kenshinz said:http://www.lensmateonline.com/S1macrocomp.html
effects of Hoya close up filter and DCR250 on my previous camera Canon S1-IS
For 10x or 12x zoom digital camera, a +4 diopter filter like 250D or lesser (6T) is good enough for taking insects. From the link, it shows that Canon S1-IS + 250D can gives a magnification of 7/8" which is 2.1875cm ( 1" = 2.5cm ) full frame. A higher diopter +10 filter like DCR-250 will suffer of shallow DOF.
Unless you are using 3x to 6x zoom digital camera, DCR-250 will be a better choice