Nothe APP question

[muletopia]

Last night I tried for a nebula in the middle of the milky way,.acquired OK.
In APP at the step "remove back ground' i could not find any area big enough to create the required 5 boxes.
I proceeded without this step and the result was as expected, there was no moon.
When the moon is up what do you do?
Chris

[The_bluester]

I have sometimes had to zoom in a fair bit to find suitable spots for the background calibration. Picking an area that has a starry background does not seem to make a massive difference to the final colours, but picking an area with nebulosity will, my understanding of that step is that it is trying to calibrate the background to grey, so a starry background will calibrate reasonably well, but nebulosity will really throw things off.

[Nikolas]

squares for background calibration don't have to be large just choose the areas with no stars and draw small squares
I personally use the light pollution tool as it's more forgiving you can draw 5 or more squares almost anywhere, just experiment