Camera lens cleaning pens use fine carbon particles to help cleanly remove smudges from your glass. Do you know what else has carbon particles? Soot. Here’s a short 2.5-minute video in which photographer Mathieu Stern shows how you can use ordinary candle soot to get the same cleaning power as popular lens pens.

If you get fingerprints or other oily smudges onto the front of your lens, using an ordinary microfiber cleaning cloth can smear the oil around instead of removing it. Soot helps to quickly remove all of the oil with just a few rubs, and you can make some soot by waving a spoon around over an open candle flame.

Source: Petapixel