# Photo manipulation question **URL:** \ **Category:** Factual Questions\ **Created:** [September 23, 2004, 6:03pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716 "2004-09-23T18:03:04Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [September 23, 2004, 6:03pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/1 "2004-09-23T18:03:04Z")
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? ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [September 23, 2004, 6:05pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/2 "2004-09-23T18:05:47Z")
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.” ---
**Author:** ![GreyWanderer](https://avatars.discourse-cdn.com/v4/letter/g/7cd45c/32.png) [@GreyWanderer](https://boards.straightdope.com/u/GreyWanderer)\ **Post date:** [September 23, 2004, 6:06pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/3 "2004-09-23T18:06:27Z")
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. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [September 23, 2004, 6:14pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/4 "2004-09-23T18:14:15Z")
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. ---
**Author:** ![Bill\_H](https://avatars.discourse-cdn.com/v4/letter/b/a5b964/32.png) [@Bill\_H](https://boards.straightdope.com/u/Bill_H)\ **Post date:** [September 23, 2004, 6:24pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/5 "2004-09-23T18:24:28Z")
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. ---
**Author:** ![Terminus\_Est](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/terminus_est/32/3087_2.png) [@Terminus\_Est](https://boards.straightdope.com/u/Terminus_Est)\ **Post date:** [September 23, 2004, 6:40pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/6 "2004-09-23T18:40:46Z")
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. ---
**Author:** ![Earthling](https://avatars.discourse-cdn.com/v4/letter/e/90db22/32.png) [@Earthling](https://boards.straightdope.com/u/Earthling)\ **Post date:** [September 23, 2004, 6:42pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/7 "2004-09-23T18:42:01Z")
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](http://www.80four.co.uk/tutorials/tools.html)):[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] ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [September 23, 2004, 6:55pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/8 "2004-09-23T18:55:32Z")
Thanks all. I’ll give it a shot (I do have PhotoShop 7.0, but haven’t used it much yet). ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [September 23, 2004, 7:07pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/9 "2004-09-23T19:07:44Z")
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. ---
**Author:** ![Turek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/turek/32/18782_2.png) [@Turek](https://boards.straightdope.com/u/Turek)\ **Post date:** [September 23, 2004, 7:10pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/10 "2004-09-23T19:10:37Z")
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. ---
**Author:** ![galt](https://avatars.discourse-cdn.com/v4/letter/g/35a633/32.png) [@galt](https://boards.straightdope.com/u/galt)\ **Post date:** [September 23, 2004, 10:00pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/11 "2004-09-23T22:00:20Z")
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: 1. Using the rectangular selection tool, draw a rectangle starting at one end of the horizon and ending at the opposite end of the horizon. You should end up with a rectangle with the horizon crossing it diagonally from corner to corner. 2. Bring up the Info panel to see the width and height of this rectangle. 3. Using a calculator that does trig functions (e.g. the windows builtin calc.exe), divide the height by the width and then take the inverse tangent of the result. The final result is the number of degrees you need to rotate the image to get the horizon level. 4. Select the entire image and do the rotation. See [http://www.codsquad.com/~galt/rotate.jpg](http://www.codsquad.com/~galt/rotate.jpg) for an example in case my explanation is hard to follow. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [September 23, 2004, 10:09pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/12 "2004-09-23T22:09:13Z")
> [@galt](#): > > 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: > > 1. Using the rectangular selection tool, draw a rectangle starting at one end of the horizon and ending at the opposite end of the horizon. You should end up with a rectangle with the horizon crossing it diagonally from corner to corner. > 2. Bring up the Info panel to see the width and height of this rectangle. > 3. Using a calculator that does trig functions (e.g. the windows builtin calc.exe), divide the height by the width and then take the inverse tangent of the result. The final result is the number of degrees you need to rotate the image to get the horizon level. > 4. Select the entire image and do the rotation. > > See [http://www.codsquad.com/~galt/rotate.jpg](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… 😃 ---
**Author:** ![Earthling](https://avatars.discourse-cdn.com/v4/letter/e/90db22/32.png) [@Earthling](https://boards.straightdope.com/u/Earthling)\ **Post date:** [September 23, 2004, 10:54pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/13 "2004-09-23T22:54:43Z")
Psssst… **galt** , if you do what I or **Turek** recommended, there’s no math involved. At all. ---
**Author:** ![galt](https://avatars.discourse-cdn.com/v4/letter/g/35a633/32.png) [@galt](https://boards.straightdope.com/u/galt)\ **Post date:** [September 23, 2004, 11:27pm UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/14 "2004-09-23T23:27:05Z")
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. 😃 ---
**Author:** ![Larry\_Mudd](https://avatars.discourse-cdn.com/v4/letter/l/f14d63/32.png) [@Larry\_Mudd](https://boards.straightdope.com/u/Larry_Mudd)\ **Post date:** [September 24, 2004, 12:23am UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/15 "2004-09-24T00:23:33Z")
> [@Earthling](#): > > Psssst… **galt** , if you do what I or **Turek** recommended, there’s no math involved. At all. 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. 😃 ---
**Author:** ![Turek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/turek/32/18782_2.png) [@Turek](https://boards.straightdope.com/u/Turek)\ **Post date:** [September 24, 2004, 1:37am UTC](https://boards.straightdope.com/t/photo-manipulation-question/265716/16 "2004-09-24T01:37:24Z")
> [@Earthling](#): > > Psssst… **galt** , if you do what I or **Turek** recommended, there’s no math involved. At all. Well… there IS math, but YOU don’t have to do it. 😃