SONY Cyber-shot DSC-TX7 (50i)

This is neither intended to be, nor to become a "review". It's just a collection of information and notes.

Specifications · Focal Length · Recording Formats · Firmware · Special Notes · Gallery

The SONY DSC-TX7 is my third T-Series camera. I started with a SONY DSC-T3 in January 2005, because my other camera got too big, and I wanted the most compact 5MP 3x zoom camera available: "The ideal measurements for a camera are 90-60-19."
When SONY added the optical stabilizer to the T-Series, I was very tempted to get a new model, but I did not like the shape of the available models. I finally switched to the SONY DSC-T700 in October 2008, because of the perfectly flat and compact body design. Because of the 25mm wide angle, I decided to get the SONY DSC-TX7. Besides the different focal length range, the DSC-TX7 has a lot of improvements compared to the DSC-T700.

Special Issues

Sharpness and Contrast

From the beginning, I had the impression that outdoor shots are not as crisp and clear as they should be. In special, I did not manage to get a sharp iSweep panorama. After comparing my TX7 with a demonstrator model at the shop, I decided to have the camera sent in. After two weeks I could pick up the camera, where the repair note only said "Softwareupdate". The camera was well packed, perfectly cleaned, and the front slider seems to work smoother than before. However, the image quality is the same as before.

This is a side-by-side comparison of 100% crops from two still image shots of similar focal length.

Comparison: Far distance subject, DSC-TX7 vs. DSC-T700.

This is a side-by-side comparison of 100% crops from two different DSC-TX7 (mine and the demonstrator from the shop).

Comparison: Two different DSC-TX7.

I still hope that this is due to a defect, and that it will either get fixed next time I send in the camera, or the replacement model will work at least as good as the demonstrator from the shop - because I really like the 25mm wide angle, and the improved feature set.

Update: 2010-05-04 - The camera is on its way to the service for the second time...

Close Focus Mode

While doing more comparisons between the T700 and the TX7, I noticed that the TX7 seems to have different exposure strategies. When shooting in Close Focus mode with forced flash under normal light, the T700 stops down to f/5.6. The TX7 did the shots at f/3.5, with shallow depth of field and very soft corners. Even after using a strong flashlight, the camera only stopped down to f/4.5. With forced flash, exposure should not depend on the ambient light, at least not that much. I will do more tests as soon as I get the camera back. If my observations are correct, then the close focus mode of the TX7 is next to useless.

Specifications

Outer Dimensions	98mm × 61mm × 18mm
Optical Zoom	4	×
Actual Focal Length	4.43	-	17.7mm
Apparent Focal Length	25	-	100mm	(4:3 Still Images)
	28	-	112mm	(16:9 Video)
Crop Factor	5.64	×
Maximum Aperture	F3.5	-	4.6
Sensitivity	ISO	125, 200, 400, 800, 1600, 3200
Battery	SONY "Lithium N" NP-BN1 (2.2-2.3Wh)

Focal Length Comparison

Having an aspect ratio of 4:3, the camera captures a little less width, and some more height than a 3:2 Full Frame DSLR camera. Using a 24-105mm lens would cover about the same wide angle height and telephoto width, but for cropped formats, there is no single lens covering the whole range.

    3:2
Full Frame    3:2
Crop 1.3    3:2
Crop 1.5    3:2
Crop 1.6    Four Thirds
Crop 2.0

Same Width 26.0 - 104mm 20.0 - 80mm 17.3 - 69mm 16.2 - 65mm 12.5 - 50mm

Diagonal 25.0 - 100mm 19.2 - 77mm 16.6 - 67mm 15.6 - 63mm 12.5 - 50mm

Same Height 23.1 - 93mm 17.7 - 71mm 15.4 - 62mm 14.4 - 58mm 12.5 - 50mm

Recording Formats

Type	A.R.	Q.	Dimensions			P.Count	A.R.
Still Image	4:3	10M	3648	×	2736	9.98MP	1.33:1
Still Image	16:9	7M	3648	×	2056	7.50MP	1.77:1
Still Image	4:3	5M	2592	×	1944	5.03MP	1.33:1
Still Image	16:9	2M	1920	×	1080	2.07MP	1.77:1
Still Image	4:3	VGA	640	×	480	0.30MP	1.33:1
Type	Opt.	Or.	Dimensions			P.Count	A.R.
Panorama	Std.	Ver.	3424	×	1920	6.57MP	1.78:1	~120°
Panorama	Wide	Ver.	4912	×	1920	9.43MP	2.55:1	~180°
Panorama	Std.	Hor.	4912	×	1080	5.30MP	4.54:1	~180°
Panorama	Wide	Hor.	7152	×	1080	7.72MP	6.62:1	~270°
Type	A.R.	Q.	Dimensions			Bitrate	Frames
AVCHD	16:9	FH	1920	×	1080	17Mbps	50i
AVCHD	16:9	HQ	1440	×	1080	9Mbps	50i
MPEG-4	16:9	12M	1440	×	1080	12Mbps	25p
MPEG-4	16:9	6M	1280	×	720	6Mbps	25p
MPEG-4	4:3	3M	640	×	480	3Mbps	25p

Firmware

When I got my camera back from the service, the note only said "Softwareupdate", so I decided to investigate. It looks like SONY realeases only very few firmware updates for their cameras.

The firmware version is not displayed during normal operation, it has to be activated with a certain procedure. The only available update for a T series camera was for an older model using buttons instead of a touchscreen, so these instructions did not help much. But with only four buttons and the zoom lever available, there are ony very few options left for powering on the camera while pressing another button.

To activate the hidden menu item, hold the zoom lever in telephoto position (T) while powering on the camera using the playback button. Then press MENU, enter the setup mode (toolbox icon), and page down to the fourth page...

SONY DSC-TX7 Firmware Version Menu Item