Digital Photo: Beyond Pixels and Zoom

Work-in-Progress

There are so many articles on digital cameras out there, but I've yet to find an article that discusses the basic differences (let alone real concepts) between commodity, digital point'n shoot and digital SLRs ---especially from the "marketing hype" of megapixels (MP) and superzooms (8x, 10x, 12x -- even 15x now) that claim to be "SLR-like." I know this article won't be perfect, and will seem to go "too deep" in some areas while ignoring other concepts other articles cover, but I just wanted to cover the basic concepts on the "sensor size" and the resulting lens aspects that I haven't seen in a single article by others.

I hope it explains why I recommend IGNORING those $350-500 point'n shoot cameras and consider either just sticking with a sub-$200 6-8x point'n shoot, or just make the $400+ plunge into dSLR, possibly only spending another $200 on 1 or 2 more lenses. And to that end, expect a forthcoming article on how I moved into dSLR with the Pentax K100D (and it's current rebate offer), with three (3) lenses to round out my capability over any point'n shoot "superzoom" option for around $650 total.

Marketing: Megapixels and Optical "Superzooms"

Today the digital camera market is flooded with countless digital camera options. Everywhere you turn, it's megapixels from five (5) starting under $100 to a whopping ten (10) starting under under $200 along with "optical zoom" of 3x, 6x or even 8x, 10x and 12x (let alone even one 15x now) in the "superzoom" range at $300-500+. Compact, consumer, "pro-sumer" and "near-dSLR" (which will be discussed) are common terms which reviews try to categorize digital cameras as.

And yet, semi-professionals won't touch them. These users, or reviewers, quickly point out the poor noise characteristics of images beyond ISO200 in poor lighting, shutter speed and focus issues, especially at higher zooms, etc... And despite the monikers and marketing, these limitations seem to be clear barriers that keep many people away. Why is that?

Image Quality: "Sensor" Size Matters!

As most digital camera owners already know, most digital cameras (ignoring CMOS and other solutions) replace an area of film where an image is captured by opening the camera's shutter with an a solid state charged coupled device (CCD). The common, modern point'n shoot digital camera of of today typically has a 1/2.5" or possibly a 1/1.8" CCD. The 1/2.5" CCDs are now 7.2MP commodity with 8.0MP just coming out and 1/1.8" CCDs are hitting 10MP and will be 12MP soon.

I will not dive into the history of the imperial fractions (which DPReview addresses here), but understand that an 1/2.5" CCD has an image sensor of approximately 5.8x4.3mm in size and an 1/1.8" CCD has an approximate 7.2x5.3mm size. That is little more than 20mm square and a little under 40mm squared, respectively. That's quite a bit of density in such a small area, at least compared to 35mm -- also known as "135 film" and, in the digital realm, "full frame" -- which is 36x24mm and over 800mm squared -- 20-40x the area!

Side Note: Most consumer CCDs are 4:3 aspect, whereas 35mm (and APS-C) is 3:2 aspect.


Even today, "full frame" digital cameras are still very cost prohibitive ($5,000 although some are dropping to half that as of late), although this may change in the near future (discussed below). There are some fully digital 35mm cameras and there are many solutions for adding digital "backs" to existing, professional 35mm cameras. The megapixel range for these solutions started at over 10MP years ago, and are crossing 20MP now. Well beyond what a consumer needs and almost overkill, especially considering the 20-40x increase area, hence quality of light and image hitting the sensor.

And yet there are additional considerations, especially cost-wise.

Lenses: Zoom--er, Zoom "Range"

Today's point'n shoot digital cameras over-market their optical zoom, which is really their "zoom range" and not really an precise indicator of actual magnification or field of view (FOV). In general, the definition is applied rather ambiguously, although there does seem to be some uniformity in the point'n shoot industry now. I.e., the base, 1x zoom seems to be just slightly larger lens than the CCD -- nearly 1:1 -- and almost everything else is a multiple from that.

E.g., on a 1/1.8" CCD point'n shoot camera, the sensor is around 7.2mm horizontally, and the smallest zoom lens setting is around 7.5mm. If that camera has a 8x zoom -- again, really "zoom range" -- then the largest zoom lens setting is around 60mm. In comparative 35mm terms, this is effectively around 37.5-300mm.

In reality, at 35mm, the "normal eye/focus" 1:1 view is not considered actually at 35mm, but 50mm. What that boils down to FOV terms depends on focus, but is around 40 degrees at infinity (widest angle). Most point'n shoot cameras dip some 25% below this, giving a good 50 degrees FOV (around 0.75x "normal") and then narrow (zoom) from there. So for a typical point'n shoot, FOV is around 17 degrees for 3x zoom (2.25x "normal"), 8.5 degrees for 6x zoom (4.5x "normal"), 6 degrees for 8x zoom (6x "normal"), 5 degrees for 10x zoom (7.5x "normal") and so forth. These are just approximation and will vary when the "widest" (smallest) lens size differs greatly from the horizontal CCD size.

The most important thing here to note that the "nice thing" about point'n shoot with small CCDs is that you can have a great zoom range -- like 6x, 8x, 10x or even 12x -- and the lens size is still 50mm or smaller at its longest zoom, typically no more than a few inches sticking out maximum. Which brings us back to 35mm. A zoom range of 4x -- like 28-105mm (which would be like having a common point'n shoot of 0.5-2.0x zoom) -- is already a good sized barrel, yet doesn't cover much "zoom" in the traditional point'n shoot view.

Which is why 35mm is about interchangeable lenses. Wide lenses with zoom ranges that are at the "normal view" (50mm) and below as well as zoom lenses that go from the "normal view" and beyond, sometimes they already start well beyond. There is also the concept of a "prime" lens, a lens that has a fixed size and, therefore, a fixed zoom. Now you're talking cost. Also add in the fact that with such a large sensor area for image fidelity, you're also starting to see an added cost in lens quality -- as any cheap lenses will quickly show poor image quality too.

In other words, the cost of image quality starts growing exponentially with the cost of multiple lenses, which should be of craftmanship that also grows in cost, exponentially.

APS-C: Commodity Digital Single Lens Reflex (dSLR)

Around 2003, a much larger, common sized CCD broke the $1,000 barrier, one close to Kodak's Advanced Photo System "Classic" (APS-C) of around 25.1x16.7mm. At roughly 400mm squared, APS-C sized CCD sensors give about one half the area of 35mm film, while still an area an order of magnitude greater than a 1/1.8" CCD. As such, they became the mainstay of the new crop of affordable, entry to mid-level digital Single Lens Reflex (dSLR) cameras.

The concept of the Single Lens Reflex (SLR) on its own is often mis-represented to consumers coming from point'n shoot cameras. SLR simply means you are seeing the actual set of reflections/refractions of the image behind the actual lens that will be projected on the film, or in case of digital SLR, the sensor. Most consumer cameras use an off-set viewfinder that is not the image that will be captured, and newer digital point'n shoot cameras add the real-time capture/preview from the CCD on to the LCD.

But SLR and, subsequently, dSLR is often stated to represent a series of technologies and features, including interchangeable lenses, more advanced capture (including many frames per second, fps) including added digital processing capability and filtering in the case of dSLR, etc... In a nutshell, when you're paying for the larger CCD (let alone in the case of a CMOS sensor), the physical SLR mechanism that clearly adds cost in mirrors and lenses, etc... adding the other features is a no-brainer, and clearly adds a great number of features in the digital SLR arena over the digital point'n shoot.

The majority of today's prosumer and semi-pro dSLRs are APS-C sized. In addition to the immediate size advantages of the body over a "full frame" 35mm, there are lens size considerations. Now only a 200mm lens is required to get a 35mm effective 300mm lens. And any minor defects in the lens often doesn't show up nearly as bad as a "full frame" 35mm, allowing for the use of lower-costing, newer, often marketed as "digital" (really APS-C) sized lenses. The diameter of theses "digital" interchangeable lens also now shrinks to around or sub-50mm instead of 60-75mm. All the while, at the same time, several vendors still use standard 35mm mounts so older, compatible 35mm lenses can be used, preserving some investments some photographers have made in their lenses.

Much better quality combined with an option of lower costing lenses (that have 4x zoom ranges) has made the entry-level dSLR a more interesting option -- especially now at sub-$500 for many bodies -- than $400+ superzoom point'n shoot cameras that are incapable of the quality (especially in lower light), rate of capture, etc... Especially as more and more dSLRs offer point'n shoot like modes -- making them as simple or as powerful/customizable as consumers want.




dSLR: Know What You Are Getting Into

Ironically, consumers who come from the digital point'n shoot world are sometimes unhappy with dSLR -- both feature and monetary-wise. Know some simple facts.

The first one is cost. Lenses cost money. No, it's beyond that, lenses are often more of the money maker than the dSLR "body." Many -- no, virtually all -- vendors including a really crappy (with exceptions) "kit lens" with the camera -- they want to sell you lenses. In most cases, don't bother with them, just get the body. Although that also means that you have to either consider dropping a few hundred dollars more for just a lens, or buy one used. After all, there is little sense in going SLR at all for its precision fidelity if you're not going to get at least one, solid lens. At the same time, you can do lenses "on a budget" by only building your kit of 2-3 lenses, and getting used or "good value" lenses.

Side Note: Now the good news is that once you make an investment in a lens, some vendors often support their lenses for a long time, which means they make future products compatible with those lenses (remember, the camera body itself isn't their big money maker). Pentax, a name not very well known with consumers, is extremely well known among anyone who has taking a photography course in the last quarter-century (let alone anyone using a film larger than 35mm). Their M42 and K mounts are still used, and even their pre-digital auto-focus (and auto-aperture) lenses are usable on their newer dSLR cameras. This is very unlikely to change in the future either, with one caveat (as I'll discuss below). And there is always the option of purchasing used lenses.

Another biggie is how "image stabilization" is "replaced" from the standpoint of the point'n shoot familiar consumer. Sometimes, it's not in dSLR, and a simple point'n shoot with image stablization would be better for those that just want to "go around and shoot" in their hands in good lighting. Originally most dSLRs addressed stablization at the lens, adding very significant cost ($500+ for a 100mm+ lens type). But a few, newer dSLRs, like the Pentax K100D and K10D, as well as the Sony Alpha, address it as best as it can in the body, for all lenses (although the Sony's mount doesn't have nearly the existing lens family as the Pentax K mounts do). This is a consideration if you want to zoom without a tripod and you've chosen a camera and/or lens (depending on the solution) that does not offer any.

Yet another big show-stopper is the size. dSLR bodies, despite how small they may try to make them these days, are bigger than most point'n shoot cameras -- even superzooms with their fixed zoom lenses in comparison to a dSLR with just a standard 4x zoom range lens. If you're finding you just want a camera for taking pictures in good lighting, don't need more than 4-5x "normal eye" away (marketed around 6x zoom), or even just 2x "normal eye" (marketed around 3x zoom), then you don't need a dSLR -- and you'll have less to pack when you travel. If you want a camera that has can do poor lighting or deal with other, environmental concerns, can take wide-angle shots of scenery (a big deal reason to go SLR), etc..., then you probably want SLR.

Side Note: Now there are some "pancake" sized "prime" (single lens size) that reduce the camera size and shrink the overall size (sometimes even to less than a superzoom with its fixed zoom lens), but you'll pay for them ($300+ new) and be limited to its fixed zoom (often around 1x). Of course, you still often build a "lens kit" of at least 2-3 lenses for any dSLR -- typically at least a wide zoom lens (for scenery to normal shots) and a narrow lens (for portraits to longer range zoom). In many cases, the "kit lens" can suffice for the former, although many consumers find themselves eventually replacing it.

And, lastly, the subtle, almost hidden set of issues are the difference from some common point'n shoot approaches. One is the lack of real-time preview on the LCD that digital point'n shoot users are used to. It's only only available on some very late model (and very expensive) dSLRs. The viewfinder, the whole basis of SLR, is why people go dSLR -- what you see is what you get, and a far more clear than what can be put on an LCD, including for focus (especially if manually focused). Some newer models can give you a preview on the LCD, but for the most part, you'll be in the viewfinder for quality. And there are, slight usability differences as well -- although today's entry-level dSLR can be used almost like a point'n shoot, only offering the power and customization for those who want it.

There are plenty of 1/1.8" CCD cameras that give you a good range of zoom with "good enough" -- even for 8x10" in some cases -- with good lighting. As long as you aren't capturing too much motion, or doing professional portraits, they work perfectly fine for 90% of moments.

Why I Personally Moved to dSLR

Personally, I finally made the move to dSLR for the lower lighting, sports and, to a lesser extent, scenery aspects -- with a lot of caveats and some clear "thresholds" that were finally crossed.

I am not a knowledgeable photographer in the least bit, and I'm just getting familiar with many concepts. Despite being a traditional engineer who has had theoretical courses in physics and basic optics and many other concepts commonly used in photography, I had never, neither used nor even consider many simple, photo concepts technically/practically at all. I was happy with a point'n shoot until it came to lighting and sports, as well as the limited FOV for scenery. Especially sports, as I so tired of tracking photos at events and throwing away 80% of the shots, let alone couldn't snap off pictures quickly. And I don't know how many times I lost 100% of the shots in low lighting situations.

The major barriers that prevented me considering dSLR were clearly cost and select features. Heck, I was even still set on buying a 1/1.8" CCD (boy does just about every 1/2.5" CCD I've used suck for my purposes) point'n shoot superzoom for $400-500 just a couple months ago. I didn't want to spend much more than $500 in the worst case, and being that I attend sporting events as a regular spectator, I can't exactly drag in a tripod, so I needed some sort of equivalent to point'n shoot image stablization.

By chance I saw the prices on the Pentax K110D at a few resellers after the $50 rebate, which brought it down under $350. The Pentax K110D doesn't have the same "free floating" CCD (which Pentax calls "Shake Reduction") like its more costly K100D so I disregarded it. But then I started reading up on the newer, APS-C "digital" marketed K-mount lenses -- such as the Pentax DA 50-200mm that would give me the basic reach I wanted for sports -- I took a renewed interest. The Pentax DA 50-200 is not only sub-$250, but they were offering it with a $150 when purchased with just the K100D body. So for around $500 after rebate, I could have a dSLR with "shake reduction," a good, low-cost, "point'n shoot equivalent 8x zoom," and add to it.

The used lens options for the 30 year-old Pentax K-mount finally sold me, especially after the reviews I read on the unit itself and various lenses that could be had for around $100 used or "just not commonly sold." And that's what I'll cover in the next blog post. But before I do, I want to comment in a final section of this blog article on the future of APS-C sized dSLR versus the near-future reality of commodity, "full frame" (35mm) dSLR.

Will "Full Frame" dSLR Become Commodity? Probably ...

There is a raging debate whether or not dSLR will move away from its APS-C sizes if and when "Full Frame" (35mm) CCDs become commodity.

Right now there are only a few "Full Frame" dSLR cameras, which use CMOS sensors and hover around $5,000 (with some dropping under $3,000 as of late), which offer close to 20 megapixels. And at those prices, there are other digital "back" options to same or even higher quality 35mm (135 film) cameras, let alone even a handful of 60mm (60x45mm aka 120 film aka "medium format") options that even Pentax is jumping into with its forthcoming 645D at 18MP and full 645 lens compatibility (the film-based 645 series is still sold, Pentax being one of the few vendors that still offers such a medium format camera).

But despite the downplay of the future, there will be a day where 35mm "full frame" CCDs becomes commodity, possibly as early as 2010 and will likely offer beyond 20MP. So there's the real possibility that all of the APS-C sized, "digital" marketed lenses will be useless for those cameras (let alone cameras designed only for 6-10MP), and become increasingly less commodity in a possibly shrinking APS-C sized dSLR camera (of aging 6-10MP, maybe 12-15MP at last model) market from then on-ward. And who knows, with the digital processing, lenses may not need to be as perfectly designed as they were now, just as some digital lenses today can be made cheaper and lighter without a lot of perfections that drives the costs up to $500, $1000 or even higher just a few years back before dSLR took hold. So does that mean any investment into an APS-C sized camera and selection of lenses is not a good idea?

At this point, it's really hard to say. I'm personally not dropping any serious money into APS-C sized, "digital" marketed lenses. As I'll cover in my review, other than the Pentax DA 50-200mm, I haven't and I probably won't -- other than maybe considering the Pentax DA 16-45mm if and when I decide to drop the $300 (after rebate) for it. I'm personally trying to stick with standard, Pentax K mount (but late AF model) 35mm lenses at this point, so I can recycle them in the worst case (as well as buy them cheaper used in many cases as well).

So the only suggestion I can make to anyone is not to drop over $1,000 in APS-C sized lenses today, and not even a few hundred for those of us that are clearly consumer-level and not even semi-pro. Be smart, buy a solid APS-C sized lens when they are well regarded for the price/performance (like the Pentax DA 50-200mm for Pentax, or the Sigma 17-70mm for Pentax, Canon, Nikon and other mounts, etc...), and consider what quality, existing 35mm mounts -- while still having all the compatibility/features on the newer dSLR models -- would be a good investment if and when "full frame" 35mm dSLR becomes commodity.