GoPro 10 with add-ons for Zoom and mph start/stop - can it be done ? - would buy today

[swbca]

@Cnewbert My Orbit will rotate out to 90 degrees from the boat path and more. I don't see how you ski out of the camera view unless there is so much slack the rope it isn't pulling the orbit forward. In your shot above, I don't understand why you aren't close to the center of the image. Does your Orbit have a limit on its rotation ?

 

This is 35off from my phone on Orbit without any zoom. The skier looks about the same size as yours but doesn't show the wake like yours and shows about half as much of the boat interior. @skibug I hope someone can explain how the skier can look close to the same but your GoPro field of view is about double the phone. I though I understood photo optics but I don't understand this.

[Cnewbert]

@swbca It’s probably not useful to compare apples to oranges… a GoPro image vs a phone image. If you had a GoPro photo using the same lens setting and zoom ratio as mine, we could accurately compare the tracking between the two. My Orbit rotates to either side its full range, well beyond 90°. You can see I have actually quite a bit less slack in my rope than the skier in your photo, so I doubt excess slack is the issue with the tracking lag. But obviously if I used a zoom ratio any higher than 1.4x with the Linear lens setting I’d be out of frame at apex, or if my skiing improves and I get higher on the boat I’d be out of frame even at 1.4x. But there is definitely a degree of lag in the Orbit’s tracking such that the skier can get well out in front of the optical axis of the lens. No matter what, it will never keep the skier dead center, as the ski rope is not rigid and the Orbit uses the direction of the rope just inches in front of the pylon to rotate the camera. Maybe I’ll take the Ski Doc off and spray some WD-40 inside the workings and see if that doesn’t reduce the lag a bit. Considering the speed of a skier across the water it wouldn’t take much friction drag at the pylon to result it some tracking lag.

 

One other project I intend to play with when I find the time is to modify the camera mount on the Orbit so the camera is centered directly over the rope and not sitting off to the side, creating parallax. One of these days…

 

 

[swbca]

@Cnewbert My other question . . the skier in my picture is only slightly larger than in yours, but is also on an 8 foot shorter rope. This suggests to me that the equivalent focal lengths are fairly similar. So if the skiers in the two photos are similar, how is your field of view twice as wide ? Is there more edge magnification with the GoPro ? When the skier is directly behind the boat, does he look smaller ?

[MichaelWiebe]

@Cnewbert From the picture above, it looks like the GoPro may not be exactly parallel with the Ski-Doc Orbit. It looks like it's facing left vs. parallel. You will notice that, if the skier is closer to the edge of the video on one side vs. the other.

Hope that helps.

 

PS: For now, I am filming with the GoPro Hero 9, Ski-Doc Orbit, and I use the GoPro Quik app to crop the video afterwards (it must be saved to your phone/tablet first. This is the same as using zoom while filming, but when using the GPS speed trigger, the zoom function is not available. At least not on the QR Control app.

[Cnewbert]

@MichaelWiebe I’m not quite sure which photo you are referring to, as the all ones I’m looking at only show a skier on one side only. I know my camera is perfectly aligned as I have put index marks on the mount to assure it’s not a skewed to one side or another one day to the next. I use the same set up as you minus the GPS speed trigger. My photo is a direct screen grab from the video without subsequent zooming, appearing full frame as shot at 1.4x.

[Cnewbert]

@swbca the skier should look the same size regardless of whether he is high on the boat or directly behind at CL, as his distance from the pylon mounted camera is determined by the rope length alone and that doesn’t change during the pass. I really can’t answer your other question without some knowledge of the phone camera used. Aspect ratio perhaps? I just don’t know honestly. I’m just showing what my GoPro looks like at 1.4x with the linear lens setting and why I can’t use a higher zoom ratio. Naturally I can look at my video frame by frame with the GoPro Quick app, and zoom in on anything I want a closer look at. I find this sufficient for my purposes. I do look forward to lubing my Orbit to see if that has any effect, possibly reducing the tracking lag a bit.

[skierjp]

@Cnewbert i wonder if a piece of pipe insulation to tighten up the gap between the 2 upright rope guides would help? My Ski Doc has a place where it has a sticky spot in it that doesn’t help.

[Cnewbert]

@skierjp I’ve thought the very same thing. Just a little slop at that point will get magnified at the handle. I was thinking of sliding some heat shrink over the guides, maybe a few layers… however many it takes to snug up the rope between them so the Orbit will respond to the rope movement more quickly. Meanwhile, I removed my Orbit from my pylon for the first time in a year, so I could spray some WD between the moving parts. I noticed there is a tension adjustment screw I’d forgotten about or never knew about in the first place. It was probably covered in the instructions, but you know how that goes. So I loosened the tension a bit. The Orbit seems to be rotating smoother now, so I’m eager to see if it tracks a bit better as a result.

[swbca]

@Cnewbert @skierjp A friend added 2 more pegs about 2.5 inches further from the Pylon than the first pair. I don't recall how he supported them out there beyond the round base, but it all looked like a factory job when he was done. The pegs further from the pylon reduce the affect of the play between the rope and the pegs. The inner pegs are sort of useless at this point.

 

I was planning on adding a some soft tube around the original pegs - similar to @Cnewbert comment. Or tapering the gap so the rope was slightly pinched at the bottom . . . not sure of an easy way to do that without it looking messy.

[Cnewbert]

@swbca I also made an extension a while back. Mine were out about 6-8” farther than the Orbit guides. It didn’t improve things much, but perhaps it was too crude and had too much play of its own. I’ll be interested to know how your friend’s works. Maybe I’ll have to revisit that idea, only make it more precise next time.

[skierjp]

The Tracker had a arm that utilized the rope in a shock tube

[Cnewbert]

So this is interesting: as mentioned above I sprayed the moving surfaces of my Orbit with WD. In the process I discovered the tension adjustment screw I may or may not have been aware of a year a ago when I put my Ski Doc on my pylon in the first place. So I loosened that screw a hair as well. The whole works seemed to operate more smoothly as a result. The two photos shown here include the original one I posted previously demonstrating how nearly out of frame I was at 1.4x. The second is from this morning after making these improvements on the Orbit’s movement. The camera orientation is identical in the two photos, as I keep the GoPro mount permanently affixed to the Orbit, along with index marks to confirm it hasn’t inadvertently moved. You can see in #2 that while I am actually higher on the boat than in #1, I am quite noticeably more within the frame. So it appears that these actions I took were successful. Soon I’ll see if I can increase the zoom to 1.5x without a problem.

 

Regarding the other issue discussed of excess slop of the ski rope within the Orbit guides, as I looked at it more closely today I realized the gap was too great for heat shrink to make much of a dent. So I got some 9/16” OD / 3/8” ID clear plastic tubing. It slides down over the guides snuggly but without force. It takes up the bulk of the free play of the rope between the guides, theoretically making the response of the Orbit more immediate. I should know more tomorrow if it has a beneficial effect. Only after that will I give 1.5x a shot.

 

 

[Cnewbert]

This is the result of lubricating my Orbit with WD-40, loosening the tension screw slightly, and putting the clear plastic tubing I described above over the Orbit rope guides to try and improve its response to rope movement. The first photo is prior to any tinkering when I was nearly skiing out of frame at 1.4x even when not very high on the boat, and the second shot is from this morning after all the attempts at improvements. There has been a definite, though not wildly dramatic, improvement. I’m noticeably higher on the boat in today’s photo, yet still well in the frame at 1.4x. I doubt the improvement is enough to keep me in frame at 1.5x, but I’ll try that tomorrow I suppose. So bottom line, these things all helped to some degree and the result is better tracking. The only thing left I might try in the future would be a more precision rope guide extension than my first crude effort a while back. The goal, as before, is better tracking that will allow a greater zoom ratio without losing the skier at apex.

 

 

 

 

[503Kento]

Thanks @Cnewbert ! I had no idea there was an adjustment screw. Hopefully it will stop raining and I can get out for a test run.

[Cnewbert]

@503Kento neither did I! Or maybe I did when I first got my Ski Doc a year ago, but I've never removed the Ski Doc from my pylon since I first mounted it, so the adjustment screw would have been long forgotten even if I once knew about it. It's under the clamp and not readily visible. You will have to expand the clamp to get at it.

[Cnewbert]

 

 

 

While I think the Ski Doc is a great product, there were two areas that I felt could be improved. First was the skier tracking, and I detailed a couple of minor things I did to improve that somewhat in my previous posts. The second was the difference in viewing angle of the skier from left to right because the camera’s lens axis does not look straight down the line. Rather, it is mounted 5” off to one side resulting in parallax. That makes it harder to accurately compare your onside and offside since the camera viewing angle is different for each.

 

So I made this simple bracket, and attaching it required almost no modifications of any consequence to the SkiDoc. I removed two of the screws from the underside holding the top and bottom plates together, the ones opposite each other at the sides, 90° from the rope guides. I then drilled those holes from the bottom completely through the top plate. I then used machine screws and nuts to attach the bracket securely. I then removed the original camera mount handle entirely, which only requires removing a single long Allen head machine screw. I offset the GoPro mount on the bracket 3/4” so that the lens is directly over the pylon, completely eliminating parallax. The whole project didn’t take a full hour.

 

So not only is parallax eliminated, the camera tracks slightly better as well, since the COM of the camera is now directly in the center of rotation of the SkiDoc. Eliminating the inertia of the mass of the camera and the camera handle mount from out on that 5” lever reduces the tracking lag a bit more as the Ski Doc responds more readily to the rope movement. The two photos show me at 28 off in both cases. In one, with the Ski Doc unmodified, I am nearly going out of the frame (1.4x zoom). The second shot using my bracket and the same zoom, I am higher the boat yet still well within the frame, possibly allowing the use of a higher zoom.

 

All it took was a piece of 1/8” x 1” aluminum bar, plus two machine screws and nuts and a 1/4/20 machine screw as a tripod screw, plus a vice to bend the aluminum.

 

I should add the Ski Doc can be restored to its original configuration and function in 5 minutes, with only the 2 machine screws and nuts being different than before, and they don’t affect a thing.

 

(For some reason the photos display in a different order than I posted, but you can still see the difference.)

 

[MichaelWiebe]

@cnewbert Wow! Super job. I love it.

The link below is done with a Hero 9 and Ski Doc at Mulberry FL on Monday (Nov. 29th).

I zoom in after the filming (editing in the GoPro Quik app), since we use the GPS speed automatic start/stop function, and the zoom resets to 0 after the first pass. :(

We want to zoom in more, and your modifications should allow this.

Maybe I can order the modification kit from you.

 

[Cnewbert]

@MichaelWiebe ha ha.., you’re in a shorty and we’re in our O’Neal Fluid Neo drysuits! 64° water is like the Antarctic to us! Mulberry must be warmer than Weirsdale. More likely, you’re much tougher. Anyhow, lookin’ good! We’re skiing in the morning and I’m going to try 1.5x zoom and see how it goes at -28. We just use manual start/stop so zoom doesn’t reset. Tried voice command but that was an exercise in frustration. Ended up screaming f-bombs at the GoPro and even that didn’t work. No need for a kit… if you have a hacksaw, a vice and a drill you can crank one out in less than a hour. Let me know how it goes.

[skierjp]

@Cnewbert I live 15 minutes from Ski Paradise on Spirit Lake. I checked Thursday our lake was 71.6 with a digital thermometer 3 feet down

[Cnewbert]

@skierjp I'm insane with envy! We were measuring 64 again today with our digital thermometer... at the surface. We need to move south!

 

[Cnewbert]

@MichaelWiebe the 1.5x zoom test with my new bracket was successful. I never skied out of frame once all morning. I’m higher/wider than the original photo I posted of the unmodified SkiDoc shot at 1.4x and with more room in the frame to spare. I’ll try 1.6x next week.

 

 

[Cnewbert]

@MichaelWiebe this is 1.6x, -32. 1.6x might be as great a zoom ratio as I can go and stay in the frame at -28 and -32. But that’s a 20% improvement so I’m happy with that. I’m not sure, but the camera might track somewhat better on a better skier who keeps more tension on the rope. The elimination of parallax is the greatest benefit with my bracket in my view.

 

 

[MichaelWiebe]

Great work. Thanks a lot.

[MichaelWiebe]

@swbca

The GoPro Labs GPS speed activation QR code now includes zoom. It worked for me today, with a Hero 9.

Please see the other thread….. GoPro speed activation.