Jun 23, 2008—At many events, Virgil gets asked about his camera. The most frequent question is “How many megapixels does it have?” People (and camera sellers) too often use megapixels as the measurement of a camera’s quality. “Not so,” says Virgil. As he explains it, megapixels aren’t all created equal. They vary from brand to brand and model to model, so that statistic doesn’t tell you very much. In the mode that Virgil generally uses on his new Nikon D3, it has 5.1 megapixels (MP). The D3 has 12 MP in its full 35mm frame size mode, but that’s too much data to use for action photography. The 5.1 MP mode reduces the sensor’s size by 33 percent and precrops more tightly on distant subjects. Some people sniff at that number and say, “Oh, my camera has 10.” Still, Virgil says he would choose his 5.1 MP over any other camera’s 10 any day. Quality wins out over quantity in pixel count. The difference is in pixel design and camera processing ability. One reason that Virgil’s 5.1 MP outperforms another camera’s 10 is that he always shoots in 14-bit RAW. By contrast, most people—even other pro photographers—shoot in 8-bit JPEG. RAW is a “lossless” format that preserves 100% of the data captured by the light sensor. JPEG is a “lossy” format that, even at its highest setting, always discards data. The amount of data lost by JPEG format depends on how much detail the scene contains and the camera’s high-medium-low quality JPEG setting. A low JPEG setting discards 75 to 80% of the original data captured. So suddenly 10 MP in JPEG is more like 2 MP in RAW. In addition, JPEGs are always 8-bit. That means there are only 256 shades each of red, green, and blue that are used to make up all color information in the photo. Each additional bit doubles the amount of color and tonal data captured. Therefore, a 14-bit format contains 64 times the tonal and color information of an 8-bit file. Another way to look at it: Instead of the 16 million colors most cameras can capture, Virgil’s camera captures billions of colors. Billions of colors means far greater differentiation of detail. Even at 5.1 MP, Virgil can make 16x20 prints because of the quality, color, and tonal range. Look at the exceptional detail of the picture on the right (from the recent GAGC picnic). If you don’t have a Nikon D3, what can you do to get the best pictures from your camera? - To improve the quality of photos you shoot, set your file format to RAW at the highest bit level available. In Virgil’s camera, that’s 14-bit. The bit level varies from camera to camera. - If you can’t set your camera to RAW, always shoot at the highest quality JPEG. With 10 MP, 8-bit JPEG, you won’t get what Virgil gets with 5.1 MP, 14-bit RAW, because his camera starts with (and keeps) 64 times the amount of information. But you’ll get a better quality picture than with a lower JPEG setting. - Every time you open and resave a JPEG file, you lose more data. The file gets compressed with each save, so each save sacrifices detail. Never save back over the original file. Always convert to a “lossless” format (TIFF, Photoshop PSD, or DNG) when you resave a picture. Then work from that file in the future to prevent any more degradation. For the next article in this series, Indoor Exposure Exposé, click here. Virgil welcomes questions about cameras, lenses, software, etc. If you have any questions to ask him, send him an email, call him at (513) 779-8934, or talk to him at an event. GAGC%205-08.htmlExposure.htmlmailto:Virgil@PawPrintsPet.com?subject=Camera%20question%20from%20PawPrintsPet.comshapeimage_1_link_0shapeimage_1_link_1shapeimage_1_link_2
When Is a Megapixel Not a Megapixel?
(Article 1 in the Camera series) by Rebecca Forrest with lots of help from Virgil Sweeden