Heading back into the darkroom and I'm looking to fit out my Omega D5 XL with lenses. I have a 3 lens turret and was going to pick up a few Flat Plates with 39mm Threaded Flanges, figuring that these would work on just about any lens I'd be buying. I was reviewing a link posted on APUG ---- http://www.khbphotografix.com/omega/LensMountD5.htm ---- and was just curious about the site saying I'd need to use an extended plate for a 105mm Rodagon. I've never worked with extended plates before on the D5, so I wanted to know A) if they're actually necessary? and B) if so, when are they necessary? I just want to make certain I buy the right equipment. (Also, it may be helpful and informative to let you know that for the near future I'll be mainly printing 6x7 and 35mm negs.....eventually getting to 4x5). Thanks so much!