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Mobile phone Gimbal enquiry


alexandercargill

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Hi there i was wondering if you folks can help. Im looking at both the smooth 4 and DJI osmo mobile 2 mobile phone gimbals. Im wondering if it is possible to take panoramas whether it be stitched or unstitched using the gimbal. If none of these gimbals allow you to do this and you know of something that can do it then im totally open to suggestion and it should be noted that i am using a galaxy s9 mobile. thanks
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Ridiculously expensive for a little table-pod with a phone clamp on top. And not even a true gimbal.

Looks like just a swivel and tilt mount to me.

 

Just swinging the phone-cam around in a level arc isn't going to get you stitchable images. There's a lot of geometric distortion with most phone-cam lenses, and you'd need software to correct the distortion before stitching.

 

Why not just buy a little compact digital camera that has a panorama function built-in?

It'll probably cost you less and give you better quality.

Edited by rodeo_joe|1
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Ridiculously expensive for a little table-pod with a phone clamp on top. And not even a true gimbal.

Looks like just a swivel and tilt mount to me.

 

Just swinging the phone-cam around in a level arc isn't going to get you stitchable images. There's a lot of geometric distortion with most phone-cam lenses, and you'd need software to correct the distortion before stitching.

 

Why not just buy a little compact digital camera that has a panorama function built-in?

It'll probably cost you less and give you better quality.

oh i have a DSLR and photoshop, i just wanted this option as a point and shoot incase i see something when i dont have the DSLR thats why im asking. Is there any decent software that stitches dng files together in phone?

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The phone might already have a panorama option; mine does, but it's not very good. It 'smudges' the images together rather than stitching.

 

There are several issues to getting really good panoramas. Smooth panning and levelling the camera are just two. The camera also needs to be swung or tilted about the optical centre of its lens, and that optical centre usually needs to be found by trial and error. In the case of a phone-cam, it might be slightly behind or in front of the actual phone. The tilt and swing pivots both need to be centred on the lens optical centre. This might need a lot of adjustment in the clamp position, since most phones have the camera placed well away from the centre of the phone.

 

So just randomly clamping the phone in a 'gimbal' gizmo won't give optimal results. Better results than swinging the phone by hand, maybe, but you'll probably still get 'jaggies' on diagonal edges unless the lens is accurately aligned with the tilt and rotation axes.

 

If you're trying to imitate an ultrawide angle lens, then the camera needs to be panned in portrait (vertical) orientation, and the phone clamp needs to accommodate this as well.

 

The camera exposure also needs to be kept constant during a sequence intended for automatic stitching. If the exposure varies, you'll get a patchwork of lighter and darker sections.

 

You'd hope that any built-in pano software would automatically correct for lens distortion, but it's not a given. Pano mode might also set a fixed exposure, but then again it might not.

 

However, no software solution is going to properly set up the tilt and swing axes of the phone or camera in the first place. That has to be done manually.

 

So, will those motorised 'gimbals' do the job? Possibly, but almost certainly not automatically. You'd have to fully investigate their functions, servo-speed and range of adjustment before knowing for sure if they'd help.

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There's certainly already a panorama option in the phone (generating a JPEG). How well it works tends to depend on how much you're moving and how close you are to objects in the scene - bear in mind you probably want to rotate around the phone rather than around yourself when you're doing it, and the less you move the less adjustment the camera will have to do while aligning. On the other hand, the user interface tends to be nicer than the equivalent in compacts. I've had reasonable luck with the integrated panorama facilities in the default Android camera app; I know Samsung put a lot of effort into their custom photo app, so I'd be disappointed if it wasn't at least as good, and the S9's camera is supposed to be reasonably well-regarded. It's certainly stabilised. You'll have more control over the result (especially regarding exposure) if you do it yourself in software, but an awful lot of people use this functionality with no additional hardware, so I really hope it mostly copes okay.

 

My understanding (not having used either) is that the phone gimbals are designed to allow smooth video shooting while hand-held, rather than anything to do with stitching. They're probably not harmful to the latter, if you're not fighting the gimbal while you turn, but then resting the camera on a monopod (or walking pole) and walking around it would probably do good things for stabilisation as well. I'd expect translation to be more of a problem than rotation, and unless you have a full steadicam rig, a miniature gimbal shouldn't really be able to help with that.

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Andrew, I believe those electronic 'gimbals' have a virtual spirit-level/plumb-bob built in that allows them to servo the camera tilt and maintain verticality while panning. I would certainly hope so, otherwise the label 'gimbal' is totally meaningless.

 

What concerns me is that they seem to lack any nodal-slide facility to align the lens node with the tilt and rotation axes. The degree of vertical adjustment on the clamp seems limited as well.

 

Agreed, there seems to be no Z-axis or translation stabilisation either. So panorama results will definitely depend on how steady the device can be held during rotation. Given that, a simple damped gravity gimbal, such as is used in a ship's binnacle, would probably be just as useful.

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Just for reference, here's a snap I took last night as I was about to go home. This is from a Nexus 6P with the default Google camera app; I'd hope the S9 would be a bit better. The exposure isn't perfectly even (although this is quite a pathological test), and the foreground alignment isn't absolutely perfect either (though the lightning conductor really wasn't lying flat), but for thirty seconds hand-held (and trying to rotate around a static camera position) it could have been worse. The full size version is reasonably sharp, except at the very edges. The horizon really does have a dent in it - there's a hill just to the left of the building, so that's not a stitching error.

 

smallcarpark.thumb.jpg.d4a0e9290fab6dad41820f3c2e45d4ec.jpg

 

I've never actually tried one of the mobile gimbals. I assumed they had some nodal adjustment, but I believe you if I'm told they don't. I assume they're mostly designed to avoid inter-frame wobble during video (the kind of thing that GoPro are demonstrating software solutions for).

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