11-12-2018 01:59 PM
Is there any post or sticky topic that summarizes all the settings advised for shooting in low light?
I would like to avoid the "jumping lights" issue, that I have seen on some foootage, where the HyperSmooth was on.
11-12-2018 02:08 PM
They will be releasing in Dec new Firmware but unsure what issues it addreses. So if you are looking for better results in low light there are Blogs by a person that can help you get started..
excellent to read,and get you going..
11-13-2018 12:36 AM
When it comes to filming in low light, you are going to run into some issues. First, it's an action camera with a small sensor. It's main purpose is filming fast action in bright daylight. Stabilization works well in this kind of environment because it needs a lot of frames and for those frames to be exposed with a fast shutter for clean and sharp images.
When filming in low light, there are three ways for the HERO camera to compensate. It can slow fps, which in turn allows it to slow the shutter down to allow more time for exposure, or it can increase the ISO (post-senor gain applied to the signal from the sensor).
It's common for people to mistakenly refer to increasing ISO as increasing sensitivity as this was true with film, however in digital sensors the sensitivity is constant but raising the ISO is just telling the electronics to amplify the signal from the sensor. The amplification process also means that any noise (grain) will be amplified too. Generally speaking, this is why using the lowest ISO value is desirable.
When it comes to shutter speed, this is just the time light is collected by the sensor. It's referred to as shutter speed because in a traditional camera this is how long the shutter would stay open to allow the film to be exposed. Faster/slower shutter and shorter/longer exposure time are interchangeable terms, with the latter being the more accurate for digital cameras. Just remember, fast = short and slow = long.
The important thing to know is that these three settings, fps, ISO, and shutter are all interrelated. Shutter speed in particular is dependent on the fps. Both shutter and the number of frames being shot are represented as a value within a second. So, fps is how many frames in a second while shutter is what fraction of a second it exposes for. The shutter can only expose for the max time of the length of one frame. So, if the camera is taking 30 frames in a second, the max exposure time is 1/30th of a second. If the camera is taking 60 frames in one second, the max is 1/60th of a second. Through this, you can see why reducing frame rates improves low light performance....kind of.
I say kind of, only because as the length of exposure time is increased, so is motion blur. During the exposure time, information is being written to the sensor. If the object moves during this time it is written to the sensor several times during that movement creating blur. If you are utilizing stabilization, which is also moving and adjusting the frame to keep the image still, this can result in a blurry mess.
To help keep the shutter exposure time shorter, the camera will first raise the ISO (if possible). The higher the ISO; however, the more noise (grain) appears in the picture. Using ISO between 100-400 is generally considered the cleanest image with ISO 800 being the upper limit of acceptable noise. ISO 1600 will provide a brighter image, but at this level and higher, the noise from the amplification is clearly noticeable.
Since hypersmooth EIS stabilization requires more frames that have been exposed a short periods of time to not produce blurry frames, there are different ways to approach trying to get the best low light and stabilized shots. First, you can opt for a resolution/frame rate that uses a less aggressive EIS. A new firmware update is scheduled for the beginning of December so we aren't sure how GoPro is addressing this, so for the time being, the only resolutions/frame rates with Standard stabilization are:
4K 24/24 Wide 3840x2160 4:3
1440p 120/100 Wide 1920x1440 4:3
1080p 120/100 Linear, Wide,SuperView 16:9
960p 120/100 Wide 1280x960 4:3
Since you are filming in low light and a longer exposure time is desirable (less fps), 4K (4:3)/24 is a good option. With this, it's also beneficial to lock the MIN and MAX ISO at 800.
The next option is to choose a resolution with 60fps to provide Hypersmooth with enough frames and then locking the shutter at 1/240 for sharp and clean frame images. This will result in darker images in low light, so you also need to boost your ISO. Locking the MIN and MAX to the same value tends to work best; however, you can also try it with an ISO range of 400 - 800 or 400 - 1600.
Lastly, and this can be done with either of the above two solutions and also in any combination (using all, some, or only one) of these settings. Setting the Color Profile to Flat is a good idea in low light as it allows for more dynamic range and more detail in shadows. Setting the Sharpness to Low smooths out the image and reduces how noticeable the noise (grain) is on and around your subject. Finally, using a WB that is manually set or that is NATIVE helps prevent color shifts and makes the image appear cleaner.