Anyone else excited about the 40mm pancake?

[Sean Setters]

It has a 7-blade aperture, don't know if it's rounded, but it probably will give you much better bokeh than the 50mm f1.8.

From DPReview: "Precision control over the circular, seven-blade aperture is enabled by the EMD, producing a beautiful bokeh effect and an aspheric lens with Super spectra coatings ensures optimal image quality from the centre of the lens to the periphery for stunning shots of practically any subject."

To me, that sounds like it's rounded--not 100% sure though.

[Sheiky]

Yep, that definitely sounds like it. Any idea what that EMD(Electro Magnetic Diaphragm) is by the way? I couldn't figure out precisely how that is different than normal.

[neuroanatomist]

Yes, the aperture blades are rounded. The EMD supposedly allows more precise control over the aperture setting.

Initially, I felt this lens was rather blah. But having this lens on a gripped body or 1D X will basically be like having no lens at all - it will barely stick out beyond the bulge of the pentaprism and portrait grip. That means the camera body - with a lens for taking pictures - can fit in a small case like my Lowepro Utility Bag 100 AW, and I can take that in my computer satchel on overnight trips, etc.

So, if the IQ is decent (will wait for ISO 12233 comparisons on that front), for a mere $200 it's interesting. Sure, f/2 would be nicer, but coupled with the ISO capabilities of the 1D X / 5DIII, f/2.8 should do fine.

[Agilulfo]

Any idea what that EMD(Electro Magnetic Diaphragm) is by the way? I couldn't figure out precisely how that is different than normal.

I don't know how it works in a lens. In other devices, such a fuel injector, a coil which produce a magnetic field capable to move a small part. Maybe in this lens an electromagnet is uses instead a gear.

Speaking about blades an non-understanding, I've never understand why the number of blades are so important to bokeh. If you want the less DOF, you must select the widest aperture. And almost all the lenses that I've seen has a perfect circle when they are wide open because blades are completely retracted.

[DavidEccleston]

Because sometimes you care about the quality of the blur when not completely wide open.

[Agilulfo]

Because sometimes you care about the quality of the blur when not completely wide open.

So, you want a large DOF, close the diaphragm, and also you are worried about the shape of the not so blurred circles. Surely there must be situations like this but I don't know if they are common enough to justify all this concern about the number of blades.

[dsiegel5151]

So, you want a large DOF, close the diaphragm, and also you are worried about the shape of the not so blurred circles. Surely there must be situations like this but I don't know if they are common enough to justify all this concern about the number of blades.

Here's a pretty easy explanation: When taking a portrait you often want your subject to be in compete focus. Thus, you would calculate the depth of field required to keep your object in focus. When doing this, you rarely will calculate a wide-open aperture. Everything outside of your subject will be blurred, or partially blurred, depending on focal length and fstop. Any type of light or reflective surface will produce nice little bokeh balls if out of focus enough. With a crappier lens you will get stop signs or petagons instead of nice little bokeh balls.

Below is an example. Notice how the dog's face is not completely in focus? I shot this wide open with the 50 f1.4. If I took more time and had a dog that would sit still longer I would have probably shot this at f2.8 or above to try to get the dogs whole face in focus (notice that the nose and ears are blurred a little). The lights in the background would still be far enough away to be out of focus. With the 50 f1.4 these lights would have been stops signs at f2.8, and not as pleasing. Thus, I would have had to make the decision...face in focus or pleasing out of focus highlights. With more advanced aperture blades I wouldn't have to make this decision.

[Dave Throgmartin]

I really like that pic dsiegel.

Dave

[Agilulfo]

Great shot dsiegel5151. And it is a perfect example of what I'm trying to say: in a picture like this, shot wide open often produce better results.

Yes, the nose and most of the hair are out of focus. But for this reason you had centered the attention in the sight of the dog. With a large deep of field, you would have captured more details of the head but -firstly- in a portrait like this I don't think those details are needed. On the contrary, you would have loosed the softness of the hair.

And secondly, no matter the number of blades, the light spots in the background would be more focused. I don't think focus is needed in this area. It's hard to say without comparison, but I think you had chosen the best aperture in this case.

[Dr Croubie]

I'm having thoughts...

Thoughts along the lines of:
EOS 3 + 40mm Pancake + iso400 B+W film (Tmax or Ilford) = Street Shooting Fun