1 Reply Latest reply on May 12, 2014 9:17 AM by ccastleb

    Q:  What size should I print lens calibration target?

    harryshin

      Hi:

       

      1.  Since I use a camera body / lens combo that isn't supported in regards to automatic lens correction profiles, I've been thinking / wanting to create my own profiles, but have been put off by doing so when glancing at the methodology of how to do it etc…  

      2.  The thing that confuses me off the bat is figuring out how large of a target I should print.   Since I no longer have a printer at home and since I'm going to have a local lab print one out, I would like to like to the job correctly the the first time and thus would like to get some specific input on this print size issue. 

      3.   Since I've read that the target print size will depend on the camera / lens focal length, I'm shooting a micro 4/3 camera with a focal length zoom of 12-60mm (i.e. 35mm full frame equivalent of 24-120mm). 

       

      Thanks for any info and if there are decent printed tutorials on this, I would appreciate any recommendations.   Harry

        • 1. Re: Q:  What size should I print lens calibration target?
          ccastleb Adobe Employee

          Hello Harry,

           

          We use several different charts internally. Selecting which chart to use depends on which lens is being profiled. Profiling a zoom lens is like profiling several primes, so we generally use a few different charts per marked focal length to complete the process. The rule of thumb I use is for each focus distance I choose to shoot, I try to select a chart that will fit in approximately 1/4 of the frame. So, for minimum focus distance on a wide lens, the chart will be pretty small. For 2x minimum the chart would be a little larger, but it might be still be small enough to print on standard 8.5x11 paper. And for infinity focus, the chart will need to be medium to large depending on the focal length being profiled.

           

          I typically use 3 charts per focal length (sometimes only 2). Below is my most common set (first 3 fit on 8.5x11):

           

          • 7x19 (18 points)
          • 15x27 (18 points)
          • 21x37 (18 points)
          • 23x37 (36 points)
          • 27x45 (54 points)
          • 41x59 (54 points)

           

          Best of luck!

           

          - Chris