How to shoot video below 100 iso on A7sii

[hwhitmore]

Situation: Shooting video on the A7sii, picture profile off, manual setting. 

Outdoors in bright light. 

 

I set the iso to 50, but when I push record it defaults to 100. 

 

Is there a video setting that will allow me to shoot below 100 iso?

Am I missing something basic? 

Are iso's below 100 only for stills?'

 

Any help would be greatly appreciated. Love the camera so far. 

 

Thanks! 

[Snowfun]

The native iso of the A7Sii is 1600 (I think) so the use of neutral density filters is a far better option. They allow you to control depth of field and have a sensible shutter angle whilst ensuring correct exposure. You can either use a screw-on variable ND, individual screw-on NDs of various strengths or a rig with a matbox and drop-ins. The cost various significantly. I use mid-range tiffen/hoya individual filters and for my humble purposes they seem to do the job.

 

A set of NDs (or a decent variable) is an essential component of these cameras (built in, in the case of the rx1004).

Tim

[Emptymind]

The ISO of 1600 is only the default when shooting in SLog2-3 it is not the default ISO. But lowering the ISO to overcome bright days is not the solution. This is what ND filters are for. Variable ND's have come a long way and do not listen to critics - Pro's do use them. The Genus one is very good for the money.

[chrisqphoto]

when you go below 100 ISO, you are going into the extended ISO range, it's native ISO range is 100-104,200 or something, but extended will let you go down to 50. those extended ISO values are for photography. the first responder to your post didn't notice that you said you had picture profiles turned off. if Slog2-3 had been turned on then yes, it would have defaulted into 1600 ISO.

but if Slog2-3 is off, it will always default to 100. sorry, in video that's as low as you go.

[Snowfun]

I could be mistaken here and would welcome clarification!

It is my understanding that a sensor - any sensor - has a "native iso". This is the highest "analogue" signal before it is digitally amplified and therefore introduces noise. Anything other than the native iso is digital and will have an adverse impact on dynamic range. Lower than the native iso is simply ignoring some of the signal - essentially darkening the image therefore. The native iso for the A7Sii is 1600 irrespective of what pp is selected (and irrespective of whatever default might be set by the camera). This is the reason why one should shoot slog at the native iso - it preserves DR.

 

For stills photography you would tend to use iso, aperture (rarely in combination with NDs) and shutter speed to get the desired effect. As I understand it (and I could easily be mistaken!) in video work it is preferable to shoot at the sensor's native iso and use ND to control the light - aperture for DoF amd shutter angle to get movement captured in the way you want.

[Silkyjr]

Is there anyone else that can add to the native ISO of a a7sii for s-log and non s-log profiles. Still not understanding correct settings