Originally posted by RioRico I guess I'm too late to influence you. I was going to ask: What do you plan to DO with what you shoot? Make prints or slideshows, or gaze at them on your computer screen, or what? I ask because with many types of presentation, minute differences in IQ just aren't noticeable. So quibbling over corner sharpness can be irrelevant. The main decision factors IMHO would be:
* Budget! How much do you want to spend to be happy?
* Comfort. How much do size and weight matter to you?
* Usability. Will the lens take you where you want to go?
I have a few wide lenses. The Zenitar 16/2.8 is faster than other fisheye zooms or UWA primes and defishes nicely to about 12mm equivalent -- but that wasn't wide enough for me, and I don't like defishing in many applications. The DA10-17 is very fishy wide, similar to the Zen but slower long, and like any FE is too specialized for general use. The Tamron 10-24 was my choice over either version of the Sigma 10-20 (of which I've heard much angst as well as love) or the much costlier DA12-24.
My copy of the Tamron is good optically, and gives me much more flexibility than a 15mm prime -- it's perfect for small spaces, inside and out, and is good for 'scapes at the long end. (My main 'scape lenses are all manual primes in the 21-24-28 range.) My absolute minimal kit would be the FA50/1.4 for low light and fast action, the Komine 28/2 CFWA for 'normal' seeing, the Tamron 10-24 for tight spaces, and the DA18-250 for everything else -- with the Raynox DCR-250 for getting close.
But you've made and acted on your decision. Great! Maybe you'll fall totally in love with the 15. And maybe you'll find later that a 10-20 or 10-24 or 12-24 is something that you need also. It could happen, eh?
I saw you had replied and I had a moment of anxiety! Oh no, RioRico is going to make me regret my decision!!!
You didn't!
I know you are a Tamron 10-24 fan. I have considered it as well, and now that the zoom is off the table for a while (presuming I keep the 15), I may consider it again in the future. Oh, it wouldn't surprise me a bit if I eventually end up with both the 15 and one of the wide zooms.
I enjoy my Samyang 8mm fisheye a lot, but I really wanted something less extreme. It's nice to have when you are in a really tight spot, though!
To answer your question, I mainly gaze at my photos on my computer screen. lol A few get printed out. I may share some with family from time to time, and I like to share with friends online if I get a good shot.
Since the cost was fairly close, I decided at this time to go with the smaller, lighter, easier to handle lens. I admit the draw of my first limited and the near legendary status of them was hard to resist.