FPS Override Question

[garry23]

@A1ex

I'm seeing if switching FPS override on will indeed help me use LV 'in the dark'.

It looks promising, but what I'm finding is that the 'brighter boost' is only active for a couple of seconds, and then LV returns to 'normal' t on my EOSM. On my 5D3 the boosted LV image remains constantly active/on.

Any feedback on this would be welcome, ie I'm using it wrong or will it not work on the EOSM?

[a1ex]

Only the "Low light" setting is supposed to increase brightness. The other settings should keep it unchanged.

These two models use the same backend for overriding shutter speed, so I would expect the behavior should be the same.

In auto modes, Canon firmware will bring the brightness back after a few seconds (brightness change from FPS override is fed back to the auto-exposure algorithm). Make sure you are in M mode, or in movie mode with manual exposure.

To complicate things, M mode does not always use the current exposure parameters for LiveView - it usually picks some other settings that result in identical brightness (exposure simulation). If both Expo Override and ExpSim are enabled, ML implements its own exposure simulation algorithm (which should behave a little better in very low light). In this case, FPS override, even in low-light mode, will no longer increase the brightness; it will just provide some extra photons, so ML ExpSim will do a better job in low light.

Some more hints about this feature:
http://www.magiclantern.fm/forum/index.php?topic=11058.msg107334#msg107334
http://www.magiclantern.fm/forum/index.php?topic=3031.msg14103#msg14103

[garry23]

@A1ex

As usual thanks for the education/info.

I'm using it in photo mode on both the EOSM and 5D3: I'm interested in using this feature to help compose in LV in dark(er) conditions.

On the 5D3 it stays bright until I switch FPS override off. On the EOSM, the brightness boost goes away after a second or so. I've check setting, eg Auto ETTR always on is OFF etc.

On the EOSM, wth expo Sim and override off, the return from brightness is more gradual, ie a coule of sec rather than 'instant' if expo sim & override are on.

Strange.

Cheers

Garry

[garry23]

Further experiments and it looks like the FPS override brightness is persistent on my EOSM is both Expo Sim and Override are set to off.

Where as on the 5D3, even if Expo Sim and Override are on, the FPS brightness remains persistent.

I can now work with this

Cheers

Garry