Is it possible to set Auto-ISO in Aperture priority mode on a Nikon D3300?

I have a Nikon D3300.

I spend most of my time in auto mode. Of course, almost all settings are locked (it is auto mode, after all). I had hoped that there would be a series of modes that give you control over some, but not all, of the settings. Or that for each setting you'd be able to manually set it or leave it at auto. But alas, this seems not to be the case.

In particular, it seems that the moment you leave auto mode, you immediately have to manually set the ISO sensitivity level. This is the one single parameter that I most want to be automated! Indeed, this is the main reason I never leave auto mode. Because it means that as soon as you turn off auto, the sensitivity goes back to whatever random setting it was at last time [which could have been months ago]. In other words, as soon as you leave auto mode, the ISO setting will be wrong (with 100% probability, because Murphy).

For example, you would think that going to aperture-priority mode would let you set just the aperture, and leave the other two variables automated. And you would be wrong, because by leaving auto you've also changed the ISO level to manual too. All of the PASM modes seem to irrecoverably put ISO to manual.

Is there seriously no way I can keep the ISO level automatic??

(You might say "what's wrong with manual ISO?" To which I would reply that I've already had one set of photos ruined because I switched to aperture priority to get a wide aperture, but I forget I had the camera set to ISO 12800, and there isn't a shutter speed in existence that can handle that on a bright July afternoon. And just this morning, I was doing some macro shots, and then the Sun came out. Looking back at the Exif data, I see shutter speeds faster than 1/1000s, indicating that I could easily have turned the sensitivity down 4x or more and got better pictures. Presumably if it was auto mode, that's what would have happened...)

This is the number #1 reason I never leave auto mode. It's too much hassle being forced to set the ISO sensitivity manually.

Answer

This is the number #1 reason I never leave auto mode. It's too much hassle being forced to set the ISO sensitivity manually.

It looks like most people actually prefer this. But if you don't, you can change the setting:

According to this article, you enable auto ISO like so:

Go to: Menu>Shooting>ISO Sensitivity Settings, and turn the Auto ISO sensitivity control to On.