Auto ISO

gramps said:
Now I notice that when I use auto iso the metadata of my images always seems to display the max, i.e. if I have auto iso set to say 1250 max then every photo I take will show the iso as 1250 in the metadata.
Does this mean that the camera is shooting at iso 1250 or is it that it just that it defaults the metadata to the maximum iso?
Or have I got another setting wrong somewhere?

Gramps, what is your base iso set at on the auto iso menu? Also what value did the iso display in the viewfinder show? I suppose the other question is, do the images look correctly exposed? I'm sure there'll be a simple explanation.
 
Just gone through mine from tuesday and they show up the right ISO in the exif when on auto.. could it be camera specific?


PS Graham... 11 hrs.. I am impressed... welcome back :)
 
Been out today in pretty bright sunlight using auto iso 6400 1/1600 @ f6.3 and exposure seems fine, (same situation on other days with different setting on auto iso).
Base ISO is set to 200 with Maximum sensitivity at 6400.
ISO display in the viewfinder also shows whatever the max iso is set as, with 'ISO Auto' flashing.
 
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Been out today in pretty bright sunlight using auto iso 6400 1/1600 @ f6.3 and exposure seems fine, (same situation on other days with different setting on auto iso).
Base ISO is set to 200 with Maximum sensitivity at 6400.
ISO display in the viewfinder also shows whatever the max iso is set as, with 'ISO Auto' flashing.

On my D700 the viewfinder displays the correct ISO, and the correct ISO is recorded in the exif data.
 
I always found AUTO ISO on Nikons to be a bit of a pain, bumping the ISO up faster than I would if I were setting everything myself

The AS mode sounds like a super idea, even better if they then re-weighted the behaviour in A and S mode

I just adjust ISO manually nowadays
 
On my D700 the viewfinder displays the correct ISO, and the correct ISO is recorded in the exif data.

This is the same on mine. Can't quite fathom what is going on in gramps case. Gramps, are all your images at iso 1250 no matter what your auto iso settings and the light?
 
I always found AUTO ISO on Nikons to be a bit of a pain, bumping the ISO up faster than I would if I were setting everything myself

Actually I think that may be happening with me, just tested on really low shutter speeds and the viewfinder ISO figure does change but it very quickly rises as I increase shutter speed.
I think I need to do a bit more intensive experiments to establish exactly what is happening.
 
Actually I think that may be happening with me, just tested on really low shutter speeds and the viewfinder ISO figure does change but it very quickly rises as I increase shutter speed.
I think I need to do a bit more intensive experiments to establish exactly what is happening.

This sounds really strange. If you change the shutter speed by 1 stop, is the iso changing by more than 1 stop?
 
Indoors under bulb light is a poor test but basically from 200 it will jump 250, 280, 320 and up on basically each stop shutter speed increase, very quickly getting to max but this is on manual so it's only the iso that can change.
Tomorrow I'll do some more vigorous experimenting in sunlight ... it does change but it obviously changes so quickly to max that I had thought it was just registering max iso all the time - I cannot recal an image taken where auto iso was used and it wasn't showing max iso.
 
Indoors under bulb light is a poor test but basically from 200 it will jump 250, 280, 320 and up on basically each stop shutter speed increase, very quickly getting to max but this is on manual so it's only the iso that can change.
Tomorrow I'll do some more vigorous experimenting in sunlight ... it does change but it obviously changes so quickly to max that I had thought it was just registering max iso all the time - I cannot recal an image taken where auto iso was used and it wasn't showing max iso.

To be honest, this sounds normal. It sounds like you have the shutter speed set to notch up in 1/3 increments. Because you are in manual mode+auto iso (i.e. the camera won't change aperture) the only thing it can adjust to maintain consistent exposure is the iso and so it bumps it up a 1/3 of a stop in tandem with you adjusting the shutter.

Without knowing the light and other settings, I'm wondering if you're just at the limits of light hence bouncing off the top of the iso limit. Only thing to do would be to either switch to A or S or to drop shutter speed or open up the aperture.
 
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