[DaveNZ (Dave)]

I've noticed some strong gradients in my images towards the end of my image run last night with my truss newtonian. I'm using a shroud and have the three small fans running on the back on the mirror cell. I was imaging in a dome pointing close to the zenith.

Early stages of dew formation on one half of the primary seems to be the cause of the gradients.

Any ideas on how to avoid this. Introducing a side fan to blow across the primary or perhaps a primary mirror heated dew system ?

Thanks Dave