Slashdot Mirror

← Back to Stories (view on slashdot.org)

Make Your Own Digital Camera ISO Test Target

Posted by ryuzaki0 on from the cool-ideas dept.

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! "

40 of 139 comments (clear)

  1. Great... by inkdesign · · Score: 5, Funny

    I love ideas that make me feel like I got less than my money's worth AFTER THE FACT!

  2. Or... by tomcio.s · · Score: 4, Informative

    frequent www.dpreview.com and get professional reviews of cameras.

    Dpreview carries digital camera reviews dating back to 1996. They are usually very detailed.

    1. Re:Or... by Zog+The+Undeniable · · Score: 3, Informative

      At the risk of creating a "me too" thread, Steve's Digicams is also pretty good. If a camera is junk, he says so, but the full size sample pictures are the really useful feature.

      --
      When I am king, you will be first against the wall.
    2. Re:Or... by jovlinger · · Score: 3, Insightful

      Steve never met a camera he didn't like.

      The intro's are just rehashes of the press releases, and all the test shots are done in bright light, out doors.

      For a camera to suck under those conditions, it'd have to ship from the factory with grease on the lens.

  3. Cost over $100 ??? by sbryant · · Score: 4, Informative

    Somebody can't read! It said over 100 pounds ($180).

    Insert comment here about people of a certain nationality making too many assumptions about units of various things...

    -- Steve

    1. Re:Cost over $100 ??? by erick99 · · Score: 2, Informative
      From the article:

      The ISO standard for measuring resolution of "electronic still imaging"" cameras is 12233, available only from the International Standards Organization for only 116 Swiss Francs (about $US93 as of this writing)

      --
      http://www.busyweather.com/
    2. Re:Cost over $100 ??? by Lord_Slepnir · · Score: 5, Funny
      You're right. I apologize to you on behalf of everyone here in america. For your convience, I have converted the price to a more european-friendly unit.

      It cost over 45.35 kilograms

    3. Re:Cost over $100 ??? by JDevers · · Score: 2, Funny

      WooHoo I knew that if I held on to those copper and iron pieces they would eventually gain in value!

    4. Re:Cost over $100 ??? by JeremyALogan · · Score: 2, Informative
      so... why would someone in the United States (as Corell University is) quote prices in GB Pounds?
      Answer? They wouldn't... if you had read the real article (you know... the one that dpnow.com links to) you would have seen the following:
      The proper way to perform these tests is to order both the ISO standard and a properly-made test chart. The latter are available, for example, from Sine Patterns LLC and Precision Optical Imaging, both in Rochester, New York. See the the I3A site for worldwide sources. Expect to pay more than $US100 for such a chart.

      Did it occur to you that maybe the submitter based his facts on the source, not the hype?
      --
      Jeremy Logan's Website.
    5. Re:Cost over $100 ??? by jemfinch · · Score: 3, Informative
      No, it said (and I quote from http://www.graphics.cornell.edu/~westin/res-chart. html):

      The ISO standard for measuring resolution of "electronic still imaging"" cameras is 12233, available only from the International Standards Organization for only 116 Swiss Francs (about $US93 as of this writing)


      Insert comment here about people of certain other nationalities applying rude, unfounded stereotypes to people of my nationality.

      Jeremy
      --
      Looking for a Python IRC bot?
  4. misdirection by Anonymous Coward · · Score: 5, Informative

    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:

    http://www.graphics.cornell.edu/~westin/res-chart. html

  5. Site by WhatsAProGingrass · · Score: 5, Informative

    Another site with better pictures

    --
    Mark
    1. Re:Site by Pieroxy · · Score: 3, Informative

      Well, not printable size, and thus, not free. The link you point to is the very reason someone got through the trouble of redoing it by himself.

      Thanks though, this is informative.

      --
      Write boring code, not shiny code!
    2. Re:Site by WhatsAProGingrass · · Score: 2, Informative

      Yes true, its not free, but just thought it had some more info people might be able to use.

      Looks like you'd need a pretty expensive printer to print these out. Some of the images are 80 cm wide.

      --
      Mark
  6. Bacground information by Mstrgeek · · Score: 3, Informative
    This is a great site dealing with Digital Camera ISO Test Targets

    http://www.gpsinformation.org/jack/photo-test/pi cs/lens-tests.html

    hope you are able to find to find the site a help

    --
    Chris Williams clw7500nc@gmail.com
  7. Tied to the quality of your printer? by sdo1 · · Score: 4, Interesting
    so you can find out how good (or bad) your camera really is!

    Or so you can find out how good (or bad) your "good quality" printer is.

    -S

    --
    --- What parts of "shall make no law", "shall not be infringed", and "shall not be violated" don't you understand?
    1. Re:Tied to the quality of your printer? by ajs · · Score: 3, Informative

      Yep, I have a Canon E300 (AKA Digital Rebel, AKA Kiss), which, at 6MP and with my good macro lens (since I don't need any depth of field for taking a picture of a sheet of paper) can literally tell you how good your paper selection is, and that's the "prosumer" grade camera. Grab yourself one of the "professional" digital cameras (like the E20), and you're going to be able to determine the components of the ink, based on the way the paper separates it through capillary action.

      These test sheets are fine for low-end cameras, but once you start dealing with professional lenses and high resolution CCDs you really need something printed by a professional printer, not some cheesy home unit (even if the home unit has the same resolution as the camera, it may not be capable of reproducing the image on paper with enough fidelity to test the camera.

    2. Re:Tied to the quality of your printer? by imsabbel · · Score: 3, Insightful

      Well, its no problem to use those good cameras as optical microsopes in makro-modus, but these target are supposed to shot from a fixed distance, plus they are BW only, so no resolution loss due to rasterization.
      Of course a colour or general quality target wouldnt be possible with that method, but plain resolution is... (given the fact that a laser printer can do REAL 1200dpi, which resolts to a shitload more pixels per frame then even a Canon 1Ds can resolve.

      --
      HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
  8. Another excellent source by poszi · · Score: 5, Informative

    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!

  9. Re:Color Fidelity by Henry+Stern · · Score: 4, Informative

    Someone obviously didn't even LTFA. The target is black and white.

  10. Or.... by Halo- · · Score: 4, Interesting
    Or find out how crappy your printer is. Seriously, what do you think is more precise, the electronics in your cheap digital camera or the moving parts and alignment of your cheap printer? Curve dithering is one of the harder aspects of printing, this target seems to rely heavily on them.

    This is a fun toy to play with, but I'd trust professional reviews.

    1. Re:Or.... by gl4ss · · Score: 2, Insightful

      actually, the chances are that the crappy printer prints more accurately than what the camera can capture.

      --
      world was created 5 seconds before this post as it is.
    2. Re:Or.... by timster · · Score: 2, Insightful

      Since the target consists only of solid black and solid white, I don't understand what role dithering has in this. Although there are curves, I don't think it's important that they be anti-aliased.

      Mostly I think this is a question of the resolution of the printer. At 800x zoom on my 100 dpi monitor I can see all the small features clearly, so I expect a 1200dpi laser would render this image just fine. At 600dpi you might miss some of the fine details.

      --
      I have seen the future, and it is inconvenient.
  11. Coralized link to pdf by Anonymous Coward · · Score: 5, Informative

    ISO 12233 Test Chart

  12. Re:Color Fidelity by Gaewyn+L+Knight · · Score: 3, Insightful

    Ummm dude... it's black and white.

    If you are going to comment at least look at it first... oh wait.. this is /.

    News for nerds... stuff people talk about without reading. :P

    --
    Telcos have alot of dark fibre in the States. Most people assume that's optical fibre...but it's actually moral fibre.
  13. new excuse! by Anonymous Coward · · Score: 5, Funny

    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.

  14. For Sale by PoopJuggler · · Score: 4, Funny

    For Sale: ISO Resolution Test Target

    $50.
    Paypal only, please.

  15. Re:Pwned. by dirkx · · Score: 2, Informative

    Right - but that is just the standard which described the card; not the actual card itself.

  16. Copyright... by kahei · · Score: 4, Interesting


    Now, there's interesting:

    Westin explains that the ISO specifications can be used without restriction for projects like his, though the copying of a commercially reproduced target is, of course, illegal.

    (see, I _did_ rtfa!) So, it's illegal to reproduce the image, but creating a new image from an exact description of the image is legal. Yet that _is_ what 'reproducing the image' is!

    The reason for this situation is that the image in question is very unusual, in that it has a freely-usable exact description in existance. But what if an exact (text) description of Mickey Mouse were made? You certainly wouldn't be allowed to create new images from it, and yet it's hard to see how Disney would own the rights to that description... hmm...

    --
    Whence? Hence. Whither? Thither.
    1. Re:Copyright... by gblues · · Score: 3, Insightful

      Well, in your example, the description of Mickey Mouse IS owned by Disney. The description that the ISO specifications provide is free for anyone. The trick is actually implementing it. The commercially reproduced version costs 100 pounds, this version costs less (but may not be usable if you have a crappy printer).

      It's sorta like the Bible. The actual scriptures are public domain, but the various translations--NKJV, NIV, etc--are copyrighted. I can go get the original Greek/Hebrew/Aramaic texts and translate them myself and get a result that is very close to an existing translation, and it is not illegal.

      Nathan

    2. Re:Copyright... by Suidae · · Score: 2, Insightful

      How exact of a discription is allowed? I can describe a high resolution bitmap very accurately by writing out the color values of each pixel, but I doubt that would be permissable.

    3. Re:Copyright... by swillden · · Score: 2, Informative

      NKJV is NOT copyrighted. You can copy it as you please.

      The NKJV is copyrighted, though the copyright holder's (Thomas Nelson) policies on the use of its material are fairly liberal. You can't print full copies, but you can quote lots of it.

      Perhaps you're thinking of the KJV, which is actually copyrighted as well, but the copyright has no legal force outside of the UK and isn't, I don't believe, enforced there, either. See the Wikepedia article for more information.

      --
      Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
  17. How *real* photographers test a new lens/camera by Zocalo · · Score: 5, Informative
    1. Throw away any test charts into the corner of the room
    2. Toss any rulers on top of the test charts
    3. Newspapers? - on top of the rulers
    4. Avoid any brick walls
    5. Pick up camera (and attach lens if applicable)
    6. Go outside (yes, it really does exist!)
    7. 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.
    8. Make some nice large prints of your efforts
    9. 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!
  18. It's not reverse-engineered by dmadole · · Score: 4, Insightful

    Can't anyone write anything tech without feeling the need to throw in a highly-charged buzzword?

    If you read the chart's creator's web page, he didn't reverse-engineer anything. He created the chart from the published international specification. That's pretty much the opposite of reverse-engineering: engineering. That is, taking a set of specifications and producing a design that meets them.

    But I guess that's not as interesting-sounding.

  19. Slashdotted.... by Infinityis · · Score: 5, Funny

    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...

  20. this helps me a lot by Anonymous Coward · · Score: 5, Interesting

    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

  21. Save Me From My Inferior Camera by lildogie · · Score: 4, Funny

    I loved my inferior camera, and my family snapshots, until I found that they had barely-visible distortions.

    Now I have to find an accurate camera and retake all those photos.

  22. digital camera reviews are nearly worthless by ckedge · · Score: 3, Insightful

    .
    Why does his "the best cameras" aka "pick of the litter" page have 10 (ten) cameras listed for each of the 12 categories? He says the "cameras are not listed in order of preference":

    http://www.steves-digicams.com/best_cameras.html

    I can see 2-4 choices per, but 10?

    Digital camera reviews are no where near as technical and detailed as they need to be to be useful, compare this:

    http://www.steves-digicams.com/2003_reviews/exs3_s amples.html

    with this:

    http://www.rcgroups.com/forums/attachment.php?atta chmentid=118010&stc=1
    http://www.rcgroups.com/forums/showthread.php?t=13 1193&page=7&pp=15
    http://www.rcgroups.com/forums/attachment.php?atta chmentid=180976&stc=1
    http://www.rcgroups.com/forums/attachment.php?atta chmentid=221673&stc=1

    Note the "pre-printed form letter" the one guy gets back from his warranty servicing with the check mark beside the following paragraph:

    "Your camera is operating according to factory specification in all modes. The phenomenon you have experienced (an orange halo visible in the bckground after taking some pictures) is not a defect in operation of your camera. It is a function of the geometry of the lens optics. Under certain lighting conditions this effect may be noticeable. Darker backgrounds will minimize or eliminate this effect."

    You can no longer find the S3 or anything like it on the market, Casio has probably quietly removed it due to huge numbers of returns and warranty servicing costs. You can only find a few on eBay, and ALL are "open return" or "used return, not tested". NONE sold by happy users.

    AFAIAC, digital camera reviews are nearly worthless, no matter who is doing the review.
    .

    1. Re:digital camera reviews are nearly worthless by ckedge · · Score: 3, Interesting

      I've seen dpreview.com of course. I don't remember anything standing out. But, on your word, I'll go back and check what it's like these days.

      [goes away, comes back 15 minutes latter]

      Hmmm, ok, I like their "buying guide" that allows you to choose features you want then list all camera's side by side. However - the table is missing a few things (like start-up-time, inter-picture delay, shutter-lag, etc), and the camera I had pointed out is given 4 stars out of 5 despite the massively poor picture quality of this camera, in fact ALL the 10 cameras have 4 stars out of 5 - the star rating is user driven. ONLY 2 of the 10 cameras have in-depth reviews by the dpreview site staff themselves.

      They do have a page where they rank cameras by their own review rankings, but it's all mixed together, it'd be a huge pain in the ass to figure out which are the ones I'm interested in and which are on the market, price differences, etc etc. They need to review a larger fraction of the cameras on the market, and add this data to the comparison table.

      One thing that is impressive is the last two rows in the comparison table, where they show a resolution chart snapshot and color chart snapshot. The color chart snapshot clearly shows the horrific quality of the camera I was talking about. Unfortunately like the reviews, they are only there for some of the listed cameras.

      I give dpreview.com 6 stars out of 10. Steve's digicams gets 4 stars out of 10.

      What I want to see is 8-10 stars out of 10 for a rewview site. Isn't this the information age? Where the FUCK ins the information? It's supposed to SAVE me time, not consume my time, and it's supposed to DECREASE the odds of crappy products thriving.
      .

  23. Take it to a professional printer... by Dr.+Mu · · Score: 3, Informative

    I printed this out on my HP4MV laser printer at 11 x 17 inches. Its 600 dpi are hopelessly inadequate for this test pattern. The best way to print this would be to take it to a print shop that has a good direct-to-film printer (2540dpi or better) and ask them to make a PMT (positive mat transfer) from the file at the highest resolution possible. You'll get a near-perfect print. But you'll pay about $25, and it may not be archival: some PMTs fade over time.