Flash causing auto-ISO to be to high - Here's a solution

Set your flash to commander mode and the ISO will not change despite being set to auto-ISO.

I got this solution from the Nikon support team and it works great for me. I was warned that the commander mode may be slightly slower than the TTL mode but I am not noticing anything.

This completely gets rid of that annoying problem of the ISO going through the roof whenever you use the TTL mode flash.

Why would you use Auto-ISO with flash in the first place? I hardly ever use Auto-ISO since that is one thing I always want to control.

I use auto-ISO (almost) all the time because it generally does a better job than I can do. But the real reason is because I've had too many experiences of forgetting to reset my ISO level when setting it manually. This is also why, when not shooting in RAW, I always use auto white balance. Same thing for why I usually shoot in P mode - it just does such a great job.

Oh I know that control is good but my question for you is why would you always use manual ISO given that the auto-ISO mode is usually so accurate?

Because I keep my ISO as low as possible for a given environment/shot to geat the greatest dynamic range and least amount of noise. If I am working in a studio environment with strobes I always keep the ISO at 100 (or whatever the lowest native ISO is for that camera). I may have to adjust upwards in certain circumstances but when I do I use whole stop ISO values since in some cases (on some sensors at least ) a higher whole stp value will give you better quality than one of the lower partial stop values.