Porsches, Pixels, and Panorama

August 2008

Back when I was trying to leap the ravine from the film work that I knew and loved to the digital world that was bearing down on me like a 917 at the end of the Mulsanne straight, I remember arguing with the slightly more informed lady at the lab which was then doing scans for me. “I want an 8 X 10. I don’t know or care about dpi. Or pixels or whatever you’re talking about.” Several scanners and computers later and with enough hours in Photoshop to have gotten a doctorate in Mandarin Chinese, I care a lot, and so should you. Here’s why.

First of all, no lecture about bytes, bits, dpi vs. ppi, and all that. This is really pretty simple, and I’ll try to keep it that way. What has happened is this. The digital age, with its evolving but varying quality cameras, has invited us to look at our pictures on our computers, and we have been rightly impressed with how good they look. The glowing screen gives us beautiful back-lit colors and impressive sharpness; we can send them to our friends to look at on their computers and they’re impressed too. We can view them full-screen; they’re huge, and they’re beautiful.

But they look miserable in print. Here’s why. Pictures look good on monitors at as little as 72 little packages of information per inch—call that dpi. High quality printing on good paper—think Panorama—needs 300. A very little math will tell you that for an 8 X 10 inch picture you will need 8 times 72 (576) plus 10 times 72 (720) or 1296 pixels total (we’re talking cell phone camera territory here) for a good big picture on your monitor. But Panorama prints at 300 dpi, so we will need 8 times 300 (2400) plus 10 times 300 (3000) or 5400 pixels for a similar size pic. Between 4 and 5 times as much information is needed. 


 

Those 5400 pixels mentioned above translate to a camera capable of a little over 5 megapixels, 5.4 to be exact. In the Panorama world, we need 5250 pixels for a full page, twice that many if the image is a “double truck”, covering two facing pages. The good news is that almost all currently manufactured “point and shoots” are 5 megapixels or better. The bad news is that we still are sent some truly tiny files; too small for even the little black and white 4 inch “From the Regions” feature

I think that often the problem goes back to that monitor that looks so good at 72 dpi; common sense tells us that our image should look good in print too, and so a smaller image is the one that is sent even though the camera might produce a lot more. Since programs often open pictures at the monitor-friendly 72 dpi—which shows the image to be a huge 42 inches wide with a 5 megapixel camera-- why not send a smaller, easier to handle version? Now you know the answer: because it’s only 10 inches wide at 300 dpi.

The other problem is of course that many images need to be cropped for a variety of reasons, and pixels are lost when this happens. Maybe only a part of the picture tells the story, maybe there is somebody or something you don’t want or need in the picture, or maybe you need to make a high quality vertical out of a horizontal (think Panorama cover). Best, of course, to plan ahead and use all of your camera’s pixels shooting what you want to show (come in close on your subject), but we don’t always know the eventual usage when the shot is being made.

If you’re not sure what size your image is and don’t have a program such as Photoshop that can tell you, right click your image in Windows Explorer and click on file info; this will give you the total pixels you have; divide by 300, and you have the number of high-quality inches of photo present, divided between the long and short axes of the image (5400 divided by 300 is18, the 8 X 10 we mentioned above). Too much is way better than not enough. Final thought: don’t trust your monitor. If you want to make a submission to Panorama, send us the whole file and let us crop and downsize it if needed. We’ll all be happier!

Keep shooting, and let me hear from you at leonardt@pca.org.