Camera apps have grids that are useful if you need to take a photo of something at a level. It also helps you line the photo up correctly and it’s really useful. That said, photos don’t always turn out as straight as you need them to be. If the angle isn’t too bad, you can straighten the photo with a simple photo editing app. Here’s how you can straighten a photo on Windows 10 using just the stock Photos app.
Straighten a photo
Open the photo in the Photo editor. Click the Edit & Create button at the top and in the menu that opens, select ‘Edit’.
A sidebar will open on the right and there will be a slider called ‘Straightening’. The knob on it is set in the middle and you can move it either way to change which way the photo is straightened.
Move it to fix the photo. The Straightening tool basically lets you freely rotate the image instead of just to specific angles e.g., 90 degrees. You can use the tool to tilt a photo too. When you’re satisfied with what you have, click the Save button at the bottom.
It’s a good idea to save the edited photo as a copy. When you change the angle of a photo, parts of it will be cropped out. The photo editing tool will limit the photo to the size it was which means when you try to straighten it, some of it will fall outside the canvas size and be cropped out.
If the Photo tool isn’t easy enough for you to use, or it’s too basic, you can try IrfanView. Go to Image>Custom/Fine rotation. You will get a new window with controls for rotating the image. Change the value in the ‘Angle’ field. IrfanView will change the size of the canvas so that when you rotate the image but if you want it to keep the original canvas size, select the ‘Keep original image/canvas size’ option.
IrfanView doesn’t have a grid to help you straighten the image. If you really need one, you can try using GIMP. It has a rotation feature. You can enable the grid from the View option on the menu bar. The rotation tool is also under View and it’s called Flip & Rotate.
Regardless of which app you use, it’s a good idea to save the new/edited image as a copy until you’re absolutely done with your project and you know you won’t ever need the original photo.