</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Aggie @ Jan 24 2003, 06:26 PM)</td></tr><tr><td id='QUOTE'>try the new maco film,,,it comes in 4X5 format for the infrared. But you need a darker red filter in the 89 range</td></tr></table><span class='postcolor'>
I've been "wringing out" MACO 820 for a while now ... Rumor has it that Konica has discontinued 750.
The 89 series filters have one drawback - they do not transmit much visible light, so, unless one uses a rangefinder, it is fairly necessary to use a tripod, compose without the filter, install it and then expose. Come to think of it, less of a problem - not that far from the ordinary - with a view camera.
Konica 750 has a "bi-modal" spectral sensitivity - with the Infra - red peak centered at 750 nanometers; so the usual #25 would cut off most of the non-infrared light. From what I've seen, there wasn't a lot to gained from a #29 or #87 - #89 filter.
I'm extrapolating - read: guessing - that the same will apply to MACO 820 - but a lot depends on one's individual "taste". Stay tuned.