D7100 remaining exposures and memory cards

[Charliedelta]

hello all,

I set my D7100 so that the memory card 1 saves RAW and memory card 2 saves JPEG. I chose the best quality of pictures on both. Of course when I switched to this setting the "remaiining pictures" dial on the control panel went down from a few thousands to 500 and change. I just came back from a trip with the dial reading 170, so I assumed I took roughly 500-170= 330 photos. When I downloaded them to my computer, it turned out I had taken over 700 (not combined RAW+JPEG, but over 700 RAW and over 700 JPEG). Is it normal that the dial underestimates the remaining memory by this much?

Also, I have two 32GB memory cards. by doing 32GB divided the roughly 30MB of each picture, I should get about 1000 pictures, not 500. did I do something wrong?

Thanks

 

[Overread]

Well no two exposures are the same and the greater the amount of detail and complexity in the light and scene the likely greater the size of the file that will result. So the camera can only ever estimate how much space a card has and how many more shots you can get on to the card.