Hi Drum. I don't know about your blank image problem, but I've done Moon images using a D50 mounted prime-focus on a Meade ETX-105 (1470mm/F14) and despite all that light I found it hard to get sharp images with a single shot, mainly because of atmospheric wobble but also when you are 'zoomed in' on the Moon it moves pretty quickly. That was without the motors in the scope going; just using it as a lens - my scope's mount isn't strong enough to run motors while supporting the weight of an SLR, thus light-weight CCD cams are preferred.
Most astrophotography like this is done by stacking multiple exposures using software like Registax or Meade's Envisage software. My best lunar image is a mosaic of 35 multi-stacked images using Meade's LPI CCD imager with motorized software telescope tracking, this means you see the live image on a computer screen and it stacks exposures real time; binning any which are below a quality threshold. You draw a box around a bright spot on the Moon and the telescope tracks that spot! Stacking, in this case, is mainly about undoing the atmospheric wobble; like heat haze.
But still; you should be able to get something pleasing with a basic setup, what scope/mount do you have etc?
Full moon is rubbish; no shadows in the craters and thus no detail; you want anything but full moon, and you want it high in the sky so there is less atmosphere between you and your subject; less coloration and heat haze etc.
(I've logged my progress over the years on my website; see the astrophotography page : )
EDIT: "The scope itself lets me get so far, but never quite makes focus." - is this actually the reality? It should go beyond good focus; just like any lens. Did you buy an adapter designed for your setup? If the adapter was sold for your scope then you should be fine I guess, but if you can't reach focus then you're never going to get a decent image, possible an extender tube would fix it; but ... .. and I do remember that the focus required for an SLR on the rear port is very different to the focus for an eye-piece in the top port - requiring a lot of turns of the focus knob; and not easy to see exactly which way to go! That could be a lot of your problem?
