ISO on 6D

Please forgive my noobishness. Maybe there's been a topic about this but I'm lazy and didn't search. I am also honest to a fault.

Anyways, I just got a new 6D. I love it. I shoot a lot in my studio/garage (notice I put studio first... no cars may enter) and I usually do it at 100ISO. I noticed there's a low setting on my 6D for 50ISO. I'm wondering if I should just use that all the time in the studio. Will that give me even better IQ and noise management than 100 already does? Again, forgive my amateur questioning. I also noticed I can get the post pictures on my memory card at 100. The amount of pictures it says I can fit goes down as the ISO goes up. It also drops a bit when I go down to 50.

PS: I took a few pictures at ISO 102400. They actually don't look too terrible! Gives an interesting creamy effect when you apply noise reduction in LR.

ISO50 will not give better results than ISO100. For the 6D ISO100 gives the best performance when comparing noise and DR. ISO50 is a ISO100 shot with EC applies and the adjusted before written so you give up a little DR.

ISO 100 all the time it is. Thanks for the explanation.

I assume you using strobes then you controlling your DR and won't see much difference between 50 and 100. Sometimes I would use ISO50 when my ND filter is not enough and I need to open up my aperture.

I only use ISO 50 if I'm trying to get a real long shutter speed, usually to blur waterfalls.

As ISO goes up, noise goes up, file compressibility goes down and so does the number of images that will fit on card. As for ISO 50, doubtless some similar effect is in operation due to the move from the "native" ISO.

irishman wrote in post #16327829
I only use ISO 50 if I'm trying to get a real long shutter speed, usually to blur waterfalls.

Unless the 6D is different then other Canon cameras, you may as well use ISO100 and over expose by a stop.

Certainly for the 5DII, ISO50 and ISO100 are identical for the raw data. The only difference is that some raw converters will apply a tone curve (or possibly a straight EC). DPP and the output .jpeg from the camera, for instance, have a tone curve applied that approximately reduces the mid tones by about 1/2 stop and the dark tones by about 1 stop.

The only time I can see ISO50 might be useful is if you shoot .jpeg or particularly like the tone curve that is applied and don't want to do it yourself in PP. Otherwise you may as well just use ISO100 with a +1 exposure compensation.

I do know some pros use it in the studio, which kind of makes some sense since you have control over the light, so if you expose ''correctly', you are probably not blowing highlights, even at +1 EC and so you may get better IQ. But I think most of us just use ISO100 and 'ETTR' (expose to the right) as much as possible without blowing highlights, then bring it back in PP.