Exposure Woes

[jjkage84]

With all of that explanation, what still seems to be missing is a damn step test as was suggested! One screen, five or six exposures to compare!

That said, yes, poor contact can certainly screw up edge definition and add to detailed open areas filling in as well. An array of tubes, even more so than a single point light source really needs good contact
Also, did you get real unfiltered black light tubes like this rather than the party type?

I understand the step test as suggested, I just did it with the dozens of screens I have done at various exposure times etc. I am being slightly facetious.

Yes. Those are the exact bulbs that I ordered.

[Stinkhorn Press]

NOT MUCH HELP:
we started with similar (all around bad) conditions. there was an awful lot of good enough and kludges to make something kinda work.

we didn't truly get GOOD and REPEATABLE exposures until we upgraded to a old, used POINT light expo unit (5K MH) AND took great care to have the emulsion-ed screens sit in a DRY location (30-35% humidity) before exposing.

up to that point it was a constant and only ever half-won battle.

we got a used expo unit for $1K. Bought a new bulb and blanket (Douthitt). Roughly $1,600 all in.
it's been like night as day as far as consistency and control. dual cure emulsion solid 7 ++ at 25-45 second ranges depending on the mesh.

i realize that may not be in the budget right now, and there are a million things you can do in the meantime to get it better (like the suggested cheap blanket fix if the vacuum itself is working) but we definitely wasted many many man hours on something that in the end wasn't THAT expensive to do fairly well, relatively cheaply. YMMV of course.