Yup, maybe brain freeze. If I understand the question correctly, either you’re going to have to crop quite a bit of that photo, or it was taken with your camera held sideways.
If your camera was held sideways, it’s easy – you open the image on your screen, do a Command A to select the whole photo, and then go to Image>Rotate, and choose to turn it either 90 degrees left or 90 degrees right. Somehow I don’t think that’s what you want, though. So…
Your original image is wider than it is high. In order to make it higher than it is wide, you’ll have to keep reducing the resolution until you get that "short" side long enough to become the "long" side. Once you get a 4 inch high image stretched out to 6 inches high, you’ll have to crop off the excess from one or both sides. You’d do this the same way you size for a 4 X 6, but reverse the dimensions in the Option Bar.
OK, so if neither of those fit the bill, give me some more clues. 🙂
George, what you’re observing is that the ‘aspect ratio’ (relative dimensions) of your pictures as they leave the camera is 4-by-3, i.e. the long side is 4 units to the short side’s 3 units. The closest you can come to a 4×6 is 4.5×6 and the math for 5×7 is similar. What you have to do to get an exact 4×6 or 5×7 is crop (remove) part of your image. If you have a
4.5 by 6, you’re going to have to get rid of a half-inch strip the length of the picture; then you’ll have a 4×6. Cropping is painful sometimes,
though – you might really not want to get rid of part of your image to make it fit those standard dimensions. But if you absolutely, positively have to have a 4×6 or a 5×7, cropping is in your future…
Chuck