PJHHobbit Loc: Kansas City, Missouri

How about switching the scale in PS Lightroom from pixels to inches?

gvarner Loc: Central Oregon Coast

Just to be correct, comments here should not reference dpi (dots per inch). That's for printer resolution. The reference should be ppi (pixels per inch), which is camera resolution. Eg., a photo that is 2000 X 4000 pixels at 200 ppi would be 10 X 20 inches and would print out to that or to any proportional equivalent, 5 X 10 for example.

John_F Loc: Minneapolis, MN

Mikey's query goes right to the heart of one of my ongoing questions. What is the dimensional size of a pixel? A pixel is a cluster of solid state electric charge traps, and each trap provides either a 'zero' or 'one' to the binary value of the pixel. How many bits per pixel and is it configured like a 'toothpick' or a 'square.' So is it fair to divide the sensor area by the pixel count to get the area size of a pixel? My Sony a6000 has a sensor size of 23.5 mm by 15.6 mm, 24.7 Mpixels actual, 24.3 Mpixels effective, and the maximum image size of 6000 by 4000 pixels for 24 Mpixels. Which pixel number do I divide the sensor area by? To my way of thinking such a number would define the resolving power of the sensor and would provide an absolute floor on the 'circle of confusion' which is fundamental to depth of field. Lets not go there.

gvarner Loc: Central Oregon Coast

Difficult to say. Larger sensors have larger pixels but I don't know if it's proportional. Intuitively I'd say a small sensor with 20 mp has the same number of pixels that a large 20 mp sensor has, they're just bigger on the larger sensor. That's why full frame sensors are better in low light. I think.

CaltechNerd Loc: Whittier, CA, USA

It's important to note, "size" in terms of physical length and width ONLY apply to a PRINT (or screen image, sort of). The image on your disk drive has NO physical size, it's just a bunch of pixels that can be printed at 72 dots/inch, 150 dots/inch, 300 dots/inch, etc. Each will produce a different physical size.

Kuzano

You may be trying to relate unrelated information.

First, understand that the word "size" by itself is confusing in images.

There is storage size on the hard drive... ie bytes, kilobytes, megabytes. Space taken up in the computer.

There is Image size related to the pixels displayed on the computer screen. Some screens are 1600x900 pixels in pixels displaye on the screen, with many other alternativesdepending on how your monitor is configured.

There is print size based on putting the image on paper. Where computers use PPI (pixels per inch) on the screen, printing translates that term to DPI, or Dots Per Inch on the paper/print media.

NOW.... I'm not going to try to explain that.

I am however going to point you to a book that you can buy on Amazon new or used.

It is called The Magic of Digital Printing by Erik Doeffinger.

Here is a link:

http://www.amazon.com/Magic-Digital-Printing-Shooting-Photography/dp/1579906893/ref=sr_1_1?s=books&ie=UTF8&qid=1461866522&sr=1-1&keywords=the+magic+of+digital+printing

This covers all the math involved from the shot to the ink shot on the media.

It would be futile, and I would never attempt to explain ANY of this on the computer screen and keyboard. Others will surely try. They will fail!