Tokina 11-16mm on a full frame sensor camera
The Tokina 11-16mm f/2.8 Ultra Wide Angle lens was designed for digital cameras with APS-C sized sensors, but can it be used effectively on a cameras with full frame sensors? Perhaps you have a crop sensor camera and want an Ultra Wide Angle (UWA) lens that may work for you in the future should you decide to make the leap into the full frame world. Or maybe you think APS-C sized sensors will go the way of the Dodo and you don't want a lens that has become obsolete. Whatever the reason you are here, hopefully you will go away understanding the potential and limitations of using the Tokina 11-16mm f/2.8 on a full frame digital SLR.
For the testing, I will be using a Tokina 11-16mm f/2.8, Canon 17-40mm f/4L and a Canon 5D Mark II. While the focal lengths don't overlap, the fact that the lenses are priced similarly and the Tokina is only really usable on a full frame sensor very near 16mm allows us to have reasonable debate between the two options. Size and weight are similar, they both have a minimum focusing distance of about 11 inches, and they both use a 77mm filter.
The Tokina 11-16mm f/2.8 will physically mount to a full frame camera body, and there is no interference with the mirror/shutter actuation. Since it was designed for an APS-C sensor camera, severe vignetting will occur throughout most of the focal length range, but it is usable at the long end of the range.
We know that the lens will mount to a full frame body, and we know that we can minimize vignetting if we use the longer focal lengths, so what else is there? It is well known that the Tokina 11-16mm f/2.8 is a sharp lens on a crop sensor. It can be reasonably assumed that the same area used on a crop sensor will be equally sharp on a full frame camera, but what about the area on a full frame sensor that is outside the area covered in the crop sensor? Below we will compare this area on the Tokina 11-16mm f2.8 to the similar area in a ultra wide angle lens designed for full frame sensors and see if the Tokina is up to the task. We also explore how using filters affects vignetting on the Tokina, and if the Canon is any better.
I did a series of test shots to get a feel for how the Tokina 11-16mm f/2.8 works on my 5d mark II. I have found the following to be true (click on the links for examples):
- Significant vignetting at the 16mm focal length at f/2.8 even with no filters or hood. The vignetting decreases to correctable by around f/4, and can be eliminated at smaller apertures.
- 14mm has significant vignetting at all apertures.
- 15mm can be used at smaller apertures, but with no filters and no lens hood.
- Some cropping is necessary when using any filters, including a slim polarizing filter at all apertures. Vignetting is more severe at the larger apertures (f/2.8).
The Canon 17-40mm f/4L wasn't without some limitations when used with filters as well:
- at 17mm vignetting is an issue when a standard circular polarizer is used - cropping is required at all apertures.
- at 17mm vignetting is an issue when a slim polarizer is used with a UV filter - cropping is required at all apertures.
- at 17mm vignetting is NOT an issue when using a slim polarizer by itself or when using a standard UV filter by itself.
As for the winner in the vignetting department, the Canon has the edge. The Tokina needs to be cropped in many instances, but since it is already a little wider than the Canon 17-40mm f/4L, there is room for a little cropping. The Canon doesn't work with stacked filters or regular thickness polarizing filters without vignetting. However, since the Canon lens can be zoomed in slightly if necessary and it works with slim polarizers or UV filters by themselves with no substantial vignetting, it is more convenient that you can decrease your post processing workload by minimizing vignetting as you are shooting with the Canon lens.
As I mentioned before, I also wanted to find out how the picture quality was in the additional area on the full frame sensor that isn't covered when the Tokina is used on a crop sensor. It is logical that the designers may not have optimized the image quality in that area since the lens wasn't designed for full frame sensor cameras. Testing showed, with the exception of the very corners of the photos, the Tokina produced a slightly sharper image when viewed at 100%. However, what the Canon lacked in sharpness, it made up for by producing slightly richer colors than the Tokina. Click here to see the comparison photos.
The verdict: Very close call. This is one that will depend on each person's needs. For me, I think I'll take the longer focal length range, richer colors, and less time having to crop the vignettes with the Canon 17-40mm f/4L. But the idea of a very sharp, super wide angle lens with a maximum aperture of f/2.8 certainly has its merits, and if those are more important to you, then you have a great option.
Tokina 11-16mm f/2.8
Pros:
- f/2.8 maximum aperture
- Excellent build quality
- Very sharp images
- Ultra Wide Angle on both APS-C and Full Frame cameras
Cons:
- Vignetting an issue under a lot of conditions
- Limited focal length range, even on a crop sensor
Canon 17-40mm f/4L
Pros:
- Canon L Series build quality
- Vignetting occurs under rare circumstances
- Rich colors
- Ultra Wide Angle on Full Frame cameras and good walkaround focal length range for APS-C cameras
- Good range of focal length makes the lens more versatile
Cons:
- Sharp, but not as sharp as the Tokina
- Vignetting when thicker filters are used or filters are stacked (UV filter + Circular Polarizer)