Photography

Megapixels: The More the Merrier?

September 19, 2008 September 19, 2008 "Oh man, they just came out with a 6 megapixel camera!! I have to get that!"  ....Remember those days? You'd go out and buy a small point-and-shoot camera that was maybe 4mp, then a month later the 6mp came out and you just HAD to have it? It's been ingrained in our brains that megapixels (mp) are such a huge deciding factor on everything related to digital image quality. This may have been true way back in the day, but times have changed. Some of the first professional level digital cameras were released back in the early '90s (Wow – it's been almost 20 years since the birth of digital still cameras; congratulations, technology!). Kodak gets the prize for the first digital single lens reflex camera (DSLR) that tipped the scales at an astonishing 1.3mp (1,300,000 pixels)...and emptied your bank account at $13,000 — one penny per pixel. Streamlining for consumers began mid- to late-‘90s with Nikon and others developing 2-3mp cameras for around $6,000 ($.0024 per pixel). Hmm...getting cheaper per unit!! Now Phase One has just released a digital camera “back” (not a full camera body with lens; just the digital sensor in a box that gets put on the back of a medium format camera) rated at a mind-bending 60mp, bankrupting its suckers (I mean patrons) at $40,000! The question is: Do you really need it? Are there other factors that go into the image quality? The sales pitch for years has told us that when it comes to megapixels, the higher the better. Why? Because it’s an easy sell. Imagine some super geek salesman telling you, “This camera is better because it captures in 16-bit color depth, records Profoto color space AND has a faster EXPEED processing engine AND embeds your GPS location right into the metadata of the file!” Um, yeah, what he said. The reality is that the only thing the number of megapixels does is make the file size bigger. For example, the Phase One 65+ boasts a 180mb+ raw file. Compare that to a smaller camera with less megapixels like the Nikon D300, which will create a raw file under 20mb. So if it isn’t megapixels that matters most in image quality, then what does matter? How about: the diameter of each pixel (the width of each); depth of each (color bit depth); and how far apart the pixels are from one another. Diameter determines how much actual light can be captured or held in a pixel. Generally, the larger the diameter, the less chance for any digital noise — a constant struggle since the beginning of digital cameras. The bit depth (or color depth) refers mostly to how many different shades of color can be captured in each red, green or blue pixel. 1-bit color is grayscale (21), 8-bit color can capture 256 different colors (28), and 16-bit color can capture up to 65,536 colors (216). Many high-end digital backs can now capture 16-bit; most DSLRs still only capture in 12- or 14-bit. Lastly, the proximity of the pixels to one another makes a difference in how much of the projected image is lost. The further apart, the more you’ll lose in the space between each pixel. The bottom line is: forget any “Napoleon complex” about having a smaller camera; remember, size isn’t the issue. You don’t need a Hummer H2 to be a successful photographer, when a Jeep Wrangler will do you better than fine.