Grain in blue sky

[revvr]

I'm using a GoPro Hero 7 Black with ND filters and I'm running into an issue whenever I have a clear blue sky; there's a ton of grain in the sky.

Does anyone know how to correct it in post? Not sure if it is a sharpening issue or a color issue.

Thanks!

[revvr]

Here's a good example when pushing the color:

[revvr]

And here it is in protune flat, straight out of the camera. Grain is still visible.

[supermesa1470]

its because the gopro7 always use higher iso that it should be,even in clear day when my gopro4 always use the 100 iso,the GP7 ,and its really not good, use high iso(sunny day around 200 iso) cloudy sky i got sometimes 800 iso ,not cool i wish it could be changed by a firmware

[revvr]

I have ISO limited to the 100-1600 range with -0.5 EV Comp while using an ND32 filter. I cannot keep the shutter at 1/48 when shooting at 24 fps and not have the whole picture blown out on a day like that.

Even if it was working at 1600 ISO this level of grain exists?

[agilestoke40735]

You must set ISO Max to 100.

[revvr]

I'm not sure I follow. Are you saying that the entire ISO range above 100 is unusable? It woould seem like a serious miss from GoPro if that were the case, particularly for those of us that need to shoot at slower shutter speeds. As an action camera, it is difficult to discard the ISO range without an operator.

[agilestoke40735]

More or less. Anything above ISO 400 is questionable. Only ISO100 is really clean.

Hero6 and Hero7 Black uses the Sony IMX277 sensor. At the price point its probably the best 1/2.3 sensor available. Of course noise and ISO performance will not be the same as an 1", 4/3" or 35mm sensor in any way, shape or form.

To quote from Abe Qislevitz blog (a member of the GoPro media team:

""Locking ISO at 100 will give your footage a richness and cleanliness you’ve never seen before from a GoPro. ISO is basically the digital light gain to make the scene brighter. In auto shutter mode, ISO 400 is the lowest value we can go, but even 400 has a good amount of noise/grain."

http://abekislevitz.com/gopro-karma-drone/

Also take a look at the Hero7 recommended settings here: http://abekislevitz.com/gopro-hero7-black/