Confusion about actual ND effects on Freewell "gradient" ND filters

[vindibona1]

I have been a huge fan of gradient ND filters since I purchase a set of PolarPro graduated ND filters for my Mavic 2 Pro. I don't think I've used a regular ND filter since getting them. We all know that regardless of how we set our exposure, if we have sky and ground in the same shot, most of the time the sky will be brighter than the ground making optimal exposure setting difficult. I've found that even when there is only ground, the gradients are so subtle, if you notice it a all it's like a vignette more than an exposure issie. I'm waiting for someone else to make a decent gradient ND filter.

I see that Freewell is now making a soft edge gradient ND filter. They look interesting. But will they do the job that standard ND filters do? I'm just having trouble deciphering what the ND descriptions are. One is listed as GND0.9 and the other is GND 1.2.

What do those designations mean in actual neutral density?

 

[Ty Pilot]

I have been a huge fan of gradient ND filters since I purchase a set of PolarPro graduated ND filters for my Mavic 2 Pro. I don't think I've used a regular ND filter since getting them. We all know that regardless of how we set our exposure, if we have sky and ground in the same shot, most of the time the sky will be brighter than the ground making optimal exposure setting difficult. I've found that even when there is only ground, the gradients are so subtle, if you notice it a all it's like a vignette more than an exposure issie. I'm waiting for someone else to make a decent gradient ND filter.

I see that Freewell is now making a soft edge gradient ND filter. They look interesting. But will they do the job that standard ND filters do? I'm just having trouble deciphering what the ND descriptions are. One is listed as GND0.9 and the other is GND 1.2.

What do those designations mean in actual neutral density?

ND filters can be described with a number of the filter such as ND16 or it can be listed by it's 'Optical Density' or it's 'Light Reduction' in Stops so and ND 16 would have an Optical Density of 1.2 and equal Four (4) stops of Light Reduction.

The 0.9(OD) is an ND8, and the 1.2(OD) is an ND16.

Here is a chart that you can reference.

 

[vindibona1]

ND filters can be described with a number of the filter such as ND16 or it can be listed by it's 'Optical Density' or it's 'Light Reduction' in Stops so and ND 16 would have an Optical Density of 1.2 and equal Four (4) stops of Light Reduction.

The 0.9(OD) is an ND8, and the 1.2(OD) is an ND16.

Here is a chart that you can reference.

View attachment 154079

Thank you. That's what I was missing- that the filters are delineated in "optical density". I'd spent over 30 years in professional photography and this is the first time I'd seen anything listed in "optical density". Perhaps these filters are worth a shot. To date I've not purchased any ND filters for my Mini 1, Mini 2 or Mini 3, but have been considering it for the Mini 3. For the best cinematic stuff I almost always deferred to my Mavic 2 Pro that has both ND filters, gradient and standard, but also a variable aperture. My next drone that replaces the Mavic 2 will definitely have variable aperture, and because in DJI's lineup only the over-priced Mavic 3 has that feature. My next drone could very well be an Autel, though its current issues kept me in the DJI camp for the time being.

 

[brett8883]

But will they do the job that standard ND filters do?

An ND filter’s purpose is to reduce shutter speed. In theory a gradient filter is reducing the exposure of only the sky so it wouldn’t change your shutter speed like an ND filter would.

In practice it might to some degree if you usually underexpose so you don’t clip highlights in the sky but I’d say at the absolute limit it would only change your shutter speed by 2 stops, certainly not 4 stops but more likely less than 1 stop depending on how much you would otherwise underexpose. Two stops isn’t going to be enough to make any difference, especially on the Mini 3, in terms of producing a cinematic shutter speed. The only time of day 2 stops would be enough is when you don’t need or what to reduce the exposure of the sky.

So therefore your question of if a gradient filter performs the same function as an ND filter I would have to say no. It would be perfectly reasonable to use both ND and gradient filters at the same time to put it another way.