Canon 70-200mm F/4: First Test Drive

The Canon EF 70-200mm f/4L USM (see how I got it cheaply) arrived Tuesday, but other than shooting a few shots inside, I didn't get a chance to really test it until yesterday. I was halfway to work when I realized I had forgotten some library books due that day, so I turned my bike around and rode home to get them. When I pulled on our court, a heron was standing at the corner. It was a perfect time to test the lens!

Luckily, he stuck around long enough for me to grab my camera and pop the new lens on. He and I then stood around staring at each other for about a half an hour while I got over 60 shots. Of course, none of the shots were remarkable because he didn't find any gophers to eat and I wasn't heartless enough to scare him into flying away just to get a good picture.

First impressions of the Canon EF 70-200mm f/4L USM:

• It is long but not nearly as heavy as I thought it'd be. It handled pretty well on my little XT, but I can see how the tripod mount would be useful. Apparently 3rd party mounts are much cheaper (~$50) than the Canon mount (~$140).
  
• The length of the lens doesn't change during zooming or focusing (an awesome feature).
• The included hood and bag are really nice.
• The USM is super quiet and fast (but my Tamron 17-50mm f/2.8 is pretty fast too, but it sounds like angry bees). I had a little trouble focusing on the heron, but I think that was more my Rebel XT not finding it's skinny little neck. The ability to hold the focus ring, autofocus (without the ring turning) then turn the ring to tune the focus is very useful (also called full time manual).
• The zoom ring is opposite of Tamron lenses. Not a big deal, but all my lenses have been Tamron to this point so I keep turning it the wrong way :(
• I think this would be a good lens for outdoor sports, but it'd probably be good to get a monopod and tripod mount ring because it is hard to hold it steady at 200mm for long periods of time.
• Image quality is quite good. So far, I've only shot wide open at F/4, but it is nice, way better than the Tamron 70-300mm f/4-5.6 even stopped down. The ability to shoot wide open without worrying about quality is really nice; click either image above to see a bigger version.
  

I am planning a more in depth review/comparison between the Canon 70-200mm F/4 and Tamron 70-300mm F/4-5.6 but I'd like to get a bit more time with the Canon before I do it.

Below are 100% crops of heron shots from both lenses:

100% crop from Canon 70-200mm F/4 USM
(ISO 200, 200mm, F/4, 1/2000 sec, processed in RAW)

100% crop from Tamron 70-300mm F/4-5.6 Macro
(ISO 400, 300mm, F/7.1, 1/400 sec, JPG)

Obviously, there are some differences between how the two images were shot: the Canon was at a shorter focal length, faster shutter speed, lower ISO, and used RAW processing. By the way, the Tamron shot is from this day, but is pretty indicative of how the Tamron performs (at 200mm it is slightly sharper though). My general feeling is I don't need to worry about the image quality of the Canon, while I have to keep the Tamron from being wide-open and avoid situations where chromatic abberation would get too bad.

Of course, the Tamron cost less than $100, while the Canon cost $500. I still contend the Tamron is still a great value for the money.