Canon EF 70-300/4-5.6 IS USM Review

In September of 1995 Canon introduced a revolutionary new lens, the EF 75-300/4-5.6 IS USM. The revolutionary aspect of this lens was the incorporation of an optical image stabilizer system which allowed the lens to be hand held at shutter speeds two stops slower than could be done with a conventional lens. Optically the EF 75-300/4-5.6 was very good at the wide end, but became a little soft at 300mm, especially when used wide open. In fact the lens wasn't bad - I've actually used one for the last few years - but at 300mm it paid to shoot at f8 and tweak up the resulting image in PhotoShop. The EF 75-300/4-5.6 IS USM was reviewed here on photo.net in February 2003: http://www.photo.net/equipment/canon/75-300IS/

Then in June of 2004 Canon introduced a somewhat similar lens, but this time using diffractive optics (DO). The result was significantly better performance at 300mm in terms of sharpness, though some users reported optical effects from the diffractive optics could cause undesirable image effects under some circumstances. The EF 70-300/4.5-5.6 DO IS was smaller, but heavier than the EF 75-300/4-5.6IS USM and it also used a true ring USM motor with full time manual focus and a dual mode IS system which allows horizontal panning. The EF 70-300/4.5-5.6 DO IS USM was reviewed here in June 2004: http://www.photo.net/equipment/canon/70-300do/

The most recent incarnation of the original IS lens, the Canon EF 70-300mm f/4-5.6 IS USM was introduced in October 2005. While being physically very similar to the original lens (within a few mm in size and a few gm in weight), there were some optical and mechanical differences. The EF 70-300/4-5.6 IS USM is 5mm wider at the wide end, uses a single UD glass element, and has a revised AF system (though it still uses a micro USM motor rather than a ring USM). It also has a zoom lock at the 70mm position to prevent "zoom creep" while the lens is being carried and it has a dual mode 3rd generation IS system which allows horizontal panning.

Here's a short summary of the specifications of these three lenses:

EF 70-300/4-5.6 IS USM Performance

Autofocus

The AF is certainly faster than that on the original EF 75-300/4-5.6 IS USM. I measured a time of approximately 0.65 seconds for the lens to go from infinity focus to closest focus. This compares to 0.9 seconds for the original lens. The turnaround time is faster too, i.e. if the lens goes from infinity to close focus and doesn't find focus, it will pause and then go from close focus back to infinity. The cycle time for the new lens is 1.6 seconds, while the old lens took 2.6 seconds.

Manual Focus

The manual focus feel of the new lens is essentially the same as the original lens, i.e. sloppy and undamped. This isn't a lens you'd want to use manual focus with unless you had to. Fortunately, autofocus seems fast and accurate, so resorting to MF isn't something that will be required often.

Image Stabilization

Canon claim that the new IS system gives an extra stop of "handholdability". This is very difficult to measure since when handholding a lens with IS there is a certain probability of sharpness, i.e. at the longest shutter speeds not every shot will be equally sharp. However I can say that visually (i.e. looking through the lens), the IS system does seem more effective and in practice when shooting in the 1/60-1/90s shutter speed range at 300mm, the new lens gave a somewhat greater percentage of sharp shots than the original lens, so Canon have certainly improved the IS. Is it a full stop better? Maybe. As I said it's something that's quite difficult to quantify. However there's zero doubt that it works! Below are 6 shots taken at 1/125s, 3 with IS on and 3 with IS off.

Sharpness

The original lens was very sharp at 70mm (as is the new lens), but became softer when zoomed to 300mm and shot wide open. I typically tried to shoot at f8 if I was zoomed out to 300mm. The performance of the new lens is improved at 300mm. Both sharpness and contrast are increased and it's possible to shoot wide open at 300mm and get good results. It's not as good as a 300/4L, but then nobody could reasonably expect it to be. Canon's published MTF data suggests that it should be as sharp as the more expensive 70-300/4.5-5.6 DO (diffractive optics) lens and I can believe that - though I did not have a DO lens available for a side by side comparison so I can't say for sure.

Below are 100% crops taken from the center of images shot using and EOS 20D wide open at 300mm.

Contrast and Flare

Under normal conditions contrast seems a little higher with the new lens. Again this is something that's hard to quantify, but qualitatively, I think it's better. Flare also seems slightly better controlled, although like almost any lens, and certainly any consumer lens, if you have the front element in direct sunlight, you will have flare and contrast problems. A lens shade (or a suitably positioned hand or hat) is the only effective way of reducing flare under those circumstances as dramatically shown below:

Chromatic Aberration

CA (chromatic aberration) is still visible in the new lens, just as it was in the original, but the magnitude and intensity of the colored fringes is slightly lower. Again, not as good as a 300/4L, but again, you wouldn't expect it to be.

Build Quality

Build quality is similar to that of the original lens. It's a consumer zoom, not an "L" series lens. That's not to say that it's flimsy, but there is some barrel wobble when extended to 300mm. The addition of the zoom lock at 70mm is useful, since the lens will extend to the 300mm position when carried on a camera and pointing downwards.

Overall Conclusions

The new EF 70-300/4-5.6 IS USM is a better lens than the original EF 75-300/4-5.6 IS USM, as it should be since it costs at least $200 more. $650 isn't cheap, and in fact it's more expensive than the EF 70-200/4L. The original lens has been discontinued, so the decision as to which is the better value of the two is now moot. Maybe you can still find a new one, but it's getting tough. Used ones sell on Ebay for around $400. I'd say the new lens at $650 is probably better value than the DO lens at $1150, as long as you can live without a silent ring USM motor and full time manual focus and don't mind the extra 1.5" in length. If you shoot at 300mm a lot, I'd say pay the price for the EF 70-300/4-5.6 IS USM. If you shoot most of the time at the shorter end, you can save $250 or so by getting the original lens used (or maybe you could find a new one if you're quick), so if funds are tight that's not an unreasonable option. I can tell you that I have upgraded to the new lens (anyone who wants to buy my 75-300IS...email me!).

Whether the EF 70-200/4 L? USM ($600) or the EF 70-300/4-5.6 IS USM ($650) is the better buy depends a lot on your application. If you're shooting from a tripod and don't need to zoom to 300mm, the EF 70-200/4L is a very good buy. You can add a Canon 1.4x TC to get to 280mm, though it takes takes time to add and costs around $300. On the other hand if you're shooting handheld and need the ability to easily zoom from 70 to 300mm without stoping to add a TC, then I think the EF 70-300/4-5.6 IS USM might well turn out to be the better choice.

Where to buy the Canon EF 70-300mm f/4.5-5.6 IS USM lens

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