would think:



As far as the slightly imperfect blade action of the Isco 135 mentioned above is concerned it is a completely manually apertured lens with no auto stop down. Like a pre-set without the pre-set ring so there is no issue with the blades' action.

have you tried shooting into bright distant lights at F11, I would love to see the star pattern the iris introduces from all the little "cusps" in the aperture circle

[Nesster]

Some more from the Komura

f/4


f/4... I barely got the kid in front into focus

...

Some star pattern bokeh from the Macro-Tak 50/4

f/8

[Blue]

...

Some star pattern bokeh from the Macro-Tak 50/4

f/8

I just had an epiphany for this years holiday seasons and it involves my second favorite Tak!

[Arjay Bee]

Although not the high number of aperture blades that Op was talking about another example of the Macro takumar Bokeh - this from the pre-set version



Keep coming back to Takumars and this has been posted in Takumar thread about 500 posts ago.

[Lowell Goudge]

Some star pattern bokeh from the Macro-Tak 50/4

f/8

Interesting is this the 1:1 macro?

my Super-Multi-Coated Macro Takumar is a 5 blade aperture collapsing to a pentagon.

[Blue]

Although not the high number of aperture blades that Op was talking about another example of the Macro takumar Bokeh - this from the pre-set version



Keep coming back to Takumars and this has been posted in Takumar thread about 500 posts ago.

Actually, the Macro-Takumar 50mm f4 is the preset model.

Interesting is this the 1:1 macro?

my Super-Multi-Coated Macro Takumar is a 5 blade aperture collapsing to a pentagon.

The 1:1 lens has Macro-Takumar has on its face plate:

Macro-Takumar 1:4/50 Asahi Opt. Co. Lens Made in Japan ser #

[Nesster]

Interesting is this the 1:1 macro?

my Super-Multi-Coated Macro Takumar is a 5 blade aperture collapsing to a pentagon.

Yes, the Macro-Tak 50/4 is a preset lens and goes to 1:1. It kind of expands out in both directions from the middle as you focus closer.

[Lowell Goudge]

Yes, the Macro-Tak 50/4 is a preset lens and goes to 1:1. It kind of expands out in both directions from the middle as you focus closer.

I know the mechanism, I have a pentax helicoidal extension tube with the same mechanism, it expands from both ends when you turn the focusing collar.

I was wondering if any other Macro-Takumars have similar apertures, or are all others the 5 blade version.

[Blue]

I know the mechanism, I have a pentax helicoidal extension tube with the same mechanism, it expands from both ends when you turn the focusing collar.

I was wondering if any other Macro-Takumars have similar apertures, or are all others the 5 blade version.

What we are saying is that is the only Macro-Takumar. The other 2 were the 50mm/4 Super Macro-Takumar and 50mm/4 S-M-C Macro-Takumar which were 1:2 and had the automatic diaphragm with A-M switch. There was no 100mm/4 Macro-Tak, just the S-M-C model. There are the bellows 100mm lenses. I don't know anything about the aperture mechanism on those.

[Lowell Goudge]

What we are saying is that is the only Macro-Takumar. The other 2 were the 50mm/4 Super Macro-Takumar and 50mm/4 S-M-C Macro-Takumar which were 1:2 and had the automatic diaphragm with A-M switch. There was no 100mm/4 Macro-Tak, just the S-M-C model. There are the bellows 100mm lenses. I don't know anything about the aperture mechanism on those.

a point of english here, but I consider any lens with the words "macro-takumar" as macro-takumars, super, and super-multi-coated and SMC are ajectives,

but the question remains unanswered