Scots pine vs Red pine...how do I tell?

[LT40HDD51]

...The trouble with red pine is traditionally it needs to be big to be worth much. We have a limited market for the pulp and no commercial mill saws it that I know of. They use it mainly for utility poles...

Around here the log home builders like it, but as you said, it needs to be big. Like 24-30" at the butt and nice and straight. We get to buy some oversize stuff once in a while from some log builders and cutters we know locally.