Focusing and exposing in infrared

Infrared light focuses at a slightly different point than visible light, and your camera’s meter wasn’t built for it. Neither is a dealbreaker — you just need a few habits.

Focus

• Converted cameras are calibrated during conversion, so autofocus and live view usually work normally. If yours front- or back-focuses, that’s worth raising with whoever did the conversion.
• With a lens filter on an unconverted camera, the filter blocks the viewfinder, so use live view and focus after the filter is on, or focus first and switch to manual.
• Stop down a little. Shooting at f/8–f/11 gives enough depth of field to cover small focus errors. Going much smaller invites lens hotspots (see the lens database).

Exposure

• Meter, then check the histogram. IR scenes fool the meter; the histogram doesn’t lie. Push exposure right without clipping the bright foliage.
• Shoot RAW. You’ll be doing a custom white balance and often a channel swap later — JPEG throws away the latitude you need.
• Long exposures with lens filters. Because the sensor’s IR-cut filter is still fighting you, expect multi-second exposures. Use a tripod and a remote or self-timer.

A quick starting recipe

1. Tripod, RAW, f/8.
2. Custom white balance off green foliage or grass.
3. Expose to the right; confirm on the histogram.
4. Fix white balance and swap channels in editing.

From here, see white balance and channel swapping for the post-processing side.