Digital Photography Quick FAQ's

Quick update 2006: I use primarily Digital cameras for everything except when I need/want the large format camera. Most of th e"comments" are still valid, but anything talking about current equipment and prices is now wrong.

I am often asked what I think about digital photography. Here are my thoughts as of May 2003. If you are reading this later than May 2004 - be careful, this page is probably too far out of date. Email me and remind me to update it!

OK, first, is Digital good for anything?

Yes!!! I have several 35mm cameras (8 at last count), I use 3 of them heavily as my main cameras. I also have a 4x5 camera (read - VERY big) that can make exquisite photos even wall sized. But I also have a low/medium end digital camera (it was close to high end when it came out several years ago.)

If your purpose is to provide images on a screen - ie over the web, then 640x480 or 800x600 is usually good enough - or in many cases, too big. If all you ever want to do is put images on the web and you just want to record everything as is, no fancy lighting,- a digital camera is frequently the best choice. Certainly if you are just doing "snap shots" it will always be the perfect solution. If you want professional quality web images - ie special lighting, portraiture etc.., then the digital cameras I've seen that sync with professional lighting systems just don't exist at a reasonable price yet. Even if you are a professional like me (or more professional) it is currently far better to use your "real" camera and then pay to scan the image in properly or get a really good ($1000-15000USD) scanner, tune it (using IT8 methods) and scan yourself.

If your purpose is to print them out, the table below gives some useful guidelines using current technology image sensors. Current technology image sensors record Green at every other pixel, and Red and Blue at every other other pixels. This means they read green for 50% of the pixels, Red for 25% of the pixels and blue for 25% of the pixels. Then they guess at how much Red and Blue was at the pixel for the Green and guess at how much Green and Blue were where they read Red and so on. This means that, on average you are only getting about 1/2 to 1/4 of the true resolution implied by the numbers below. ** Recent update. There is new technology that reads every pixel at every level. Their effective resolution is between 2x's and 3x's the image sensor size. Very cool. Currently the only manufacturer is Foveon with their X3 sensors. You can get them on a recent Sigma camera, unfortunately it is the first Sigma camera that is not compatible with Nikon lenses.

 I have no opinion yet for this column but I'm thinking at least 2400 DPI - that is, almost 10 times the magazine quality. I say that because I have seen ones film printed at 1200 DPI and 2400 DPI and the difference is noticeable. It is the difference between really good and exquisite. It may turn out that when I see a 4800DPI, I will say OH Wow! 4800 is when it is finally perfect.  Note that would make my choice here 19,200 x 28,800

1. I'm talking a high quality magazine here, not one printed on newsprint! Typically you want 250DPI or greater.
2. Note that Print sizes are given smaller dimension then larger dimension while images sizes are typically given vertical then horizontal. If you look at the numbers above you will see that I am saying that a 1024x768 image held on its side will be good for a 4x6.

The numbers picked in the second column were picked as "weird" numbers because they match common resolutions available on cameras. That is, you WILL find cameras that offer 1024x768 as an option, but you probably will not find one that offers 800x1100 or 750x1000. So for that purpose I have picked the "commonly available" numbers closest to what I think is reasonable.

Also, you will notice an interesting anomaly. I'm saying that you need nearly 200 DPI for a 4x6 image, but I'm saying that 128 DPI is good enough for an 8x10. How can THAT be? Is it a typo? NO! The simple fact is that you will normally hold a 4x6 closer to your face than you would an 8x10 so the resolution of a 4x6 needs to be higher than an 8x10.

Will the "consumer quality images" resolutions satisfy everyone? Is it good enough that people won't notice the difference? No. I have been shown, in a store, images that were 4 times that resolution and asked whether I could pick the digital from the film. I guess correctly, and quickly, and easily every time from 6 feet away. Some people can't see as fine detail as other people. I have been blessed (cursed?) with good resolution eyesight and I would only be happy with those resolutions for snap shots, holiday pictures and record keeping. But I also know that a lot of people are happy with those resolutions and have had many people ask me whether I could see a difference - suggesting that to them they were just as good!

OK, I am asked, so why are the Minimum resolutions for magazine quality images always 250DPI regardless. Think a bit before reading further.... The answer is simple, you hold a magazine the same distance whether you are looking at a small picture in the corner or whether you are looking at a 2 page spread. It is only when you cut an image out of a magazine and put it up on a wall that you could now have lower resolution with the larger images!

Here's another way to look at it:

Good quality film, in a 35mm camera is approximately 15-16Megapixels (real megapixels, not the red/green/blue alternating megapixels), so current 6 megapixel cameras are about 1/6th the quality of 35mm film. My 4x6 camera is going to give about the equivalent of 256 Megapixels, about 100 times the current quality. So there is a little way to go still!

Well, this was fun. There is much more I could say about Digital, but lets leave it off with this comment:

It may not be a matter of IF digital is going to completely replace Film, but WHEN. 2 years? 10 years? 20 years? And every year between now and then, digital will take away a bit more of film's business.

For now, I'll stick with all my different cameras and, for a lot, scan the image in from a print, negative or transparency reversal (slide.) But I plan to switch to a good digital ($5000-$10000USD) sometime - probably 2004-2006 for most of my 35mm work. I suspect by 2007-2010 digital will completely replace my 35mm cameras. Needing 256 Megapixels, it will be a least a few more years beyond that before I'll replace my 4x5 camera with digital, but perhaps a digital back on it to take advantage of the tilts, swings & shifts would be reasonable for some shots even earlier.