Canon 500mm vs 100-400mm vs Sigma 150-500mm (1 Viewer)

Finally got round to performing a few comparison shots between these three lenses while I've still got them. I've attached the combined results (all taken on 1Dm4 with fixed tripod and manual exposure, exposures equalised in the computer).

The results won't surprise too many people. The Sigma is less than 500mm (at 4.5m working distance it works out to be 415mm) and only about 70mm more than the 100-400mm. Image quality of images cropped to the same physical size favours the 100-400mm and the Sigma is about 0.5stop darker at the same aperture. The Sigma at f/6.3 is particularly poor, but still lags behind at f/8.0.

So, if you can afford the difference the 100-400mm is a far better general purpose birding lens than the 150-500mm (and is also lighter and has better close-up performance as well). Bigger isn't always better .

This is really great information.

Nice comparison and one mind tripping photo :t:

hi, I am possibly missing the plot here does that mean the canon 100-400 is only 345mm ? Please explain? Kind regards. Mike

It means that at a very close distance (around 4.5m) the 100-400mm is only effectively showing a focal length of around 350mm, at least compared to a 500mm prime at the same distance. This isn't a new fact, many lenses show a reduced focal length as they get close to their minimum focusing distance but zoom lenses are much worse than a comparable prime. The manufacturer's claimed focal lengths will be for when focused at infinity (birds might seem far away but they're not that bad!)

The main result is that the Sigma is significantly less than 500mm and not 100mm more than the 100-400mm, plus the worse image quality compared to the shorter 100-400mm even when cropped more to compensate. In other words the extra focal length of the Sigma doesn't result in a better photo.

mdb2 said:

hi, I am possibly missing the plot here does that mean the canon 100-400 is only 345mm ? Please explain? Kind regards. Mike

Click to expand...

As 'Frinky' as already said this is typical of zoom lenses, they only get their long end focal length when shooting at infinity (if ever). I saw a focal length test once between a Sigma 50-500 at 500mm and a Canon 400/5.6 prime and from around 5 metres there was very little in it - the guess was that the Sigma was getting around 420mm at most from this distance.
BTW a good test Frinky - I am not at all surprised by the results.

hi I now understand what your saying. Correct me if I am wrong, if the subject is close ie 4.5m that the maximum focal length of a zoom say of 500mm is fact not 500mm but considerably less, and this is with all zooms. But less so with prime lenses. Kind regards mike

Yes, most lenses will show focal length changes with focusing distance but zooms are generally far worse than primes. And some zooms are definitely worse than others.

Thanks for your hard work!

Can you comment on the sharpness, contrast between the Canon EF 500 F4L IS & the Canon zoom? (And do you know if the zoom is a recent model?) Thanks.

The 100-400 was bought this year and has been calibrated by Canon engineers (it had awful focusing when I first got it). The Sigma is ~3.5 years old, the 500f4 nearly 2years I think. Compared to the other lenses I think I have a good copy of the 100-400.

I was mostly interested in the focal length so didn't go into too much detail on the sharpness but I'll attach some comparisons of images scaled to the same number of pixels (apologies for the mind-bending target!) There should be 500f4 vs 100-400f5.6, 500f8 vs 100-400f8, 700f5.6 vs 100-400f5.6, 100-400f5.6 vs 150-500f6.3 and 100-400f8 vs 150-500f8. First lens is always at the bottom.

Generally the 500f4 was easily the sharpest, even with a TC on but the 100-400 isn't far off. Stopping down the bare lenses to f8 there's not a lot of difference. Of course, these shots are cropped quite a bit to the center of the shot so miss any vignetting or corner softness on the zoom.

The Sigma is lousy wide open, but stopping down to f8 (or even f7.1 IME) makes a big difference. It's still noticeably worse but a lot closer. If you can live with f8 it's not a bad lens but our weather's dim enough already!