ok so all the advice points towards getting the fastest lenses as possible, f1.2 etc however for the less financially secure (ahem) I would like to know the limitations of getting lenses in the 2.8 range instead, does it just mean i will have to compensate my lights for an extra stop or two? I ask because I am about to buy a Letus elite and want to get a 50mm, 28mm and 135mm and really want to know if its just a couple stops of light il be losing or do the actual optics suffer/have less quality etc? Thanks

PS im thinking about getting Nikon primes on an EX1 but my main concern is getting the best bang for buck (or pound in my case), so also if anyone has any pointers towards cheaper alternative lenses that are still optically stunning please chime in.

Thanks guys

Daniel,
Check out the tests at Welcome to Photozone! (http://www.photozone.de) or other testing sites. But I found photozone to have the best quality tests (MTF lab). You get centre and border resolution in about 3 focal length settings per lens, distortion, vignetting, the works! Also check out review sites with feedback from pro photographers. The more good reports you find, the safer your bet for a certain lens will be. I took advice from photo zone before I bought, and I don't regret it.
Cheers, Gerd

Thank you, Im off to follow the link :)

This is the website I used to learn the in's and out's of used Nikon lenses.

Nikon Nikkor Lenses (http://www.kenrockwell.com/nikon/nikkor.htm)

(I need to remember to send Ken a donation for creating such a helpful site)