Canon XH A1S Camcorder Review

Low Light Performance Summary
• Low light sensitivity was good—roughly what we expect from a pro camcorder. • Low light sensitivity was a bit worse than the Canon XL H1A (likely due to the different lens on the XH A1S). • Good color in low light, particularly when using auto gain settings. • Noise levels were higher than we expected to see, especially when manually setting the gain in the 6dB to 12dB range. • Noise was much lower when using auto gain controls.
	Motion & Sharpness Performance	(Page 5 of 18)	Audio

Low Light Sensitivity (4.13)

The low light sensitivity for the XH A1S was quite good, although it did put up worse numbers than the Canon XL H1A. Testing the camcorder with absolutely no gain boost (0dB gain setting) the XH A1S required 61 lux of light to register 50 IRE on our waveform monitor. With auto gain engaged (which allows the gain levels to go as high as 18dB) the camcorder needed just 7 lux of light to reach the same level. (More on how we test low light sensitivity.)

Required Illumination *

* the lower the lux required, the better the performance

The Canon XL H1A did a bit better than the XH A1S in our 0dB gain sensitivity test. Since the camcorders have the same sensors, it is likely that this disparity is a result of the different lenses featured on the two models. The Canon XH A1S only showed minor differences from the Sony HDR-FX1000 in our low light sensitivity test.

We also tested the sensitivity on the XH A1S using its alternate frame rate settings. Recording with the camcorder's 24p and 30p modes, we found the low light sensitivity drastically improved. This makes sense, as the lower frame rates use slower shutter speeds and allow more light to hit the sensor. So, if you know you'll be filming in 24p, you can expect a much better low light performance from the XH A1S compared to its 60i results.

The table below lists the amount of light needed for the camcorder to reach 50 IRE on our waveform monitor using a variety of settings:

Low Light Color (7.19)

The XH A1S did a good job with our low light color and its results were on par with the Canon XL H1A. It had slightly better color accuracy scores than the Sony HDR-FX1000, but both camcorders had similar numbers as well. (More on how we test low light color.)

0dB Gain Low Light Color Performance
Color Test Chart (above), Color Error Map (right)
The Canon XH A1S produced a color error of 6.98 and a saturation level of 43.86% in our 0dB low light color testing. (The map on the right is a diagram of the color error. The length and direction of each line indicates how the camcorder processed each particular color.)

With gain set to 0dB, the Canon XH A1S obviously struggled to produce a viable image in our low light testing. This is not unusual, as most camcorders struggle with this test. With 0dB gain, the camcorder measured a color error of 6.98 and a low saturation level of 43.86%. Despite the low saturation level, the camcorder produced some strong colors and retained quite a bit of detail. Below the XH A1S 0dB gain image is compared to its Auto Gain image, as well as the 0dB images from two comparison camcorders.

0dB Gain Comparison
Canon XH A1S	Canon XH A1S (Auto Gain)
Canon XL H1A	Sony HDR-FX1000

Obviously, the XH A1S is a lot brighter using its auto gain setting in low light than the 0dB setting. We put that comparison in there to give you a better idea of how underexposed the 0dB gain image is. The Canon XL H1A has a very similar image to the XH A1S in our 0dB test, but the Sony HDR-FX1000 has a slightly more saturated image. The Sony's colors appear deeper and more vivid, but its color accuracy isn't significantly better than the two Canon camcorders.

6dB Gain Low Light Color Performance
Color Test Chart (above), Color Error Map (right)
The Canon XH A1S produced a color error of 4.07 and a saturation level of 89.98% in our 6dB low light color testing. (The map on the right is a diagram of the color error. The length and direction of each line indicates how the camcorder processed each particular color.)

Bumping the gain up to 6dB gives the XH A1S a significant boost in low light. Its color error improves a lot (down to 4.07) and its saturation level goes all the way up to 89.98%. In fact, the 6dB gain image looks almost as bright as the camcorder's image using its auto gain setting (see below).

6dB Gain Comparison
Canon XH A1S	Canon XH A1S (Auto Gain)
Canon XL H1A	Sony HDR-FX1000

Neither the Sony HDR-FX1000 nor the Canon XL H1A had much different color errors than the XH A1S in our 6dB gain test. The saturation levels of the three camcorders were slightly different, however, with the XH A1S being the highest. The table below shows that the camcorder's color error improved even more when we boosted the gain to 12dB, although at that point the image actually appeared a bit too bright.

None of the pro camcorders we tested in this set really stand out as the best low light color performer. Each camcorder did a decent job in this test and the Canon XL H1A and XH A1S showed nearly identical results. In our low light noise testing, however, we did run into a few surprises—specifically with the poor performance from the XH A1S.

Low Light Color Score Comparison

Low Light Noise (3.57)

For low light noise, we tested the XH A1S at three gain settings: 0dB, 6dB, and 12dB. At 0dB, the XH A1S measured 1.81% noise, which isn't a great score. With 0dB gain, a camcorder should produce far less noise. For its credit, the XH A1S does have a -3dB gain setting and its noise reduction options that can be used to bring down the noise levels even further.  (More on how we test low light noise.)

0dB gain at 60 lux
Canon XH A1S 100% Crop	Sony HDR-FX1000 100% Crop	Canon XL H1A 100% Crop

The above images don't do a great job illustrating it, but the Canon XH A1S showed more noise at 0dB gain than either the Sony HDR-FX1000 (1.2175%) or the Canon XL H1A (1.5125%). This high-noise trend with the XH A1S continues as we bring the gain up to 6dB gain.

6dB gain at 60 lux
Canon XH A1S 100% Crop	Sony HDR-FX1000 100% Crop	Canon XL H1A 100% Crop

With 6dB gain, the XH A1S averaged 2.33% noise. This is significantly higher than the noise measured on the images from the Sony HDR-FX1000 and Canon XL H1A's (averaged 1.3425% and 1.5775% respectively).

12dB gain at 60 lux
Canon XH A1S 100% Crop	Sony HDR-FX1000 100% Crop	Canon XL H1A 100% Crop

Interestingly, the noise levels went down slightly when we raised the gain from 6dB to 12dB. The noise levels didn't go up much, however, with the camcorder registering 2.24% noise at 12dB gain. As we saw in the previous tests, this noise level is higher than the other two camcorders we used as comparisons. The Sony HDR-FX1000 had just 1.8525% noise at 12dB gain, while the Canon XL H1A managed 2.18% noise (very similar to the XH A1S).

The XH A1S achieved its lowest noise levels when we tested it using its auto gain setting. With auto gain engaged, the camcorder measured a respectable 1.19% noise. So, if you plan on using the XH A1S in auto mode, it should give you pretty good noise results in low light.

Low Light Noise Score Comparisons