Testing a zoom lens

When I bought my 450D I started out with the standard 18-55mm lens, and added a 70-300mm to cover most of the usual range of focal lengths. But when I’m on lunchtime photowalks I don’t want to carry two lenses, nor repeatedly change between them. I often miss shots that need a longer focal length than 55mm, so I’ve been sniffing round some longer “everyday” zooms, such as the Canon 18-135mm and 18-200mm. They are pretty expensive – today’s prices are £287 for the 18-135mm and £404 for the 18-200mm, although cheaper offerings are available from Tamron and Sigma.

Canon EF-S 18-55mm f/3.5-5.6 IS

Then I remembered that I have a 28-80mm lens that came with a 35mm autofocus SLR (an EOS 300, actually) that will fit my 600D. It’s not as “zoomy” as I had might have liked, but as I’d never used it before I thought I’d give it a shot and see if I actually used the extra bit of reach.

Canon EF 28-80mm f/3.5-5.6 II

As it turns out, at lunchtime today I quite often used the extra few millimetres. However I was extremely disappointed with the lens optics. Sharpness at all focal lengths and apertures is poor, there is more chromatic aberration than a prism, and at short focal lengths there is more barrel distortion than an actual barrel. I know it’s just a cheap kit lens from the 1990s but it is significantly worse than the present-day kit lenses.

This was just my gut reaction from taking pictures for one hour and casually inspecting them on the computer later on. I haven’t done any scientific tests so I decided to check a few figures online. You can quickly find that it has been slated by professional reviewers and casual users alike.

The Canon EF 28-80mm f/3.5-5.6 II Lens is very soft wide open – especially at 80mm. Stopping down at least 1 f-stop is required to get reasonable sharpness. Corners are soft at 28mm.

Even on a 1.3x FOVCF body, barrel distortion is obvious at 28mm until fading away at 40mm. Slight pincushion distortion is present from 60 to 80mm.

Some vignetting is exhibited with the aperture wide open. Color and saturation are not wonderful.

The Canon EF 28-80mm f/3.5-5.6 II Lens has a focal length range that falls within the normal, general purpose zoom range. I recommend, if possible, purchasing one of the lenses suggested on the Canon General Purpose Lens Recommendations page.


In the meantime, I’ll stick with the 18-55mm kit lens, and save my pennies for one of the newer Canon zoom lenses. Below I’ve included my favourite few from today’s photowalk around Clifton. Don’t look too much at these photos for the faults I described above – I’ve mostly corrected the distortions, sharpened them, and where the colour fringes were too bad, made the pictures black & white! You also can’t get an accurate look at the low resolutions on this site, although they were clearly visible to me when inspecting the JPGs on my computer at “fit to screen” – not even zoomed in for pixel peeping!

Gate hinge
Clifton house
Front door and window
Church door
Victoria Rooms

2 thoughts on “Testing a zoom lens

  1. Pingback: Digital infrared

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