Originally posted by Kozlok Sunny 16 says you'll be at 1/400 on a sunny day at f16. Assume a very bright day, and you're at 1/800. If you want to go to f8 at 1/800, you'd need a 2 stop filter. 3 should be safe for into the sun at sunset at f16, probably useable everywhere at f11 to 8.
The MX is an all manual film camera with shutter speeds of 1s, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500 & 1/1000. (No aperture priority)
You don’t really need a ND filter for everyday film shooting. Just use 100 ISO film and all is well. You will mostly shoot around 1/125 and f8 - f16.
Phil.