Testing my knowlage

Hello this is about stops and seeing if im correct.Ok here it goes
if i use fstop 5.6 and the shutter speed is at 1/10 and i use a wider aperture f4 makeing it 1/20 here is what i came up with.:p
5.6 1/10
f4 1/20
2.8 1/40
2.8 iso 200 1/80
2.8 iso 400 1/160
2.8 iso 600 1/320
2.8 iso 800 1/640
2.8 iso 1000 1/1280 fast enough to stop action.I think useing iso 200 gives you a stop more of light please tell me if im wrong.Thanks Sean .L:o

Every time you double your current ISO, you get an extra stop of light.

So if ISO 100 gives you 1 stop, ISO 200 gives you 2 stops, ISO 400 gives you 3 stops, ISO 800 gives you 4 stops and ISO 1600 gives you 5 stops etc.

So your example is not quite correct, it should read:

5.6 1/10
f4 1/20
2.8 1/40
2.8 iso 200 1/80
2.8 iso 400 1/160
2.8 iso 800 1/320
2.8 iso 1600 1/640
2.8 iso 3200 1/1280

Thanks for your help i was almost correct but almost dont count i guess in time i will get this.Sean .L

The thing to remember is that whole stops are steps of 2, up or down.

Speed and ISO are simple linear things and change by 2× up or down for each stop.

Aperture also changes by 2× up or down for each stop. But aperture is an area thing, not a linear thing. To double the area of a circular aperture, the diameter is multiplied by 1.414... (the square root of 2). The f/stop sequence in whole stops is:

1.0
1.4
2.0
2.8
4.0
5.6
8.0
11
16
22
32
45
64
91