Pentax DA 21mm/3.2 AL ltd - a pancake lens

I don't remember if I have talked about this lens before on this blog. I am too lazy to go back and check.

Pentax has a line of what they call "limited" lenses that are, well, limited. I suppose they mean that in terms of the volume of production, and the material used to make them, and that kind of thing.

I have always been a sucker for the limited edition bull crap. As soon as they slap that label on, it makes want to buy them. All of them. Silly me, because I did buy all of them.

This is what they have in their limited line up. For whatever reasons, only 21, 40, and 70 are considered pancake lenses. Well I suppose the rest of of the line up is not exactly thin.

So that you know, all of these limited lenses are APS-C sensor specific, so in theory, they are not compatible with FF, but 40 and 70 do OK I hear.

15mm/4

21mm/3.2

35mm/2.8 macro

40mm/2.8

70mm/2.0

As you can see on the picture, this is a very thin lens, and therefore the nickname "pancake."

While I know virtually nothing about optics, it is not that hard to see the pros and cons of such a design. By the way, other companies have tried this too. Nikon, Olympus to name a few. Olympus still have a few "pancake" lenses on their line up, but Nikon no longer.

One of the most obvious advantages is size. The thing is tiny. Easy to carry around. even easier to drop perhaps. I would think that because of its thinness, they would have to limit the number of elements. Sharpness might be easier to obtain, relatively speaking, that is. But, on the other hand, because of its small size, fast aperture is probably difficult to achieve.

I do think that Pentax has hit the sweet spot. There is a good balance with this lens. The focal length of 21 (roughly 35mm on 135mm (FF) format) is such that it probably resembles how our brain process what we take in from our eyes. So, if you want to take photos in the framework much in the way you see it with your own eyes, this one is it. A walk around lens is what this is. Travel photo would immediately come to mind here. For that kind of photography, small size is an advantage, and maximum aperture of 3.2 is not dark enough to be a disadvantage.

Barrel distortion is very noticeable with this lens. Some people hate that. I on the other hand like it. Those who hate it would dare using it for portraiture. I on the other hand use it excessively. Taking pictures from the airplane window would be perfect, although I have not done it . . . . .

2nd picture

Pentax K10D

DA 21/3.2ltd

1/250 @ f/5.6

0 ev

ISO 100

RAW