Hello, sorry if I ask "naive" questions, but I have had the Osmo Pocket 3 for a few days and the manual is very sparse and explains almost nothing. I make videos in 4K, 50p and D-Log M In Menu I choose 50-3200 ISO in Auto and Automatic Exposure.
Does it make sense to use an ND filter with Pocket 3? I had seen a ND/PL filter. Since I will be using the Pocket 3 while traveling and especially in seaside areas in summer, do you recommend that I buy it? In theory, an ND filter should be useful to get better video quality. But is it useful in practice???? Is anyone using it with good results?
Thanks.

I only make documentaries in 4K 50p on sunny days. Since it doesn't make much sense to use an ND filter with high framerate and Automatic Exposure, I was thinking to buy a CPL filter and always leave it on, without removing it. I like an image that is a little more contrasted, crispier and with more colour. I use D-Log M, do you think I'll get what I want with CPL filter? Thanks

My experience is with GoPros, but AFAIK the Osmo action cams are very similar, so here goes.

Assuming you want more cinematic footage than the usual jerky stuff an action cam takes on full auto, which means keeping the shutter speed close to twice the frame rate in the absence of adjustable aperture, ND filters are a must. A CPL filter will not correct exposure in the same way.

My method: Limit ISO maximum to prevent too much noise, to 800 (range 100 to 800). Leave shutter in auto.
I have a set of ND filters, the ones I carry are ND 8, 16, 32 and 64, although I have yet to use the 64.
Start with the aperture of the lens (f2.8 on the GoPros) and work out what effective aperture is required to keep the shutter speed at about that required (1/50th for me).
So an ND8 is 3 stops, equivalent to f8 and suitable for cloudy conditions. ND 16 is 4 stops, f11, for sunny conditions and ND32 is 5 stops, f16 for very bright conditions. Fit the ND to suit the conditions and allow the ISO and shutter to make small adjustments to keep the exposure correct. I hope that helps.

Dave,
out of curiosity:
1) I think f2.8 is for defauult and it is impossible to change it.
2) Don't you think that with a fps as high as 50p (I never use 25p and I don't care about blur) I can do without filters? I always use my mirrorless cameras at 50p and I'm fine with them. Maybe this makes you smile but that's how it is.
I thank you foir your reply.

1. Perhaps I didn't explain very well. I meant the fixed aperture of the camera is f2.8 and that never changes. To get the light input down to a level that keeps the shutter at twice the frame rate, we add an ND filter of the appropriate density to emulate stopping down the iris for the purpose of exposure, although it does not affect the depth-of-field of course. So adding an ND8 becomes an effective aperture of f8, for example.

2. Shooting at 50fps, the recommended shutter speed is 1/100th, just one stop different and I would still recommend ND filters. But that's for the way I like to use my action cameras. If you are happy with the action camera look as it comes out of the camera, then no, you don't need them and the CPL seems like a good idea. The difference with mirrorless cameras is, their lenses have an iris so usually ND filters are not required anyway.

1. Perhaps I didn't explain very well.
You explain well, unfortunately my english is not good. Sorry!!


2. Shooting at 50fps, the recommended shutter speed is 1/100th, just one stop different and I would still recommend ND filters. But that's for the way I like to use my action cameras. If you are happy with the action camera look as it comes out of the camera, then no, you don't need them and the CPL seems like a good idea. The difference with mirrorless cameras is, their lenses have an iris so usually ND filters are not required anyway.
Unfortunately I don't have much experience with filters and Pocket 3, so your suggestions are valuable. If you were me and if you had to film at 4K, 50P in areas with a lot of light, such as in a seaside town with clear skies or light clouds, which filter would you buy between a CLP or ND/LP? I would like to leave it on all the time.
Thanks again

I don't believe they make a variable ND for a pocket camera. They sell kits of ND filters with different levels of nd. Just pick one that is closest. The Pocket isn't a cinema camera there is only so much you can do. Pop on an ND to give you some motion blur and don't sweat the small details. You be running and gunning outdoors in auto.

You explain well, unfortunately my english is not good. Sorry! It's a lot better than my almost non-existent Italian!

Given the conditions you specify, I would most likely fit an ND16 and then the camera will take care of any variations as you shoot. To leave the filter on all the time you'd need a variable ND, K&F Concept make a couple to fit the Pocket 3, but they don't go completely clear so would need to be removed to shoot indoors to help reduce picture noise when the ISO ramps up. I prefer the fixed ND filters so I know exactly what strength I have fitted.

As Pete says, NDs for action cams are sold in sets, so you would have at least 3 to choose from. Many kits come with polarizers as well, so you'd have the lot. It depends on how you operate in the field, but with a little ingenuity it's dead easy to change one.

I agree with Dave. Generally 4-6 stops for sunny conditions. I’ve always found ND naming to be non intuitive.
4 stops ND16
5 stops ND32
6 stops ND64

Given the conditions you specify, I would most likely fit an ND16 and then the camera will take care of any variations as you shoot. To leave the filter on all the time you'd need a variable ND, K&F Concept make a couple to fit the Pocket 3, but they don't go completely clear so would need to be removed to shoot indoors to help reduce picture noise when the ISO ramps up. I prefer the fixed ND filters so I know exactly what strength I have fitted.

Out of curiosity: What did you choose about Focus Mode? Did you choose Single or Continuous? I think Continuous is better but .... I'm afraid that to chase the focus sometimes it will go out of focus. What do you think about it?

Out of curiosity: What did you choose about Focus Mode? Did you choose Single or Continuous? I think Continuous is better but .... I'm afraid that to chase the focus sometimes it will go out of focus. What do you think about it? Sorry I can't help with that, my action cams are fixed focus GoPros.

Out of curiosity: What did you choose about Focus Mode? Did you choose Single or Continuous? I think Continuous is better but .... I'm afraid that to chase the focus sometimes it will go out of focus. What do you think about it?

The Pocket 3 continuous focus mode is incredibly fast and accurate so I use it almost all the time. Single shot mode lets you preset the focus, but its probably easier just to tap the screen at the point you need to focus on and it will instantly pull focus.