Wednesday, October 29, 2008

SX110IS Movie mode review

Like most digital cameras the Canon SX110 IS can record movies. Unfortunately, Canon chose the MJPEG format for saving the movies, which means that a 32 minute, 640x480 movie takes a whopping 4GB. Most modern cameras record in a more efficient format, like MPEG 2, or even MPEG 4. MJEPG looks great, mind you, but it takes much more space than any of the MPEG formats. Canon probably did this to save on MPEG licensing fees, but I'd rather pay a little for more compact files (or course, you can recompress your movies after downloading them, if you want).  

Movie resolutions include 640x480, 320x240, and 160x120, with smaller movies allowing much longer recording time. All movies are recorded at 30fps, a come-down from some earlier models, where you can choose 15,30, or even 60 fps. 

Once you start recording a movie the optical zoom and focus stay fixed. Luckily, the exposure does automatically adjust, so if you start filming indoors and then rotate the camera toward a window the camera will adjust. Though the optical zoom does not function, you can use the digital zoom to smoothly increase the magnification up to 4x. This doesn't look blocky, since the camera's native resolution is much higher than 640x480.

This post is part of a series that reviews the Canon SX110IS.

Thursday, October 23, 2008

Canon SX110IS review: 10x zoom lens performance in the real world

The Powershot SX110 has a 10x zoom lens, which is quite a step up from the compact cameras which typically only have 3-5x zoom. In this section, I'll show some real-world pictures demonstrating how much difference 10x zoom makes compared to a 4x zoom, and also show how usable 10x zoom is in moderate indoor light (answer: not so much).

At right is a wide-angle picture ("0x zoom") taken on a nice sunny day, at ISO 80. You can click on the image for a full-sized version. Note that the bus was a bit over-exposed so I had to adjust the brightness down a bit by pre-focusing on the sky, (IE holding the shutter button down halfway), and then reorienting on the bus. This is why the rest of the picture is a bit dark, but it was necessary in able to preserve detail on the bus, which I will zoom in on next.

This shot is taken at 10x zoom. Much less light is hitting the sensor because we have zoomed in all the way, but as you can see the image is still very clear and low-noise, with no blur, even though the camera is still in ISO 80. You can click on the image for a full sized version.

What would 13x zoom look like? I took advantage of the fact that the camera can do interpolation-free zooming if you take your picture at a lower megapixel setting; in this case zooming in past the optical limits of the lens is identical to cropping the image down to a smaller size. If you shoot in 4 megapixel mode this allows the 10x zoom to become a 13x zoom. As you can see in the picture at left, 13x doesn't make much of an improvement on 10x, but it's a nice feature if you tend to shoot in less than 9MP mode, as I do (9MP files are much bigger, and most of the time I'll never have a need for all those extra pixels). Note: the image at left has been resized down to 25% of its original size to save server space.

So far we've seen that the zoom functions great outdoors. What of indoors, where the light level is typically much, much lower? I took the next series of shots in the kitchen, with all the lights on. The room is pleasantly lit with 2 conventional 60 watt bulbs, and is far from dark, but isn't as bright as an indoor room with a large sunny window would be. At left we have the 0-zoom shot. It's already dark enough that I had to use ISO 400 to get a sharp shot. Detail is OK, but but Hi-ISO noise is certainly visible. On the upside, there's no blur.

At ISO 400 and full 10x zoom the result is a blurry mess. I tried taking several photos in case my hand just happened to be shaky, and couldn't do much better.

It wasn't until ISO 1600 (!) that the blurriness went away. Unfortunately, as you can see, most of the detail is now lost in CCD noise.

For comparison, I also took the same shot with my more compact Powershot SD850IS, also zoomed in to its max(4x), at ISO 200. This shot is interesting for 2 reasons. First, it shows the difference in scaling between a 10x zoom and a 4x zoom. It's definitely clear that a 10x lens takes you a good bit further in. It's also interesting because it shows how much more appropriate a 4x zoom is for indoor shots than a 10x zoom is. Now, you don't have to use the full range of a 10x zoom lens, and if I took this shot with the SX110 at 4x zoom, I'm sure it would look much better than at 10x zoom (unfortunately, the SX110 doesn't report zoom level, so I couldn't easily create such a shot for this webpage). The point is that all of the extra range that the SX110 offers is of little advantage if you'll be taking medium-light indoor shots like this one. On the other hand, zoom isn't really needed indoors. All of your subjects are close enough that you can just walk the 2-5 feet closer needed to get the proper framing. It's only outdoors where the long zoom becomes truly useful.

So, in conclusion, the zoom lens works great on this camera, in bright daylight. The difference in zoom between 4x and 10x is quite noticeable, and will allow you to get much closer to your outdoor subjects that you can't just walk up to.

Later in the day, and for moderately lit indoor shots, however, it's not really much more useful than the 4x zoom lens you would get on a good compact camera.

This post is part of a series that reviews the Canon SX110IS.

Monday, October 20, 2008

Canon SX110IS Review: image stabilization and HI ISO noise in low-light photography

In this section I consider how well the camera works in low-light situations. Given the SX110's image stabilization, the hope is to get relatively low-noise, low-blur shots without having to use a tripod. In general it does well on the low-blur criteria, but not so well on noise.

At right you can see a hand-held shot with image stabilization on, at ISO 80, with a 1/1.3 second exposure (~0.7s). I have a pretty steady hand, but even I was surprised to see how little blur there was in the photo. The SX110's image stabilization works amazingly well. Shift-click on the photo to view it full-sized, however, and you will see that there is definitely both blur (unsurprising for a ~0.7s exposure!) and CCD noise (a bit disappointing, but the light level is quite low).

This photo was taken at ISO 200, with a 1/3.3s exposure. Already, things are much better. The unzoomed photo at right actually looks quite sharp, but if you click on it for the full sized version you will see that there still is some blur. CCD noise is worse, but not much.

Next, I turned off image stabilization, and used the same ISO/exposure (200,1/3.3s). As you can see, the result is quite blurry, perhaps even without viewing the image full size. Note, just how much blur you would get in this situation would vary by user and chance, since it all depends on how firm and steady your hand is. Any way you cut it, however, you can see that image stabilization is buying you a lot.

With image stabilization back on, I raised the ISO to 400, with a 1/6s exposure. The result seems to be slightly more resolvable detail, if you view the image full screen. For instance, try to read the text on the pill bottle. The amount of noise, unfortunately, also goes up, though this is only really noticeable if you zoom all the way into 1:1 pixels, or if you have a really, really huge monitor (the image is 9 megapixels, which is 3456 x 2592).

Next up is ISO 800, with 1/13s exposure. Now the CCD nosie is significantly higher, and the level of detail doesn't seem to have improved at all. This ISO level might be useful if you have shakey hands, or a faster-moving subject than my desktop still-life pictured here. Otherwise, I would stick to ISO 400 or below.

In conclusion, the image stabilization works great. You can get good low-light shots even at ISO 200. Unfortunately, the CCD noise is pretty high - higher than I would have guessed given the size of the lens (which allows more light to enter the camera, which should, in theory, result in less noise). This is not as big a deal, however, if you don't need all 9MP of resolution. Viewing the photos on my 1280x1024 monitor, CCD noise only became objectionable at ISO 800. While monitors will continue to grow in resolution, it's going to be quite a while before even a few of us have 3456 x 2592 displays where you could actually display each pixel of a 9MP image. The other important point to keep in mind is that the actual ISO is pretty unimportant in the end: what you care about is whether you can get good low-blur, high-detail images without using the flash. If ISO 200 is good enough for that, who cares if some noise creeps into ISO 400.

This post is part of a series that reviews the Canon SX110IS.

Canon SX110 Review: lens distortion - lab tests and real world images

The SX110 has a 10x zoom lens. With such a wide range you might be concerned that image quality might be compromised either at the wide or telephoto setting. On the whole, however, image quality is good throughout the whole zoom range.

At right is the camera at its widest zoom. Some barrel distortion is visible (IE, curved lines which should be straight), but it's not bad. Note, however, that most cameras have this to some extent. On the positive side, the corners of the image are just as sharp as the center. Many cameras, particular more compact models, have blurry corners. Many Canon SD cameras exhibit this problem fairly clearly, such as last year's SD850IS. It's nice to see that the SX110 does not.

Next is the lens at the other extreme of the zoom range, in full telephoto. Here, there is no indication of the barrel distortion seen at the wide angle setting. Again, there is also no corner blur. Thus, the lab tests show that the lens performs quite well.  What of real-world shots, however? In particular, does the wide-angle barrel distortion show up in photos of the real world? See the next few pictures. 

In this picture, which is designed to highlight the problem, it is possible to see distortion. Even so, it's not nearly as obvious as in the lab test. Given that you are unlikey to take a picture like this unless you are trying to show off the flaws in the optics, it's not too bad.

This picture is perhaps more representative of the real-world images which would show off this problem. The support columns clearly bend out toward the middle, whereas in real life they are as straight as your typical 2x4. Whether or not you find this objectionable is really a question of taste, but I personally don't notice it unless I'm looking pretty carefully.

This post is part of a series that reviews the Canon SX110IS.

Sunday, October 19, 2008

Canon S110X review: real-world test photos

In this series of pictures I show how well the Canon S110X Superzoom camera performs in real-world situations. 

This picture shows a close-up of a Lego robot. The light level was moderate, and I kept the ISO low (200), and took several pictures, saving the least blurry. If you click on the picture for a full sized image, you'll see that there's still some CCD noise in the image, but very little.

This picture was taken in outside a dramatically lit storefront, at night. Even though the ISO was inly 200, it came out with very little blur, or noise.

This picture was taken on an somewhat overcast day. The color is pretty accurate.

The camera did a good job of capturing this shot, impressive given the wide dynamic range. I had to tweak the exposure a little, using the manual mode of the camera, to get it to come out looking this good.

This sunset shot looks nice enough on my computer screen, but it doesn't really capture the colors as they were in person. This is a problem for most cameras, to be fair. Note that this was taken from a moving car, but is relatively blur-free.

This portrait shot shows good color balance and a nice depth of field effect (The face is in focus while the background is not. To get this effect I stood relatively far from my subject and then used the 10x lens to zoom in on the face).

The colors came out really nicely in this foggy day photo.

Another sunny day shot, showing that in full automatic mode the camera does a reasonable job of exposure, but still somewhat clipped.

This photo was taken in full manual mode (the focus was set automatically, but the exposure and F stop were set by hand). This is great fun to play around with, but time consuming, and not without risk. This picture was taken on a sunny day, but manages to look overcast. To be fair, it was one of the first pictures I took using full manual mode. The moral here is that full manual mode is a nice feature, but it will take some time to get good with it.

I took this picture late in the evening at a local mall. What with people moving around, it was very hard to get a low-blur image, without cranking the ISO way up. Instead I used the burst mode on the camera and just took 10 pictures in quick succession. After downloading the photos from the camera I could quickly pick through the set and find the clearest, most pleasing photo, which is this one. Many of the others were also reasonably sharp, but some where quite blurry. Image stabilization can make your pictures sharper, but it can't make moving people stand still!

This post is part of a series that reviews the Canon SX110IS.