Canon EF 70-200mm f/4.0 L USM Lens

The ef 70-200/f4 is a fabulous lens. It's very sharp, has good depth of field at f4 and is a joy to use.

The focus can be set to 3m to infinity or 1.2m to infinity. The shorter length is very good for close ups of flowers or similar. If its left on 1.2m it may hunt when trying to focus. You can also set to manual focus.

One issue with the lens is back focus, if you are shooting at something when there is a bright, or high-contrast background, you may find the camera has focussed on the background.

I use my 70-200 f4 on an EOS20D, I have taken thousands of shots with that combination, photogrphing; cricket, riding, birds, flowers, people, aircraft and stars. Other than the minor issue of back focus, I have had trouble free shooting. The lens is well worth getting.

I have been using the Canon EF 70-200mm f/4 L USM Lens for a year now. I am so much pleased with the superior clarity and build quality it offers, that I feel I am aquainted enough to write a review about this amazing lens.

1. Construction:
The lens is very well constructed - faithfully stands up to what the magical letter 'L' denotes.

a) Barrel: The lens barrel and the mount are made of metal. The barrel is painted in off-white and bears the adorable red ring at the end. The lens is sure to make heads turn but when you look at the pictures that this lens take, you would forget to notice the attention you are getting.
b) Rings: The zoom ring feels smooth and softly damped when turning. Unlike some non-L series lens, the ring does not stutter/lock when it is turned from its initial position. There is no backlash between the rings (zoom and focus) and the lens barrel.
c) Switches: There are 2 switches, one for selecting the focussing mode (auto/manual) and other to select the focus range (1.2m-infinity and 3m-infinity). The use of former switch is self explanatory. The latter switch is used based on the distance between the camera and the subject. This helps the lens to focus quickly depending on the situation. Please bear with me while I try to explain. If the subject is present within 3m from the camera, the first position (1.2m-infinity) is selected. In this mode, the lens starts to attain focus from minimum focus distance to the subject. Else, the other position (3m-infinity) is used. In this mode, the focus range of 1.2m to 3m is ignored and the lens starts to focus from 3m onwards thereby reducing the time required to attain focus on the subject. Many would be aware of it, however it is better to let the others know about it.
d) Dimensions: Weighing at 630g and measuring 172mm long, this lens is slightly heavy for my 450D but feels perfectly balanced in hands. It's neck can be used to mount the lens (instead of the camera) onto a tripod using a tripod ring. The lens does not extend while zooming or focussing so remains as-is at all times.

2. Image quality (IQ):
This is the best part that I enjoy writing. The image quality is excellent. The difference between the IQ of this lens and that of standard kit lens (I know it is not fair but just for sake of comparison) is astronomical. Even when shot wide open (F/4), the image is so sharp with rich tone and contrast throughout the frame (center, border and corners). I never hesitate to shoot wide open unlike other lenses which need to stopped down (F/8, etc) to produce the best quality possible. I haven't noticed flare (whitish bloom like effect when a bright light source is in the frame) or CA (reddish or bluish fringes) in any of my pictures. Wide open and sometimes even narrower (based on the distance from the subject), the out of focus (a.k.a bokeh) clarity is too good. On a normal day with enough light, you would need a shutter speed of 1/70 sec at 70mm and 1/200 sec at 200mm to shoot without shake. Though not always, nature has been favourable to me in this aspect. I have this lens fitted to my 450D (crop sensor) so I cannot comment on any vignetting or light fall off issues which 'might' exist if used on a full frame sensor.

3. Zoom range:
On a crop sensor camera (like my 450D), the 70-200mm focal length range equates to 112-320mm (1.6x) which is abundant enough to reach closer to subjects, example of such situations being sports and wildlife photography. It is definitely not a walk-around lens (at least on a crop sensor camera). On a tripod, it can also be used for shooting the sky at night.

4. Auto-focus speed and accuracy:
Auto-focus is extremely fast, quiet and most importantly accurate. Make sure you make use of the focus switch to ensure quicker focussing.

5. Accessories:
The lens, belonging to 'L' family, comes packaged with a grey leather pouch and a hood. Like most of the hoods, this hood can be joined to the lens in inverted position thereby making the lens compact to carry.

Pros:
- Excellent image quality in terms of both sharpness and color tone/saturation (in fact astronomical if you are moving from kit lens)
- Beautiful and uniform out of focus (a.k.a bokeh) making best use of the wide aperture and long zoom range
- Solid built quality
- Compact when compared to lenses of similar focal lengths
- Excellent resale value if life doesn't treat one well

Cons:
- Slower for low light situation (not a con for me as I clearly understand the situations wherein this lens has to be used and also that I don't see myself realising the potential that the premium price difference between the non-IS and IS version (or the F/2.8 variant) would offer. I have come across few situation where I felt that it could be little faster but in those cases, I increase the ISO and/or shoot in RAW to improve it later.

Equivalent alternatives:
- None in my opinion, considering the image quality and resale value (in case life becomes busy to carry on photography as a hobby).

Other notes:

1. To people who may be stuck up in deciding between Canon EF 70-200mm f/4 L USM Lens and Canon EF 70-300mm f/4-5.6 IS USM Lens:
Before buying this lens, I had gone through the tough time of deciding the better of the aforementioned two lenses. I am glad that I bought the L one. The 70-200mm L is a bit longer (172mm) and heavier (705g) than the 70-300mm (142.8mm and 630g) but feels perfectly balanced in hands. And the image quality, WOW! I was amazed at what my 450D was able to deliver in spite of being a 12MP sensor. I then realized that it is not the sensor that primarily matter but the lens.

2. Warning:
In most of the forums, the most common advice that professional photographers give to amateurs/hobbyists (like me) is that once you start using a 'L' series lens, anything less than a 'L' lens is less. And I completely agree to it. After experiencing the 'L' effect, I have even changed my standard kit lens (18-55mm IS) to 17-55mm IS USM (way superior to the standard kit lens, but that's not important for this review). So take it from me - anything less than 'L' is indeed less!

3. Understand the lens:
During my analysis before buying this lens, I had read many reviews by professional photographers favouring this lens. On the other hand, I had also gone through contrary reviews by people complaining about the slow F/4 aperture speed. I am thankful to the former because they knew what they were talking about. Photography is my hobby and I don't see myself needing the IS or the wider aperture of the elder siblings of this lens, or simply affording them. So when you buy this lens, make sure that you understand what this lens is capable of.

4. Accessories recommended:
Definitely buy a good UV or protector filter (Hoya). You do not want a scratch on this beautiful lens. A lens pen (Hama) is recommended to keep it clean and ready for next use.

5. Accessories to avoid:
If you are interested in tripod rings, make sure that you buy a genuine Canon make. Third party makes are inferior in quality and tend to damage the paint coating of the lens. Also avoid a polariser filter on this lens when there is only just enough light. It reduces the light entering the lens by a stop or 2.

Highly recommended for anyone who do not need IS.

I have several L lenses and currently use the 5D and 7D Camera bodies. The 70-200mm is one of Canons finest lenses and the F4 version is sharper than my F2.8 by a long way. Unless you need the extra light then save money and go for the F4.

Pros

Excellent image quality
Very sharp even wide open at F4
Good colour and contrast
Lightweight

Cons

Silly lightweight case supplied
No tripod mounting ring supplied with this version
Warranty only 12 months. it should be longer for a Pro lens