Confusion on Live View and Shot Result Preview

[khollister]

New A7RV owner here (and new to Sony as well). So I have read the Help Guide several times and experimented with Live View on/off and using Shot Result Preview instead.

If I turn Live View Effects Setting OFF (disabling Live View) but instead use Shot Result Preview (the idea being to not burden the AF with a stopped down aperture in darker ambient light), it seems once my shutter gets below about 1/10, Shot Result Preview is too dark. And the slower the shutter speed gets, the darker the preview is.

If I compare the captured image to the preview, the exposures are the same except with slow SS - then the captured image looks correct and the preview is too dark.

When the shutter speed is above 1/10 or so, the preview seems to work as expected.

What am I missing here?

[Cameratose]

I've dug through this and can find no reason this would be happening, other than the note that states if you turn live-view off, the exposure will be different than the EVF. I think this is what you're experiencing.

You don't mention ISO or aperture. Since both of those affect light, how were you able to determine this is related only to shutter speed? Have you tried this with a fast lens and open aperture to see if you can go slower than 1/10 without it affecting your view, just as a reference?

One thing of note, these cameras are pretty good focusing in low light. I'm pretty sure the A7R V is good down to -4 EV. I shoot the A7 IV and A1 in low light a lot, I never turn live view off. Have you tried it that way and gotten poor results?   

Edited August 6 by Cameratose

[khollister]

2 hours ago, Cameratose said:

I've dug through this and can find no reason this would be happening, other than the note that states if you turn live-view off, the exposure will be different than the EVF. I think this is what you're experiencing.

You don't mention ISO or aperture. Since both of those affect light, how were you able to determine this is related only to shutter speed? Have you tried this with a fast lens and open aperture to see if you can go slower than 1/10 without it affecting your view, just as a reference?

One thing of note, these cameras are pretty good focusing in low light. I'm pretty sure the A7R V is good down to -4 EV. I shoot the A7 IV and A1 in low light a lot, I never turn live view off. Have you tried it that way and gotten poor results?   

I realize that the EVF does not match the exposure with LV OFF - that's what the Shot Result Preview is supposed to "fix" on a momentary basis rather than full time. 

Good idea on the exposure - I had the camera on aperture preferred and drove the shutter speed down by stopping down the lens. I bet this is EV related, not specifically shutter speed. I will make some better tests to try and verify it is an EV threshold.

I also realize this is largely a theoretical problem regardless of whether we are talking about AF in low EV conditions or using non-TTL flash (studio strobes with no modeling lights), but I sort of stumbled into this while exploring the camera and was puzzled.

Thanks for responding and I will bet money that it is EV driven. I need to see if Live View craps out at the same EV.