Review of the Canon EF 70-300mm f/4.5-5.6 DO IS Lens

I was interested in finding a compact, relatively light telephoto zoom lens in the 75-300mm range to put in a light kit with wide-angle zoom that I could travel easily with and use for grab and shoot purposes with my Canon APS-C camera (20D / D60). Ideally, it would yield reasonable quality prints that I could enlarge well above an 8x10 inch print size if needed. I compared two compact Canon zoom telephoto lenses with other larger, heavier lenses. This review focuses on comparisons between Canon's relatively expensive EF 70-300mm f/4.5-5.6 DO IS lens based on diffractive optics against the inexpensive EF 75-300mm f/4-5.6 III USM.

Canon EF 70-300mm f/4.5-5.6 DO IS USM Lens

Lenses Used in Tests
Which of these 300mm lenses would you want to carry all day on your shoulder, back or around your neck, and how much lens performance are you willing to sacrifice?
Click here for lens specification on size and weight.
Review Summary for Canon EF 70-300mm f/4.5-5.6 DO IS USM Lens
Lens strengths:
  • Compact and relatively light
  • Overall excellent image quality from 70 to 200mm
  • Well built
  • Fast focusing function (even with a D60)
  • Image stabilization works superbly for low ambient light uses
Lens weaknesses:
  • Mediocre image quality at 300mm. You will be disappointed with the 70-300mm DO at 300mm if you have ever shot with a good EF 300mm prime lens or a higher quality zoom such as the EF 100-400mm L IS at 300mm. These latter two lenses offer noticeably sharper images in enlargements above 8x10 inches (A4).
  • Image-destroying lens flare under conditions of moderately bright background lighting into the lens. This lens is more prone to flare than any other lens I have used.
  • High cost

Resolution and Modulation Transfer Function


Resolution of the EF 70-300mm f/4.5-5.6 DO IS lens was found to be comparable to other Canon zoom telephoto lenses tested in the range from 70mm through 200mm. Resolution of greater than 60 line pairs per mm was achieved at all focal lengths tested except at 300mm. Images produced by the lens were free of significant chromatic aberration at all focal lengths tested. At 300mm, the EF 70-300mm f/4.5-5.6 DO IS lens was only able to achieve resolution ranging from low 40's to high 50's line pairs per mm. Photographs of birds and other wildlife taken at 300mm and enlarged beyond 8x10 inch print levels noticeably lacked the sharpness and contrast that were achievable with a 300mm prime lens.

Method for Lens Resolution Measurement with Kodak Technical Pan

Digital Camera 50% MTF at 200mm and 300mm

What the EF 70-300mm f/4.5-5.6 DO lens lacks in resolution at 300mm, it appears to make up for with higher contrast and higher MTF scores. 50% MTF was calculated at 200mm and 300mm using this method.

Comparison of Image Sharpness at 300mm

Comparison of Image Sharpness among 300mm lenses using a life size taxidermy specimen

Comparison of Image Sharpness Various Focal Lengths

Comparison of images produced under ambient lighting

Bokeh of the EF 70-300mm f/4.5-5.6

Click here for comparison of diffuse out of focus background examples.

Lense Flare of the EF 70-300mm f/4.5-5.6

Comparison of images produced at 300mm under constant studio lighting (The DO lens flares badly under bright background lighting)

Out of focus background highlights with diffraction grid pattern and aperture diaphragm pattern.
The hexagonal pattern of the aperture diaphragm is notable in the background.
In this photo of a white-eared catbird in the San Diego Zoo, I stopped the lens down to f/10 to try to squeeze depth of field out of the image. This is shot hand-held in the shade at ISO 800, 1/100th sec at 185mm with a 20D. The image-stabilization saved the day.

Other comments on performance characteristics of the EF 70-300mm f/4.5-5.6 DO IS USM lens

Using Polarizing and UV filters with the EF 70-300mm f/4.5-5.6 DO IS USM lens
A lens tip page by Xavier Henri pointed out benefits and disadvantages of using filters with the lens:


The Canon EF 70-300mm f/4.5-5.6 DO IS USM is a compact, very fast-focusing zoom telephoto lens that provides generally excellent imaging function including excellent image stabilization at a high price. It is a weak performer at 300mm. It generally provides noticeably better performance than the cheaper consumer 75-300mm lens. Under some lighting conditions (e.g., backlighting of subject into the lens), the lens flares and renders images unusable. Because of its compactness and generally excellent performance with image stabilization, the lens is very useful for travel or other applications where you don't want to carry a heavy, long and easily noticed lens.

Gallery of images taken with the EF 70-300mm f/4.5-5.6 DO IS USM and Canon D60

Equipment Review Index

© 2004, William L. Castleman
Posted 07 August 2004; last revised 06 June 2007