Pacific Mall North Buildings in IR

Pacific Mall North Buildings -- Canon 20D IR Modified & Pentax-K 28mm f3.5. Click to see larger.

One of the difficulties of taking pictures with IR cameras, other than focus shift, is exposure.  Buildings and non-organic objects generally don't emit large amount of infrared energy, and thus would take much longer to expose.  For this reason, for IR shots, you can't really rely on the camera's metering system, which is optimized for visible light spectrum.  Histograms are much better for this purpose.  Trial and error is also a good way to go.

There is one feature on Canon lenses that not many people know about.  Those Canon lenses with Ring Ultra Sonic Motors (USM) can focus past infinity.  This is a feature that lets you shoot critically sharp IR pictures, because the infinity focus point for IR pictures normally goes past the focus point set for visible light photography.   Another benefits for USM lenses is that you can adjust focus at any time without switching the lens to Manual Focusing (MF), as all Ring USM lenses (and the EF 50mm f1.4, which uses a micro-USM motor but allows MTF) allows Full Time Manual focus (FTM).