Choosing a Canon 70-200mm lens

I’ve recently been through a very difficult buying decision and I’ve read that it’s one which many Canon shooters face – which 70-200mm lens should I buy?  If you search on this subject, the internet is full of opinions, but I found many didn’t help me to make my choice.  The bottom line is – it’s a completely personal choice, noone can really tell you which to choose and you need to decide for yourself.  So why am I writing a post about it, then?!  I thought I would share the factors that influenced my choice in case the thought process I went through helps anyone else make their decision.  More after the jump…

Options and narrowing the field

Canon currently make four variants of the 70-200mm zoom lens in their L range: f2.8 IS, f2.8, f4 IS and f4 (IS stands for Image Stabilised – I’m British so it’s -ised, not -ized!).  In addition to these lenses, there are some other available options which shouldn’t be written off out of hand:

  1. 75-300 IS f4-5.6
  2. 75-300 L IS f4-5.6
  3. 100-400 L IS f4-5.6
  4. Primes: 135mm f2.8 soft focus and 200mm f2.8 L II (selected to meet my budget – a 135mm f2.0 L is available)
  5. Other manufacturers e.g. Sigma, Tamron

After thinking through these options, I concluded that I was looking for a Canon (option 5 out) zoom (option 4 out) from the L range (option 1 out) with a constant aperture (options 2 and 3 out).  So I was back to the four I started with.  I then applied my first limiting factor (my budget) and removed the f2.8 IS II from my list as I simply couldn’t afford it.  The f4 (non-IS) is priced as the lowest of the remaining group and as I could afford the two more expensive models left I discounted this option quite quickly.  So my short list was:

  • 70-200mm f4 L IS
  • 70-200mm f2.8

Image quality (IQ)

This was the factor I was weighing most heavily.  I was looking for sharpness across the frame, high contrast, minimal chromatic aberrations and well-controlled flare.  Vignetting was not such a big issue for me as this can be corrected in post-processing.

I spent a long time on The Digital Picture, reading the lens reviews and comparing the test chart images.  I also read up on as many reviews and forum comments as I could find.  I’m not going to plagiarise anyone else’s work by regurgitating their comments, but the general consensus seemed to be that with real-world images, sharpness and contrast on both lenses was comparable.  I was seeing marginally better contrast and sharpness in the f4 lens in the test charts but you probably can’t tell the difference on a real subject.  The flare seemed to be better controlled on the f4 lens (check this comparison at 135mm / f4 on both lenses) and as I tend to shoot a lot outdoors, this was a plus point for me.

Score: almost even, but for me the point fell just to f4 IS.

Weather sealing

I mainly shoot outdoors, so a weather-sealing lens was an attractive attribute – not a deal-maker/-killer, but a definite plus.  The f4 IS has it (with a filter), the f2.8 doesn’t.

Score: point to f4 IS.

Weight and balance

The f2.8 lenses are nearly double the weight of their f4 counterparts; the IS doesn’t add a significant amount compared to the wider aperture.  Without being able to see both lenses “in the flesh”, I was struggling to envisage the weight difference but a friend very kindly showed me their 100-400mm L f4-5.6, which is a similar weight and size to the f2.8.  To my mind it was (a) heavy and (b) not well balanced on the Canon 5DmkII body.  I was also concerned that I would end up leaving the f2.8 at home because it was heavy to carry and thereby negate the point in buying a lens!

Score: point to f4 IS.

Maximum aperture

The f2.8 maximum aperture is 1 stop more than f4, resulting in twice the shutter speed (or half the ISO) for the same exposure value and a shallower depth of field / more blurred background.  These attributes make it an attractive option for portraits and sports.

My normal subjects don’t include sports on a regular basis and while I am working on increasing my portrait work, it won’t be the main use for this lens.  When I am facing lower light conditions, I am more likely to be shooting subjects where I’m happy to sacrifice action-stopping shutter speeds for hand hold-ability, so the IS is more of a benefit to me than the shutter speed.

There’s no escaping the depth of field issue…except that I do have a 100mm f2.8 macro lens which will be perfect for portraiture and shallower depth of field.  Granted, it’s a prime lens, so I wouldn’t have the advantage of the aperture over a range of focal lengths up to 200mm, but it certainly helps.

Score: point to f2.8 (but with a lower final weighting because of the factors I’ve outlined).

Image Stabilisation / Stabilization 🙂

See above – the f4 IS has it, the f2.8 doesn’t.  Simple, really.

Score: point to f4 IS.

Compatibility with Extenders

I was moving from a lens that reached to 300mm, so I wanted to be able to retain something close to this reach without severely impacting the image quality I’d gained.  I decided that a 1.4x II extender would give me sufficient reach but that the 2x II extender would be too much of a compromise on IQ.  This meant I would be left with a 280mm reach (200mm x 1.4) at a maximum aperture of either f4 or f5.6.  Both lenses are compatible with the Canon extenders, so it came back to the question of what maximum aperture I needed / wanted / could live with.  Neither lens had a significant advantage for me on compatibility.

Score: neutral.

My Decision

You can see from my scores above where I was heading with this, but still I was drawn back to the concern over missing the extra stop of light and shallower depth of field.  The crunch question for me was this:

“Am I a landscape photographer who would like to shoot some portraits, or a portrait / sports photographer who shoots some landscapes?”

My answer was the former and this meant I felt that the f4 IS was more appropriate….for me.  Sure, one day I may hanker after the f2.8 again, but I don’t think I’m going to miss the extra stop or shallower depth of field unless my photography changes significantly.

So here are my new toys, taken with the 100mm macro lens I mentioned above:

Canon 70-200mm f4 L IS lens and 1.4x II Extender
Canon 70-200mm f4 L IS lens and 1.4x II Extender

And one of the 70-200mm f4 L IS on the Canon 5DmkII, taken with my Canon A620 compact:

Canon 5DmkII with 70-200mm f4 L IS lens
Canon 5DmkII with 70-200mm f4 L IS lens

I found it a difficult choice.  In the end, my best advice is to ignore the zealots who insist their choice is the best, take on board the issues and other people’s experience and then make your own, informed decision.  I think you’ll be much more satisfied.