CT&D #18. Photo Resolution and Image Fidelity

What is a topic in photography that presents the most difficulty understanding and / or engaging with?

Although I have covered this concept previously somewhat in digital photography, when looked at it again in this class, resolution and image fidelity still confuse me regarding technical details. From what I understand, a photo depicts a subject whose composition consists of squares of different colors called pixels. As each pixel contains different colors (including shades and shadows of every color a figure may show), the sum of every pixel essentially makes up said figure as a whole.

Furthermore, the sharpness of a photo (as in how the detail in lines, shapes and color are shown clearly and smoothly) depends on its scaling since the closer that one zooms in on a photo, the more noticeable the pixels are and vice versa. So far, this is what I understand. However, my question is how can high resolution and low resolution graphics be interpreted from this? (I know it relates to it).

In addition, how does adjusting a camera (i.e. aperture) contribute to altering resolution as well as ways utilized in Photoshop? As these questions relate to raster images, knowing these answers would help me in dealing with them through graphic design to achieve creative and enhanced results for applications that require them.

Instructor Response: 

George,

Good practice is to capture as much information as you can. The larger the amount of information you start with, the more you can zoom and still have a usable image. This being said, it is specific to the application. If you only need an image for web (72 ppi) then you can crop in significantly more than if you need an image for print (300 dpi).

For camera settings, capture the largest file you can. RAW being best because there is no compression of the image information.

JPEG formats significantly compress image information. Aperture controls the depth of field in an image not the resolution. Photoshop can help you see what sizes you can work with from a capture. Sharpening can help images, but too much can be noticeable and deter from the image.