You must be new to photography as well. They do not have the same effect. Dialing EV down will darken the image but it will not change the shutter speed as the ND will. Also you can a go past a the darkening of -2 with the ND filters.
ND filters help get the shutter speed down enough to approach the "180 degree shutter angle rule" as has been discussed here before.
There is no digital setting substitute for an ND filter. If there was serious photographers would not be spending money on filters
Greg, thanks for pointing this out. It appears my remark out of context may leave OP and other readers with an incorrect impression that I would recommend shooting at higher than necessary shutter speeds.
I agree with everything you said.
Of course ND filters are called for, but from my experience and from what I've read about GoPro, I believe that I can restate my original post: You
"should be able to" dial in for full sun just with the camera's settings in video mode.
"Dialing down" will change effective shutter speed... it will increase it, and from a metering perspective, 1/8000 at f2.8/400 EV Comp -2 (2 stops) should provide sufficient headroom in most circumstances.
So, why would I say that? I'm not advising the use of super high shutter speed in video production for most circumstances—we live by the 180 degree rule for film and digital video work, and there's the pesky prop shadow and strobing to watch for with these flying contraptions. The OP was concerned that he was not able to properly expose the image, even with an ND8, and upon inquiry reported that he had not tried to control exposure at all using the camera's settings. I was attempting to point out that that GoPro should be capable of producing a properly exposed image even "without" a filter, so that with an ND8 he should definitely be able to at least keep it from blowing out with a forced higher shutter speed via EV Comp. So, if you leave your filter set back at the studio, you can have the confidence that you can still get a properly exposed image.
Now if what I'm saying here is incorrect then please help me out. Otherwise, I hope this expansion on my first post serves its intended purpose—pointing out what the camera is capable of achieving all by itself.
[Aside: IMHO it's also important to consider that as a means of controlling exposure, filters are no panacea. Any time you add glass you are degrading the image (sharpness, resolution, loss of color neutrality, IR contamination), and with more aggressive the filtration there is a greater potential for some IQ issues to pop up.]
BTW, nothing I've said here makes me a good photographer. I have a degree in photography and use filters for technical reasons and to creative effect every day on the job. But, I think it could be said that I am still new to photography. More importantly, I have only begun to explore GoPro, and feel fortunate today to be able to do that with your help. Thanks again.
