Originally posted by Cerebum OK, anyone's head exploded yet? No? OK good, let me explain. I have the 70, 40, 35 & 21mm limiteds. I feel the 40 & 35mm cover the same ground and I have the same feeling about the 21mm and the 15mm. As the 15mm is the dearest of the limited primes I haven't been tempted but one has slipped into my price window and is so tempting. The trouble is I don't want to spend £250 on a lens I will rarely use, so, what does it do that the 21mm doesn't? Why is it so popular and why does it hold its value? And, what do you use it for?
I used to have the 3 lenses, 10-17, 15, and 21 at the same time. IMHO the Field of View of the 21 and 15 are not close. I used to think they are close enough to skip one of them, but when I own both, I can see the differences after spent enough time with them.
Rendering:
I like the rendering of 15 over 10-17. I mainly take night photos in the city. So I really love the starburst of the green ring 15. The first time I saw the starburst effect from 10-17, I was like, this is ...
... criminally ugly! Even without a starburst in the image, 15 and 21 still look better than 10-17 day or night for me. Like any Pentax Limited lense. It has its own imperfection but instead of degrading the image quality, the imperfection of the limited seem to make the image look more alive. You have a lot of DA limited, I am sure you know what I mean.
Field of View:
15 is not wide enough after I see what 10-17 can do. On the other hand, I can stitch 2 - 3 images of 21 if I really want the rendering similar to 15. And switches to 10-17 when I want wide to the extreme and de-fish it if I have to. I later sold the 15 because it stays home for almost a year. I still miss the rendering of 15 but it is just not wide enough for me. And the prime cannot do zoom burst. That is another reason I let it go.