I have a photo that I want to enter in a contest. It’s a landscape shot of a lake, mountains and sky. The only problem with the pic is that the horizon on the water is slightly tilted. If I could crop and rotate only slightly, this would be a perfect shot.
Is it possible to do this with PhotoShop? If so, how? Or do I need to print the photo, cut it ‘square’, and re-scan?
I’ve done it in Photshop LE, so I’m sure you can do it in the full version.
It’s in the Edit commands as “Rotate Canvas.”
Should be an option to tilt the image a few degrees. Then cut out a smaller square from that. No need for printing.
Don’t know what the option is called, as I don’t have Photoshop myself, but it’s standard in most image edition programs.
You don’t even need Photoshop - just about any image editing program will have a “Free Rotate” option under the Rotate menu item, which lets you specify the number of degrees to tilt it by. Any number of my photos have been rescued this way 
Incidentally, even just 1 degree is a surprisingly big tilt — I always seem to overestimate how much correction I need to apply.
In the off chance you don’t have PhotoShop already, likely Paint Shop Pro is a better program for you. Though it doesn’t have all the features of PhotoShop, it’s very powerful, but much much more intuitive. For example, to do your current task at hand, you drag a line onto your picture, and set the ends of the line so that it’s parallel with what should be level. I.e. you set it so the line rests against something that should be horizontal, such as the bottom of a building, or along the skyline. Then press a button, and it rotates the picture as you like.
Assuming you have Photoshop 7.0, simply open the image file, go to Image|Rotate Canvas|Arbitrary. Enter the value in degrees you want to rotate [hint: you don’t have to enter a whole number] select CW or CCW, and click OK.
Following up on the previous post, in case you already do have Photoshop but can’t figure it out, there’s an easy way to straighten out images (please reference the Photoshop Toolbar):[ol][li]Click on the color picker and hold down the mouse button. A sub-menu should appear.[/li][li]Click on the Measure Tool (icon looks like a little ruler)[/li][li]Go to your image. Click on one end of the horizon and drag your mouse across the water. Release mouse button.[/li][li]Go to the menu. Image > Rotate Canvas > Arbitrary. Click OK. Voila, your horizon is now, well, horizontal! No need to figure out how many degrees your camera was tilted off.[/li][li]Go to the Toolbar again and click on the Crop button. Drag your mouse across the area in the photo you want to crop. Press return.[/li]Save image. Bask in the glow of your accomplishment.[/ol]
Thanks all. I’ll give it a shot (I do have PhotoShop 7.0, but haven’t used it much yet).
BTW, if you’re entering this photo in a contest, it might be worth checking what the rules are about “digital manipulation”. Some are more strict than others, although since this is something that is easily done by simply cropping a physical print, I think you’d be fine.
Another technique in Photoshop…
Click on the crop tool and draw an arbitrary sized crop area.
Click and drag outside the crop area. Your crop area will rotate.
Line up one side of the crop area with the horizon in your image.
After the crop area is rotated the correct amount, drag the corners of it so that it covers the image area you want to keep.
Double click within the crop area.
Voila.
It’s hard to eyeball a nice, accurate rotation to make the horizon level, since the triangular whitespace left over tends to throw off your perception of the result, so I use this method to get it as precise as possible:
See http://www.codsquad.com/~galt/rotate.jpg for an example in case my explanation is hard to follow.
Jeez-zus…only on this message board… 
Psssst…galt, if you do what I or Turek recommended, there’s no math involved. At all.
Ok, so my way was nerdly overkill based on developing the habit years ago and not realizing that newer versions of photoshop have much more sophisticated methods. Hrmph. It’s still more satisfying to do the math yourself, damn it.
You can also create a horizontal guide by clicking and dragging from the ruler. (If you don’t have horizontal & vertical rulers at the edges of your image already, press control-R to turn them on.)
…even on those pokey old versions of PS. But extra nerd points for the calc technique.
Well… there IS math, but YOU don’t have to do it.
