Pentax-M 40mm f2.8 Pancake - Sample Pictures

My first SLR was a Pentax Program Plus with the Pentax-A 50mm f1.7, and that camera was with me for more than a decade. It captured some of my life's most memorable moments and will always occupy a small niche in my heart, though I don't shoot Pentax any more. Still, I hold on to a few Pentax lenses, and the 40mm f2.8 pancake is one of them.

The lens is about the same size as the Canon 40mm f2.8 STM and I am sure they share a similar optical formula of the Tessar variant. Mounting it on the 5D Mark II looks kind of funny, but it looks perfect on smaller cameras like the Pentax MV, MX, etc. I really have no complains about its optical performance. Stopped down a bit, the lens is sharp from corner to corner, on full frame. Even the bokeh is quite nice. It's a little hard to focus with the very thin focusing ring, but it's a pancake lens, after all. One thing bothers me, is that like so many manual focus lenses, this one hits the 5D II's mirror, even at minimum focus distance.  I was forced to use the live-view, in very strong sunlight, but it was nearly useless.

If you are a Canon shooter, I would recommend the EF 40mm f2.8 STM. It's sharper than the Pentax, for not much more, for a new one, and it auto focuses, and does not hit the mirror.

All pictures below taken with the Pentax-M 40mm f2.8 Pancake, and the Canon 5D Mark II.

Canon 40mm f2.8 STM Pancake Lens

In case you haven't heard, Canon is selling pancakes, the tiny 40mm f2.8 pancake lens, that is. This is the first time in Canon's lens making history that they introduced an interchangeable pancake lens. They did designed and made some pancake lenses used on point & shoot film cameras before but not on SLRs. So what's the big deal? It's tiny, of course. More than that, it's cheap, and most importantly, it's optically excellent. The picture below shoes how small the lens is, compared to its big brother, the Canon 50mm f1.2L.

The little brother - Canon 50mm f1.2L vs 40mm f2.8

Size is relative, of couse. When compared to other pancake lenses, the Canon is not the smallest. Let's not compare it to the wafer thin auto focus Pentax 40mm f2.8 SX, it's even larger than the older Pentax-M 40mm f2.8 and the Contax Carl Zeiss 45mm f2.8 Tessar, as you can see below. When mounted on my 5D II or 1D III, it looks kind of funny, but on the small Canon 100D, the combo will look incredibly small and compact.

The three Amigos: Pentax-M 40mm f2.8, Canon 40mm f2.8 and Contax 45mm f2.8

If you haven't read Roger Sicala's test on the Canon 40mm f2.8, please do read it. Roger is a great writer and his blog is always worth your time to read. I haven't used this lens much, but for those pictures I have taken, it's a great little lens and I like it a lot. If memory serves me correctly, the Canon 40mm f2.8 is sharper than both the Contax and Pentax pancakes, especially at the corners. It doesn't focus as fast as a USM lens, and is noisier too. I don't see how this lens, which was made for video using Stepper Motor (STM), the focusing noise will surely be recorded.

Should you buy one? Yes. Sometimes when it's on sale, it goes as low as $150, not much more than the Plastic Fantastic EF 50mm f1.8, but a much better build lens, and optically better. You won't be disappointed.

Bicycle - Canon 5D Mark II & 40mm f2.8 STM @ f2.8

An Intermission

Honda Motocycle -- NEX-5 & Pentax-M 40mm f2.8 Pancake.

I was planning to do a comparison  between the Canon FD 55mm f1.2 SSC and the Minolta MC Rokkor 55mm f1.2 today, but I was not able to get out during lunch.  Hopefully tomorrow will be better in terms of timing, so that I can shoot some pictures with the two lenses.  I really want to get some low light shots since these are very fast lenses and I am sure many would like to see them perform side by side in this regard.  But, we have a long holiday weekend this week in Canada, and I plan to take it easy so the lens battle will have to continue next week.

Yummy Pancakes: Carl Zeiss Tessar 45mm f2.8 vs Pentax 40mm f2.8

Today we see two pancakes compared: Contax Carl Zeiss 45mm f2.8 Tessar, and the Pentax 40mm f2.8.  Both lenses are really small thin lenses with similar optical design.  The Zeiss is 5mm longer than the Pentax, which turns out to be perfect, as I don't have to take know of which lens took which picutre.  The Pentax pictures are always wider when taken from the same spot.

All pictures were taken with RAW + JPEG, and all the pictures you see here are jpeg straight out of the camera, without any further processing, just to make sure they are processed identically in-camera.  The Sony jpeg engine is absolutely horrible.

Size comparision: Left - Carl Zeiss Planar 50mm f1.4; middle - Zeiss 45mm f2.8; right - Pentax 40mm f2.8.

So, which one wins?

Both are winners.  The Pentax is a hair sharper than the Zeiss wide open in the center, but the Zeiss seems to have a nicer bokeh, and a tiny bit better at the corners.

Pentax 40mm f2.8 @ f2.8

Carl Zeiss 45mm f2.8 @ f2.8

If you care about edge sharpness, you won't be disappointed with either lens.  It would be like splitting hair to tell the difference, although I would say the Zeiss is ever so slightly better.  It's amazingly good on the far corners wide open, one of the traits of a Tessar design.

Far corner 100% crop -- Pentax wide open @ f2.8

Far corner 100% crop -- Carl Zeiss wide open @ f2.8

I think both lenses cost about the same, but I am still a bit surprised how good the little Pentax pancake is.  Both are worth owning.

bokeh -- Carl Zeiss 45mm f2.8 @ f2.8

bokeh -- Pentax 40mm f2.8 @ f2.8

Note that I didn't post any pictures with apertures smaller than f2.8.  Stopping down the lens improved the sharpness a little, but not as much as you would expect.  Both are very sharp from wide open.  The only draw back is the rather smaller maximum aperture of f2.8.  But hey, you want small size, you have to pay for that with less light coming through the lens.

Big Tree in Moss Park

Big Tree - Panasonic GF1 & Pentax-M 40mm f2.8 Pancake.

The weather has been nice and warm this year and consequently, the trees change colour gradually without turning brown from cold weather.  It's just beautiful everywhere you look, even in the city.  Autumn has always been my favourite season.  Too bad usually by November, snow will come and you can feel winter even before it's officially here.  Winter is too long in Toronto.