What's sharper, Canon 20mm 2.8 prime or F4L 17-40?

TheCheeseheadTheCheesehead Registered Users Posts: 249 Major grins
edited November 3, 2012 in Cameras
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!

Comments

  • ThatCanonGuyThatCanonGuy Registered Users Posts: 1,778 Major grins
    edited June 16, 2012
    The 20mm is a fine lens, but I don't think it's L sharp. Plus with the 17-40 you get the added versatility of the longer focal length. The 17-40 is much more suitable for walkaround stuff when you need wide.

    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:
    i-zWbJbGb-M.jpg

    On a 20D:
    i-msfbwGf-M.jpg

    Here are some with the 24mm 2.8 on a 5D2:
    i-RH739mW-M.jpg

    i-DPZm6N6-M.jpg
  • TheCheeseheadTheCheesehead Registered Users Posts: 249 Major grins
    edited June 16, 2012
    Thanks so much! My 50mm 1.4 is crazy sharp, how do they compare to that?
  • Matthew SavilleMatthew Saville Registered Users, Retired Mod Posts: 3,352 Major grins
    edited June 17, 2012
    Canon is not really known for ultra-wide sharpness. Their forte is in bokeh and L prime sharpness, that's about it. Having said that, the 20 f/2.8 and 17-40 are pretty decent, especially if you're stopping down a few stops as a landscape photographer. If you're shooting wide open as a photojournalist or star trail photographer, you can pretty much kiss your corners goodbye, though.

    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=
    My first thought is always of light.” – Galen Rowell
    My SmugMug PortfolioMy Astro-Landscape Photo BlogDgrin Weddings Forum
  • ziggy53ziggy53 Super Moderators Posts: 24,118 moderator
    edited June 17, 2012
    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!

    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
    ziggy53
    Moderator of the Cameras and Accessories forums
  • jmphotocraftjmphotocraft Registered Users Posts: 2,987 Major grins
    edited June 17, 2012
  • ThatCanonGuyThatCanonGuy Registered Users Posts: 1,778 Major grins
    edited June 18, 2012
    Thanks so much! My 50mm 1.4 is crazy sharp, how do they compare to that?

    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 thumb.gif
  • TheCheeseheadTheCheesehead Registered Users Posts: 249 Major grins
    edited June 18, 2012
    Thanks do much for the input! Honestly guys, I don't do a whole lot of landscapes, (but when I do, it's with a Dos Equis). Most of what I do, honestly, is family type shots, on location (which means vacation photos) where I want alot of the background behind my kids, to tell the story more or less. I guess the most important things that I want sharp are my subjects eyes. I do occasionally shoot city scenes on a tripod, but not too often. Something like this NYC photo would be a typical shot (Canon 2.8L 16-35 I rented).
    Thanks!
    ImageUploadedByTapatalk1340069245.334345.jpg
  • ThatCanonGuyThatCanonGuy Registered Users Posts: 1,778 Major grins
    edited June 18, 2012
    24 would probably be best for those because it's so much smaller and lighter than the 20. It's lighter than the 50 1.4 I think.
  • TheCheeseheadTheCheesehead Registered Users Posts: 249 Major grins
    edited June 18, 2012
  • ziggy53ziggy53 Super Moderators Posts: 24,118 moderator
    edited June 19, 2012
    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.
    ziggy53
    Moderator of the Cameras and Accessories forums
  • jmphotocraftjmphotocraft Registered Users Posts: 2,987 Major grins
    edited June 19, 2012
    Looking at this comparison it would seem that the prime is sharper right?

    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?
    -Jack

    An "accurate" reproduction of a scene and a good photograph are often two different things.
  • Manfr3dManfr3d Registered Users Posts: 2,008 Major grins
    edited June 19, 2012
    My 17-40 is sharper than the 20mm 2.8 that I've tried (on fullframe). The center of the 20 was
    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).
    “To consult the rules of composition before making a picture is a little like consulting the law of gravitation before going for a walk.”
    ― Edward Weston
  • Brett1000Brett1000 Registered Users Posts: 819 Major grins
    edited June 21, 2012
    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!

    don't know but usually primes are sharper than zooms but the differences can be small
    There's also 35mm f2, 35 f1.4
  • Manfr3dManfr3d Registered Users Posts: 2,008 Major grins
    edited June 21, 2012
    the 20mm 2.8 is an exception to this rule, thats why it gets mixed reviews.
    “To consult the rules of composition before making a picture is a little like consulting the law of gravitation before going for a walk.”
    ― Edward Weston
  • TheCheeseheadTheCheesehead Registered Users Posts: 249 Major grins
    edited June 30, 2012
    Thanks guys, I bought the 20mm, and fairly happy with it . Seems sharpest at 6.3. Not as sharp as my 50 1.4 though. I'll have to rent the 17-40 and test it out.
  • shawncshawnc Registered Users Posts: 718 Major grins
    edited October 31, 2012
    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 thumb.gif
    I just took advantage of the Canon promotion on the 50 f1.4. Took it on vacation for a week and looking at the pics last nite, I was amazed at the sharpness even wide open. I normally shoot mt 24-70 f2.8L and my 70-200 f2.8L IS, but I am pretty motivated into looking more at the primes in the future. In fact that's why I am in this thread, doing some research. I will of course use my zooms for my event photog, but leaning heavily to primes for my landscape etc.
  • ziggy53ziggy53 Super Moderators Posts: 24,118 moderator
    edited October 31, 2012
    I have an EF 50mm, f1.4 USM and I do love the lens. Do realize that the lens has an "issue" when it's wide open and dealing with high-contrast subjects; halation.

    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. thumb.gif
    ziggy53
    Moderator of the Cameras and Accessories forums
  • Brett1000Brett1000 Registered Users Posts: 819 Major grins
    edited November 2, 2012
    Thanks guys, I bought the 20mm, and fairly happy with it . Seems sharpest at 6.3. Not as sharp as my 50 1.4 though. I'll have to rent the 17-40 and test it out.

    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)
  • Matthew SavilleMatthew Saville Registered Users, Retired Mod Posts: 3,352 Major grins
    edited November 3, 2012
    http://slrgear.com/reviews/showproduct.php/product/31/cat/11
    (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=
    My first thought is always of light.” – Galen Rowell
    My SmugMug PortfolioMy Astro-Landscape Photo BlogDgrin Weddings Forum
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