When you use Neutral Density or Infrared filters, the challenge is to get the right exposure, because you cannot see anything from viewfinder. Camera meter reading would be misleading. Solutions: Camera must be on Tripod with Cable Release
- Choose Quality (should be Raw), the ISO and White Balance
- Compose / focus / take meter reading / note the exposure (f-stop and shutter speed) / take the picture without filter
- Check in histogram (or by other means) to see that the picture in terms of composition and exposure are as desired
- If satisfied / put camera and lens on Manual / place the filter on the lens / have the same aperture (f-stop) as in (2) / only you have to play with shutter speed
- The shutter speed will depend on how many stops to add with filter. This is a matter of trial and error / Follow the filter factor / e.g. ND 1000 will need an increase in shutter timing by 10-stops
- Now you check the following Table and depending on what your original shutter speed was without filter in (2) / also the f-stop being same as in (2) / by how many stops you want to increase the shutter / choose seconds, minutes or hrs. from the Table / shutter timing has to be increased (put on BULB if it is more than 30 seconds) / shoot
Suppose, according to my exposure reading in (2), without filter, shutter was 1/60 at f/8. Now I want a 10-stop increase in shutter with filter. / Following the Table, I will need 16 seconds of timing to shoot. If not correct, I have to increase or decrease the shutter stop and accordingly, the shooting time.