New York Times - David Pogue on camera sensor size

David Pogue wrote an illuminating article on digital camera size, discussing how hard it was to figure out the size of a camera sensor, and why it mattered. A very good point. One of the things I like about the camera specifications listed at Digital Photography Review is inclusion of the sensor size in terms of area and pixel density. (Area is handy because bigger is better, but pixel density is more revealing in my opinion, because it incorporates pixel count. Lower pixel density is better.)

Pogue then goes on to laud several cameras as having larger than average sensors for their class, such as the Canon Powershot S95. They are very good cameras with excellent image quality, but the landscape is more complex than just sensor size.

For example, the Canon S95 (4x zoom range) has 23MP/sq cm, while the Sony HX5 (a 10x zoom camera) has a pixel density of 37MP/sq cm. Lower pixel density generally translates to lower noise and cleaner images in low light. For reference, a large sensor SLR camera like the Canon EOS 1-D Mk IV has a pixel density of 3MP/sq cm - and takes incredibly low-noise images in low light. It also weighs several pounds.

So while larger sensors have an advantage, buying a pocket camera on that basis leaves out an important dimension of flexibility - the lens zoom (focal length) range. Camera manufacturers use smaller sensors in compact cameras with large zoom ranges because a 'long lens' size is roughly proportional to sensor size. In order to make a pocket-size camera, they put a smaller sensor in the camera. For many users, living without a 10x zoom range greatly limits the shots which can be captured. In particular, travel shots and action shots can be tough with a 4x zoom.

The other part of the landscape which is changing is sensor design. Digital camera sensors have become much more effective at capturing clean photos in low light as the sensor technology has been refined. For example, the latest generation of Sony sensors utilizes their "Exmor" sensors, which improves sensitivity by putting the circuit wiring below the image-sensitive layer of the sensor. Even in low light (for example using ISO 1600), very satisfying photos can be captured relative to prior sensors, and the technology improvement can larger overcome the difference in sensor size between these compact cameras.

Before buying a camera, consider the kind of pictures you'd like to take (including zoom range), the degree of 'automatic' versus 'manual' control you prefer, and compare real photos captured by reviewers and other users. Try the "Comparison Widget" as a quick way to compare photos of different cameras side-by-side (for the cameras already reviewed.)

Loving and hating Microsoft

My wife is a serious Outlook user. For her its the nexus of all things organizational. Tasks, calendars, and email all converge in a carefully honed system which keeps our household and generally at least one major educational organization at a time (PTA, etc.) afloat. That said, Outlook 2003 had some issues and failings and I decided to let her try OneNote, an element of Office 2010 as part of a longer-term transition plan.

Mistake #1 - believing the installer works as described. I installed OneNote by first electing to 'install alongside instead of replacing' Office 2003, selecting custom installation, and only picking OneNote, with all other Office apps 'installed on first use'. No errors or warnings! Great.

But Outlook 2003 was simply.... Gone. Nowhere to be found. Word and Excel 2003 were still available, but in fact NO version of Outlook was installed anymore.

Mistake #2 - not doing a full backup of the system directly before Mistake #1. I did have a backup of the Outlook 2003 data file - but it would be some real effort to roll back the system.

Mistake #3 - not verifying feature consistency. Always know ahead of time what the customer values. Some things that look small (like showing start and end time explicitly in appointment details in week-view of calendar) were very important to her and are simply unavailable in Outlook 2010.

After listening to some choice words and tweaking some really hard-to-decipher details (like the way tasks are ordered and displayed), Outlook 2010 is close enough to working like Outlook 2003 had worked to be acceptable. I'm halfway out of the doghouse and some of the new features of Outlook 2010 (like color-based categorizing) are proving helpful. That said, I've been reminded how important it is to verify critical features when rolling a system out to users, and ALWAYS have a rollback plan.

I've also been reminded about the dangers of believing the documentation.

Enjoy the holidays....

The Next camera you buy

Have you bought a camera lately? If you bought a cell phone within the last eighteen months, you have almost certainly bought a camera too. Do you love it? Probably not. Even the best of the cell phone cameras (arguably the iPhone 4 camera right now) is far less versatile than a $150 camera from Walmart. The reason isn't cost or complexity - it's lens size. An optical zoom lens of 'interesting' quality is just too big to wedge into a sleek smartphone. We're left with a fixed field of view and mediocre sensitivity. It's a disappointment considering the hype! It turns out that your average 'good' pocket camera - I've recently been a fan of this Nikon - has about 10 optical 'elements' (lenses) to deliver fairly sharp images through a 10x zoom range. There are two general ways to get lots of versatility with fewer/smaller lens elements. Either you use variable focal elements such as liquid lenses ala Varioptic or you 'relax' your constraints on preserving nice flat images and allow more 'distortion' which you later remove digitally. It's the latter approach which pays greater dividends. By cooperatively designing optics with digital correction in mind, better end-point images can be achieved. Ultimately, smaller, cheaper, and simpler lenses can be used to achieve the results formerly requiring exotic and heavy lenses. Canon's S95 uses in-camera correction to deliver significant reduction in distortion over its zoom range. As the compute power to run these algorithms move downstream, cell phones with powerful optical zoom lenses should appear, with Japan as usual the harbinger for broader market growth.

From iPhone intention to Droid X

I had every intention of moving to the iPhone 4. The user interface, camera, and design are all clearly top-notch. Antenna glitch aside, it's a stunning piece of engineering. And then... AT&T happened. I had an old 'AT&T blue' data account and SIM, and the back-end order systems which manage migration have bitten me before. In this case, they busted during the iPhone 4 initial release frenzy. On top of that, AT&T had massive challenges (9 months of incorrect billing) on my business land-line account. Finally, my attempts to use the Nexus One on AT&T, watching every other call never reach the handset, convinced me I was destined to switch carrier.

In a more ideal world I would have chosen between the iPhone 4 and the Droid X on Verizon - but in 2010 AT&T remains the only iPhone 4 carrier and the choice is already made. Droid X it was to be.

The Droid X is a fine phone and very capable smartphone device. I am impressed by the display, the soft keypad, and by the range of Android widgets and apps. The camera is the only bit of dirt in the sauce. While billed at 8MP of resolution, images look distinctly soft even when taken in bright light. A small 1:1 sample of a document image gives a good idea of what you can expect.

Downscaling the image as a point of reference, the 'true resolution' is closer to 3MP with the remainder being noise and blur. On the positive side, the images are not mangled by excessive in-camera sharpening, so a certain amount of post-processing (unsharp mask for instance) can yield slightly more appealing results.

This is yet another classic case of wasted pixels though. Had Motorola done their homework and selected a good 5MP module as Apple did, a significantly better camera could have emerged. As it is, I'll be enjoying the data-centric side of this phone while still fondly remembering the camera in my now-venerable Nokia N95.....

Breaking down and getting an iPhone 4

As a career imaging technologist and amateur enthusiast, I've pointedly avoided the iPhone until now. While great as a communications tool, the camera was definitely a few steps shy of cutting edge. Even the 3Gs, with autofocus 3MP sensor, was notably a slow camera. With the announcement of the iPhone 4, it's clear that Apple has moved out of 'overcoming objections' and now has a device which a 'camera guy' can enjoy carrying around. By picking a reasonable (5MP) resolution and a sensitive sensor, the camera will finally be a credible capture device. The sensor, possibly a Sony Exmore type sensor, should be significantly faster in response than the sensor in the 3Gs. Shots 'in motion' are suddenly possible. Full-motion video becomes a reality. I have a strong suspicion based on the sample pictures we've seen that the sensor they've selected will be matched by a decent lens package.

Combine a solid camera with a screen that can resolve 960x640 pixels, and suddenly it's more than a phone with an afterthought of a camera....

I'm looking forward to seeing it firsthand.

Convergence - mobile, still, and video

The largest increase in amateur photography of the past generation has been driven not by the internet or the advent of digital cameras. The mobile phone camera has changed the landscape of photography. According to the Photographic Marketing Association, 70m cameras were sold in 2003, a significant number. In 2010, more than 10x that number of camera-equipped mobile phones were sold. This explosion has impacted the way people capture, communicate, and consider digital photography; a casually captured image can be used for comparison shopping, social communication, or ad-hoc news reporting.

So the upside - lots more opportunities to capture images and video. The downside for many would-be photographers is a disappointment in the quality and flexibility of the camera platform. Lacking some of the compelling features of a point-and-shoot camera, such as optical zoom, can be frustrating. More importantly, the photographic sensitivity (ISO speed) of popular phones such as the iPhone 3Gs makes shooting clear images of a moving subject all but impossible.

Herein lies a significant barrier - the size and cost of the optical package required to support quality image capture is not easily pushed into a thin phone case. This is also perhaps the largest opportunity for the next-generation phone to usurp the point-and-shoot camera market. New lens options such as the Varioptic liquid lens promise a thin package capable of optical zoom. Other directions such as folded optics (seen on Panasonic and Sony cameras) could keep the slender profile of the phone intact.

The larger issue of sensitivity is increasingly looking like a nearly-solved problem. Evolving sensor technology combined with reasonable optics is competitive with point-and-shoot cameras.

Video capture usage has been spurred by Youtube and enabled by efficient encoding using H.264-based encoding such as MP4. Most smartphones now support video capture in these formats already.

The largest outstanding question now is one of market and behavior; will consumers perceive enough value in a high-quality camera embedded in a phone to pay the extra cost of development and manufacturing involved in providing it. Nokia invested considerably in the cameras of their smartphones - complete with Carl Zeiss optics and xenon flash - and didn't own the market as a result. My prediction - the next generation of smartphones from RIM, Apple, HTC, Nokia and Samsung will include at least one breakthrough camera-centric design which seriously lets a user put their point-and-shoot camera (and camcorder) away for good....

When does a dSLR matter....

We recently became 'soccer parents' and started taking more sports photos. What we discovered was that a modern point-and-shoot 'superzoom' camera can't take pictures quickly enough shot-to-shot to capture sports, especially fully zoomed out. At best you get roughly one shot per second. Even when the image got captured at the right time, the level of image noise when used at short exposures at a 35mm equivalent of 300mm zoom just doesn't cut it.

Two soccer images, taken from both the Panasonic ZS3 and the Pentax K-x, illustrate this. They are both shot at ISO 800, fast exposure time, and at relatively long zoom. The ZS3 image has this 1:1 crop at ISO-800 showing the noise becoming intrusive in this picture, taken at 210mm equiv focal length.



The Pentax K-x we're using now can take clean images at ISO 1600, and captures photos in bursts at over 4 frames per second. The 55-300mm lens (85-450mm equivalent in 35mm) isn't super-fast at F4-5.8, but the sensor size and sensitivity makes up the difference and provides a very attractive tool for the price. The 1:1 crop at ISO-800 shows minor noise and some color fringing, but successfully captures the moment at 450mm equiv focal length. It does have some other issues to work through - the blown highlights in the ball and shallow depth of field. Closing down the lens a stop or two would have helped. Learning a new camera is like that.

Choosing a camera - this is not a review

A friend asked me if I knew about the new micro 4/3 cameras, which caused me to consider where they fit in today's universe of photographic tools. My conclusion - cameras like the Olympus PEN and Panasonic GF1 are very cool walk-around tools, but they don't really fit most people's needs just yet.

Most casual photographers, capturing their 'pets, kids, and sunsets' as a Kodak executive once explained to me, have to satisfy a broad range of needs with their gear. Our little Panasonic ZS3 needs to capture videos of kids skiing, piano recitals, casual wedding snapshots, and travel events. The 12x zoom lens becomes a tremendous asset and well worth the cost of fairly poor low-light performance relative to a 'big-sensor' camera. It's definitely a tradeoff, but this camera will take some very nice photos in friendly lighting conditions.



This year we added a Pentax K-x DSLR to our household. The kid's sports events - soccer and baseball - require more length and light-gathering than the little Panasonic ZS3 can deliver. It's far from pocketable with that 55-300mm lens on it, but with clean images at high ISO and a fairly fast burst mode, it lets us capture some great action shots (well, as great as the action permits!)



And there is the rub with the current generation of micro 4/3 cameras - at least for our family. They don't have the signal cleanliness, focus speed, or burst speed of the best 'entry' APS-C DSLRs, and even if they did, the auxiliary viewfinder and a long lens turn them into an awkward do-anything package.

Dedicated 'street-scene' photographers will surely love these compact, high-quality cameras for their discreteness and clean images, but they will remain a niche product until they can go head-to-head with the current generation of amateur DSLR without looking like a compromise in performance.