Lens Test 4
Concerned, I searched the archives of every Canon EOS related discussion groups, reviews for any indications that this was normal. While I managed to find one person who identified significant distortion at 28mm and posted his test photos at his website, I was hungry for more. Most people who reviewed this lens had only mentioned verbally the level of distortion (whether barrel or pincushion) in their own non-qualitative terms. Whats' more, I did a rough count and gathered that while 50% mentioned significant distortion, the other 50% seemed to not notice it much. In my search for more confirmation, I planned a more comprehensive set of comparison tests designed to be used as ammunition for my case to be presented to Canon Singapore.

• Indoor comparative lens test using EF28-135 f/3.5-5.6 IS USM, EF50 f/1.8 Mk II and Tamron 28-200 f/3.8-5.6 LD Aspherical (IF). (Roll 4 - Kodak Elite II Chrome 100)

  Frame	Focal (mm)	TV	AV	IS	Remarks	Click On Thumbnail
  1	28	1/5	8	OFF	AV mode with hood, NO UV, tripod & remote shutter release TC-80N3 & Mirror Lock Up activated
  2	28	1/10	5.6	OFF	"
  3	28	1.4	11	OFF	"
  4	35	1.3	8	OFF	"
  5	35	1/5	5.6	OFF	"
  6	35	1.8	11	OFF	"
  7	50	1/5	8	OFF	"
  8	50	1/10	5.6	OFF	"
  9	50	1.4	11	OFF	"
  10	100	1/5	8	OFF	"
  11	100	1/10	5.6	OFF	"
  12	100	1.4	11	OFF	"
  13	135	1/5	8	OFF	"
  14	135	1/8	5.6	OFF	"
  15	135	1.4	11	OFF	"
  16	28	1/5	8	-	Settings as above but lens used is Tamron 28-200 f/3.8-5.6 LD Aspherical (IF)
  17	28	1/8	5.6	-	"
  18	28	1.5	11	-	"
  19	35	1.3	8	-	"
  20	35	1/5	5.6	-	"
  21	35	1.6	11	-	"
  22	50	1/4	8	-	"
  23	50	1/5	5.6	-	"
  24	50	1.8	11	-	"
  25	100	1/5	8	-	"
  26	100	1/8	5.6	-	"
  27	100	1.5	11	-	"
  28	135	1/4	8	-	"
  29	135	1/6	5.6	-	"
  30	135	1.5	11	-	"
  31	50	1/5	8	-	Settings as above but lens used is EF 50 f/1.8 MkII
  32	50	1/8	5.6	-	"
  33	50	1.4	11	-	"
  34	28	1/100	11	ON	AV mode with hood, UV and lens used is now again EF 28-135 f/3.5-5.6 IS USM
  35	50	1/125	11	ON	"
  36	135	1/160	11	ON	"

(See enlarged images taken from this test comparing their sharpness.)

Armed with all my four test results, I went to Canon Singapore to try to get some explaination or any possible rectification for my significant barrel distortion. I spoke with a Customer Service Technical Supervisor who examined my photos. As she hasn't handled any previous enquiries similar to mine before, she offered to do some tests on their own EF28-135 lens to see if same amounts of distortion are present. The agreement was that if their results show less distortion, she would have to feedback to Canon Japan for further instructions of whether to replace with a new piece or if any rectification can be done.

The following week, she called me up and invited me back to Canon Singapore and showed me their results. She had taken some photos using both the EF28-135 as well as the EF28-105 for comparative purposes. To my eye, it looks like while their EF28-135 showed almost similar amounts of barrel distortion at 28mm, their EF28-105 was slighty better at 28mm. Thus, I had no alternative but to accept my lens as it is since this was a design issue.