Further to my recent mental hand-wringing about diffraction, I decided to try a little self-education. The following video shows a sequence of shots at increasing f-stop of a convenient wall in my garden (I understand walls are in fact necessary for this sort of exercise. Or cats. But they move too much. And I prefer walls).

The camera is the Olympus E-3 firmly bolted to a tripod, lens is the 12-60 set at 33mm.

Even with various levels of compression screwing around with the results, I think it is pretty clear that the image quality starts off ok, improves towards f/8, stays ok-ish until f/11, and then dramatically collapses.  This is, of course, what is supposed to happen, but bearing in mind the old film-era advice of “crank it up to f/22” it is pretty scary.

diffraction test   on Vimeo.

No sharpening done, just standard Aperture conversion of the RAW files.

Finally, I did it. I got around to getting a Canon FD lens adaptor for my Olympus E-P2. Back in Ye Olde Days, I was a Canon FD user, and I had some truly awesome lenses for that system. The 135mm f2.0 was probably the best lens I ever used. A pity I gave it away…  However, I have still got the 50mm f1.2L, and the 20-35mm f3.5L.  And they’ve been sitting on my shelf for years, just a whim away from eBay.

So my Novoflex adaptor arrived today. Yes, I know it’s the most expensive, even outrageously so, but it has a pristine reputation for “just working”, unlike many others. I’m tempted by the shift adaptors, but maybe some other time.

It took a while to coax the 50mm in to life.  It was in a strange state, and I couldn’t get the aperture ring to work, even when mounted on my Canon A1. The 20-35 worked straightaway, but the 50mm was the one I was interested in, and it was stuck either at f1.2 (mounted) or f16 (unmounted). Anyway, I eventually got it working. I seem to recall it was always a bit recalcitrant.

So here’s a photo. Of flowers, of course. At f1.2, of course. And the bit we’re all interested in is the out of focus part.  I think we call this “testing”.

Some flowers. At f1.2.

The photo is straight off the card, into Aperture, and out again. Default settings, nothing added, no sharpening, nothing at all.

I’d say the results are promising 😊