----- Original Message ----- From: "Lawrence Kwan" Subject: Re: K10 Debug Mode
> On Fri, 16 Mar 2007, William Robb wrote: >> I downloaded a chart that some guy with a D70 made. It's printed off on >> an >> 8.5x11 sheet of paper. I used the 31mm, at about a 2 or so foot range. >> I haven't checked focus with any other lenses yet, that will be my >> project >> for tomorrow. > > There have been some criticism about the above chart using a 45 degree > angle method. I have no idea whether those criticism were valid, and some > claim that this would introduce errors and force FF or BF. > > Another chart http://www.geocities.jp/pen_pen_pentax/focus/ was "claimed" > to be better as the focus target was vertical. > > I would also like to know if these test charts were better or should we > use real life objects. > > Another word of caution is the lighting. Users have noticed variation > whether you are using daylight or tungsten light. I read the fellow's paper (for the life of me, I don't recall his name), and he took quite a bit of effort to debunk the naysayers. Pretty much, it came down to the camera not knowing or caring if the test chart is on an angle, since it is only being asked to focus on a discrete line on the page. I used diffuse daylight. If the light spectrum makes a difference, then one should run these sorts of tests in the light type used most often. My own thought on that is people who don't know how to run a test shouldn't be running tests. William Robb -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
