Dotted overspray is common with AB and produces a “soft-edge” camo scheme. If you are after a hard-edged scheme, you need to mask the area using either tape, silly putty, or some other method. You can minimize it by adjusting pressure, thinner, angle of spray, etc. but it won’t eliminate it entirely. HTH.
I also get the same problem , what i like to do is I thin the paint just a little more than normal an i lower the air pressure right down . this minimises the dotted pattern if you move in close to the model and hold the AB at a 45 degree angle to where you want to spray this gives a nice soft edge aswell as minimising the dotty pattern.
Take a look at the camo on the tanks/planes in my sig. All these kits were painted freehand with no masks. Remember, on the real thing,most of this camo was done in the field with a compressor and a spray gun. Don’t fault yourself too much, the real tanks had a little overspray as well.
You didn’t specify in your thread what kind of paint you’re using, but with acrylics, here’s how I acheived the results you see below:
Dial the regulator down to 10lbs., get as close to the subject as possible. When beginning, start the line on a card, so as not to blotch,the brush is already moving when the paint hits the model, so you get a relatively clean line, (no golf balls!). On the King Tiger pattern, I outlined the section first. By this I mean, the base coat is dark yellow, so when applying say, the red brown, outline the camo patterned section first, then fill in. This way, you get a clean demarcation line between colors. On the Panther, the “branch” type effect was done using the card method above. Starting and stopping is where I used to run into trouble.
I agree with stuka, the key here is to reduce pressure, get close and you’ll get a nice soft edge.