The Canon EF 20mm f/2.8 USM Lens fits in a nice wide angle focal length space below the ultra-common 24-something and 28-something zoom lenses.
There is a noticeable FOV (field of view) difference between 20mm and 24/28mm.
People often look for a prime lens for their ultra wide angle needs.
Many people don't use these focal lengths with great frequency (myself included) and look to save some money by buying a non-zoom lens.
Primes are often smaller, lighter, cheaper, sharper and faster than their more versatile zoom counterparts.
Upon upgrading from a 1.6x FOVCF body to a 1.3x FOVCF body,
I was questioning whether I needed to keep the expensive
Canon EF 16-35mm f/2.8 L USM Lens
in my kit.
The Canon EF 20mm f/2.8 USM Lens would be as wide on my 1.3x body as the 16-35mm was on the 10D, just as fast and significantly less expensive.
My L zooms cover my needs beyond 24mm.
I purchased the Canon EF 20mm f/2.8 USM Lens and compared it directly to my
Canon EF 16-35mm f/2.8 L USM Lens
(which is very similar both optically and physically to the
Canon EF 17-40mm f/4.0 L USM Lens) at 20mm.
Pictured above and below from left to right are the Canon EF 20mm f/2.8 USM Lens, Sigma 20mm F/1.8 EX DG Lens and Canon EF 16-35mm f/2.8 L USM Lens.
My first out-of-the-box impression was that the Canon EF 20mm f/2.8 USM Lens is nicely built.
I would put the 20's build quality between the
Canon EF 50mm f/1.4 USM Lens and the
Canon EF 85mm f/1.8 USM Lens,
but not up to the weather-sealed
Canon EF 16-35mm f/2.8 L USM Lens' quality.
Overall, I am satisfied with the 20mm on this point.
The Canon EF 20mm f/2.8 USM Lens autofocuses quickly and quietly. Another good point.
The Canon EF 20mm f/2.8 USM Lens not big, but I wouldn't call it small.
It is smaller than the
Canon EF 16-35mm f/2.8 L USM Lens.
Pictured above from left to right are the
Canon EF 50mm f/1.4 USM Lens,
Canon EF 20mm f/2.8 USM Lens and the
Canon EF 16-35mm f/2.8 L USM Lens.
Shooting tests quickly revealed the differentiating points between the two lenses.
First, the Canon EF 20mm f/2.8 USM Lens exhibited less barrel distortion than the
Canon EF 16-35mm f/2.8 L USM Lens.
Second, although the Canon EF 20mm f/2.8 USM Lens was not as sharp as my
Canon EF 16-35mm f/2.8 L USM Lens,
it showed decent center sharpness.
At f/2.8, the 20 was slightly soft.
At f/3.2 and beyond, center sharpness was good.
Unfortunately, that is about the end of the positive aspects of this lens.
The Canon EF 20mm f/2.8 USM Lens' corner sharpness was disappointing even on a
1.3x FOVCF body.
Color and contrast on the Canon EF 20mm f/2.8 USM Lens were well below that of the
Canon EF 16-35mm f/2.8 L USM Lens.
There seemed to be a strong purple hue to the 20mm's images.
Vignetting is very strong when the Canon EF 20mm f/2.8 USM Lens is used wide open -
even on a 1.3x FOVCF camera.
Somewhere between f/4 and f/5.6, the vignetting became reasonable.
The following photos are identical auto exposed, auto white balanced shots taken at f/2.8 with these two lenses on a
Canon EOS 1D Mark II.
The photo on the left (from the Canon EF 20mm f/2.8 USM Lens) shows obvious vignetting.
The purple coloration is also present.
The photo above is an f/8 comparison.
The vignetting is much better, but the photo from the Canon EF 20mm f/2.8 USM Lens is still slightly underexposed
(a consistent issue) - and still purple.
The Canon EF 20mm f/2.8 USM Lens exhibits noticeably more flare than the 16-35mm L does (both lenses tested with hoods attached).
CA (Chromatic Aberration) is also present in the Canon EF 20mm f/2.8 USM Lens.
So you need an ultra-wide angle lens?
My strong recommendation to you - save until you can afford the
Canon EF 17-40mm f/4.0 L USM Lens
or better yet, the
Canon EF 16-35mm f/2.8 L USM Lens.
Image quality at 20mm is significantly better with these two lenses.
Plus, you get the versatility of a zoom lens with a significantly wider angle focal length available.
If all you can afford is the Canon EF 20mm f/2.8 USM Lens, buy it and enjoy it.
It will capture memories just fine.
Recommended Shopping Resources (Using these links to make your purchase supports this site)
Canon EF 20mm f/2.8 USM Lens at B&H Photo
Canon EF 20mm f/2.8 USM Lens at Adorama (Imported)
Canon EF 20mm f/2.8 USM Lens at Adorama
Canon EF 20mm f/2.8 USM Lens at Amazon.com
Canon EF 20mm f/2.8 USM Lens at J&R
Find the best price on the Canon EF 20mm f/2.8 USM Lens
Rent the Canon EF 20mm f/2.8 USM Lens (Using these links supports this site)
Canon EF 20mm f/2.8 USM Lens at LensRentals.com
* If out of stock, ask the rental company if they can accommodate your need.
More Canon EF 20mm f/2.8 USM Lens Reviews & Information
William Castleman
FredMiranda.com
