</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Lemastre @ Jan 4 2003, 02:49 PM)</td></tr><tr><td id='QUOTE'>there&#39;s some sort of hiccup in the AP&#39;s program that makes the meter&#39;s reading for grade 3.5 filters wrong. &nbsp;The manual instructs you to subtract about a third or half a stop of printing time from whatever the meter tells you. &nbsp;This is done simply enough, though, by tapping the time button. &nbsp;(Why is that adjustment not built into the software?) </td></tr></table><span id='postcolor'>

since the RHD-Analyzer allows calibration only to full paper grades. The half grades are interpolated. In the special case of grade 3.5, this interpolation has a little error on certain papers (e.g. Ilford MGIV). This has to do with the fact that the exposure transition from grade 3 to 4 is not linear. The same might happen to a Grade 0.5, but it is hardly visible at these soft grades. The only solution to this would be a calibration to half grades. But this would complicate calibrations otherwise. I prefer it the way it is.