Sony Cyber-shot DSC-TX7 Performance, Timings and Image Quality

PERFORMANCE
The TX7 takes only a couple of seconds to start up and shut down. Shutter lag is not a problem, as the performance tables below readily show. Focus acquisition times are very short, and this held true in my own experience with the camera. I rarely had problems finding focus, even in low light. The TX7 is also very quick when taking successive photos. I was able to fire off a shot every two seconds or so for 15 shots without having the camera pause to write to the memory card. Using the flash slowed shot-to-shot times by about a second or two. As the studio timing shows, the TX7 has an extremely fast continuous shooting mode of 11.4 frames per second, but the camera pauses thereafter for about 15 seconds to write to the memory card.

Shutter Lag (press-to-capture, pre-focused)

AF Acquisition (press-to-capture, no pre-focus)

Continuous Shooting

*Note: Continuous shooting framerates are based on the camera's fastest full-resolution JPEG continuous shooting mode, using the fastest media type available (300x CF, SDHC, etc.). "Frames" notes the number of captures recorded per burst before the camera stops/slows to clear the buffer.

The TX7's flash can be set to auto, on, off and slow syncro, where the camera uses a slow shutter speed in combination with the flash that allows for more background detail. Sony states that the effective flash range is 0.08 to 3.8 meters at wide angle, or 0.5 to 3.1 meters at telephoto, when using automatic ISO sensitivity. Red-eye reduction (through the use of the flash) can also be set. A self timer can be set for 2 or 10 seconds to allow the photographer to get in the picture or to avoid camera shake caused by pressing the shutter button.

The TX7's NP-BN1 rechargeable lithium-ion battery is supposed to last for 230 shots, but I noticed the battery level going down after fewer than 100 shots. I did spend a considerable amount of time searching through the menus, which probably shortened battery life.

Lens Performance
I found images from the TX7 to be consistently good, if a bit soft, with just occasional blurriness in the corners and no vignetting (darkening at the corners). As usual with small cameras, purple fringing occasionally appears in high contrast areas, such as on the borders of the white portions of the boats below.

There is slight barrel distortion at wide angle, but no pin cushion distortion at maximum zoom.

Wide Angle

Telephoto

Video Quality
The TX7 produces excellent AVCHD video, especially if you have the equipment to view the 1080i HD videos properly. The stereo sound is very good, and the sounds of quacking ducks and rushing water came through very well in my test videos.

At this time not every video player is equipped to play AVCHD videos without software add-ons, though this is likely to change as AVCHD coding gets more popular.

*Editor's Note: Since 1080i AVCHD videos are difficult to get online without a lot of compression, we didn't post the sample videos for this review. The TX7 records in the much more web-friendly MP4 format at 1080p and VGA resolutions as well.

Image Quality
I'm pleased with image quality produced by the TX7. Colors are pleasing, while not being overly saturated.

The TX7 does tend to overexpose highlights more than I would have liked.

The camera has white balance settings for auto, daylight, cloudy, fluorescent 1 (white fluorescent lighting), fluorescent 2 (natural white fluorescent lighting), fluorescent 3 (day white fluorescent lighting), incandescent, flash, one push (which will adjust the white balance depending on the light source) and one push set (memorizes the basic white color that will be used). The TX7 also has underwater white balance settings when using the camera with an optional underwater housing. Auto white balance works well.

Auto White Balance, 3200k incandescent light

As shown below, the TX7 produces sharp images with good color and virtually no noise through 200 ISO. Noise intrudes a little at 400 ISO and becomes a problem at 800 ISO. Shooting at higher than 800 ISO should only be done in an emergency.

ISO 125	ISO 125, 100% crop
ISO 200	ISO 200, 100% crop
ISO 400	ISO 400, 100% crop
ISO 800	ISO 800, 100% crop
ISO 1600	ISO 1600, 100% crop
ISO 3200	ISO 3200, 100% crop

Additional Sample Images