Sony Ericsson claims the U1 (Satio) is capable of giving a mediocre compact camera a run for its money, and I have basically said that I more or less agree with that statement. But just how does match up to a high-end professional DSLR camera? That’s what I wanted to find out and judging by the feedback from you guys, it seems you’re pretty much with me on this one.

I must admit that this is in no way a fair comparison! My DSLR setup included the top-tier Nikon D700 equipped with a professional grade Nikkor 24-70mm f/2.8 lens and an external omnidirectional flagship Nikon SB-900 flash unit, meaning that I am not limited to using direct flash. Keep in mind that the entire setup is worth more than £4,000 and we’re putting it up against a relatively simple camera phone with a price tag almost ten times lower.

In this article we’ll be taking a closer look at how the contenders do at night photography. We’ll kick off with six comparative shots using flash and then end with a comparative shot without the use of flash. Before going any further though, let’s take a look at some of the more technical aspects of things…

Sony Ericsson Satio

The Satio has a 12 megapixel CMOS image sensor, which is believed to be the Sony IMX060PQ. This means that it’s a type 1/2.5″ sensor (5.76 x 4.29 millimetres) with an aspect ratio of 4:3. Being it’s a type 1/2.5″ sensor it has a so-called crop factor of exactly 6.25x. This crop factor is used when calculating the effective focal length of the lens. On the back of the phone it says that the focal length is 5.9 millimetres, which translates into around 37 millimetres in full frame terms (in other words that’s the effective focal length). The aperture is fixed at f/2.8 or an effective 2.1 millimetre opening. The shutter speed of the Satio was about 1/30th of a second with a variable ISO-setting ranging from ISO 125 to ISO 200 on all the flash pictures.

Nikon D700

The Nikon D700 also features a 12 megapixel CMOS image sensor, but this one is a so-called full frame sensor with an aspect ratio of 3:2. This means that the sensor has no crop factor and that the focal length written on the lens is equal to the effective focal length. This means that I should set my lens to a focal length of around 37 millimetres to match the focal length of the Satio. However, by mistake I had changed it to 32 millimetres when taking the pictures. This does not affect the image quality and only means that I’m getting a slightly wider picture with the D700. To match the aperture of the Satio, I had fixed my aperture at f/2.8 or an effective 11.4 millimetre opening. I had set the shutter speed to 1/125th of a second and the ISO-speed to ISO 100 on all the flash pictures.

The following pictures show 100 percent crops of the area in focus. By pressing the links below the picture, you can download the original files. The Nikon D700 is on the left and the Satio is on the right. Enough said. Let’s get on to some picture samples!

Picture sample #1

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The Satio has rendered the image incredibly over saturated.

Picture sample #2

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Heavy noise reduction kicks in on the Satio, resulting in blurry areas with little detail.

Picture sample #3

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Fairly good rendering of edge detail on the Satio.

Picture sample #4

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Image noise is a serious problem with a small size sensor.

Picture sample #5

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Impressive difference in fine, tiny details with low contrast. Can you distinguish noise from details in the Satio sample? Probably not.

Picture sample #6

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These crops show the great difference in resolution between the two cameras.

Picture sample #7

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These are the photos that were shot without the use of flash. This means that the Satio increased its light sensitivity by kicking up the ISO-setting to a maximum of ISO 500. This naturally also means that there’ll be a lot more noise in the image, which is quite clear from the picture. Being in auto mode, the Satio chose a shutter speed at 1/8th of a second, under-exposing the picture about 3-4 EV stops. I tried to replicate the shot on the Nikon D700 using the exact same settings – 1/8th of a second shutter speed, f/2.8 and ISO 500. The result is the top left image (first download link). It is clear that this is already a much improved picture and that the Nikon D700 handles low light situations much better than the Satio. However, it is still underexposed, although not as much as the one from Satio. Changing the camera mode to aperture priority resulted in a much nicer picture (second download link) and a shutter speed of almost a full second.

Conclusion

The biggest problem with a mobile phone camera is the compact size of its image sensor. The sensor area on the Nikon D700 is almost 35 times larger than the sensor area on the Sony Ericsson Satio. Being that the camera resolution is almost identical, this means that the Nikon D700 is capable of getting a lot more light particles (photons) to its sensor. In other words there is (for the most part) not a need to digitally boost the light sensitivity of the camera sensor, which is the case of the Satio.

Noise is really the biggest problem with mobile phone cameras today. They’re generally pretty good at determining correct exposures, setting a white balance and to some extent even getting colours right.

The issue of image noise has resulted in another problem – getting rid of it. To do so, engineers have come up with advanced image algorithms to reduce the noise levels. While these do indeed work, they come with a hefty price. They often result in loss of important details, especially in areas of high complexity or low contrast. This tends to result in an almost flat looking image.

Another thing I’d like to point out is the limited dynamic range of a mobile phone camera. The Nikon D700 is known for its incredible dynamic range and its rendition of high contrast transitions is beautiful. This sort of thing is impossible with the small size sensor in a mobile phone camera. The Satio is capable of storing 8 bits of information per colour channel (red, green and blue), whereas the Nikon D700 can store up to an astounding 14 bits per colour channel. In other words, the Satio can reproduce of total of up to 16,777,216 different colours (16.7 million). That’s quite a lot of information, right? Sure, but it’s peanuts compared to that of the Nikon D700. 14 bits of colour information per colour channel results in a total of 4,398,046,551,104 effective colour channel combinations or in other words different colours (4.4 trillion). This naturally means that the camera is capable of producing much nicer high contrast gradients and transitions.

Having said that, I don’t think the Satio camera is a poor one. I actually think it did quite well, considering it “only” has a small size image sensor. But at the same time I’d like to point out that the results aren’t unexpected.

What do you think about the results?

PS: Yes, I know I am a bit geeky when it comes to camera technology and photography