It’s a common mistake for those new to photography to take a photo with the intention of cropping it later. They may do this because they don’t want to get closer to their subject or maybe just because they don’t know the disadvantages of cropping.
Why to Avoid Cropping
When composing photographs, it’s a good idea to think about what you want the final product to look like. That is, frame the photo so that you can avoid too much cropping during post-processing because the more base image you have to work with, the less noise the photo will have and the more focused it will be.
One of three things happens when you crop a photo:
1. Pixels are removed from the image which makes the image smaller. For example, if you crop 2 inches off the top and right of an 8×10 inch image, you’re left with a 6×8 inch image, NOT an 8×10 inch image like the original.
2. Pixels are removed from the image where you crop and then pixels are added to the image to retain the size. The pixels are added by whatever image editing program you are using and sometimes it does this quite well, but the program is just making an educated guess on what to add and where based on surrounding pixels. Sometimes the image editing program you’re using doesn’t do a good job of this and can result in a soft or otherwise decreased quality of the image.
3. Pixels are removed and the remaining pixels are enlarged to retain the size of the image. This causes enhanced pixelation.
Alternatives to Cropping
If for some reason you can’t or don’t want to get closer to your subject and if your lens allows it, zoom in. Be aware that the more you zoom in, the more likely it is that your image will be blurry due to camera shake. This problem can be prevented by increasing the shutter speed (you’ll have to widen the aperture, increase the ISO, or change another setting to get the same exposure) or by using a tripod or steadying the camera in some other way.
If you’ve zoomed in as far as you can and still want the subject to fill more of the frame, try moving closer. It’s a step (literally, haha) that some beginner photographers don’t think to take.
Crop, If You Must
Sometimes your lens won’t zoom in as far as you’d like or it’s not possible to move closer to your subject. In this case, crop the image by all means. Just do it as a last resort now that you know how cropping works.