I bought two 37mm wideangle converters for my Canon HF100 and wanted to see which one is superior.
Here are the specs and pros/cons:
Canon Wide Converter WD-H37 (NOT WD-H37C) .7X , 37mm, no front filter thread, $129.95
Pro: focus throughout zoom range, no softness on left or right sides, no vignetting
Con: no front filter thread, less wide angle
Century Optics Wide Angle Adapter .55X, 37mm, 43mm front filter thread, $124.95
Pro: front filter thread, very small length & diameter, more wide angle
Con: focus only up to half of zoom range, soft focus on 1/8 left and right sides, some vignetting at widest angle
Test Criteria:
Still image Mode, AV Mode, Evaluative AE, Cloudy White Balance, image size 1920x1080, Mounted on tripod, perpendicular to brick wall, no direct sun, bracketed exposures to get images as close as possible, photoshop resizing (no post processing or sharpening).
Century Optics 1/360, FL 4.8mm, F1.8 IMG_0263.JPG
1/90, FL 4.8mm, F4.0 IMG_0264.JPG
1/30, FL 4.8mm, F8.0 IMG_0269.JPG
Canon 1/360, FL 4.8mm, F1.8 IMG_0281.JPG
1/90, FL 4.8mm, F4.0 IMG_0282.JPG
1/30, FL 4.8mm, F8.0 IMG_0285.JPG
Here is the photo (half size) from the Century (f4.0, 1/90):
Here is the photo (half size) from the Canon (f4.0, 1/90):
The following pictures show left, center and right 100% views. For comparison F values of 1.8, 4.0 and 8.0.
Some findings:
For both adapters: F4.0 appears sharper and F1.8 (not surprising) and F8.0 (unexpected).
On the Canon, F8.0 is blurrier than F1.8 (unexpected).
The Century has blurry left and right sides (about 1/10 of width or so) that is very noticable at f1.8 and not too bad at f4.0.