Previous page Next page

Photographic tests

White balance

The TX1 IS has five white balance presets (daylight, cloudy, tungsten, fluorescent and fluorescent H) in addition to the default auto white balance. There is also a 'custom' white balance setting, which allows you to point the camera at a white or gray object and set the white balance manually. The custom white balance setting is remembered even if you turn the camera off. In normal outdoor shooting the auto white balance works perfectly. Indoors it's a bit more hit and miss, as we've seen with most Canon PowerShots incandescent (tungsten) lighting causes a fairly strong orange color cast (though switching to manual gives a perfectly neutral result).

Auto White Balance Fluo Preset Auto White Balance Incandescent preset
Fluorescent light - Auto white balance average,
Preset white balance average
Incandescent light - Auto white balance poor,
Preset white balance excellent

Flash

The TX1's tiny built-in flash has a quoted working range (using Auto ISO) of 2.0m (6.6 ft) at the wide end of the zoom and 1.2m (3.9 ft) at the tele end, which is on the weak side (to say the least) but is just about acceptable for social snaps across the dinner table or down the pub. There is an anti-red-eye mode, but this slows down the picture taking process, doesn't work that well, and puts even more strain on the already rather insipid battery life. The in-camera red-eye removal isn't fully automatic, but it does work.

Click here for flash test chart

Skin tone - Excellent color and exposure.
To see the same shot with red-eye removed in camera click here

Macro

The TX1's 'normal' macro capabilities are nothing to write home about; at the wide end you can get as close as 10cm, capturing an area around 10x7.5cm. At the long end of the zoom the nearest you can focus is 1.0m (around 3.3 ft), though you end up filling the frame with roughly the same area (11x8cm). The TX1 has the same 'super macro' mode we saw on the S2 IS / S3 IS; this allows you to focus right down to 0cm (yes, 0cm) from the front of the lens, capturing an area around 15x11mm - though obviously there is a limit to how useful this is (there aren't many things you can actually photograph from that close, and you tend to block out all the light with the camera's shadow). You'll also see fairly strong chromatic aberration in the super macro shot, and soft corners, though for 'real world' shots it's a lot less obvious.

We found the TX1's autofocus system to struggle slightly at very close distances, often taking two or three attempts to lock onto the right point, but once there it was generally very accurate.

Resolution

I would not have been surprised if the ambitious range of the TX1's tiny lens had resulted in less than class-leading resolution, but in fact the results aren't bad at all, and are broadly in line with most of the other 7MP cameras on the market. There are some slightly unpleasant moiré effects visible at the very highest frequencies (and distinctly jagged edges on some diagonals) but nothing you'd see in a normal photo / print.

Crops

Click here for the full resolution test chart

Horizontal LPH

Absolute resolution 1575 LPH
Extinction resolution 1800 LPH

 

Vertical LPH

Absolute resolution 1500 LPH
Extinction resolution 1900 LPH *

*moiré visible

Distortion and other image quality issues

Considering the zoom range that Canon has squashed into the TX1's tiny body distortion is pretty well controlled. There is moderate (1.1 % barrel) distortion at the wide end of the zoom (click here for test chart), but it's nothing to worry about unless absolutely straight edges are critical (in which case just zoom in a little) There is a small (0.2%) amount of measurable pincushion distortion at the telephoto end of the zoom (click here for test chart).

General comments

I should say first of all that - outside the studio in the real world - the TX1 produces considerably better output than I expected. I was prepared for some serious compromises but found that for the most part the results are as good as any compact 7MP camera - and a good deal better than many. Of course there are problems; at the long end of the zoom there is a touch of softness, particularly at the corners, and if you look very closely on-screen you can see fine detail being lost to NR even at ISO 100, occasional mild fringing and the usual problems with highlight clipping in very contrasty scenes, but overall I doubt the typical user would have any serious complaints. Certainly not in a normal sized print.

Highlight clipping

In common with virtually every compact camera we've tested in the last few years the TX1 struggles to capture scenes with a very wide dynamic range (bright sunny days with deep shadows), and as usual the exposure system tends to produce blown highlights in such situations. You can combat it to some extent by underexposing slightly, but this, unfortunately, is one of those things you currently just have to live with.

100% crop 390mm equiv. F5.6
100% crop 390mm equiv. F5.6

Purple fringing

Despite spotting some chromatic aberration and purple fringing when viewing our studio test charts at 100% we were pleasantly surprised to find that out in the big bad world the TX1 actually produces very little visible fringing (it's far better than the S3 IS in this respect). You're most likely to see a faint purple or red fringe next to an area of extreme over-exposure, but you have to look for it (and unless you're producing poster prints it's not going to be a major issue). The sample below is the worst we found.

100% crop 390mm equiv. F5.6

Noise

With tiny, high pixel count chips noise is always going to be an issue, and to a large degree this is more a test of the effectiveness (both measurable and visible) of a camera's noise reduction system. Designers have to balance the desire to produce smooth, clean results with the need to retain as much detail as possible (if you blur away the noise, you blur away image detail too).

With the TX1 Canon has taken a relatively light-handed approach to noise reduction, with the result that there is mild noise visible in shadow areas even at ISO 100, and by ISO 400 and above it is strong enough to show in anything but the smallest print. The advantage of this approach is that you don't start to lose too much detail until you get to ISO 400, and even then the results look fairly sharp compared to many competitors. That all said, you can still see the effect of NR on really fine low contrast detail (such as distant foliage) at all ISO settings - this, it seems, is something you cannot escape from these days, no matter what camera you choose.

ISO 80 ISO 100 ISO 200 ISO 400 ISO 800 ISO 1600
100% Crops

Noise graph

Indicated ISO sensitivity is on the horizontal axis of this graph, standard deviation of luminosity is on the vertical axis.

Low contrast detail

What the crops and graph don't show is the effect of noise reduction on low contrast fine detail such as hair, fur or foliage. An inevitable side effect of noise removal is that this kind of detail is also blurred or smeared, resulting in a loss of 'texture'. In a new test the crops below show the effect of the noise reduction on such texture (hair) as you move up the ISO range.

100% Crops
ISO 80 ISO 100 ISO 200
ISO 400 ISO 800 ISO 1600

The TX1 uses fairly light NR, which means that there is a little more noise than you'll see with some competitors at ISO 80-400, but a touch more detail too. That said it's only really at ISO 80 or 100 that you can be sure of capturing really fine low-contrast detail. and by ISO 800 it's just a mess.

Previous page Next page
4
I own it
1
I want it
6
I had it
Discuss in the forums

Comments