What happened to the old style aperture blades?

[Arcturus]

I like using vintage medium format folders (1930's-40's), and I notice that they use many more aperture blades than cameras that came after it. There are so many that the opening always stays round, or very close to round at all stops. Average modern lenses usually have the standard 5 straight blades, and premium lenses can have 6 or so. I see the same 5 blades in my 1970's TLR's and rangefinders. So why did lens makers stop using the old style aperture blades in favor of simpler ones if they make those out of focus pentagons that many people find objectionable?

I found a picture on Flickr that shows the type of aaperture blades I'm talking about.
http://www.flickr.com/photos/nesster/4356261367/in/pool-camerapedia

 

[Jeff L]

Best guess would be $$$
...and maybe speed requirements of auto apertures.

 

[artobest]

Interesting subject. Yet, in my opinion, bokeh, being an unquantifiable characteristic, is very fashion-led. My Zeiss/Rollei lenses have five blades and produce noticeable pentagon-shaped specular highlights, miles from the 'creamy' softness we are all supposed to aspire to, but to me, this out-of-focus rendering is highly picturesque and often rather beautiful.

 

[thegman]

Interesting subject. Yet, in my opinion, bokeh, being an unquantifiable characteristic, is very fashion-led. My Zeiss/Rollei lenses have five blades and produce noticeable pentagon-shaped specular highlights, miles from the 'creamy' softness we are all supposed to aspire to, but to me, this out-of-focus rendering is highly picturesque and often rather beautiful.

Indeed, I'm not into shallow-DOF at all, I'd rather most of my photos had front to back sharpness. But all things considered, I'd rather a more natural rendition of OOF areas. It is of course a fashion thing though, and the current craze for Noctilux-style, shoot everything at f/0.95 will likely go away soon enough.

 

[jp498]

I'd have to guess the smooth/creamy aesthetic must have went out of style for a while in post modern photography. If you were 100% in focus groupf64 style shooting, it doesn't matter, just like iris shape isn't important in the enlarger because ever piece of silver is in focus. Shutter choices are a big part of this. Old pre-war compound shutter have more blades than copal for example. Copal 3's have more blades than copal-1's but I'd guess that's a because it's a bigger opening, not just because they can.

In LF many of the barrel lenses (no shutter) have lots of nice curved blades. I like these and use them with the focal plane shutter of the speed graphic. Quite a few options for old lenses and aperture styles in LF.

 

[Matthew Wagg]

The only lenses I have that have lots of apeture blades is my Pentacon 4/200 which has loads, its circular at all apetures, unfortunately it doesn't focus close and its focal length is of limited use to me. I'd love a 50 and 85mm with as many blades.

 

[BetterSense]

Quality standards.

Lens manufacturers realized that they could get away with going cheap, so they did. The least-common-denominator mechanism at work.

 

[tony lockerbie]

The optical design also has a lot to do with the quality of the oof areas, not just the aperture blades, although they can help a lot. I personally like using shallow dof for certain photographs, gives a more pleasing 3D effect, so the quality of the oof areas are very important (notice that I haven't used the "B" word yet)
I suspect like others have stated, that the dollars have caused the modern trend towards minimal blades, but also the auto diaphragm function must require less moving parts. It is pleasing to see that some manufacturers are coming back to designing lenses that have a more pictorial quality rather than clinical sharpness (Cosina/Voigtlander are a good example)
From an aesthetic point of view, those old multi bladed apertures are a thing of beauty.

 

[rawhead]

I'm with Tony; my best guess & understanding is that the 20-blade diaphragms of late would be an extreme pain in the ass, if not outright impossible to implement in modern auto-focus / auto-aperture lenses. With the advancement of technology, remember, so has increased things like FPS; when you have a camera *body* (and shutter mechanism) that touts 12 frames a second, during which the aperture blades need to open up and stop down 12 times per minute as well, there is huge demand being placed on the rigoursness of the blade.

This explains why even high-end (e.g., Canon L) lenses tend to be very limited in terms of the number of blades (e.g., 5). If cost was the number one reason, then we would expect that the high-end, premium line of lenses to have more blades.

 

[Arcturus]

I can see how auto exposure and rapid fps would be a problem with so many aperture blades, but even more recent manual aperture lenses have only five or six. Maybe it's both the cost and/or auto exposure, depending on the camera. The out of focus area isn't important to me since I mostly do stopped down zone focusing, but it seemed strange in this bokeh obsessed day and age.

 

[rawhead]

Of course, cost is also a factor. But, unlike AF lenses, fully manual (incl. manual stop-down) lenses where cost is not an issue, you still can find plenty of blades. Case in point, my Hartblei/Carl Zeiss Superrotator 80mm f2.8 with tis 12-bladed aperture.

 

[David A. Goldfarb]

The main reason is the auto-aperture function, where you can meter and focus wide open, and then stop down to the shooting aperture automatically as the mirror flips up, before the shutter opens. Starting with some late Graflex reflex cameras, auto-aperture is a relatively modern phenomenon, and it's hard to make it work with 20 aperture blades, without adding an uncomfortable amount of shutter lag. My Zeiss 85/1.4 ZE has 9 blades, which is about as many as you'll find in a small SLR lens with auto-aperture function.

 

[BetterSense]

I have a copal automatic shutter for a copy camera that has 5 blades. It doesn't get much less automatic than that.

My XA cameras have only 2 blades. I have seen single use cameras with only 1 moving aperture blade with a tapered slot in it.

 

[David A. Goldfarb]

You can have a small number of blades in a manual aperture shutter, but a large number of blades in an auto-aperture shutter isn't so easy.

 

[elekm]

I do notice that rangefinder camera lenses tend to have more aperture blades, while SLR lenses tend to have fewer. And from a mechanical and physics point of view, it does make sense that it would be complicated to move 11 or more interlocking pieces of paper-thin metal in a fraction of a second.

 

[StoneNYC]

Have you looked at the angle of the rounded more than 6 blade apertures? The curve and angle can introduce more sticking and error and shutter failure that need repair more often, I think it has to do with the mechanism and how long it will last without repair than anything, it doesn't cost them THAT much more for 8 blades then 5, it's that you introduce more components that need to be smaller to function and could easily break more often. I don't think it had anything to do with the aesthetic.


~Stone

Mamiya: 7 II, RZ67 Pro II / Canon: 1V, AE-1, 5DmkII / Kodak: No 1 Pocket Autographic, No 1A Pocket Autographic | Sent w/ iPhone using Tapatalk

 

[mopar_guy]

Ilex Paragon 6-1/2inch lens in a No. 3 Acme Synchro shutter has ten aperture blades, and my Olympus OM 100mm f2 Zuiko has nine aperture blades and it is an automatic aperture. Not so much difference. Cheap lenses have fewer aperture blades.

 

[mopar_guy]

Oh and my Mamiya RB67 Pro SD K/L 127mm L lens has eight blades.

 

[dehk]

Less blades are also easier for auto reflex lenses.

 

[bsdunek]

My Olympus XA only has two aperture blades with V-shaped ends so it has a square aperture. Works fine but does make little squares for boka.

 

[StoneNYC]

My Olympus XA only has two aperture blades with V-shaped ends so it has a square aperture. Works fine but does make little squares for boka.

I might like the square on lights look


~Stone

Mamiya: 7 II, RZ67 Pro II / Canon: 1V, AE-1, 5DmkII / Kodak: No 1 Pocket Autographic, No 1A Pocket Autographic | Sent w/ iPhone using Tapatalk

 

[Jim Jones]

. . . Cheap lenses have fewer aperture blades.

My Leitz Super-Angulon f/3.5 21mm in M-mount wasn't cheap, but has only four blades. Those four blades do have to stop down to a very small opening at f/22. In comparison, the many blades of old large format lenses had an opening of several mm at their minimum aperture. These were easier to make and less delicate than that tiny Leitz iris.

 

[georg16nik]

My Leitz Super-Angulon f/3.5 21mm in M-mount wasn't cheap, but has only four blades. Those four blades do have to stop down to a very small opening at f/22. In comparison, the many blades of old large format lenses had an opening of several mm at their minimum aperture. These were easier to make and less delicate than that tiny Leitz iris.

Jim,
Leitz Super-Angulon f/3.5 21mm was made by Schneider.

 

[Dan Daniel]

I have a Roleiflex 2.8C, the last Rolleiflex model with 10 aperture baldes. Last year of manufacture was 1954, I believe. After this, the Synchro-Compur shutter units that Rollei used came with 5 blades.

Minolta Autocord shutters seem to have gone from 10 to 8 blades around 1956? Not certain when the Seikosha MX shutter was replaced by the Citizen. After using a couple of Autocords with 10 blades, I sold the first one with a Citizen shutter within a month- couldn't stand the different look of the 8-bladed aperture compared to the 10-bladed.

Yashica- Copal- had 10 blades into the early '60s it seems before going to 5 blades.

Anyone know when Hasselblad came out with the first leaf-shutter model? This would give some credence to the auto-aperture thing as the lenses needed to stop down quickly. Any other camera making such demands on apertures around 1954-5?

 

[Slixtiesix]

I think the Hasselblad 500c was introduced in 1957. The older lenses for 1000F/1600F indeed had round apertures with many blades. In fact the five blades is the Thing I dislike most about Hasselblad and Rollei lenses from the 2nd half of the century, though Hasselblad had round apertures at least in the 110/2 and 150/2,8.