So Im thinking of getting a few rolls of rollei 400 infrared to both use as a normal black and white film and with a 720nm filter for surreal near-Ir shots (such a shame there are pretty much no other options at all let alone colour Ir film). The odd question comes in because of the camera Id like to use it with. Im thinking Id like to use it with an Olympus Trip 35 (rather than my Nikkormat FTn), for a couple of reasons, but Im not sure itll even be possible let alone practical. I know it will be fine for straight up B&W - just meter for ASA 400 or maybe lower to get more highlights and shoot away. The problem with using it with an almost completely opaque filter is that the meter on the trip, which basically dictates entirely what the camera will do in auto is around the lens, and being a selenium meter, it probably wont pick up much, if any near-Ir light, so will lock the shutter completely. I can still use it in "manual" though. Manual mode locks the shutter speed to 1/40s, and I believe will allow the aperture to be set manually. Iv read the effective film speed for this film with a 720nm filter is somewhere between ASA 3-12, with about 6 being best (the camera's meter doesnt even go down to 12 let alone 3). Would I be right in saying that with Sunny 16 to approximate the aperture for 1/40s shutter speed and ASA 6 Id have to stop the lens down to somewhere around f/5.6-4 to achieve "correct" exposure? Im not even going to go into the fact actual Ir levels depend on more than if it's sunny or overcast, but I will assume given Im in the tropics, coming up to summer at close to sea level Ir will pretty much always be off the chart anyway. The main reasons for wanting to use the Trip instead of an SLR, are that: 1. I intend to use it mainly for B&W and other film Ill be using for more candid shots anyway, leaving the SLR for colour and more carefully considered shots. And 2. The zone focus (as opposed to TTL) means I can still focus without having to take the filter off before every shot to focus, then potentially move it in the process of putting the filter on to shoot. Anyway, do my calculations sound right? Am I crazy? Does anyone else like this film (either as a conventional B&W film or for whacky near-Ir madness)?