Yeah my meter allows both reflective and incident metering but just I did not have the presence of mind to check that way but what you suggested was a great troubleshooting technique. thanks a ton for pouring ur valuable suggestions, this will help me a lot...
You're welcome. When I first delved into learning flash for portraits, this info was all new to me - so I included it not only for you but also for the benefit of other members.
If you use HSS or full power non-HSS on the Godox AD200 (or any Godox ADxxx strobe), keep in mind you will get a limited number of shutter actuations before the thermal protection warning kicks in. That will cause the strobe to stop working until it cools down. I don't know the number offhand, but I *think* it's somewhere between 15-30 images. My point is the number of images with HSS or full power without HSS is very low. If you are planning to take a lot of images, then an ND filter would be a better option although it has it's drawbacks as I mentioned above. From what I've read, many portrait photographers who use an ND filter tend to prefer the variable ND filter instead of a fixed ND filter. A downside to the variable ones is your lens hood won't fit with the ND filter in place. But the good thing is you can focus through it then rotate the filter to the desired marking (usually there are dots on the edge of the filter to show the number of stops) - of course keeping the camera on a tripod to not alter any distance for focusing.
Even with an AD600, it too would require HSS, full power non-HSS, or an ND filter in really bright conditions. The downside is its weight. However, if you are shooting a lot during the midday hours with really bright sunlight and are using the AD200, then a scrim or some type of diffuser between the sun and your subject might be an easy solution to avoid overheating your strobe. Even if you aren't using HSS, firing the strobe repeatedly at full power will also overheat the unit causing the thermal protection notification to appear.
From what I hear, Profoto strobes seldom run into this overheating problem...but then again, their prices are :eyetwitch:.