Every now and then I receive e-mails with questions about IR photography. A few days ago I received such an e-mail from a photographer from Holland. He wanted to enrich his photography and use IR for street stuff among other things. Since such infos may also be interesting for you, if you are an IR photography beginner, here are his questions and my answers:
I understand that if I convert a camera to full-spectrum, I will then have to use filters. Whether its an aerochrome emulating filter (or set of filters like you’ve show us on your website – amazing!), or an infrared 720 nm filter (for infrared BW photography) on the lenses. But I assume that in these cases, I cannot look through the viewfinder anymore as it will be too dark. So I use Live-View. When in Live-View, the images are clear and bright on the LCD screen?
Yes, that is correct. If you buy a full spectrum camera or convert it yourself, then you have to use external filters. And yes, at higher than about 670nm you won’t see anything in the viewfinder. Live view is not a problem and is even highly recommended especially with full spectrum because you won’t have focus problems. The image in the screen will be bright and well visible.
Do the shutter speeds have to be quite slow to capture a scene? Do you think one can capture street photography – so people moving rapidly, say at least at 1/400th ?
Yes, no problem. In general. With the standard filters like 720nm or a red filter et cetera no problem at all. You can shoot like with visible light, depending on the aperture with 1/1000 or even shorter. It is a bit more difficult with dual or triple bandpass filters. There you have to use a relatively high f-number to get the plane of focus right. Don’t ask me why, but with the TB (Aerochrome) or even the DB850 (Blue Trees) you get strange blurs when shooting at f/3 or f/4. But even with the DB850, which swallows a lot of light, I can still shoot at f/11 at 1/200 or even shorter. And that’s at about ISO 400, so you could also turn up the ISO.
If I convert my camera solely to infrared 720nm or 850nm, I then do not need any filter on the lens, from what I’ve understood. I can just shoot normally?
Yes, quite normally, through the viewfinder. The filter is installed directly in front of the sensor, and the camera is (hopefully) calibrated by the converter. I did this with my Nikon D700 and am extremely happy with it. Bought a filter myself, cut it, installed it and then calibrated it so that everything is in focus even at open aperture. The disadvantage is that you can only shoot 720nm or 850nm. It’s just a question of what you want.
