Canon EOS Rebel T1i

Sharpness

We were disappointed by the T1i’s sharpness performance, across the entire gamut of focal lengths and apertures. Where most cameras will have a maximum line widths per picture height result of over 1500, the T1i peaked at 1360, with an average of only 868 line widths, and a minimum of around 550. This is much lower than we normally see. We suspected the poor results might be due to a hardware problem and asked Canon to supply us with a second camera that the company had tested to insure it was performing up to spec. In our retesting, though, the sharpness results didn’t improve. More on how we test sharpness.

Image Sharpness and Chromatic Aberration

Focal Length:

18.0mm

37.0mm

55.0mm

Click blue squares to change sample crops below
f/3.5 f/9 f/22
f/4.5 f/11 f/29
f/5.6 f/14 f/36

Image Stabilization (6.62)

The T1i uses lens-based image stabilization, and shooting with the 18-55mm kit lens, we experienced mixed results. When it improved the resolution of captured photos it did so quite well, but is was a bit of a crapshoot as to when it that improvement would take place. Also, the T1i’s overall sharpness problem meant that a relatively minor improvement resulting from image stabilization could be interpreted as a significant percentage improvement in our testing.

To test the capabilities of the image stabilization system, we shoot a slanted-line target at a number of shutter speeds, with Image Stabilization on and off, testing separately for horizontal and vertical stabilization. Our specially designed rig has two levels of vibration, a high shake setting that approximates the shake you’d find when shooting with one hand or when moving, and the low shake setting that’s close to what you would experience when standing still and holding the camera securely.

First we looked the effectiveness of stabilization at our lower shake speed. While horizontally, it generally seems that the stabilization system will improve results, if only slightly, vertically the stabilization makes matters worse up until 1/15 of a second, where it produced a huge improvement.

At the higher shake speeds, image stabilization seems slightly more effective horizontally, though not at really high shutter speeds. Vertically the results are mixed, but stabilization never makes a huge difference one way or the other.

Image Stabilization Comparison Table			Expand
	Low Shake IS Off	Low Shake IS On	High Shake IS Off	High Shake IS On
1/500
1/250
1/125
1/60
1/30
1/15
1/8

We only have stabilization data for two of the four comparison cameras, namely the Nikon D5000 and the Pentax K2000. The T1i scores comparatively well in this section, but this is in part due to the relatively large percentage jump a small improvement produces when the top resolution is low to begin with, which is the case here.