I can't comment on the 35 L, as I've never used it and budgets usually limit how many primes . It largely depends on what you are shooting though. I actually find my 24 to be wide enough for my uses and rarely need to go wider on FF (which is why I sold my 17-40). On the other hand though, I rarely crop my images taken with the 24, unless one leg decides to grow during the shoot and I have to straighten the images. I'm using it almost entirely for landscapes though and have only taken a few portrait shots with it and then it has been to show the environment surrounding the subject, rather than for any extreme effects.I recently had the same question... so i went into lightroom with one of my weddings and sorted by focal length on my 24-70. i had about 150 shot at 24, and only 15 at 35. Since its a zoom and can be used at focal lengthes around 35, i added up all the shots from 30-40mm and it was still less than at 24.
So i bought the 24.
Maybe you can do the same? rent the 24-70 and shoot an event or something, then see what you used most!
I've noticed that, for me at least, when I look over the EXIF metadata from shots with zoom lenses, something like 80% of the shots are at the extreme ends of the zoom range - that's true for my 16-35 right through my 100-400. Honestly, I've got a lot more shots from my 24-105mm at 24mm than from 30-40mm - but here's what the EXIF doesn't tell you - many (most?) of those shots at 24mm are cropped a bit, often right into that ~30-35mm AoV.
I think there may be a natural tendency to rack zooms to one end or the other, so if testing with a zoom to determine the best FL for a prime, you may be better off setting the zoom to the possible FLs and shooting at each for a while rather that looking retrospectively.
Sorry to necropost! But I figured I would just use this thread instead of starting a new one. That's interesting that you usually crop to around 30ish...
I am looking at getting either the 24 or the 35, and I was wondering... what is the main difference in the feel of the two perspectives? On a FF camera, the 35 1.4 sees about the same as 24 on a 7D?
Also, which lens is typically better? Many seem to rave about the 24 1.4's contrast and colour rendition. Is the 35 similar, or does it fall short? Thanks!
One consideration, if you get the 24 and decide you need to crop, you can do, albeit at the expense of a few pixels, but you can't add in pixels if you decide you needed to go wider than the 35 allowed in the space available. If you have a zoom that covers the range, then I would add my voice to trying out what you would expect to shoot at the two focal lengths and see which suits your needs the best.