Originally posted by Sandy Hancock Even one top notch wide prime would be a great start. 24mm would seem the logical focal length. Add well-behaved optics for landscape and astrophotography (good edges, low coma and flare resistance) and a maximum aperture of f/1.8 (a compromise between speed and compactness) and it could be a winner.
I have had the DFA15-30 for a week now, and it is proving to be a very fine lens. It is however very big and heavy, and it cost a bomb. The difficulty with filters is also an issue - the front-mounted slot-loading filter kits have just landed at my local B&M, but even they don't know what the retail price will be yet!
I have excellent primes at 20, 24, 28 and 31, and the "long" end of the DA10-17 (de-fished in Lightroom) will suffice if I really need to go wider. If I shot architecture for a living I would keep the 15-30, but given my needs I think I will return it.
I am seriously considering the Irix 15mm when it comes out, although I am waiting to see what sorts of results folks get with it. My experience with the DA 15 versus the DA *16-50 tells me that the bigger and faster the glass, the more prone to flare it will be and the fact that the 15-30 is so big and doesn't allow for easy use of filters makes it lower on the list and that's what concerns me about the Irix -- at f2.4 and with who knows what coatings, it is hard to tell if it will be the sort of lens I am looking for.
For landscape photography, which is my thing, I really don't need a super fast lens. A prime somewhere between 15 and 20mm and f4 would be perfect, assuming that it was decently sharp wide open. Combine that with pixel shift and you would have the ability to capture medium format level images.
Anyway, I do understand where biz-engineer is coming from. I tend to have a little more patience. I have waited a long time for full frame and if necessary, I can fill in with a Samyang lens or two if necessary until Pentax gets their primes in order, but I'm hopeful that this is the sort of niche that they look at filling relatively quickly.