My obsession with trees & fog continues – on this walk I managed to drop a lens cap. Could I find it? not a chance, rather annoying because it was the only thing keeping the front of the lens dry in all the fog.  At least it was a cheap item to replace (a free one from my daughter 🙂 ) not like the time I lost my  Nikon DK-17M magnifying eyepiece from the Nikon F4, that was rather costly.
If you have never tried one of these, I would recommend getting one, especially if using manual focus lenses; it gives a 1.2x magnification, making the viewfinder appear much larger, without causing problems for the dioptre adjustment.