Please, if you choose to respond: Read the whole post first. No flames. Correct my math if it affects my question but please don't add any more unless absolutely necessary to your explanation. What I really want is the answers to the 3 questions. If I am to continue to advance in photography I need to understand this stuff.

I shoot a D7200 which is a crop frame camera. It has a sensor size of 23.5x15.6mm providing an area of 366.6 sq. mm. (which is 53% less than a D5) that contains 24.3 million individual pixel sensors which means there are ~66,284 pixel sensors per sq. mm.

If I reduce the camera setting from 1.5 to 1.3 do I retain the 24.3 mega pixels with a density of 66,284 pixel sensors per sq. mm or are the number of pixel sensors reduced from 24.3 mega pixels to some lower number (I don't want to do any more math, my head hurts already ).

What I think I understand

1. Is that on the sensor, the number of pixel units per sq. mm. is not the only factor that effects resolution.

2.The area of the sensor determines the amount of data the image the contains. The larger the sensor the more pixels there are to crop in PP.

3. I had a hard time crafting this statement. A full frame or half frame does not 'crop' it just limits the field of view and number of pixel units based on the sensor size.

That is also my hope, Larry, and a number of times we talked about getting together, but looked like something always came up to delay it. If you ever make it back up this way would love to have you and family visit with us and maybe take a few shots. We are about twenty miles east of Williamsburg and now have wood ducks nesting in our nest boxes and a few eagles and a number of ospreys close by with one pair nesting on the cover of our neighbor's pontoon boat which temporally puts it out of service, and almost forgot the resident grumpy great blue heron! Take care and hope that your hip condition improves soon!