ISO question

Why do some cameras start out with ISO 200 instead of 100 ?Like the Nikon D40 for example. Are cameras with ISO of 200-1600 rated the same as 100-1600?

Nikon uses ISO 200, as their base ISO, whereas Canon uses ISO 100 as their standard. ISO 100 & 200 are very similar in what type of image the produce, but it does depend on the sensor & the technology to a point. There are several threads running here on the boards regarding Native ISO's. Use the Search function. It's your friend

https://photography-on-the.net/forum/showthre​ad.php?t=522691

What James just said ^^^ Nikon seem to always start at ISO200, obviously the 'base' ISO of the CCD chips they use, whilst Canon seem to always be ISO 100, although I believe the newer Nikon CMOS chips start at 200 as well, although you can lower it to 100 but I don't think you gain any quality, just longer exposures if needed.

ps249 wrote in post #5787434
Why do some cameras start out with ISO 200 instead of 100 ?Like the Nikon D40 for example. Are cameras with ISO of 200-1600 rated the same as 100-1600?

ps249,
When I first switched to DSLR's 6 years ago, the Canon having lower ISO made them the winner for me
I still would rather have a camera thats native ISO is 100