Redesign of manual shutter speed interface in video mode

[Martin Suchomel]

Hi Mark, your work is much appreciated. You deserve more contributions.

Could we please revise the shutter speed interface in video mode?  

Shutter speed is a function of the frame rate and shutter angle.  
With a traditional shutter angle of 180°, film is exposed for 1⁄48 second at 24 fps.  
This is why this frame rate + shutter speed combo is often recommended for video shooters trying to emulate the “film look”. (1⁄48 second at 24 fps. 1/50 at 25fps or 1/60 at 30fps. )
On smartphone videos, the minimum shutter speed is dictated by your frame rate.

Most frequently used shutter speeds are:
a) 180°   (1⁄48 second at 24 fps. 1/50 at 25fps or 1/60 at 30fps. )
b) 360° shutter (maximum image blur)  1/30 for 30fps, 1/24 for 24fps, 1/25 for 25fps etc. This one is popular mainly to gather maximum light in dark scenes but too much image blur can be undesirable for camera pans or scenes with lot of movement)
c) 120°, 90°, 60°. 45°, 30° here I am flexible as many PRO videographers attach variable ND filters to keep the film look in bright sunlight. For general population doubling the shutter speed each step should be sufficient to avoid overexposure. Maybe it could look similiar to this:
-for 30 fps:  1/60, 1/90, 1/120,  1/240,  1/480,  1/960, etc
- for 25 fps :  1/50, 1/75, 1/100,  1/200, 1/400, /1/800, etc
- for 24 fps:  1/48. 1/72,  1/96, 1/192, 1/384, 1/768, etc
- for 60 fps:  1/120, 1/180, 1/240, 1/480 , 1/960, etc

Current implementation of shutter speed increments is in increments of 5 - this does not work well with 24fps, causing rolling shutter. also each adjustment causes variable frame rate to occur when adjusting while recording is active. Also options allows choosing Invalid settings slower then framerate which are even reflected on live preview but not in the recording. I guess that increments of 5 might could be usefull if one is trying to overcome some bizzare light flicker issue. Other relevant forum posts:
https://sourceforge.net/p/opencamera/discussion/general/thread/dd6bd1b23b/

* Additional suggestions for User Interface:*
Swipe gestures to allow for manual ISO/shutter speed adjustments.
It would be absolutely amazing if interface would support changing ISO by swiping left / right and change shutter speed by swiping up/down.  Pinch to zoom which is currently  default behavior might interfere with this but that can be safely disabled as there is not much demand for digital zoom which is something that is usually done in post.

For bonus points while adjusting iso/shutter by swiping left/right or up/down then for the time being when a finger is in contact with screen you could:
- show vector-scope wit x4 zoom just like curent manual focus implementation or zebras with (no zoom)
- boost screen brightness (return to user set brightness few seconds after finger is lifted to reduce battery usage. (Maximum brightness helps a lot to properly exposure the screen but keeping it set to max for whole recording generates too much heat/drains battery)

Many thanks
Best regards,
Martin

[Anonymous]

I also am wondering about this. The lack of a manual/fine adjustment of the shutter speed makes for a difficult to achieve 180° shutter angle. At the very least, having an ability to use these specific shutter speeds (dependent upon FPS) in video mode would go a long way.

OpenCamera is the closest thing there is on Android to Blackmagic on iPhone, and every little trick helps