How to refit Nikon D40X into an infrared camera?

The so-called infrared camera is actually that the photosensitive element can sense invisible light other than red wavelength, that is, infrared light. Ordinary films are not sensitive to infrared rays, so there are special infrared photographic films, which are strictly controlled because they are easy to shoot perspective effects.

In the digital age, CCD\CMOS can be completely sensitive to infrared rays. Therefore, a filter called low-pass filter is added in front of CCD\CMOS to filter out infrared rays. In other words, as long as you have strong hands-on ability, you can take infrared photos by removing the low-pass filter. To put it bluntly, all digital cameras (except Leica M9) have been converted into infrared cameras.

However, remember that there is a slight deviation between infrared focusing and visible focusing. There is a red dot on the old lens, which is a reference for compensation in infrared focusing. Now the lens basically cancels this design, but it is not difficult to find it. Just try a few more times and make a mark yourself.