[stevebrot]

Ha ha! I remember some of the 120 film Point and Shoot cameras I used as a kid had a rotating metal disk with round holes of various diameters as the aperture. Indeed I think the same system was used on some Instamatic and later disposable 35mm cameras. The joys of fixed shutter speed cameras.

Or how about the ones where the blades on the leaf shutter doubled as the aperture blades?


Steve

[kaiserz]

That's a reference to an idiomatic expression in English. The latest, greatest fad is often referred to as "the greatest thing since sliced bread."

Thanks, that's exactly what I meant. But not really a "fad" Just as the latest and greatest.

Not sure what you intend with that statement.

Like MPrince said, i'm using that idiomatic expression, to express how much I like the round blades. Sorry for the confusion, and no pun intended.

It all depends on whether you like sliced bread

As for the "round" aperture opening. Here is a general breakdown:

• The greater the number of blades, the rounder the opening
• Large number of blades are sort of incompatible with auto-aperture (lens stops down automatically at exposure time), particularly if high exposure rates are part of the design objective
• Many preset and fully manual aperture lenses have high blade counts and essentially round aperture
• Curved blades help when the blade count is low
• Shorter focal length lenses, especially vintage primes, tend to have lower blade counts. For example, my S-M-C Takumar 28/3.5 and Tamron 28/2.5 both have only 5 straight blades.

Now, to put things in perspective...

• The professional quality lenses for my view camera only have five straight aperture blades
• Even high acclaimed optics may have low blade counts. For example, the 35/2.8 Zuiko on my Olympus XA only has two! (Yes, the aperture is square.)
• Round or regular plane figures are not the only options. Some of my FSU rangefinder lenses have a fun-looking curved pincushion look to them.

Finally...

If you truly want round, SHOOT WIDE OPEN!


Steve

I do like slice bread, cause they're convenient (;

And thanks, I guess I just have to shoot wide open. The sigma 30 1.4 is in my cross-hairs right now. I guess once I get some tax money, that would be possible for me to obtain (:

[Anvh]

Why do you like round blades?
You aren't fooled by the myth that they make better bokeh i hope...

[kaiserz]

Why do you like round blades?
You aren't fooled by the myth that they make better bokeh i hope...

No sir, It's just my clients like them(And I like them too). I think I found a work around though. There's this one software that I found that simulates round aperture bokeh. which might work.

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Last edited by kaiserz; 01-13-2013 at 07:15 AM.

[Anvh]

There's this one software that I found that simulates round aperture bokeh. which might work.

You say no in the first sentance and then you say this...
There is no such thing as round aperture bokeh.


If you want a certain kind of bokeh then you need to look at the opics of the lens, not the aperture.

http://toothwalker.org/optics/bokeh.html

[kent]

Jupiter - 9 might work well with it's 15 blade aperture. I've seen some samples from f/2 to f/16 and bokeh circles were round on every aperture setting.

[Na Horuk]

The sigma 30 1.4 is in my cross-hairs right now.

The one that produces triangular bokeh? Google that thing, just so you wont be surprised

[Anvh]

Technically speaking that isn't bokeh.
As far as i know the light points where the image is created with doesn't actually have a seperate word.
However the highlights are called out-of-focus highlights (OOFHs) and the shape of those are effected by the aperture, the optics and magnification.

[lytrytyr]

The one that produces triangular bokeh? Google that thing, just so you wont be surprised

@Edgar_In_Indy posted a sample here recently (first image):

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/211121-sigma-3...ml#post2235192

[Rondec]

Technically speaking that isn't bokeh.
As far as i know the light points where the image is created with doesn't actually have a seperate word.
However the highlights are called out-of-focus highlights (OOFHs) and the shape of those are effected by the aperture, the optics and magnification.

To me, bokeh refers to the rendering of out of focus areas. This includes highlights, if they are present in the image and yes, the Sigma 30, has a tendency towards octagons. Not the end of the world, but I do prefer circular highlights. All of my current lenses render highlights in a more circular fashion than not. Not necessarily exact circles, but not certainly rounded edges.

[Anvh]

Like you said, "to you" but in all honesty you are simply referening to the out of focus blur and in this case the background out of focus blur.
I know some people call that bokeh as well... but that is because the meaning of the word is missunderstood or not known... or it sounds more interesting that way.
The only thing that trully effect bokeh is the optics of the lens and nothing else, it's about how the light is spread out in the "blurdisks/ image points"

As for the Sigma 30mm
The effect of the triangle shape is caused by vignetting and not by the shape of the aperture.

[kaiserz]

Jupiter - 9 might work well with it's 15 blade aperture. I've seen some samples from f/2 to f/16 and bokeh circles were round on every aperture setting.

I do believe they're too narrow for me though D:

The one that produces triangular bokeh? Google that thing, just so you wont be surprised

Wow, I saw em... I guess I need to shoot that thing wide open then if ever. Or I can get the "bokeh" software from alien something(I forgot the right name of the software but it has alien in it).

To me, bokeh refers to the rendering of out of focus areas. This includes highlights, if they are present in the image and yes, the Sigma 30, has a tendency towards octagons. Not the end of the world, but I do prefer circular highlights. All of my current lenses render highlights in a more circular fashion than not. Not necessarily exact circles, but not certainly rounded edges.

I see. I also prefer the circular highlights. I do hope pentax makes a new wider lens with their patent round aperture thing, that would be really sweet.


Anyway I would like to thank you guys for "genuinely" trying to help me out. I do know that you guys understand what I meant when I said round/circle/tirangle Blur or bokeh/boke in japanese. Thanks for the help guys (:

[Anvh]

Wow, I saw em... I guess I need to shoot that thing wide open then if ever.

Read my comment above yours (the last sentence) and you know that it isnt the aperture causing that...
Actually if you close down the lens it might go away.

Thats what i mean that most dont have a clue when it comes to the background blur and follow the round aperture hype...

[bdery]

ust btw, I suggest you buy lenses based on other criteria, because the shape of the blades isn't really that important. If you compare the 40mm ltd and the 40mm XS, I doubt you could notice a difference in most situations. Or the old and new 100mm macro.

While not all-important, round apertures DO improve the bokeh of an image, all other things being equal. It is not an essential thing, but I wound not dismiss it either.

[Anvh]

While not all-important, round apertures DO improve the bokeh of an image, all other things being equal. It is not an essential thing, but I wound not dismiss it either.

In another thread about this they could not pick which one was the DFA100 and which the DFA100 WR, as long as there aren't any highlights to give away the shape of the aperture you won't spot it.
Only when you've less then 5 you would be able to spot it.