The Hamm's beer 'Scenarama' sign uses an unusual technique to simulate the effect of moving water in its scenes. A transparent sheet of plastic, the same height as the nature pictures on the front of the sign, is slowly scrolled in a continuous loop across the backlit scene.
As the pale white vertical lines on the scrolling plastic sheet intersect with the pale white lines on the 'water' portions of the nature pictures, an entrancing ripple effect is created, causing the bizarre illusion that the water is actually moving. Primitive by today's standards, but pretty high-tech and effective back in the day. I guess it's the rudimentary nature of this type of sign that adds to its collectibility today.
For some reason, people fall all over themselves for these old Scenarama signs, wirh good examples selling on eBay for many hundreds of dollars. The great thing about these old Hamm's signs is that all you have to do is remember the Hamm's name and you're almost guaranteed a profit when you see one and can get it at a good price.
A word of warning is in order when it comes to older Hamm's memorabilia. Remember, many of these signs are over 40 years old by now, which means that unless they've been kept in a closet somewhere, they're likely suffering some sort of damage or corrosion, as well as burned out lights and broken scrolling motors. By all means, plug in any sign you're thinking of buying if at all possible, especially if the seller wants more than 25 or 30 bucks for it. Broken and damaged signs do indeed sell, but why find out after the fact that your profit is going to be substantially less than you thought? This sign sold for $415 on eBay.