When I introduced my Auto-Focus charts, It was both accepted by many people but also discredited by others. I received many constructive comments and suggestion, and some were incorporated in the current design.
The time I took to design the charts was to help other Pentaxians. I sent the charts to Pentax and asked them for an opinion. Because Pentax is International, with the head office in Japan and also because they now are owned by Hoya, I will not mention the names at Pentax but here is the email received from them.
Hi, Yvon.
Actually the chart worked just fine for me. A co-worker also tried it. He’s an old hand with the popular one on DPReview, but he says your chart seems just fine. He and I both liked that it folded out to a 45° angle block, which seemed to make the process pretty easy.
Thanks for working on this and making it available.
Best regards,
~~~~~ PENTAX Imaging Company
You can check and download the charts for free here: AF Charts
Thank you for reading. With Pentax, you're in good company,
Yvon Bourque