Which lenses should you choose for your Canon EOS 5D Mark III?

By Kevin Carter - Wednesday April 03 2013

Lens Recommendations
Standard lenses | Telephotos | Wide Angles | Introduction | Canon EOS 5D Mark III vs. Nikon D800: Competition is closer than expected!

General Overview

While it’s clear the rival 36-M-Pix Nikon D800 is a phenomenal camera with the highest pixel count available in a compact DSLR, the 22.3 Mpix Canon EOS 5D Mark III isn’t necessarily outclassed. While both share a similar HD video capability the 5D Mark III has a highly sensitive and accurate 61-point focusing system, durable pro-level build, excellent live view implementation, and can capture stills at up to 6fps (compared with 4.5 fps for the Nikon). In terms of pixel count and stills output, 36 Mpix to 22.3 Mpix sounds a lot but in real life conditions, it’s not as much as the figures suggest.


As you might expect, the image quality of the lens significantly affects the amount of detail that can be captured. In fact, when paired with certain lenses, and making very good use the sensor’s capabilities, the EOS 5D Mark III mounts a serious challenge in terms of resolving power or ‘Sharpness’ to the Nikon D800. Indeed, the two cameras are much closer than expected.


Mounting a high quality lens makes all the difference. From our database, the resulting P-Mpix scores from various body/lens combinations reveals the D800 and Canon EOS 5D Mark III may be closer in resolving detail than expected.

We have tested 85 individual lens models with the EOS 5D Mark III and assimilated a huge amount of data. Of those, we’ve measured 47 primes ranging in focal length from 14mm to 300mm. Breaking that down further, 17 are wide or ultra-wide angle including the new optically excellent Sigma 35mm f/1.4DG HSM A and Canon EF 35mm f/2 IS USM, the Canon EF 28mm f/2.8 IS USM and the exquisite but pricey Carl Zeiss Distagon T* 2,8/15 (15mm f/2.8) ZE. Standard and short telephoto lenses account for another 25 lenses, while a further 5 are telephotos (including 3 Canon models, two of those being exotic, pro-grade f/2.8 types).

Zooms may also be sub-divided into the same categories of wide-angle, standard and telephoto. Of the wide-angle zooms we have assessed 7 lenses including the current pro-offering from Canon, the EF16-35mm F/2.8L II USM as well as the Tokina AT X 16-28 F/2.8 PRO FX.

Standard zooms tested include the vaunted but pricey Canon EF 24-70mm f/2.8L USM II, the compact EF 24-70mm f/4L IS USM and the new surprise budget stabilized choice, the Tamron SP 24-70mm f/2.8 Di VC USD. 

Finally, we have 20 telephoto zooms to consider data from, including the popular 70-200mm f4 and f/2.8 types, various 70/75-300mm and 2 super-zooms.

Results overview & efficiency

From our recent Nikon D800 overview it’s clear the camera is the leader in outright P-Mpix (Sharpness) and overall DxOMark scores, but the rival Canon EOS 5D Mark III is not as far behind as the pixel counts suggest.

We certainly wouldn’t advocate switching between them based on that alone. Indeed, with the right glass, the sensor in the Canon EOS 5D Mark III is capable of closing the gap between them in resolution to negligible values, and that other reasons for choosing between them may be more relevant or important.

Time will tell if the differences in price and features will weigh more heavily in favour of one over the other, but, some care must be taken when choosing lenses in order to maximise the potential image sharpness. As system cameras, working with several lenses, there are times when it’s important to know which lenses are capable of recording the highest levels of sharpness.

Nikon D800Nikon AF-S Nikkor 85mm f/1.4G219940
Nikon D800Nikon AF-S NIKKOR 85mm f/1.8G69040
Nikon D800Sigma 35mm F1.4 DG HSM A Nikon89939
Nikon D800Carl Zeiss Makro-Planar T 100mm f/2 ZF2 Nikon184036
Nikon D800Samyang 85mm f/1.4 Aspherique IF Nikon32836
Nikon D3XNikon AF-S NIKKOR 85mm f/1.8G69035
Nikon D800Sigma 85mm F1.4 EX DG HSM Nikon96935
Canon EOS 5D Mark IIISigma 85mm F1.4 EX DG HSM Canon96935
Nikon D3XNikon AF-S Nikkor 85mm f/1.4G219934
Nikon D800Nikon AF-S Nikkor 24mm f/1.4G ED220034
While it comes as no surprise to see the Nikon D800 grab first positions in the Top 10 DxOMark camera/lens combination scores, the Canon EOS 5D Mark III ranks second, just ahead of the 24 Mpix Nikon D3X.
Nikon D800Sigma 35mm F1.4 DG HSM A Nikon89923
Nikon D800Nikon AF-S Nikkor 85mm f/1.4G219922
Canon EOS 5D Mark IIICanon EF 300mm f/2.8L IS II USM659922
Nikon D800Carl Zeiss Distagon T 25mm f/2 ZF.2 Nikon170022
Canon EOS 5D Mark IICanon EF 300mm f/2.8L IS II USM659921
Canon EOS 1Ds Mark IIICanon EF 300mm f/2.8L IS II USM659921
Nikon D800Nikon AF-S NIKKOR 28mm f/1.8G69921
Nikon D800Samyang 14mm f/2.8 IF ED UMC Aspherical Nikon40920
Canon EOS 5D Mark IIISigma 85mm F1.4 EX DG HSM Canon96920
Canon EOS 5D Mark IIICarl Zeiss Makro-Planar T 100mm f/2 ZE Canon184020
More surprises await when we compare the Sharpness scores between the two camera brands, where the Canon EOS 5D Mark III occupies no less than 3 positions out of the Top 10.
Nb lenses
Score Mean
Score Median
Canon EOS 5D Mark III8515152423
Nikon D8006214152626
Out of a total 147 lenses tested, the Canon surprisingly delivered a higher mean sharpness than the Nikon D800, although it matched the median sharpness and was bettered in the DxO Mark scores overall.

When comparing the huge volume of data accumulated over measuring 147 lenses, one very surprising result was revealed. The average sharpness scores of the Canon EOS 5D Mark III matched the Nikon D800 and if the results were based solely on the mean average, the Canon actually out-performed the Nikon.

When using specific lenses (such as the new Sigma 35mm f/1.4 DG HSM A) the Nikon can out resolve the Canon. However, taken as a whole, the statistics reveal the EOS 5D MK III is capable of similar sharpness and of achieving a close DxOMark camera/lens score to the Nikon D800. Moreover, that’s despite the latter camera’s 60% extra pixel count.

Even the DxOMark mean and median scores can be explained by the small difference (-1/3 stop) in the Low Light ISO score between the cameras.

While the Nikon D800 is capable of getting the best from any lens that’s fitted, it is essential to select lenses specifically to maximise the potential resolution of the sensor. If you’re trading in a Nikon D3X, for example, you may want to confirm that your existing lenses are capable of meeting (or maybe even exceeding) your expectations.

While that same principle of choosing the best glass also applies to the Canon, it’s not quite as crucial. In financial terms alone, this may be an important consideration if you have already invested in a sizeable range of lenses. Lenses on the Canon EOS 5D Mark III are without doubt very efficient.

In future tests, it will be interesting to see if the Sony sourced sensor in the Nikon D800E variant with its altered (zero strength) OLPF (Optical Low-Pass Filter) is significantly more efficient at resolving detail or if it’s as a result of the differences in fill-factor (affected by RGB filter transmission, micro-lens design and circuitry) between the Canon and Nikon sensors.

Either way, the Nikon D800 sensor simply isn’t as adept at resolving detail, pixel-by-pixel, as the Canon EOS 5D Mark III. There’s another surprise as well.


With only a 6-percent increase in pixel count, the Canon EOS 5D Mk III averages an increase of 15% in our Sharpness (P-Mpix) scores over the earlier EOS 5D Mk II (based on the 85 lenses in our database).

Although the Canon EOS 5D Mark III has a different sensor with a slightly increased pixel count of 22.3 Mpix, against the EOS 5D Mk II’s 21.03 Mpix, the new Mark III can boast an average increase in Sharpness (P-MPix) of 15% over the earlier Mark II model (based on the measurement data from the 85 lenses tested).

Canon hasn’t simply delivered a sensor with a minor increase in pixel count; they’ve significantly re-worked the architecture to provide an increase in sharpness.

Studio and landscape photographers looking for advice may also be interested to know the new EOS 5D Mark III has improved sharpness, lens-to-lens, than the older, now discontinued 21.1 Mpix Canon EOS 1Ds Mark III.

Sigma 85mm F1.4 EX DG HSM Canon96935
Sigma 35mm F1.4 DG HSM A Canon89934
Canon EF 100mm f/2 USM44033
Canon EF 35mm f/2 IS USM85033
Carl Zeiss Makro-Planar T 100mm f/2 ZE Canon184032
Canon EF 300mm f/2.8L IS II USM659932
Canon EF 85mm f/1.2L II USM186931
Carl Zeiss Distagon T 35mm f/2 ZE Canon103031
Canon EF 24mm f/1.4L II USM155031
Carl Zeiss Distagon T 35mm f/1.4 ZE Canon184331
Canon EF 24-70mm f/2.8L II USM229928
Tamron SP 70-200mm F/2.8 Di VC USD Canon169928
Canon EF 70-200mm f/2.8L IS II USM249927
Tamron SP 24-70mm F2.8 Di VC USD Canon129927
Canon EF 28-70mm f/2.8L USM126924
Canon EF 70-200mm f/2.8L USM130024
Canon EF 70-200mm f/2.8L IS USM169523
Canon EF 70-200mm f/4L IS USM121023
Sigma 70-200mm F2.8 EX DG APO OS HSM Canon169923
Canon EF 16-35mm f/2.8L II USM139922


Given the somewhat lowly-looking pixel count of the Canon EOS 5D Mark III the potential sharpness is, surprisingly, one feature where the camera exceeds expectations. Providing the camera is matched to specific lens models, sharpness can even exceed the Nikon D800 under certain circumstances (when that camera is used with lesser capable lenses). This is great news if you’re looking to invest in one or own one already. If you’re a Canon user and are looking to upgrade, or maybe even switch because of the sensor’s perceived lowly capabilities then this should put your mind at rest. Please look out for next part of this review, where we’ll look at the finer points of the results for camera and lens combinations to choose from and those lenses that you may want to avoid.