Sony DSC-HX1 Review
Special Recording Modes
The HX1 takes advantage of its fast continuous shooting speed and high speed shutter (which solves the problem of distortion with the electronic shutter normally used for high speed shooting in compacts) for three special shooting modes.
Regardless of the usefulness of these special scene modes, Sony should be commended for trying something other than just upping the resolution and increasing the zoom reach (though of course it did increase the zoom range). These modes have the potential to make your photography easier, help you spend less time in front of the computer, and more time out taking photographs. Anything that encourages the taking of photographs has to be a good thing.
The first - and the most impressive - of the new features of the HX1 is a sweeping panorama mode, which allows you to shoot a panorama in one sweep by holding down the shutter, and panning the camera from left to right (or whichever direction you select) - during which time the camera shoots continuously. The speed of your panning is tracked as you move and, so long as you don't go too fast, it doesn't matter if you vary your speed during the actual 'sweep'.
The HX1's processor will then stitch the images together (using data from the IS sensors to track your motion) and save the resulting panorama on your Memory Stick When shooting in this mode, the largest image size has a resolution of 7152 x 1080. Flash is not available in this mode, and any movement in your picture during panorama shooting can result in strange artifacts. You can use the camera in vertical (portrait) orientation to get a more resolution into the shot vertically, or in landscape (horizontal) orientation to get very wide panoramas.
The sweeping panorama mode combines a number of frames to construct the resulting panorama, and generally the results are superb (you have to look hard to see any joins), though there are problems if you try to capture a scene that contains significant movement, such as the street scene shown below. To avoid these problems, it is best to avoid scenes containing fast moving objects. Of course this is true of any stitched panorama (and is most obvious when the moving subject is near the camera).
You'll also get distortions if you tilt the camera too much during the sweep, though in practice it's pretty easy to pan in a relatively smooth manner for the best results.
|This car starts at the left most edge of the panorama.||As the photo was taken sweeping from left to right, fragments of the car was captured towards the right edge of the frame.|
|Here is the full photo. Feel free to download this image for a closer look. Depending on your intended usage of the photo, this problem could actually be used to cool effect.|
You have to keep panning until the HX1 tells you to stop; if you don't sweep through a large enough angle to fill the pre-defined frame, gray will be used to fill in the rest of the image (this can also happen if you sweep to fast or move up and down too much, at which point the HX1 gives up).
|Here you can see the edge of the recorded image, with the HX1 filling the rest of the image with gray.|
According to Sony, Twilight mode should help you to take sharper, less noisy shots in low light situations, by shooting six shots in a continuous burst, and then combining them into a single image. This is achieved using a process known as image stacking (exactly what the HX1 is doing under the hood we can't say for sure).
Image stacking is a process where two or more (6 in this case) images are layered and combined to improve the signal to noise ratio. This works because noise in an image is random and will vary from shot to shot. The process of stacking irons out inconsistencies between the frames, and since (in theory) the biggest difference from frame to frame in the burst will be the noise pattern, the noise will be smoothed away. So then, six images stacked taken at any given ISO, should give you less noise than a single image at that some ISO. That's the theory.
In practice of course it's not quite that simple. To really rid an image of noise using stacking you need more than six images (this is especially true when the source is very noise to begin with) and, crucially, you need the framing of the shots to be identical (we're presuming Sony does some processing to align the images before stacking as this mode is designed to be used without a tripod) for the technique to be fully effective. That all said, as the results below show, it certainly works, especially when used on a tripod and when the Auto ISO doesn't need to go ridiculously high (in Twilight mode it seems to try to stay away from ISO 1600 and higher unless absolutely necessary).
Twilight mode is available either manually selected by turning the mode dial to that location, or via the intelligent auto mode, where the HX1 will select Twilight mode if it detects the need. Being an auto mode, twilight mode is quite straight forward to use - just press the shutter button, and the camera will do the rest. The main thing you need to remember is that it will lock you out of the camera for a number of seconds as it processes the six images into the final image saved to card.
|The Twilight mode is situated between the sweeping panorama mode and anti shake mode.||Twilight mode is to all intensive proposes a scene mode; the only exposure control you have is exposure compensation, with the camera taking care of the rest of the settings. In use we found that the highest ISO setting the camera used was 800.|
|When in twilight mode, just shoot as you normally would. Once the HX1 takes the six shots it processes them in camera. During this process (which takes a few seconds) the camera cannot be used.||Once the processing is finished, the resulting image is saved. Unlike continuous shooting, only one image is saved, with the six images combined into one.|
Like the sweeping panorama function, the twilight mode stacks images together and produces a single image. Also like the sweeping panorama function, the twilight function is prone to problems with objects moving though the frame.
|The crop has been brightened up for you to more easily see the problem. Part of the man walking down the street has been cut out replaced by the black of the store front.|
In the studio we setup a low light scenario with areas of low contrast detail to see how the noise levels of twilight mode would compare to manually selecting aperture, shutter speed, and ISO.
|Sony HX1 ISO 400 Aperture Priority Mode||ISO 200, 1/5, F3.5|
|Sony HX1 Twilight Mode (ISO 640)||Twilight Mode, ISO 640, 1/8, F3.5|
|Sony HX1 ISO 800 Aperture Priority Mode||ISO 800, 1/10, F3.5|
|Sony HX1 ISO 3200 Aperture Priority Mode||ISO 3200, 1/40, F3.5|
In this situation twilight mode as selected ISO 640, which is not a user selectable setting under manual modes. The shutter speed of 1/8 is accurate for ISO 640 and falls in between the 1/10 selected by ISO 800 and 1/5 selected by ISO 400. You can see from the crop that while the fine detail is comparable to the ISO 400 result, it is noticeably less noisy, and the exposures (slight white balance differences aside) are very similar. In low light situations where ISO 400 or above is required, and there is not much movement in the frame, then twilight mode would be a good choose to reduce noise in the image.
Anti Motion Blur Mode
Like the twilight mode, the Anti Motion Blur mode on the HX1 combines 6 images taken in a quick burst to form one picture. The priority in the anti motion blur mode is to reduce the amount of blur (instead of reducing noise like the twilight mode). After the 6 images have been taken, the HX1 does a difference analysis and tries to take the sharp parts of each of the six shots to create a single, sharp result.
The manual points out that the system is far from perfect:
Reducing blur is less effective in the following situations:
- Image with erratic movement
- Image with a main subject too close to the camera
- Image with little contrast such as sky, sandy beach, or lawn
- Image with constant change such as waves or water falls
With all these conditions, placed on it, the Anti Motion Blur mode is not nearly as useful as it may first appear (and the results are pretty inconsistent). It is most useful in situations where there is little movement in a scene (such as someone talking and waving their hands at the same time) or as an aide to further reduce camera shake.
Being an auto mode, Anti Motion Blur mode is quite easy to use. Just press the shutter and the camera will take 6 exposures, and combine them into one image. During the processing time, you cannot use the camera. Anti motion blur is available in intelligent auto mode,where it can be selected by the camera if it feels the need.
|The Anti Motion Blur mode is situated between the easy mode and twilight mode.||Like twilight mode, anti-shake mode is an auto mode, with the only exposure adjustment being exposure compensation.|
|After the six shots have been recorded, the HX1 processes them in camera. During this process you cannot use the camera.||After the camera has finished processing these images, a single image is stored to card, with the individual images used to produce it discarded.|