Pixellation After Cropping


Often, we shoot a photograph that needs to be cropped. The original framing is a little loose and the photo needs to be trimmed to improve the overall composition. This was not problematic in the days of film, but with digital images, I often notice a lot of noise, pixellation and softness when I crop a small part of a photograph. How can this aspect be controlled?
B Chakraborty, via email

This article was originally published in March 2015.

While cropping an image, you lose a lot of pixels. For instance, if you crop a tiny part of a 10MP image, the final picture may only be 4 or 5MP. Due to this, the maximum size at which you can print this image decreases. If you then try to make a large print from such a file, it may result in problems like excessive pixellation or noise. One must keep in mind that the average resolution of a digital camera is in the range of 10–12MP, with some expensive high-end cameras having a resolution of over 20MP. On the other hand, even inexpensive consumer film can give images of over 20MP, if scanned carefully. This makes it easier to enlarge a small part of an image while shooting film.

In an ideal situation, you must avoid cropping. Get close to the subject and confirm your framing before you trigger the shutter. However, if it is unavoidable to get the framing perfect and you really need to crop, you should keep a few things in mind. Ensure that you achieve critical focus while shooting the image. If your photograph is even slightly out of focus, the problems will be amplified when you enlarge the image. Using a high quality lens also allows you to enlarge your images to a greater degree. Finally, when cropping a part of an image and enlarging it, it is advisable to shoot in RAW. RAW images can be interpolated more easily and with less image artifacts, as compared to JPEG shots. Finally, if none of this works, you can try adding some grain artificially in a software like Photoshop. This will give the overall image some texture and ensure that it does not look soft.

Tags: Cropping, Interpolating an image, JPEG, Pixellation, Question of the Day, Raw