<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <!--Converted with LaTeX2HTML 98.1p1 release (March 2nd, 1998) originally by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds * revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan * with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --> <HTML> <HEAD> <TITLE>Column NDVALUE</TITLE> <META NAME="description" CONTENT="Column NDVALUE"> <META NAME="keywords" CONTENT="vol2"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> <LINK REL="STYLESHEET" HREF="vol2.css"> <LINK REL="next" HREF="node612.html"> <LINK REL="previous" HREF="node610.html"> <LINK REL="up" HREF="node608.html"> <LINK REL="next" HREF="node612.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html9161" HREF="node612.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html9158" HREF="node608.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html9152" HREF="node610.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html9160" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="icons.gif/contents_motif.gif"></A> <BR> <B> Next:</B> <A NAME="tex2html9162" HREF="node612.html">Column NDETUSED</A> <B> Up:</B> <A NAME="tex2html9159" HREF="node608.html">Passbands</A> <B> Previous:</B> <A NAME="tex2html9153" HREF="node610.html">Column FILTCODE_n</A> <BR> <BR> <!--End of Navigation Panel--> <H3><A NAME="SECTION003253300000000000000"> Column NDVALUE</A> </H3> If ``neutral'' filters are used, their quantitative effect should be stored in a column named NDVALUE. The real number stored here should normally be the factor by which the intensity measured through the ND filter should be multiplied to be on the same scale as data taken without the ND filter. Therefore, the numbers are normally all bigger than unity, except for the un-attenuated passbands, for which one normally puts unity in this column. Because ``neutral'' filters are not really neutral, the value will differ somewhat from one passband to the next. <P> <BR><HR> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>
