Joe I don't know if you have worked with Peleng 8mm fisheye or not but I own one and can certify its crispy sharp quality fully. As I mentioned the main problem with Peleng is the internal reflections when pointed to a sourse of light. Of course if you don't like the rough typical russian make or the manufacturere, that is a different issue. But at that price, Peleng is a bang for buck and I am yet to see one unhappy owner of this lens.

I fully agree with Purpulbyron that after seeing Pinkness works, sharpness is not a really needed element especially in low light conditions where even added noise in pp can add as it is quite naturally expected.

I gave a full spectrum of options with merits and sacrifications of each that hopefully if read, will give an idea as to which direction one wants to go.

I take your points on board Sassan, and it is a very dedicated thing to offer the excellent information of options available, but I haven't made any assumptions that sharpness is not needed, particularly as it was requested, even after I looked through the excellent website of pinkness. Surely the website is of pictures taken, not of pictures wanted to be taken?
In low light conditions the Peleng 8mm, or even Peleng 12mm and Zenitar 16mm lenses aren't sharp if what you're use to is a 10-20mm Sigma, Canon or Nikon equivalents. Great lenses to try tho ;)

If I could just add. I tried out a work colleagues 8mm Peleng (I even owned a 16mm Zenitar for a while too)....I think I must not been lucky with the lenses. ;(
Something to point out to others is that the quality control with these lenses perhaps isn't the same as the big manufacturers...You got a good one Sassan! ;)

I use a 17-40 f4 with my 350D and 30D (both 1.6 x crop's so 27-64mm) and it is a cracking lens, pin sharp with great colour's and contrast. I have three 'L' lenses but this one is the sharpest. Would be a wide angle on the 5D I guess.

I use the 15-30 on a full frame... considering the demands from the sensor, it's a terrific lens. It has been put up in tests against some serious expensive competition and held it's own (surpassing some in certain areas).
Its AF is noisy...but that's not a serious issue with an UW lens. Biggest drawback is the inability to use filters on the front of it.

There's some distortion around the edges at 15mm but it is a very sharp lens. Bargain at £250

The 17-40 L has a varied reputation on the web... some love it, some think it's one of the poorest L's. The 16-35 L is the one to aspire to.

And thats what i have done, i have ordered the Canon 16 - 35mm mark 11, it has some great reviews. a little expensive but i think its the next best step.

Thanks eveyone for your advice, ill be posting some examples soon of pics on my new 16 - 35mm

www.h-pinkness.com