Jump to content

Why are Leica using less aperture blades on newer designs?


tedd

Recommended Posts

Advertisement (gone after registration)

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

The Thambar-M retained the 20 blades of the original. As a result the bokeh balls are truly spectacular and have 3d pop. 

Edited by LocalHero1953
  • Like 4
Link to post
Share on other sites

44 minutes ago, lct said:

My favorites are the 6 blades of the Elmar-M 50/2.8 so far but i don't hate the 4 ones of the S-A 21/3.4 either.

Thanks for that. A couple of other thoughts spring to mind.

1) If Peter Karbe says we don't have to stop down Leica lenses - why worry about the number of blades we'll never see or use. ;)

2) The most successful and professional of the medium-format film systems - Hasselblad - standardized on five blades in most (if not all) of their lenses. For 60 years. Doesn't seem to have stopped thousands of pros earning millions (if not billions) of dollars with that gear. ;) Often with some of the dreamiest bokeh in the business.

https://www.pebbleplace.com/reviews/medium_format/hasselblad_110mm_planar/index.html

...........

As to the original question, I guess one would have had to be a fly on the wall of Leica lens-engineering meetings 1960-present to know for sure, But I would imagine cost was one reason, and robustness may have been another, along with the ever-present problem for Leica M that the blades have to function in as compact a lens as possible.

One blade doing the job of two is less expensive (and yes, even Leica does have to consider costs), and one wide blade may be less prone to twisting/torquing around its length than two narrower blades.

Another factor may be that Leica has used L-shaped aperture blades for a long time - the blade pivots from the end of one of the legs of the L, and the other leg is what actually cuts off light when stopping down. Which may be because of.....

Also remember that many pre-1960 many-blade lenses had non-linear aperture mechanisms - the aperture ring had to be moved a lot more to stop down one stop from f/2 to f/2.8 than from f/11 to f/16. It was an innovation across all lens makers to make the aperture setting steps evenly spaced, by changing the geometry of the blades and their movement. Because some photographers asked for that, and it would eventually become required for coupled metering systems (at least in SLRs).

For example, the 50mm Summarit f/1.5 had 16 blades, and uneven stop spacing. By 1980 (at least) the successor 50mm Summilux f/1.4 had even spacing, but only 12 blades.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

  • Like 3
Link to post
Share on other sites

1 hour ago, adan said:

Thanks for that. A couple of other thoughts spring to mind.

1) If Peter Karbe says we don't have to stop down Leica lenses - why worry about the number of blades we'll never see or use. ;)

2) The most successful and professional of the medium-format film systems - Hasselblad - standardized on five blades in most (if not all) of their lenses. For 60 years. Doesn't seem to have stopped thousands of pros earning millions (if not billions) of dollars with that gear. ;) Often with some of the dreamiest bokeh in the business.

https://www.pebbleplace.com/reviews/medium_format/hasselblad_110mm_planar/index.html

...........

As to the original question, I guess one would have had to be a fly on the wall of Leica lens-engineering meetings 1960-present to know for sure, But I would imagine cost was one reason, and robustness may have been another, along with the ever-present problem for Leica M that the blades have to function in as compact a lens as possible.

One blade doing the job of two is less expensive (and yes, even Leica does have to consider costs), and one wide blade may be less prone to twisting/torquing around its length than two narrower blades.

Another factor may be that Leica has used L-shaped aperture blades for a long time - the blade pivots from the end of one of the legs of the L, and the other leg is what actually cuts off light when stopping down. Which may be because of.....

Also remember that many pre-1960 many-blade lenses had non-linear aperture mechanisms - the aperture ring had to be moved a lot more to stop down one stop from f/2 to f/2.8 than from f/11 to f/16. It was an innovation across all lens makers to make the aperture setting steps evenly spaced, by changing the geometry of the blades and their movement. Because some photographers asked for that, and it would eventually become required for coupled metering systems (at least in SLRs).

For example, the 50mm Summarit f/1.5 had 16 blades, and uneven stop spacing. By 1980 (at least) the successor 50mm Summilux f/1.4 had even spacing, but only 12 blades.

Hello Andy,

I think that 6 or so diaphragm blades for a Single Lens Reflex camera lens is 1 of the compromises that optical designers make when designing lenses for a camera where the diaphragm is first set by a person or by a camera/lens & then closes for each exposure & then either re-opens on winding the shutter as per a Hasselblad 500C, or re-opens automatically, as in a Leicaflex SL.

Simplicity helping to increase reliability in an already complex mechanical situation.

Best Regards,

Michael

Edited by Michael Geschlecht
Link to post
Share on other sites

12 hours ago, lct said:

...that young people prefer round bokeh balls I suspect......those round things are too boring for me...

I must admit never once having given thought to Boke before I joined this forum; it's not something which I condsider to be remotely important. I have a similar complete disinterest in Sun-Stars. If the impact of a photograph is dependent on the quality of either of those by-products for its success then...well; I'm the wrong target-audience for that snap.

One aspect of aperture blade-count which does have some amount of relevance to me, however, is 'Ghosting-Flare' when the shape of the aperture is recorded / seen in the resultant image. I have my own personal preferences as far as which shapes I do- and don't like. One which I dislike (mildly) is the result of a 5-blade design. By way of illustration I'll attach a snap (taken, with a c.1960 28mm f3.5 Nikkor / Nikon F2, back when the world was still young);

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

I know that a 5-blade aperture will provide, under the correct circumstances, a 10-point sun-star and, for those who give a hoot, 10-point sun-stars are considered to be wondrous things but I find that pentagonal ghosting is rather too distracting and so - in this instance - would have preferred that the lens' aperture diaphragm had an extra blade or three in there...

Philip.

Edited by pippy
  • Like 6
Link to post
Share on other sites

On 6/18/2022 at 6:12 PM, tedd said:

An easy example is the 50mm Summilux. A common complaint with the ASPH version is the 9 aperture blades create a ninja star highlight shape between f2 and f8. The old version, with 12 blades, does not do this. I'm sure there is a very good reason for dropping the extra blades, and obviously bokeh balls are far from everything, but I am interested to know "why." 

I do realise also that 9 blades should be more that enough to create round highlights (the Olympus 45mm f1.8 is a great example of a cheap, 7 bladed lens with lovely OOF), so again, what was Leica prioritising here? 

 

Indeed, “bokeh balls” are far from everything. The Summilux-M 50mm ASPH is THE lens that lured me to add the Leica M system. The excellent results with a human subject, and a smoothly-blurred background, especially vegetation and architectural features,, were what drew me to decide to buy the lens, which was a locally-available, well-preserved, pre-owned sample, before I knew which camera body I would be acquiring. (It was a happy coincidence that the dealer had just received two new M10 cameras, in a time when it was just becoming possible to buy a new M10, without having to first be on a waiting list.)

I certainly noticed the interesting “star” highlights, in that specific aperture range, when I started using my Summilux-M ASPH, but did not let it bother me.

Later, I added a Thambar-M 90mm, which does have plenty of aperture blades, producing one of the most-rounded apertures in the industry, so, I now have “rounded bokeh balls” well-covered, when I need that effect. (I bought this one pre-owned, also. Every Leica-brand lens that I have bought, thus far, has been acquired pre-owned.)

Edited by RexGig0
Link to post
Share on other sites

4 hours ago, pippy said:

I find that pentagonal ghosting is rather too distracting and so - in this instance - would have preferred that the lens' aperture diaphragm had an extra blade or three in there...

Matter of tastes indeed. I prefer hexagons personally (Elmar-M 50/2.8) but the shape of bokeh balls is more interesting a topic than onion rings or lack thereof IMHO.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Edited by lct
  • Like 2
Link to post
Share on other sites

4 hours ago, RexGig0 said:

Using the images, in this linked article, as examples, the bokeh “balls” may be slightly more pleasing, in the pre-ASPH Summilux image, but the Summilux-M ASPH is doing a more-pleasant background blur, as my eyes see it...

One completely unexpected (by me at least) aspect of the test is that of the 'two-stops-down' images the 'best' Boke Balls (IMO) are those of the 50mm Summarit. Didn't see that coming at all.

Philip.

 

  • Like 1
Link to post
Share on other sites

1 hour ago, Huss said:

I find this topic very interesting so I googled it and it brought me back here.  Even though this is where I started.  Weird.

Ah, that's because aperture blades are set out in a ring.

Pete.

  • Like 3
  • Haha 1
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...