Card board back and A/C silver duct tape. Tilt back slightly so the sun can reflect off of it. Morning is better before everything in the environment heats up.I made the grid so I could easily measure the amount I’m off
1. Frozen water bottles are great.
2. Baggie of ice taped/stapled to cardboard.
3. Wet-wipes. The evaporation creates a nice contrast.
I found the wet wipes to be the best because you can see exactly where it hit.
Frozen water bottles (even cold water) if you have no target stand.
It’s contrast you are looking for. Not necessarily heat. Even if it’s cool outside, ice is usually colder than the air.
May need to work on thermal adjustments. If you can’t see hand warmer then change color setting, gain, contrast, if not auto focus make sure rear ocular and front focal are tuned in.What is your method for zeroing your thermal scope in summertime daylight?? Tried the air activated handwarmers with mediocre results. Thoughts?