I used the example of a brick wall to try to keep the whole "shadows will have more noise" issue out of the equation.
Instead of a brick wall how about just a nice evenly lit 18% gray card?

All I'm trying to learn is....will an image taken at a high ISO have the same noise characteristics if it is properly exposed in low light vs high light.
In other words.....leaving the ISO set high the shutter and/or aperture are adjusted to achieve proper exposure.
(Short burst of intense light vs long exposure to low light) Any theoretical camera and sensor.

I would think that the amplification of the sensor signal stays the same since the ISO hasn't been changed and that the same amount of light (same number of photons) is gathered so the noise should be the same.

Three years ago I decided to purchase my first DSLR Camera it was a Nikon D3100 with the 18-55 kit lens. Within two months and with a lot of help from the Internet I had learnt how to use my camera in any of them modes it had to offer. Slowly bit by bit my kit grew in size, first a lens then a tripod, then another lens and a better more expensive tripod with matching ball head quick release mount, a sling back type bag for quick access, an sb600 flash slowly a second one followed then a flash trigger and 2 receivers. This was only about 8 months into my Journey. very dear friend of mine lent me his Nikon on D5100 for a couple of weeks while he was on holiday, it was great so much better than mine, it had a built in interval timer so I made a timelapse movie, the lowlight capabilities were outstanding compare it to mine too. even little things like the screen resolution on the back blew mine out of the water.
It was almost a year later I finally upgraded my body, it felt like forever before I could afford a new one, well what with buying myself a Lee Filters foundation kit and 7 different filters, and not forgeting another lens (macro this time) my kit was getting to big for my bag. Well the day had come, my new Nikon D7100 was here, but what's this, it doesn't fit in my bag, I needed a new one, I also treated my new body to a new lens, a 70-200 f2.8.
I finally solved my Nikon D3100, 2x lenses and first bag to my nephew.
In October last year I went to Florida for three weeks and took most of my camera equipment and a lens that I borrowed off a friend for wide-angle landscape photography, most days I found myself going out with just one lens and the body. My kit had become to heavy, and if I'm completely honest a real pain in the backside to the point where when I got home I put it all up for sale.
Well this was back in November, and last night, after I had completely forgotten all about it being up for sale, completely out of the blue I got a phone call saying they wanted to buy the whole lot for almost the price I had asked for. I got a say I did overprice it a little bit just in case I had sensible offer.
When I was in America with all my kit, going out daily with only one lens on my camera even that started to get my nerves, so on a couple of occasions all I took with me was my mobile phones camera.

So what to do now with all this money?
do I buy another DSLR and have it sit indoors while I'm out having fun with my phones camera, I absolutely love photography but do we need all this kit. Come on guys what's your opinion what would you do with my money if it was your money to spend?