Just posing the title question to any photographers out there.
I’ve always adjusted the SS, and wondering why my Air3S is shooting AEB and changing the ISO ranging from 100 up to 700.
Only noticed this morning when using a prog I havnt used for ages.
For one thing, it explains the noise I’ve had in some shots.
I’m not a photographer as you know ‘ just a novice ‘ 
I think this maybe a silly question but do you leave your iso in auto if so,
My air 2 used to do the same until I put the iso on manual then just used the shutter speed values if that makes sense,
Not tried with the Mavic 3 as I try to keep everything in manual.
Edit : I think you’ll find when the iso is on auto & your doing AEB shots & it does the shots 3/5/7 or whatever at different ss exposure values the iso will jump around / vary when it’s doing it to try & compensate the ss lighting conditions ‘ I think ‘ …
Cheers Rich👍.
Nar mate, ISO is never on auto. SS sometimes, depending.
Tbh, I’ve only just started using the AEB with the Air3S, never used it with any other drone. The reason with Air3S is that it takes toooo long to process one shot, so by the time you’ve adjusted the SS for the next shit and waited for it to process the 1st, the damn drones had more chance of moving causing ghosting (50mp).
Ah ok sorry for my misinformation ady,
I did feel a bit Gimp explaining to someone who knows more than me ‘ My Bad ‘ 
That suggests you have the SS set to manual … in which case, it won’t change in AEB, leaving only the ISO for it to change.
No bad info from you mate, perfectly reasonable question about the ISO👍
How when the ISO isn’t set to auto🤔.
Besides, regardless of whether I set to manual or auto in pro mode, with it being in AEB mode shouldn’t it automatically adjust the shutter speed ( as I’ve always understud that is what you adjust with bracketing) Nad not the ISO.
Like a say, only just started using AEB (not keen tbh) because of the bloody time it takes for the 3S to get onto the next 50mp shot.
Cameras with an iris also vary the aperture for AEB … but the Air 3S doesn’t have one of those.
Three ways to change exposure on a normal camera - SS, f-stop, ISO … the Air 3S only has SS and ISO, so if the camera is set to manual shutter speed, then it will vary the ISO … no other option.
I have the shutter speed and ISO set to manual all the time, but more often than not, I shoot 5 exposure AEB’s, the Mini 4 Pro changes the shutter speed and keeps the ISO at 100.
Cheers John. That’s the way I’ve used it, AEB, with the Air3S, I’m pretty sure of it.
Always did it manually with the Air2s because it was quick enough taking the image in the first place.
Thanks all for the input. Gonna have play at the weekend, must be something I missed🤷
Had a play yesterday. Like I said, I’ve always adjusted the SS and kept the ISO at 100 in the past, never used AEB with any drone (didn’t really want to, for the reason the adjustments, 0.7 of a stop and not a full one from what I understand).
Anyway with the 3S it takes double if not triple the amount of time to process a single image than the Air2s. This, as you can expect, gives more chance of ghosting when merging, as the drone has longer in between shots to move position.
Yeh, software in post can reduce ghosting when aligning, but the more distance in the ghosting, the more that gets cropped automatically.
Soooooo, I did a few tests, changing either ISO or SS to auto and the other to manual. The exifs told all kinds. Pretty random tbh, I won’t bore you with the details. Dog shit if I’m being honest.
The best kind of ratio I was getting was with both SS/ISO set on Auto… But then the ISO took the piss an went way beyond 800. Not good.
All in all, thanks for any input anyone has posted, but on the results I got over the weekend, AEBs getting binned off from the results I got