I just thought I'd post that I've done some contacting today (4x5 and 6x12 ADOX negatives) and just starting to "feel out" what I need to do and how.
I've used Ilford RC MGIV on postcards and used a single naked lamp 15 watt bulb at 70cm above the paper.
"ideal" exposure seems to be too high intensity with times at about 2 seconds (I'm timing by 1 one-thousand 2 one-thousand counting).
My plan is to next make a 'can' (to use a stage lighting term) to house the bulb and hold a filter (I'll then do some better timings with a stouffer wedge) and compare densitometery of the print to that of the negative (using an Espon 3200 flatbed scanner).
My settings at present are:
2 seconds naked bulb @ 70cm seems to yield a good print
from a "wide range" negative.
developing time around 30seconds in Dektol.
I think that's short, so I'm keen to get advice as to how to do better on my next run. I very much like the contrasts I obtained (with no filtration on the MG paper) using this method, but clearly lower intensity would be better to enable longer exposure and hence more accuracy in the paper exposure.
I'll post a few images after the paper drys ... now, to lunch!