What's sharper, Canon 20mm 2.8 prime or F4L 17-40?
TheCheesehead
Registered Users Posts: 249 Major grins
I'm looking for something wider on my 5D, but sharpness is a must. What is sharper, the Canon 20mm 2.8 prime, or the F4L 17-40? Thanks!
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If I were you I'd try the 24mm f/2.8. The old non-IS one. It can be found for $250 used and it is really a bargain. I think the copies vary, but when you get a sharp one, wow. It's tack sharp, performs great on the 5DII, and is perfect for walkaround (36mm or so) stuff on a 1.6x crop body. And it's so small. It's probably my favorite lens and maybe Canon's best-kept secret.
Here are a couple with the 20mm:
on a 1D Mark II:
On a 20D:
Here are some with the 24mm 2.8 on a 5D2:
The bottom line for me is that primes are small, light, and cheap. If the sharpness is roughly the same, I'd go with the prime for landscape / star etc. photography, and the zoom for more event / photojournalism / portrait photography.
Of course if you're truly interested in sharpness, nothing beats the Zeiss 21mm in that range. It is truly flawless, even better than the already flawless Nikon 14-24...
=Matt=
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You don't mention the application, like vista landscape, etc., but if this is for a nature superwide application you might also consider a Samyang/Bower/Rokinon 14mm f2.8 manual focus lens. Very good sharpness and pretty inexpensive.
It has a complicated "mustache" distortion, that is difficult to correct, but the most recent versions are fairly well corrected and distortion should not be visible for typical nature scenes. I would not recommend the lens for architectural or real estate.
http://www.photozone.de/canon_eos_ff/532-samyang14f28eosff
http://www.4photos.de/test/Samyang-14mm-2.8-en.html
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An "accurate" reproduction of a scene and a good photograph are often two different things.
I haven't used the 50 1.4, but I have used the 1.8 which is supposed to be similar. I'd say the 50 is sharper stopped down to 2.8. At f8 the 50s and 20/24 are probably very similar. I neer did any real testing with my 50 1.8, but it was really sharp.
Here's one with the 20mm on a 1D2 at f8:
http://www.trentphoto.net/photos/i-qtT4WXg/0/XL/i-qtT4WXg-XL.jpg
The 24/5D2 photos I posted above are at f8 and f2.8
Thanks!
ImageUploadedByTapatalk1340069245.334345.jpg
Looking at this comparison it would seem that the prime is sharper right?
Looking at this singular test, I would say that the two lenses, the resolution at center is roughly equal, with the Canon 17-40mm, f4L USM showing a bit better contrast. The Canon 20mm, f2.8 USM is holding resolution a bit better to the edges, but seems to suffer a little from halation. The 17-40mmf4L does show a tiny bit more CA at the edges. The prime has better curvilinear distortion.
Overall, both are very nice lenses, with the zoom more versatile, while the prime is faster due to the larger aperture.
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No. At f/4, the prime is slightly sharper mid-frame, but faster than that the picture gets fuzzy. I'd want a prime to be sharp in the center wide open, like the 35/2 or 24/2.8. And then the 17-40 beats the 20/2.8 at f/5.6 and beyond. I think the 17-40 is lightweight enough that in this particular comparison, all the 20/2.8 has going for it is compactness. Do you need that badly enough to give up 17-19mm and 21-40mm, and mid-to-corner sharpness? And then to know that faster than f/4, the lens goes downhill quickly?
An "accurate" reproduction of a scene and a good photograph are often two different things.
really nice at f4, but the corners were much much worse than on the zoom. Too bad really,
because the 20 has nice ergonomics and would team up really well with the 28 1.8, 50 1.4
and 85 1.8 if only it performed nearly as good as them. If you are looking for sharpness at
20mm, I'd look at the 17-40 or if you need f/2.8 at the 16-35mm f/2.8 L II (much more expensive).
― Edward Weston
don't know but usually primes are sharper than zooms but the differences can be small
There's also 35mm f2, 35 f1.4
― Edward Weston
https://www.flickr.com/people/scardenphoto/
Halation is a type of "fringing", mostly seen around very bright subjects, and especially visible in adjoining dark regions. I like the effect for people stuff (portraiture as well as informal). The effect diminishes as you stop down, and by f4 it's not visible to normal inspection.
I don't regard it as a negative by any means, and I like using the effect when I can.
Moderator of the Cameras and Accessories forums
primes are generally sharper than zooms and the 20mm is probably not an exception
But I'm more of a zoom person (except for portraits)
(Canon 17-40)
http://slrgear.com/reviews/showproduct.php/product/80/cat/10
(Canon 20 2.8)
Neither are flawless wide open, however by f/8 the difference is clear: The 17-40 beats the 20 2.8 in corner sharpness by a hefty margin, though neither are flawless.
Honestly I've given this advice so many times before- it just comes down to what you need- The 17-40 is great because it's super sharp and can zoom; great for general landscape photography. The 20 2.8 is cheap and gets you to f/2.8, which might be more useful if you're into star photography etc.
=Matt=
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