I was browsing the super8database earlier, although i already had a read of the Projectors and stats section i thought i would bring it here for those who may not have seen it.
The Projectors and stats includes one particular piece regarding how many projectors took various spool sizes and one thing did surprise me. It's the fact that only one percent of machines took the 1200ft spool. Because so much talk goes into the Elmo 1200 series and the Beaulies, i for one completely overlooked the amount of projectors made and are still out there that only take a 400ft spool and that 600ft capacity is the next most popular, so it's easy to see why film dealers only released films on nothing larger than a 600ft reel.
I recall a fellow collector mentioning his some years ago regarding selling films on ebay. While i try to put spools back onto their original reels i have sold features on 800ft and 1200ft spools in the past, clearly, as my friend said, this could potentially put some people off bidding. Looking at this chart it's easy to see how this could be as many buyers would only have the smaller spool capacity and may not have the ability or equipment to break films down themselves.
An interesting and eye opening chart and write up. The database just gets better.