Hello Phil, Wednesday, July 17, 2002, 2:58:25 PM, you wrote: PV> I'm interested in the digital IR discussion. I apparently missed PV> earlier discussions, so I'm completely in the dark about how it works. PV> Could someone elaborate. Surely there is more to it than just filters. PV> Are some digital CCDs more sensitive to IR than others? All CCD's are inherently sensitive to near infrared. The hot filter in front of the CCD is supposed to filter out all the infrared radiation while passing through only visible spectrum. Fortunately the hot mirror design is not efficient enough, so it does let through some amount of infrared. Your Fuji S1 will work fine with an infrared filter - I've seen several IR shots done with it. Just put on the IR filter and start shooting :) One advantage the Sony F707 has is that it has a 'nightshot' mode where the hot mirror is moved away from the CCD thus allowing all infrared to pass to the imager. Unfortunately Sony succumbed to the hype of couple years ago of a possibility of 'x-raying', i.e. 'seeing through' certain kinds of cloth, so they disabled any manual adjustments in the nightshot mode and limited the shortest exposure to 1/60 sec at fully open aperture - this still permits hand-held IR shots. This results in a less than perfect setup of course, but it can be easily overcome by adding the infrared and proper neutral density filters to bring the light level down. Digital infrared (with regular digicams that have the hot mirror) is a tripod-based work with exposures of around 1-2 seconds - this varies wildly for the aperture and light levels of course. The filters you can use also vary wildly in price - 40$ for 87 or 87c at Harrison and Harrison to 200+ for some Hoya filters. Ebay sometimes has a good deal on IR filters (as long as nobody else wants the same lot :), B&H photo has usually some filters in stock, but seems that 58mm or larger filters are on special order or out of stock. I can't wait till the next weekend to get out and try some IR portraits... -- Best regards, Victor mailto:vrem@swbell.net
