Canon Big White Conundrum - 200-400 vs 400 f2.8 IS II vs 500 f4 IS II

As recommended, I rented the 200-400 lens for a couple days to do some photography at a wildlife park close to home. This is the summary of my observations:

1. Stellar performer in very good light but not a good candidate for mediocre (or low) light.

2. Heavy lens and not very easy to use on a bean bag.

3. Requires high shutter speeds for better sharpness (could be user error).

4. Quality of images drops proportionally once the subject distance increase above 22meters.

5. F4.0 Prime had a slight edge in image quality and AF.

My 2 cents - the lens is best suited for safaris where light is abundant and the subjects are closer to you (such as African parks). I would have to look at the 500 IS II or 600 IS II for my needs.

Please do take the above statements with a pinch of salt since I had only 3 odd days with the lens.

This elaboration is for any folks interested in learning more about how I arrived at the above conclusion:

a. Image quality: The image quality was pretty good throughout the focal range 200-560. Even with the extender on, image quality did not take too much of a hit. However, there were two important observations - once the subject distance was greater than 22 meters (just an approximation) the image details suffered significantly. This was clearly visible on all images where the focused subject was further away. I can’t figure out why – but even in good light this was a very prominent trend. Anybody else notice this?

b. Bokeh Aesthetics: The bokeh is very nice but I personally prefer the 500’s bokeh.

c. Shutter Speed: The second noticeable data point was the shutter speed needed to get tack sharp images – almost all images less than 1/800 were not that sharp. Anything above 1/1600 was a definite keeper. The lens is not that forgiving in this case as compared to the 500 IS II. I assume a more refined shooting technique for lower shutter speeds can help.

d. Ergonomics & Handling:

The lens is heavy so hand holding shooting was not doable (expect for very short durations). Having to rely heavily on the bean bag, posed a new challenge - the zoom ring overlapped with the bean bag and hence required the lens to be lifted each time I wanted to zoom in/out. I assume you could work around this situation by using a less wider bean bag. Also, the subjects were very skittish so I could not take advantage of the versatility of the lens. However, the switch to engage the extended was very convenient and easy to use.

e. In my case, I shot primarily at and above 400mm (for over 90% of my shots). Also light is a huge challenge for the type of forests in India, where thick canopies are very prevalent. A 500+ at f/4 would have been highly welcomed in such situations.