EF 28-135mm f/3.5-5.6 IS USM

Others' Opinions:

First posted on http://www.photozone.de/canon.htm, and subsequently contributed by the author himself, Mr John Sokash (email address not provided at his request):

I am posting this info for all to use. I always mount a filter on the front end of my Canon EOS lenses to protect them from dirt and other abuse. Usually this is a Tiffen 812 or TMC Haze. I tend to leave this filter on at all times, because I don't want to tear up the filter threads on the front of the lenses by frequently taking a filter on/off. So on those occasions when I want to use another filter, it usually gets stacked on top of the protecting filter. This leads to the problem of vignetting.

The lenses that I used to shoot a test roll of film are the Canon EOS 20mm f2.8, the Canon EOS 28-80 f3.5 to f5.6 Mark I (1992 time frame) and the 28-135 f3.5 to 5.6 IS lens. In general, vignetting with stacked filters has always been a problem with these three lenses, namely at the wide end. One conclusion that I reached was that stopping down the lens, going from f2.8 to even f 11 with the 20mm wide angle lens did not decrease the vignetting one bit. Vignetting is strictly related to focal length.

As far as the 20 mm f2.8 lens is concerned, one 72mm filter is the maximum. If you want to change it from a Tiffen 812 to a Circ Polar, you must change the filter. For the Canon 28-80 f3.5-5.6 Mark I lens, vignetting is only at the 28mm focal end, and is gone by zooming up to 35mm. Even at the 28mm end, the vignetting noticed with a circ polar on top of the Tiffen 812 protection filter is minimal, maybe 3 percent of the image at the corners. For print films, given the photodevelopers do not always reproduce the negative at 100 percent, you might even get away with the slight vignetting at the 28mm end, not showing up on the finished prints.

The hardest vignetting problem to solve was with the Canon 28-135 f3.5-5.6 IS lens. The trick here is to use a 72 to 77mm step up ring and then mount a thin 77 mm circ polar on top of it. The wide angle vignetting problem is gone by 35 mm focal length. I tried a regular 72mm circ polar and a regular 77mm circ polar with a 72 to 77 step up ring, stacked on top of the protection Tiffen 812, but the vignetting problem carried past the 35 mm focal length, almost out to 50mm focal length before it was gone.

For the record, I tried some vignetting test shots with a Canon 50mm f1.8 Mark I (older metal mount) lens, using a 52-58 step up ring and two 58 mm filters stacked on top of the ring, and no vignetting was noticed.

Related Links

• WWW Photo Zone (Combined Results)

• Dave's Comparison of 3 Canon Mid-Range Zooms

• Photodo MTF Test Results

• Patrice Chiniara's Comments

Feel free to give me feedback or new links.

All pictures scanned from Canon brochures, in which the original image is actually about 10 times smaller than the image that you see above.
Hence, the resolution of the above image is limited by the original size of the brochure image.  The image above is life-size.