Why don't I ever see a slow, light prime?

[CraigDouglas]

I'd love canon (or anything compatible with 5D) to make something like a 24mm F5.6 or F8 that wouldn't need so much glass but would be great as a lightweight landscape lens to lug up hills. Get rid of autofocus and any IS stuff, just a 24mm lens that's optimum aperture is something like F11 or F16. Obviously it would need to be something like a 5.6 or 8 so you can actually see through the viewfinder to frame and focus but I'd never use it that wide.

If there is something like this available that I'm missing, please let me know, otherwise why don't they make something like this? Too niche?

 

[StewartR]

I think what you're describing is too niche.

Plus I'm not sure that having an optimal aperture of f/11 or f/16 is a good idea these days, since the high pixel counts of some DSLRs mean that diffraction starts to affect image quality at f/8 or even wider.

Anyway, why not just get an old MF lens with a Nikon F / Pentax K / Olympus OM / Leica R / Contax / Yashica / M42 mount and an adapter? One of the virtues of the Canon EF mount is that it has a smaller registration dstance than virtually any other mount, so you can mount just about anything on it if you have an adapter. (Other than a Canon FD lens, ironically!)

 

[Deckard]

Ditto, get an old MF lens. I bought an old Vivitar 28mm f/2.8 for a similar purpose of widish angle, lowish natural light shots for a pittance. Sadly 28mm isn't very wide on a crop sensor body so not the greatest for really expansive landscapes.

 

[tbm]

Tbh this sounds like a bit of a pointless exercise, and certainly one that's too niche for any of the mainstream manufacturers to consider.

The 24mm lenses that are currently available in EF mount are already pretty light (24/2.8 is 270g) and the 5D weighs 810g plus battery, giving a total of say 1200g. Even if the mass of the lens was halved, you'd still only be saving around 10% of the total..

If you're stopping down significantly, the difference in optical quality between the 24/2.8 and 24/1.4 is probably negligible too, so save yourself some more weight on camera whilst retaining some in your pocket

 

[maarten.dhaese]

The Canon EF 24 f/2.8 is pretty sharp even wide open on a 5D.

Corners are sharp too which is not something you get from all Canon wide angles.