Stitching software and digital cameras make panoramic photos far easier than ever before. However, to get the best results, you need a special tripod head. These can cost hundreds of dollars, but making your own isn't that hard. Even better, it's dirt cheap.
There's some amazing software out there for panoramic photography. Various software packages warp, stitch and blend sequences of photos so that they (ideally) look like one big, high-resolution, panoramic shot. However, getting these shots to turn out perfectly isn't easy when handholding your camera or using a normal tripod, especially when some parts of the image are fairly close to the lens.
The issue is "parallax", or, to rip something out of the American Heritage dictionary since I'm not about to try to explain it myself, "an apparent change in the direction of an object, caused by a change in observational position that provides a new line of sight." To fix this, you need to get the camera to rotate about a specific point that is forward of the screw socket in your camera.
Panoramic heads can be very expensive in the $300 to $500 range for "name brand" heads. Several designs for closer to $100 are available on the web, but look a tad on the flimsy side.
Building your own panoramic head for an SLR isn't too hard or expensive. The parts for the design shown here cost about $10. Every part here is available at a store like Home Depot.
Once you get past some of the misinformation out there, the only really hard part is figuring out the dimensions. The downside is that the mount is only useful for a specific camera/lens combo. On the other hand, you can't mistakenly mess up one of the critical adjustments once you've built it, and the homemade mount is as light as a couple small pieces of wood.
My woodworking skills aren't top-notch, but there's really not much need to make it look even this nice. Don't worry about appearance, just get the key measurements close and you'll have a fully functional new toy.
Step 1: Theory and Speculation
Before we start, we need to make a guess as to that magic rotation point mentioned previously. This is where the misinformation comes in.
1. The point the camera must rotate about is the "entrance pupil", not the nodal point as is often stated. Better yet, who cares what they call it, there's a test to figure it out.
2. The rotation point (entrance pupil) is NOT necessarily halfway down the lens. In fact, on many cameras, it's not even close to that.
So, what's the test to find the entrance pupil?
Our mount will hold the camera sideways, but for now it's easiest just to hold it horizontally. Position two objects on a table so that they line up when viewed through your lens a couple of batteries work perfectly for this. Now pan your lens right and left as you normally would. You'll see the objects move relative to each other that's parallax.
Now, let's find a better pivot point. Put the tip of the index finger of your left hand somewhere along the bottom of the barrel of the lens. Now rotate the camera about that point. Try to hold that left hand as steady as possible (c'mon, you're a photographer, you got steady hands, right?) Still see a shift? Move your finger/pivot point along the lens until that shift goes away. On my Canon 17-85 EF-S, the point was 4 1/8 inches forward of the screw socket.
This photo shows the camera straight ahead, and the batteries aligned:
Now the camera is turned to the side. The alignment is quite close, but not perfect - we can see the left edge of the rear battery poking out: