Hi, we have two different opinions about a so basic and at once vital conception like resolution. I hope a enquiry about it be appropriate in this forum. I put below the two versions and I would be grateful for any help in order to determine which is the right one. Thank you in advance.
1.a. The image size professionally is, in both analog and digital, measured in metric units (centimeters and its multiples or inches). And the resolution is always measured in pixels/metric unit. The result of this two variables (which is a specific amount of pixels) is, in general conceps in digital photography, only the resulting amount of pixels, only that. Finding a reason for what in some digital cameras is erroneously spoken about «image size» in pixels without that image being for the web, I find that really there is a fixed relation between size and pixels, independently of resolution, but it refers to the image file’s size, measured in MB, which certainly is always directly proportional to the amount of pixels.
1.b. When we do a photo with a digital camera, the size is always the same, those that lens is able to catch. And resolution is the amount of pixels in which that photo is going to turn into, in other words, the density of pixels that a size of photo is going to be: those that lens is able to catch and give to the «scanner» of the camera in order to transform it by the scanner in a whole spectrum of pixels, and which is going to determine the accuracy of the photo’s details, that is: its resolution.
2.a. In photography with digital camera, resolution (px/cm, px/inch) doesn’t exist, photography with digital camera exclusively works with image size in pixels, which is named resolution. The same occurs in digital image in screen (for example web, also screen proyection): photography with digital camera exclusively works with image size in pixels, which is named resolution.
2.b. In photography with digital camera, the size of the caught photo isn’t always the same: generally, the photosensor is a Area Array CCD, that consists in a reticulated matrix of hundred of thousands of microscopic photosensitive cells (photodiodes). Each photodiode matchs with one pixel, so the more photosensor the CCD have, the better the quality obtained with the camera will be. Those number of photosensors can be associated to a physical size (that which they themselves take up inside the camera, that isn’t the one of the image because it doesn’t exist as we physically know it), this physical size in any case would be variable by changing the resolution with which we take the photo (size in pixels x pixels).