Originally posted by Phaser i'm asking because i have the da 40mm 2.8 and i find it a bit on the narrow side and a bit too slow for indoor photo without flash. I like the 18mm end of the kit lens but it's very slow and not that good.
The FA* 24/2 looks nice but it's pricy.
Which lense would serve me my needs the best?
Looking att the prices I guess it is harder to make a fast wide angel than a fast normal lens (since there are that many "cheap" 50mm) allso when you increase the focal range the faster lenses are becomming more expensive. So is it that much easyer/cheaper to make a fast 50mm? and why?
or is the marked demands just not big enough for cheap fast wide lenses?
If you like the wide end of your DA18-55mm and the FA24 is too pricey for you then I'd recommend the Sigma 24mm f/1.8 or the Sigma 20mm f/1.8 as a wider alternative to the DA40.
The Sigma 24mm isn't as soft and doesn't suffer from as much distortion as the 20mm does ... but the 20mm is closer to the 18mm end of your kit lens.
Basically, I'd probably suggest getting the Sigma 20 and learning to either live with the softness/distortion or learn to post process your images.
There are sharper wide angle lenses with less distortion ... but they are either more expensive and/or slower than f/2.8.
As for why it's cheaper to make a fast "normal" lens than a fast "wide" lens ... the wider you get the harder it is to control distortion. Also, the wider you get, the larger the glass needs to be to give you a fast aperture. Take a look at the front element on the Canon 15mm f/2.8 fisheye and compare it to the front element on the DA 21mm f/3.2