Hi Alan, On Sun, 22 Dec 2013 15:07:24 +0200 Alan C wrote: > >Many thanks for the "tutorial". I'm sure it will be of use to others too. This >is the link for Bob Atkins test chart:
You're welcome! >http://bobatkins.com/photography/technical/lens_testing/reschart.zip > >It has plenty of "grids", etc. but no ruler. Ok, that is a nice chart to test how good a lens resolves detail, but totally UNSUITABLE for focus adjust. This is an image about how a proper focus-adjust looks like, and how its used (it is the one I use): http://regex.info//i/JEF_024924.jpg This is another post about a slightly different one, with images: http://photography-on-the.net/forum/showthread.php?t=750736 And yet another one, on a pentax forum, including images too: http://pentaxdslrs.blogspot.nl/2012/01/front-or-back-focusing-problems-free.html As you can see, a contrasty focus TARGET is needed, and a sort of ruler, ANGLED to have its numbering or lines at different distances. But it should be well OUTSIDE the active focus-area of the camera (so use center-spot). Unfortunately I can't find the PDF for the one I am using now, but I do have one that is quite similar that you can download from my own website. It includes a description on how to use it, and you can simply print out the one (out of 20) page that is the chart itself, to use that. It is at: http://www.dfsee.com/download/focus-test-chart.PDF Regards, JvW ------------------------------------------------------------------ Jan van Wijk; http://www.dfsee.com/gallery -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
