This post originated from an RSS feed registered with Java Buzz by Elliotte Rusty Harold. Original Post: Canon EF 70-300mm f/4.5-5.6 IS DO USM Feed Title: Mokka mit Schlag Feed URL: http://www.elharo.com/blog/feed/atom/? Feed Description: Ranting and Raving Latest Java Buzz Posts Latest Java Buzz Posts by Elliotte Rusty Harold Latest Posts From Mokka mit Schlag

This weekend I took the Canon EF 70-300mm f/4.5-5.6 IS DO USM out for a spin. The DO stands for “Diffractive Optics” which makes the lens a little sharper and a lot more expensive than the regular Canon EF 70-300mm f/4.5-5.6 IS USM lens. There were some nice photos like this Yellow-rumped Warbler:

However, it’s still not sharp enough for my taste, as seen when you zoom in:

If the photos were consistently this good, I’d probably settle for this lens; but they weren’t. Most were much less sharp than this. I shot mostly at ISO 400 and maximum aperture to push the shutter speed as fast as possible. Many of the photos came out looking fairly grainy. I haven’t noticed this before with the 50D, which usually does a fairly good job at higher ISOs. Next time I’ll try bringing the ISO down to 250 or so. I should probably also try bringing the aperture down a stop or two to see if that increases the sharpness.

I actually shot this warbler by using the built-in flash at only 1/250s (the maximum sync speed). One thing I don’t quite understand is why the slower shutter speed when using flash doesn’t cause problems. Typically you want at least 1/n seconds shutter speed for an n mm lens; e.g. 1/300s or faster for a 300mm lens. In practice I find that even with image stabilization I do better with much faster speeds than that, 1/4n or even faster. However most relatively close bird photos–i.e. warblers and other passerines as opposed to hawks and shorebirds–are taken with a flash, so next weekend I’m going to try this lens again with a 580EX II flash and see how much difference that makes.

Just maybe the 70-300 DO is good enough once I add the flash, but if not the next two lenses to try are the Canon EF 100-400mm f4.5-5.6L IS USM Telephoto Zoom and the Canon EF 300mm f/4L IS USM prime. I know at least one photographer who gets amazing results with the 300mm f/4 prime and a 1.4x teleconverter, so that may just be the way to go. Past that point, the lenses are just too heavy and expensive. (The Canon EF 400mm f/5.6L USM prime isn’t that much heavier or more expensive than the 300mm, but it doesn’t have image stabilization, so it doesn’t really work for the handheld shots I like.)