Adding ND filter to GoPro with Gimbal

[Earldgrayjr]

I just received my gopro with peau supermount mod. Any chance that there is a video of how you balanced the gimbal with the filter on?

I didn't do one (though I keep meaning to) but somebody else did, and there are also pictures here that are close to mine.

It really isn't that hard.

You can use the weights that came with the gimbal, if you aren;t using them otherwise, or use coins.

Start (with the power off) with the hood and what ever filters you will ALWAYS use (I use at least one) and ad weight to the lower left back of the gimbal camera mount, to get the camera to sit up so the front of the camera is perpendicular to the ground. if it is right, you should be able to move the camera up and down and it will stay anywhere.

Next put weights on the far left of the gimbal (facing the Solo) so that the camera sits level left to right.

Finally, add a flilter. Notice that you are out of balance again. Depending on the filter add weights to compensate for it. (I use a nickel and an aluminum penny with the PEAU filters) You can experiment with double sided tape until you get the weight right for your filters.

Once you have the weight right, take off the doublke sided tape, and stick one half of a velcro piece to the coins and the other to the existing weights. If yiou are using all PEAU, they should all be the same. Make up how ever many sets of velcro/coins you need, putting the other half of the velcro on the coin before it.

That's really it.

Keep in mind, it doesn't need to be "exact". The gimbal has lift of it's own, and will take up slack. You are just trying to help it, and save the motors, both for longevity of them, and also allowing some "headroom" in flight, so they don't have to work as hard all the time, and have some "umph" left when you need it. .

You may also notice that the foam spacer now won't fit if you have weights permanaently fixed like I do. I just cut a "U" shaped block of foam from some other packing material that slides in the top above the camera and the "U" shape holds the gimbal arm. My "block" sticks out in front so I can grab it easy, and also snugs up against the controller in the backpack. Together it and the case holds the gimbal and camera snug for travel. I could have cut the stock foram spacer, but started experimenting and wasn't sure. When I got it right, I just used that.

Not to say I am "all that" or anything, but I keep thinking one day I will make a series of videos showing/explaining (right or wrong) how I do everything from start to finish, but so far I just can't seem to get around to it

 

[alex covo]

THANK YOU! That was far more info than I could have hoped for. I'll definitely give it a go. Seriously, thank you so much for taking time out for such a thorough explanation!

 

[Earldgrayjr]

No Problem.

Most of this stuff somebody showed me somewhere at some time.....
We are all obligated to send the elevator back down for the next guy just like us

 

[Maddog]

THANK YOU! That was far more info than I could have hoped for. I'll definitely give it a go. Seriously, thank you so much for taking time out for such a thorough explanation!

Earl is a good doobie- he's helped a lot of us noob's!

 

[Nazgul]

Has anyone experimented with adding an ND filter (and hence more weight) to the GoPro on the gimbal? I have the Hero 3+ Black and used the 6g weights included in the kit to balance. When I add the ND filter, it throws this balance off when the Solo is powered down. With power on the gimbal kicks in and keeps the camera level. BUT, what kind of wear and tear is this putting on the gimbal motors? Are there any suggestions for adding weights to restore the default balance?

I use today on my GP 3+ black the ND4 filter without rebalance the gimbal. All was OK.

 

[Maddog]

I use today on my GP 3+ black the ND4 filter without rebalance the gimbal. All was OK.

Good to know- thanks for the update!

 

[RVgeeks]

I use today on my GP 3+ black the ND4 filter without rebalance the gimbal. All was OK.

The gimbal may (and usually will) work fine with an ND filter in place, but you are likely doing un-seen damage to your gimbal, stressing the motors and wearing it out early.

Keep in mind that the gimbal is designed to stabilize an already-balanced camera set-up, not to balance the camera by using the power of the gimbal motors. That's the reason that 3DR includes such incredibly specific little weights that need to be added for different camera types. It's that sensitive and that important.

When powered down, the camera should stay put in whatever position you put it in, whether aimed up or down or tilted to one side or the other. Try this test...... with the power off, set up the camera the way you're doing it now, with an ND filter in place but no other weights to compensate for it besides any 3DR-provided screw-in weights. Take hold of the camera and aim it upwards (straight ahead). When you let go, the camera will not stay in that position, but will immediately fall forward due to the weight of the filter. Now, standing in front of the camera, take hold of it again and tilt it to your left (which will be the camera's right side, since you're facing it). Let go, and the camera will immediately fall to your right (camera's left). That's because the lens is on the left side of the camera, so the weight of the filter is pulling it down to that side.

Now remove the filter and do the same thing, and you will see that the camera will stay in any position you put it in, because it is perfectly balanced.

The reason this is so important, and why 3DR took the trouble to perfectly match those little upper and lower weights to each camera, is because the gimbal is not designed to be pulling in any particular direction to stay level. Without it being balanced, the motors will be working non-stop to hold the camera back (up) and right (camera's perspective, since the lens is on the left side).

The gimbal can do it, but you are setting it up for early failure and reduced life by making every moment of its use an extra struggle to hold up the front and the left side of the camera, 100% of the time.

Check out my post, earlier in this same thread, for how I set up my gimbal to be perfectly balanced with a Hero 4 Silver. Your 3+ Black may need something other than two nickels. I experimented for over an hour with various combinations of nickels, dimes and pennies scotch taped to the rear and side of the 4 Silver to get it right. Once I did, I simply have to add the coins when I fly with a filter, and remove them when I don't.

Hope this helps, as I assume you'll want your gimbal to not only work, but to work for a long time.

 

[Maddog]

RV- I also have the H4 Silver and was able to balance my PolarPro filters with 2 pennies. I placed them where you have your nickels, so maybe the PolarPro's are a bit lighter than yours.

 

[RVgeeks]

RV- I also have the H4 Silver and was able to balance my PolarPro filters with 2 pennies. I placed them where you have your nickels, so maybe the PolarPro's are a bit lighter than yours.

That's indeed possible (I have BlurFix Air filters). Either that or two pennies = 1 nickel.

 

[Maddog]

That's indeed possible (I have BlurFix Air filters). Either that or two pennies = 1 nickel.

Um- is that the new math I've heard about?
1 penny in back
1 penny on the side

 

[RVgeeks]

Um- is that the new math I've heard about?
1 penny in back
1 penny on the side

LOL. I thought you meant two pennies in each spot instead of once nickel. Wow. Your filters must really be light!

 

[Maddog]

LOL. I thought you meant two pennies in each spot instead of once nickel. Wow. Your filters must really be light!

I dropped one once and it hit the ceiling!

 

[Nazgul]

The Polarpro filters are 6 gr. I gues is lighter than Snake filters.

 

[EyeWingsuit]

I used an ND 16 on some glaciers a couple weeks ago. That was a no brainer. If your getting white specular blown out highlights off snow, ice, certain rocks, or water (white caps on waves) or off boat decks (some boat decks are pure white), then an ND 16 might make sense.

Basically a combo ND8/CP (circular polarizer) is my go to filter, and occasionally I'll use an ND 16. Then in Final Cut I'll adjust the exposure.

It's not just about the exposure. If you're shooting a bright area and the camera is setting shutterspeed based on exposure, the fast shutter speed creates crunchy, contrasted video that no amount of post can fix. The ND allows for slower shutter speeds, smoothing out the crunchy edges.

 

[erikgraham]

It's not just about the exposure. If you're shooting a bright area and the camera is setting shutterspeed based on exposure, the fast shutter speed creates crunchy, contrasted video that no amount of post can fix. The ND allows for slower shutter speeds, smoothing out the crunchy edges.

Yup. And to go along with that, if image quality is important to you, you also need to make sure your shooting at 30fps. 60fps degardes image quality a lot. Unfortunately on a GoPro there is no way to set shutter speed. The best we can do is "encourage" a slower shutter by using a lower frame rate, limit ISO to 400, and add an appropriate ND filter.

 

[Maddog]

Yup. And to go along with that, if image quality is important to you, you also need to make sure your shooting at 30fps. 60fps degardes image quality a lot. Unfortunately on a GoPro there is no way to set shutter speed. The best we can do is "encourage" a slower shutter by using a lower frame rate, limit ISO to 400, and add an appropriate ND filter.

So is 60 FPS something you would use if you were going to use slo-mo in post?

 

[EyeWingsuit]

60fps shouldn't be degrading your image but high shutter speeds into 60fps can significantly degrade the image/contrasts. Slower shutters (sub 1/1000) into 60p should output a silky-smooth edge, contrast, and movement. Stack on an additional ND or two to bring that shutter speed down. Ideally, we'd be able to shoot at p60, 1/120, ISO 100 (assuming sunny day) but that's just not gonna happen with a GoPro. If you're using ProTune (and you should be), set WB to Native, exposure to -2.0, and sharpness to Low, and you'll have some additional range in post.
If your'e using a Hero 3+ or newer, notice that the default setting is High Sharpness." Shifting that will also give some smoother edging.

 

[erikgraham]

So is 60 FPS something you would use if you were going to use slo-mo in post?

Yes. Absolutely. Although...

Some subjects shot at 30fps can be slowed down very effectively if you use software like Final Cut and it's Optical Flow functions (an advanced form of frame blending). For example, I shot some water falls recently in Iceland in 4K at 30 fps and was happy to discover that I could slow things down to a crawl without any (noticeable) ghosting in the interpolated frames. On the other hand, I haven't been able to pull that off with footage of people or animals.

I shoot almost exclusively in 4K for the best image quality. If I want to shoot at a high frame rate for slow motion I switch to 2.7K (at 60 fps). The difference in image quality between 2.7K at 30 vs 60 fps can be hard to discern, but the difference between 4K and 2.7K (at any frame rate) is very obvious.

 

[erikgraham]

60fps shouldn't be degrading your image but high shutter speeds into 60fps can significantly degrade the image/contrasts. Slower shutters (sub 1/1000) into 60p should output a silky-smooth edge, contrast, and movement. Stack on an additional ND or two to bring that shutter speed down. Ideally, we'd be able to shoot at p60, 1/120, ISO 100 (assuming sunny day) but that's just not gonna happen with a GoPro. If you're using ProTune (and you should be), set WB to Native, exposure to -2.0, and sharpness to Low, and you'll have some additional range in post.
If your'e using a Hero 3+ or newer, notice that the default setting is High Sharpness." Shifting that will also give some smoother edging.

I have to strongly disagree with you. On a GoPro, there is a clear loss of image quality between 30 and 60 fps. Depending on the subject matter and lighting conditions it may not be obvious at first, but it's there if you know what to look for. Just search YouTube for side-by-side comparisons.

As for ev comp... it has absolutely no effect on shutter speed on a GoPro. It's applied in camera after shutter speed has been calculated and set. I'm not saying you should not make adjustments to ev comp. I'm just saying it won't effect shutter speed.

 

[Maddog]

On a sunny day should I use my ND8 or ND8-PL (polarizer) filter?