5D3 - Raw Video Auto Exposure - Hard Stops

[sletts02]

When recording with auto exposure in .h264 you get nice gradual changes of exposure. When in Raw recording you get hard stops of exposure (I assume ISO changes).

Is there any way to have auto exposure with smooth exposure changes in auto mode?

[a1ex]

Yes, but you have to compute the exposure compensation for each frame in post.

Tip: try the post deflicker algorithm.

[sletts02]

Yes, but you have to compute the exposure compensation for each frame in post.

Tip: try the post deflicker algorithm.

Just delved a bit deeper, I take it the 'gradual exposure' in the video menu doesn't help?

Post flicker algorithm - in what program sorry? Thanks for the help alex =)

[a1ex]

It's in shoot.c, look for FEATURE_POST_DEFLICKER. Basic idea: compute the median of the image (which is statistically robust, unlike mean) and keep that at some preset level by applying exposure compensation (which, in raw linear space, is just a multiplication).

[sletts02]

It's in shoot.c, look for FEATURE_POST_DEFLICKER. Basic idea: compute the median of the image (which is statistically robust, unlike mean) and keep that at some preset level by applying exposure compensation (which, in raw linear space, is just a multiplication).

That went over my head sorry Alex - I google'd FEATURE_POST_DEFLICKER but didn't come up with the goods.

I guess I am asking: Is there a reasonably automated way to do this either in camera or in post? At the moment the hard stops of ISO aren't really useable for my needs.

This is what it would be used for (shot .h264). As you can see I need the auto exposure as I go from interior/exterior without any stops/transitions. I was hoping to use RAW (or dual ISO!!!) to give a really balanced scene.

[Audionut]

Look in the shoot menu.

Some info here:  http://www.magiclantern.fm/forum/index.php?topic=5705.0

[a1ex]

That one is for photos only.

What I'm suggesting is that anyone with minimal C skills can paste that code into raw2dng and add an option for it

[sletts02]

That one is for photos only.

What I'm suggesting is that anyone with minimal C skills can paste that code into raw2dng and add an option for it

If only I had minimal C skills! Would it be a video-by-video basis, or could it be something that can be automated for all videos and built in to raw2dng?

If it's the latter that would be amazingly useful!!!

PS Just had a quick Dual ISO test and I am impressed! The photo came out stellar, but the video didn't work (Some frames worked but others say 'Doesn't look like interlaced ISO, I am guessing due to a wide lens and not enough dynamic range, will test out during the day tomorrow).

[a1ex]

It should work for all videos, there's no extra metadata needed for this.

[sletts02]

It should work for all videos, there's no extra metadata needed for this.

Wooo! Great! ETA? Tonight 

Seriously though, thanks for all your work Alex et. al!

[Audionut]

There was a subtle, polite, but subtle hint in there to do it yourself 

[sletts02]

There was a subtle, polite, but subtle hint in there to do it yourself 

I would love to contribute to the cause, alas my knowledge of coding is non-existent. I am more than happy to test and spread the word about ML however 

I am sure it would be a feature that would be appreciated by more than just myself though! Run and gunners, wedding videographers, event videographers, obviously real estate and commercial scene, single operated steadicam, etc etc.

I'm happy to make a donation for the feature too 

[sletts02]

Quick update: $100 is on offer to whoever can get this working. More details here: http://www.magiclantern.fm/forum/index.php?topic=7739.new#new