One Man's Quest for a Decent Multi-Purpose Lens
At the end of March 2001, I finally bought the lens which I have been hearing about for so long in discussion groups. This was going to be an exciting time for me as this will be the first Canon branded ZOOM lens with the Image Stablisation technology that everyone has been raving about.

Lens Test 1
When I got the lens, I immediately went and did some simple lens tests just to see the quality of my lens. For the sake of comparison, I decided to use the EF 50 f/1.8 MkII as a benchmark for the various components including colour, contrast and sharpness. In the tests, I had a few different situations:

• Indoor shots (handheld, P mode) with paper pined to the wall (Roll 1 - Kodak Elite II Chrome 100)

  Frame Focal (mm) TV AV IS Remarks Click On Thumbnail 1 28 1/20 3.5 ON with hood & UV 2 35 1/15 3.5 ON " 3 50 1/13 4.5 ON " 4 100 1/10 5.6 ON " 5 135 1/8 5.6 ON " 6 50 1/60 2.0 - EF 50 f/1.8 MkII with hood & UV 7 50 1/13 4.0 - "

• Outdoor shots (handheld, P mode) with newspaper on the ground (Roll 1 - Kodak Elite II Chrome 100)

  Frame Focal (mm) TV AV IS Remarks Click On Thumbnail 8 28 1/320 11 ON with hood & UV 9 35 1/320 11 ON " 10 50 1/320 11 ON " 11 100 1/400 10 ON " 12 135 1/400 10 ON " 13 50 1/800 7.1 - EF 50 f/1.8 MkII with hood & UV 14 50 1/400 10 - " 15 50 1/200 14 - "

I also took some shots to test the effect of its' Image Stablisation. When I got the results back, the first thing that struck me was the tonal difference in the photos between the EF28-135 and the prime EF50. The former displayed a much warmer tone compared to the latter.
See enlarged images taken from this test comparing their sharpness (comparable) and tonal difference (EF28-135 has a warmer cast).

Lens Test 2
Feeling uncomfortable, I decided to do some more tests (I had around 10 frames left in a roll that was used for my annual company dinner) as I didn't know if the UV filter caused the tonal difference.

• Further tonal difference tests (handheld, P mode) (Roll 2 - Kodak Supra 400)

  Frame	Focal (mm)	TV	AV	IS	Remarks	Click On Thumbnail
  25	50	1/200	9	ON	with hood & NO UV
  26	50	1/250	8	-	EF 50 f/1.8 MkII with hood & NO UV
  27	50	1/25	29	ON	with hood & UV
  28	50	1/25	29	ON	with hood & NO UV
  29	50	1/80	22	-	EF 50 f/1.8 MkII with hood & UV
  30	50	1/80	22	-	EF 50 f/1.8 MkII with hood & NO UV

The results of this test confirmed that the filter was not the culprit and the warmer tone was due to the lens itself.