Usually don't need one in Perth but last night it was clear but a lot of mositure in the air and after wasting over half my captured frames due to dew I think I might need to buy one
Check to see as it may need to be dried out using the heater. Good pratice to do this when the weather changes and I only ever had the problem when I did not do this. Still Theo sells the heating ring or you could try a small heating strap if it persists.
I had the centre of the glass fog up a month or so back on a warm 99% humidity night. I'd been scratching my head trying to work out why the edge of the field would focus but not the centre, so pulled the camera off to see what was wrong. It was definitely on the outside of the nose piece.
My heater arrived from Theo during the week. Last night and tonight were both extremely humid and I had no problems. Until the cloud rolled in.
