Tuesday, June 28, 2011

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.


  1. I think the colour seems richer on the Pentax, it's the winner for me by a hair.

    I'm loving Lens Battle week!

  2. Ever used a Konica Hexanon AR 40mm f1.8? Pretty close in size to these guys.

    1. I definitely do not like the Konica Hexanon AR 40mm f1.8, unless stopped down significantly. The bokeh is nervous. Likewise for the 50mm f1.7. I did own two Konica Hexanon 50mm f1.4. Both were significantly sharper, and with much nicer bokeh -- I prefer them to my old Nikon 50mm f1.4, and also to photos I've seen of the similar Canon.

  3. I had a Konica 40/1.8 and it's quite a bit thicker than these two, and not as sharp wide open either, at least with my copy.

  4. This one is void. You couldn't get the flying insect in the Ziess pic so all bets are off, LOL.
    Seriously, great work. I am probably going with the Ziess... just because it is Zeiss. As to Sound Gallery's point Pentax is a little richer it seems but nothing one contrast or saturation bump won't do in post. Here's a related post from me.


  5. Thank you for the comparison. These two Pancakes are used as relay optics in microscopy in front of projection eyepieces. The Tessar is usually a bit better at the edges but costs a lot more than the Pentax.