08-19-2020 08:00 AM
I am used to using ISO, aperture and ND filters to get to the perfect 180 degree shutter angle (shutter speed is double FPS) and depth of field for a correct exposure. But as the GoPro 8 has a fixed aperture (2.8), my ability to control the exposure is limited to around 'ideal' conditions, where I can set the ISO perameters narrow enough to give me the ability to set the ideal 180 degree shutter angle setting.
But if it goes too bright, then I am in trouble. I cannot stop down the lens. So in the absence of ND filters (I know PolarPro are shipping them, but hypersmooth doesn't work with them) I would have to use AUTO in the shutter speed setting. But what are the perameters? Are they the same as I can set manually (1/25th to 1/400th) or do they go wider than this? As we know, any shutter speed over double the FPS is going to look weird (for a cinematic look). But it's a GoPro, not an Arri Alexa, so clients are going to have to put up with a bit of weirdness, I just want to know HOW MUCH weirdness is involved with Auto Shutter.
08-19-2020 01:08 PM
I assumed it is the same as manual settings, 1/fps - 1/4000. I got 52 mm filter adapter to use HD filters (they hold on camera 100%). To help the stabilization I use 60 fps timeline, for MTB 1/120 worked OK. The main problem is that one has to set exposure by brightness of the display but it works OK.
08-19-2020 01:14 PM
Since you fiddle with exposure - one note.
If you use exposure lock you cannot use QuickCapture, camera resets the lock once you switch it off. The only way to lock the exposure in QuickCapture is to set shutter and ISO manually.
08-19-2020 03:15 PM
One more note:
I looked back on 1/60 sec MTB videos and the stabilization really fails. I cannot find my 1/120 videos but I think it was usable. MTB is not good example of cine footage since shutter in AUTO works well.
08-19-2020 11:46 PM
...as I understand it, the stabilisation works by locking onto sharp bits within the frame and locking onto them. If you're using a slow shutter speed (especially at a high frame rate) then the movement between each frame will blur, giving less chance for the stabilisation to work. This blur is good in normal action (life) as it reflects what our eye sees. But sports and fast action looks a little better at a higher frame rate.
This is the problem with presets. They don't really work because every situation has a different set of issues to navigate.
08-20-2020 03:24 AM
The 180 degree shutter rule can help create a "natural" motion blur, but in general, it's a terrible shutter speed for an action camera. Not only does it make slow motion look like crap, it completely ruins EIS like you get with Hypersmooth. To be clear, "cinematic" settings on an action camera is pretty dumb.
No, 24fps is not the "best" frame rate. It only became the cinema standard because 16fps (the original cinema standard) couldn't sync to the Vitaphone for "talkies" movies.
No, the 180 shutter angle rule is NOT the "best" shutter speed. If it was, all cameras would be designed to shoot at this rate by default. It would be easy enough to calibrate the sensor and lens to do so. But they don't. Why? Because it's NOT a very useful shutter speed. Yes, it can give an enhanced sense of speed, but if you want to slow down your footage or take a screen grab, it's going to look like a blurry mess. Also, EIS stabilization needs a shutter of at least 1/120 (1/240+ is best), so unless you are recording with 60fps or faster, DO NOT use the 180 degree shutter angle rule.
Fast shutter = clean/crisp shots frame by frame
24fps should only be used for recording talking or when you need an enhanced sense of speed AND you don't need EIS Stabilization (it still works, but not as good and certainly not with the 180 degree shutter rule).
24fps should be used in your editor timeline for movie projection. It doesn't matter what frame rate you record with (except talking, which will sync better if recorded in 24fps).
30fps timeline should be used for traditional TVs that project at 30hz (record in 30fps for taking scenes)
60fps or faster should be used for watching video on Computer and tablets/phones which generally project at 60hz and higher.