Comment by dofm
8 hours ago
That is from the normal (24mm) camera slightly stopped down (f/1.8), judging by the EXIF.
Odd bokeh was one of the risks of adding a mechanical aperture, and bokeh is very often weirdest at the first or second down from open.
I would hope that the telephoto lens does not show this so severely (because it has a fixed round aperture) but all mobile phone lenses in my experience have had a tendency towards a sort of concentric-ringed, quasi-soap-bubble bokeh; it's a common part of the challenge of really tiny optics (that you either like or dislike). (The iPhone X was really distinctive in this regard). So it's not too surprising to see the aperture do this on top of that.
As a general rule you don't see it in average images, but I guess sensors are now high-enough resolution that it's becoming more obvious, and the blades of a mechanical aperture might make it quite noticeable in some situations.
> Odd bokeh was one of the risks of adding a mechanical aperture, and bokeh is very often weirdest at the first or second down from open.
Why? Where can I read/learn more about this?
This is usually due to the blade shape and quantity I believe. The aperture is most likely to be less circular on the widest apertures after fully open unless you have quite a lot of aperture blades, as the curve to make a rounder aperture is usually applied more towards the tip of the blade, and you're only seeing the base of the blades at wider apertures. That varies a lot by aperture design, however - if you have the more banana-shaped blades where the retaining pin and pivot pin are at opposite ends (like in a Yashica TLR) then I believe they can maintain a more consistent curve along the length. Those also suck massively to reassemble, but that's a different story.
I haven't seen a diagram of how the aperture in this new iPhone is designed yet. There's a lot of different ways to do it, with lots of odd shape possibilities.
> This is usually due to the blade shape and quantity I believe.
Also because of things like angle of incidence?
The purely round lens will generally have nice round (or at least cats-eye) bokeh across the frame with an edge that degrades softly as a result of aberration, so beams of light from different angles tend to blur into each other.
As soon as you get aperture blades, you lose that soft edge, get contrast but also a lot of competing shape influences at different angles. They will tend towards more rounded shapes as you stop down more.
And that is putting aside that some aperture shapes are just really insane when they are nearly wide open, right? (Konica 40mm f/1.8 AR I am looking at you with your shuriken bokeh)
> I haven't seen a diagram of how the aperture in this new iPhone is designed yet. There's a lot of different ways to do it, with lots of odd shape possibilities.
Not a diagram but one closeup photo:
https://petapixel.com/2026/09/19/apple-explains-why-the-ipho...
and an animation:
https://petapixel.com/2026/09/09/iphone-18-pro-has-apples-fa...
Six blades with a slightly rounded hook in them by the look of it. Very noticeable sun stars at f/1.8, nice looking results at f/2.8.
Absolutely insane mechanical challenge and assembly challenge.
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Polygonal aperture openings are not the cause of soap-bubble bokeh, it's the cause of polygonal stopped-down bokeh.
Heavily ringed bokeh just comes from the optics.
> Polygonal aperture openings are not the cause of soap-bubble bokeh
Errr, quite obviously not, indeed. But then I didn't say they were?
I said all phone lenses tend to have soap bubble bokeh as a consequence of their optics. Almost all phone lenses don't have mechanical apertures; they have fixed ring apertures and also tiny aspheric lenses.
(In the industry it's seemingly called "onion ring bokeh" to distinguish from soap bubble, presumably because it has more than one ring.)
However! The first stop down of a mechanical iris has a tendency to have odd effects on the lens's bokeh.
You get an interference of the aperture blades and the wide-open bokeh. With a lens that is prone to ring bokeh, slightly stopping down will smear the edge of the bubble, but in this case it is also clearly boosting contrast as you expect (and an irregular shape at different angles)
> But then I didn't say they were?
Is that a question?
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An aside re: telephoto lens: Duo doesn't have one! It creates the effect of a 2x lens by enlarging the unmagnified image.
Following on for clarity, this is why the Duo lacks a dynamic aperture. Seems they must have been quite squeezed for space.l indeed.
Even on the 18 Pro Max the 8x zoom of the telephoto lens is just the 4x using the same 12 MP crop of the 48 MP sensor to "double" the 4x optical zoom as the last generation. I hope we can get some level of optical zoom on a future Duo.
Soap bubble bokeh comes from overcorrected SA. Onion rings and related brightness anomalies/unevenness in bokeh are mostly the result of molded aspheric lenses. Stopping slightly down has not significantly impacted bokeh (apart from apodized lenses) since rounded aperture blades have been invented about fifty years ago.
The iPhone 18 aperture does not have rounded blades (except the tip). Six hooked blades, very truncated hexagon aperture (perhaps exactly a regular dodecagon, it’s a little difficult to tell from the promo images)