I have an Omega C760 Dichroic on the XL base, purchased used. I was gung-ho about my new qusai- darkroom until I tried to make my 1st enlargement. I am using a grain focuser, but just can't get a sharp 8X10 image using an EL- Nikkor 50mm for 35mm negs. I tried a bubble level (inaccurate, I know) and found it ok left to right, but front to back is waaaay off, and I can't seem to find any knobs to adjust in that direction. I read about using a device to align it, but these things are expensive! I also read how one individual used a black neg scored with a razor corner to corner, and how he fiddled until center and corners were sharp. I'll try this, but the angle of the head seems like it would be a problem. Is this the normal set-up with this enlarger, or should I be trying to shim it somehow? I've read many posts on how this enlarger is difficult to align, and keep in alignment. Any advice will be greatly appreciated.