Pentax K-X

	Video: Low Light Performance Summary
Comprehensive video testing and analysis by Jeremy Stamas and the staff of
• Overall low light performance was disappointing compared to the competition. • Low light sensitivity was not up to par and the camera didn't produce accurate colors in low light, although color saturation levels were high. • Noise levels in low light were much worse than the competition. One of the highest noise levels for a video-capable DSLR we've tested.
	Video: Motion & Sharpness	Page 14 of 21	Video Features

Video: Low Light Sensitivity (0.97)

Testing the Pentax K-x with its kit lens, the camera didn't do a very good job with low light sensitivity. Still, compared to some of the abysmal results we've gotten from other video-capable DSLRs, the K-x's numbers don't look too bad. The K-x required 23 lux of light to register 50 IRE on our waveform monitor. Of the DSLRs we compared it to below, only the Nikon D5000 had a better low light sensitivity (the Panasonic GF1 and Canon T1i were just slightly worse than the K-x). Click here for more on how CamcorderInfo.com tests low light sensitivity.

Video: Required Illumination *

* the lower the lux required, the better the performance

Of course, much of a camera's low light sensitivity score comes down to what kind of lens you are using. The kit lens on the K-x is an f/3.5 18-55mm lens, so it isn't that fast. If you shoot video with a lens that has faster aperture settings, you're likely to get better low light sensitivity in video mode on the K-x.

Video: Low Light Color Performance (5.67)

In low light, the K-x didn't have very good color accuracy, with its score dropping significantly from our bright light testing. The camera measured a color error of 6.27 in low light, although its saturation level remained a high 101.2%. The camera was still capable of producing solid, vivid colors in low light, but its overall image had a slight pink-purple hue, which we think attributed to its poor color accuracy performance. Click here for more on how CamcorderInfo.com tests low light color performance.

Video: Low Light Color Performance
Color Test Chart (above), Color Error Map (right)
The Pentax K-x produced a color error of 6.27 and a saturation level of 101.2% in our low light video testing. (The map on the right is a diagram of the color error. The length and direction of each line indicates how the camera processed each particular color while capturing video.)

In the comparison images below, you should be able to see the slight pinkish tone we're talking about on the Pentax K-x. The Panasonic GF1 and Canon T1i offer more of a natural grey tone in their images, while the K-x appears more colorful in the grey portions of the image. All of these camcorders maintained strong saturation levels in low light, although the Nikon D5000 continued to produce an overexposed image, which made some of its colors look washed-out and bland.

Video: Low Light Comparison
Pentax K-x	Nikon D5000
Panasonic GF1	Canon T1i

Video: Low Light Color Score Comparison

Video: Low Light Noise Performance (6.73)

The Pentax K-x managed disappointing results in our low light noise test. The camera averaged 1.8375% noise, which is significantly higher than the competition. In the crops below you can see this extra noise on the image from Pentax—especially when compared to the relatively clean images coming from the other cameras. Click here for more on how CamcorderInfo.com tests low light noise performance.

Video: Noise at 60 lux Auto
Pentax K-x 100% Crop	Nikon D5000 100% Crop	Panasonic GF1 100% Crop	Canon T1i 100% Crop

The good news for the K-x is that the camera still captured a sharp image in low light—sharper than the Nikon D5000 and Panasonic GF1. Still, with this extra sharpness comes more noise, which is definitely noticeable in the cropped image above. Yes, the GF1 and D5000 show some signs of noise and discoloration, but it is not as prominent as on the image from the K-x. The Canon T1i looks quite good in comparison, but you have to remember that it is the only camera shown above that can record 1080p video (the rest max out at 720p).

Video: Low Light Noise Score Comparison