Comparision between 20 2.8USM and 24-70 2.8L

[wooi_loon]

Hi,

I'm trying to get some idea how is the sharpness of both 20mm 2.8USM

and 24-70 2.8L at the wide end? I know I'm not suppose to compare a

fix focal lens to zoom lens and also a non L to L lens, but I really

want to find out the optical quality of both lens. Basically shoot a

lot of lanscape, that's why plan to get a widest end. Currently using

Elan 7e with my 24-85 USM, but then not really satisfied with the

picture. Hope can get some tips. Thanks.

Regards,

[isaac sibson]

I have the 20 f2.8 and the 24-85.

 

I find that 20mm is not a general use landscape lens, whereas 24 can be. It is good for tighter spots though, where you can't get the distance from your subject (I think perhaps Yosemite would be a place where it would be useful). You need a good, strong foreground with the 20mm.

 

20mm is very different to 24mm in my opinion, and they don't stand direct comparison.

[benb]

I have the EF 20mm f/2.8 lens. I've attached a small picture, unfortunately I don't have a higher-resolution file available right now. I have this picture hung on my wall at 8"x10" and it's razor sharp, you can count the pine needles in the foreground as well as the backlit leaves way off in the distance. This was 1/30th at f/8 though, on a tripod with a remote release.

 

This lens is soft in the corners wide open, but you'll only notice it if you shoot wide open hand-held and have a subject that has grass, leaves, pine needles, etc.. I haven't exactly done a scientific experiment with it either, this softness could be depth of field. I routinely use it in low light wide open and am happy with the results, in those situations the subject seems to usually be something that you won't notice softness in the corners.

 

This is my first and only super-wide lens, and I haven't had a lot of difficulty finding subjects. It can be fantastic indoors if used carefully, and wonderful for all kinds of outdoor stuff, but it is obviously very nice for extreme close-far shots. On the other end of the spectrum though, it has a short minimum focusing distance so you can isolate certain kinds of subjects with narrow DOF.

 

Construction, focusing speed, noise, etc... are very nice. It appears to be about 90% metal, I kind of wonder why it wasn't made into an L lens, it doesn't seem like it would need to be improved much more. It has Ring-USM, Full time manual, internal/rear focusing, etc..

 

Ben

[noshir_patel]

Wooi, I would expect the 24-85 to be pretty good if stopped down to the sort of aperatures you would normally use for landscape photos. Are you sure it's not a technique thing? I use the 28-135 which I belive is of comparable in quality to your lens and I can get a reasonably good 16x20 by scanning and getting digital prints done.

 

Bear in mind that if you are using hyperfocal distance tables (or depth of field tables), most of those assume you are not going to enlarge past about 6x8. I have found that if I follow these tables without compensating for this that I cannot produce an acceptably sharp enlargement. You might want to either stop down more than the tables say or generate tables for a smaller circle of confusion (which basically means amount of acceptable blur). (I have a Palm program that does the computations for me.)

 

Back to your actual question...

 

I can tell you the 20 f/2.8 is very sharp. I own this lens, but not the 24-70 f/2.8.

[rsriram]

This may not directly address your question but should throw some light on the issue.

 

I use an EF 24/2.8 for landscapes. I sometimes (rarely now) use a 28-105 which is optically on the same league as your 24-85. The 24/2.8 beats the 28-105 in terms of colour saturation, sharpness and lack of distortion at all apertures and with the 28-105 at all focal lengths. Period. The 24/2.8 I use is blisteringly sharp. The 20/2.8 is also supposed to be in the same league. My 70-200/4L is great but not as sharp as the 24.

 

There are other factors to consider. The 24-70L is almost 1Kg (9xx grams?) The primes weigh much less, are much smaller and take smaller filters. At one point I seriously considered getting a used 28-70L but the size, weight and cost of filters put me off.

[majid]

The late noted landscape photographer Galen Rowell is on record in "Mountain Light" saying he found 20mm too wide (and too hard to control perspective with). He used a 24mm Nikkor as his workhorse lens.

[wooi_loon]

Actually I never have any prime lens and L lens, that's why not really know how sharp are the prime lens and L lens. For my 24-85mm, I found that at some condition ( especially in low light shooting with 85mm end), the picture not very sharp even at 24 end, and I mostly shoot for lanscape. that's why need some comments for wide focal prime and L lens. As Issac and Fazal stated that 20mm is not really suitable for lanscape, I have no experince at all with this lens. Another question:

Sriram claimed that his 70-200L not as sharp as 24mm, anyone can give some comments? I'm glad that you all give very imformative comments on my query, thanks.

[yakim_peled1]

My 50/1.8 was, optically, much better than my L zooms (17-35/2.8 and 70-200/4) when used wide open. Sharpness (in both), flare and distortion (in the former). You name it. I thus sold them.

 

 

My experience with the 17-35/2.8 proved me how anything wider than 24mm is much too wide for me. I second Isaac on this.

[cliff_lesergent]

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<p>With recent advances in lens design, many of the premium zoom lenses are matching or exceeding prime lenses in quality. <br>

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Canon's EF 20mm f2.8 USM lens is not one of their best efforts, and is certainly not as good as the EF 16-35mm f2.8L (I currently own both).  

I don't do any formal lens testing, but here's a link to a description of the EF

20mm f2.8 USM on a site that posts very honest and objective reviews: <a href="http://www.naturfotograf.com/index2.html">http://www.naturfotograf.com/index2.html</a><br>

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It would not surprise me if the new EF 24-70mm f2.8L, with its UD and aspheric elements, also performed better than the EF 20mm f2.8 USM</p>

 

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[alan_krantz]

I would think the 24-70 has significant distortion at the 24 end. I wonder about chromatic aberration. It has been reported that the 24f2.8 (prime) has chromatic aberration and the 17-35 (see dpreview of the canon D1s) has chromatic aberration ...