Since I did that spray pattern test with the Omni 4000 a while back I thought it would be interesting to see how my other airbrushes compared in terms of the thinnest and thickest lines possible.
I did this test a while ago with Model Master Acryl flat black thinned 2:1.
I thinned the paint with a 50/50 isopropyl alcohol/filtered water mix and shot it onto another piece of pellon material on my T-shirt easel.
I shot each airbrush at 25 psi with the needle as close to the surface as possible for the thinnest lines, and then pulled the airbrush back to about 3" from the surface and pulled the trigger all the way back to blast as thick of a line as possible. The test results are as follows:
The Vega 1000 is an older model built by Thayer & Chandler before they went out of business. It is a gravity-feed model with a 1/8 oz color cup and looks very similar to the Omni 5000. It does not have a single needle/tip combination like the Omni's do though and instead has the fine #1 needle and tip.
The Omni 3000 is a siphon-feed model and is internally the same as the Omni 4000 and Omni 5000 with a single needle/tip combination.
The Vega 2000 is one of the older models also made by Thayer & Chandler before Badger took them over. I bought it as a kit with three needles and tips and use it for T-shirt airbrushing with the #3 needle and tip in it.
You can tell in the photo that it sprays a thicker line with the #3 needle and tip than does the Omni or Vega 1000, but what was interesting was that the finest lines were not much thicker than any of the others including the Omni 4000 that I tested a while back. This is not a comprehensive test by any means as there were not enough variables involved, or different users spraying through the airbrushes. Some of you can probably spray a thinner line than I can with these same airbrushes so the results may differ. What I do think these tests show is that for the modeling paints we use the airbrush is not as critical as some would have you think.
Most anyone could spray freehand camo on 1/72 and 1/48 scale aircraft with any of these airbrushes and obtain excellent results with a little practice.
As I have said before, the airbrush needle and tip are made to the size they are for the specific medium that they will be spraying. That is why I always ask people why they want something like an Iwata HP-B or something similar for model building. The needle and tip are so small that they could obtain as fine of a line and have better overall performance with something designed for the mediums we use on models. If you were to spray inks, water colors, or any of the other mediums made with extremely fine pigments meant for an illustrators airbrush, then that Iwata would be a better choice because that is what it was designed for.
I hope this helps out someone wondering about the capabilities of airbrushes and I look forward to more tests done by Greg (plasticmod992), Karl (plum1030), or any of you others on this fine forum.
Mike