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Make Your Own Digital Camera ISO Test Target
dpnow writes I run a digital photography site and came across what I thought might be an interesting story. It's about a Cornell university researcher that has reverse-engineered the design of the ISO 12233 resolution test target, used by all the best digital camera testers. These usually cost over $100 but a free pdf download of the target is available. Print it out on a good quality printer and you have your own ISO-spec test target so you can find out how good (or bad) your camera really is! "
I love ideas that make me feel like I got less than my money's worth AFTER THE FACT!
the article links to a story which links to the actual content you want. To get to the real content, thus bypassing the advertisements that they wanted you to view in the first place, go here:
. html
http://www.graphics.cornell.edu/~westin/res-chart
Another site with better pictures
Mark
With description of the optics and details of the resultion measurements is here. He created also his own chart which includes shades of grey for better measurements of MTF50.
Save the bandwidth. Don't use sigs!
ISO 12233 Test Chart
I have no intention of doing what this article talks about, yet it is still very useful to me in another way : instead of telling people I'm rearranging my sock drawer and that's why I can't go out galavanting on Saturday night, I'll tell them I'm testing my digital camera's resolution with a reverse engineered ISO 12233 resolution test target.
Someone should sell t-shirts with this thing on them.
It cost over 45.35 kilograms
- Throw away any test charts into the corner of the room
- Toss any rulers on top of the test charts
- Newspapers? - on top of the rulers
- Avoid any brick walls
- Pick up camera (and attach lens if applicable)
- Go outside (yes, it really does exist!)
- Shoot numerous pictures of various subjects, at varying apertures, focal lengths and durations. Using a flash for some of the shots would be a good idea too.
- Make some nice large prints of your efforts
- Do the prints look OK to you? If they do, congratulations - consider the test passed, and you might even have a few prints you can actually use for something as well. If not *now* it's time to retrieve the test charts, rulers etc.
Seriously, the only people that really need these charts are people that are designing or calibrating imaging systems. A charming term that I think was coined over on DPReview to describe everyone else is "measurebator". Believe me, if you've got a lens bad enough to make a difference visible in a print, then you'll know it without any test charts. I had a lens that backfocussed, a Nikon zoom lens I got for my film camera some years ago. I picked up the problem without test charts just fine (I often focus on an eye in portraits), and so out came the rulers, or in my case a newspaper. The largest focussing error in the series of test shots that I took was less than 2mm at a range of 3m.Needless to say, I've never touched a test chart, or any facsimilie thereof, since then. The *only* chart that I do have is a Gretag Macbeth colour chart (it's a grid of 24 coloured squares) to get colour balance correct. I also have a couple of Kodak Grey cards for setting white balance if you want to nit pick and call one of those a "chart".
UNIX? They're not even circumcised! Savages!
I don't quite see how taking a picture of "error 500: Internal Server Error" is going to tell me anything one way or the other about my camera. However, it might explain a thing or two about their server...
I'm in a robotics lab working with a CMUcam. This should help us a lot. Those people whining that "real photographers dont use test charts" seem to neglect that some of us are trying to calibrate cameras for sensors and not just pretty pictures.
thanks poster