The purpose of this test of exercise was to determine the difference in image quality produced by these 2 lenses especially when used with a full-frame DSLR with relatively high mega-pixel count.
Unless stated otherwise, the images were shot with a Canon EOS 1Ds Mark.II on Aperture Priority mode, metered using spot meter on the same spot for all shots of the series. Camera was tripod mounted and all shots were taken with a 10sec timer.
All images were shot in RAW and processed using default parameters on Adobe Lightroom 1.4.2 to approximate how images are produced and processed by a working photographer.
Color, Contrast & Vignette
First, the big picture of how the lenses perform overall.
If one were to study the images closely, you would find that colors are good for the 24L even while wide open but it does have visible vignetting same as all large aperture lenses while wide-open. Vignetting for large aperture lenses are generally treated as a deficiency but when used creatively, it can enhance the look of the overall image for more artistic images.
Do note that at f/2.8, the 16-35L II fare very, very well as the vignetting visible on it while wide-open (@ f/2.8) was similar to what we see on the 24/1.4L. Very impressive performance for a zoom lens compared to a prime lens.
By f/4.0, both lenses exhibit little detectable vignetting and further stopping down on both lenses offer little if any improvement.
Closer Look at Image Quality
As we look closer at the images produced by these 2 lenses at 100% and f/2.8, a much more telling difference can be found. The 24L is obviously better than the 16-35L II in terms of detail, contrast and micro-contrast at the corners and edges of the frame when we look at the image at 100%.
But do note that there is a bit of Chromatic Aberration creeping in on one of the 24L images. So… is the 16-35L II’s corners and edges so soft at f/2.8 that it is to the point that it is unuseable for any demanding work?
The image above is after applying “Smart Sharpen” at 100%, 0.5pixels on Photoshop. I would say both images would definitely be useable and good but with some sharpening, the 24L image looks rather amazing but the 16-35L II image has improved quite a bit.
Wide-Open & 2-stops down
We have 2 rows of images for a nearer field of focus, both lenses were set on tripod and made to focus on a line which is around 6ft from the camera, a slightly more typical distance that one would use a 24L at.
The comparison above is for F/1.4 for the 24L and F/2.8 for the 16-35L II plus F/2.8 for the 24L and F/5.6 for the 16-35L II for the center of frame. Nothing much needs to be said once you look at the comparison images, the row on the right for the 24L is clearly superior to the row on the left for the 16-35L II.
This is again a result so obvious and expected that it needs little explanation, the advanced coating technologies employed on the 16-35L II and it’s design optimized for CMOS sensors gives it extremely good performance in terms of CA.
While CA is extremely distracting and annoying it is, it is often easy to correct CA with one adjustment layer and some simple masking work during post-processing but in any case, a CA-free do speed up the workflow significantly especially where you have high contrast scenes and critical images or images destined for high quality printing.
The shots above have been taken handheld and wide-open on both lenses but with the 16-35/2.8L II set at 35mm instead of 24mm. The advantage is clear here, the 24L is capable of much better background separation compared to the 16-35/2.8L II even with the 16-35/2.8L II set at 35mm.
The quality of the bokeh however, it seems the 16-35/2.8L II renders it much more smoothly and pleasingly than the 24/1.4L. The 16-35/2.8L II does benefit from being a lens that is nearly 7yrs more advanced than the 24/1.4L, hence it wouldn’t be surprisingly if modern techniques for lens modeling and design has improved upon that.
In all honesty, the 16-35/2.8L II is a very good lens but it does pale in comparison against the 24/1.4L. Comparing zooms with primes are NEVER a fair comparison as we can see on this test, even if 7yrs more of development and technology behind it, the 16-35/2.8L II is not as good as the 24/1.4L optically.
Do remember that when you look at the test images that all tests were conducted using a 16MP full-frame camera so it does serves as sort of a “stress test” for both lenses.
Though optically not as good, the 16-35/2.8L II was really designed as a photojournalist lens first and foremost, with flexibility and build quality to handle rigorous use while delivering very good optical performance.
The 24/1.4L is a specialist low-light wide-angle lens for creative low-light work. And as such, both serve their purposes very well but I will definitely stick with my 24/1.4L except when flexibility is paramount.