Core Electronics Forum

Video camera remote control for Lathe demonstrations

I’m wanting to setup two video cameras over a wood lathe for demonstrations purposes ,which will allow the demonstrated action video to be sent wireless to two large TV’s being used as a monitors (IE one camera being used for overhead view the other for end view)
I would like to use a remote WIFI / Bluetooth operated joystick or joysticks to controlling zooming facilities on each camera .
Is anyone able to suggest a setup using Raspberry Pi’s and or models,suitable cameras ,and Joystick or other suitable remote control ?
The cameras ,one is suspended approximately I metre above the lathe ,the other camera is mounted on a tripod about 1-2 metres to the side of the lathe .
Phil B.

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Hi Phil,

Welcome to the forum :slight_smile:
This sounds like a cool project with a few aspects to it. I suggest tackling it by breaking it down to the simplest elements and getting those parts working before trying to take on some of the trickier parts.

I’m not familiar with any camera with a remote control zoom function that I’ve seen used with a Raspberry Pi, however since you’re trying to record a lathe demonstration you may find zoom is unnecessary if you have a camera with enough resolution.

If it were my project I’d start with just trying to get video recording on one Raspberry Pi with a camera and tripod that is output to a screen with a long HDMI cable, and see what sort of clarity you can get with a basic camera module before committing to a more expensive camera with zoom.

Start simple with a basic Pi kit and a camera with an adjustable lens.
We have a camera comparison tutorial here

and a guide to getting started with Pi cameras here

How far away do your monitors need to be from the lathe?
Also, how close do you need the camera to view the workpiece?

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Hey Philip,

Welcome to the forum!!

Could a baby or surveillance camera work, it keeps things simple, but also removes a lot of fun.
The HQ camera has a couple of lenses with adjustable focus but there is a function between the zoom and focus lenses, software zooming could also be an option at higher resolutions (even the Pi v2 camera should work as a proof of concepthere).

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Hi Phil, I have tried my old Logitech C920 camera. Just plug and play, can autofocus easily. Here is a compatibility list of cameras that have been tested. In combination with VLC player, can stream. I don’t have any use for streaming, hence I did not try.

If you already have a couple of webcams, would be easier. Mounting on tripods can be tricky, but tie-wraps and duct tapes can always help :slight_smile:

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Trent thanks for the support,cant believe how helpful you all are,Thanks.
Ok need to do a bit of reading to catch up on how to use a R.Pi and the cameras available ,
To start with the overhead camera which looks down vertically above the lathe chuck and bed would need 6to be about 1-1.2 meters and will be support on a substantial telescopic arm attached to a nearby wall,so practically no movement .
The second camera will be mounted on a tripod set up on the floor near the tail stock of the lathe needs to be no further away than 1.5 -2.5 metres from the work area above the bed of the lathe,this camera needs some zooming as when demoing close up detail .
I have just recently purchased in October a Pi 4 with 4GB of ram from Core think it is running the latest ver of Debian ,but not sure about Bullseye will check
Phil

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Liam,thanks for the welcome ,will investigate your suggested solution, Its all a new project as said ,
will keep you posted on my progress and in the meantime will have a look at the baby monitor idea.My daughter had one of the some time back will check its still available.
Phil

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G177630, well how handy is your post ,just happen to have a Logitech 920 sitting on this very screen in front of me ,so that will be a trial taking place shortly.as its got its own software zoom and focus software might be onto something ,Thanks for your help and interest,will keep you posted on progress
Phil

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Glad to be of help, Phil. I did not install anything to RPI to get it working. Saw my image on the screen and disconnected before the lens and screen crack.
I am not much of anything with coding. I do not know if VLC can stream two cameras at the same time, but there are codes out there.

Apparently, there is a whole OS called Motion Eyes OS, which is dedicated to cameras. One can install a program called Docker, which is a container in which other programs and OS can be run, without fully modifying the RPI OS.

There is no tutorial here on installing Docker. But, someone can help you, if you want to go that way.

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Hi Phil,

Sounds like you’ve got a few avenues to explore, do update us once you’ve run some tests!
I’d love to know how well the software zooming within a high-resolution video works as an alternative to a hardware lens that needs to be physically manipulated to work and then needs to be refocussed.

I’m not sure if it can run two instances either but docker would be a good workaround if it can’t. I’m yet to find a media application that VLC can’t handle, it’s a real swiss army knife of a program.

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Hi All.
Could be wrong but my understanding of “software” or digital zoom is chopping out a smaller and smaller bit of the pic and enlarging to full size. Sooner or later the pixels are going to be so big the image will be unusable whereas optical zooming retains the original resolution.

Can someone please explain how software can handle optical focus without motorising it. If the image is optically out of focus there is nothing I can see where software is going to fix it. You can sharpen images up and do all sorts of things but that is not really focussing.

Trent, a good quality lens will not have to be refocussed. Of course like everything else this quality comes at a price. Actually it is an interesting test for any camera to see of you can zoom without refocussing.

In this application I think the solution would be to provide enough light to be able to close the lens iris small enough to get a greater depth of field and changing focus would not be so much of a problem.
If you could get down to f11 or f16 the depth of field would be close to infinity and once initial focus is set any slight out of focus caused by zooming an “ordinary” quality lens might be acceptable. I would emphasise here that quality is improving and these days most medium quality lenses are pretty good. The high end stuff more for professional photography use is still very exe but.
Cheers Bob

Edit. Just trying to remember what we had to do in the days of vidicon tubes in TV cameras (mostly CCTV). There you firstly had “beam focus” where the beam could be focused on the vidicon target. Then came optical focus. There was another criteria that affected focus as the lens was zoomed. This was called “flange back” and was the distance between the back of the lens and the vidicon tube target. This was quite critical and entailed physically moving the whole vidicon/deflection assembly. From memory this was adjusted for minimum focus shift between wide angle and full zoom. I could be wrong bit I would think the same thing would apply to the distance between the lens and the image sensor in the modern digital camera. When you purchase a camera with the lens already fitted all this would have been optimised during camera design and manufacture I would think.

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Hi Robert, I have seen this in GoPro cameras and was not enthused.

As Phil mentioned the Logitech software (on Windows) actually moves the lens. I had noticed it years ago when I used to do video chats with friends and family.

Even F/8 would not be bad. I am not sure if the so called 35mm equivalents apply to Webcams. Probably they do, but haven’t used them to test that aspect. Prefer my DSLR for real photography.

With cell phones, it is usually f/2.4 or f/1.8. Fun stuff, happy memories. Good for portraits. That’s about it.

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Apparently it can be done, Trent.

Read somewhere that the bandwidth of the USB bus may be the limiting factor (some thread from 2014). Logitech C920 is USB 2.0.
With the USB 3 from the same bus, probably RPi can handle two cameras, may be it can allot bandwidth if two cameras are connected to USB 2 and USB 3 ports rather than both to USB 2.

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Hi G

All very clever stuff. Camera specific software could move the lens but it would have to be motorised somehow within the camera. Last time I looked zoom and focus were physical things and required some mechanical movement.

Agree, though even the portraits leave a bit to be desired. I am afraid I am a bit old school. If I want to speak to someone I will use the phone. If I want to take their picture I will use my camera. I have a nice little Sony camera with all the bells and whistles. Even blurs the background for effect when in portrait mode. Has another great feature, a pop-up eye level viewfinder (hate those screens which are impossible in bright daylight). Focus and zoom are motorised within the camera and operated by a switch or a ring around the lens which can have selectable functions, very clever stuff.
Cheers Bob

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Hi Bob,

This is what I was thinking of, not great in every application but I did work for a previous engineering job I was working on with a series of Hikvision CCTV cameras. They were moving away from PTZ control and trying to get the same benefits by compensating with higher-quality video.
Here’s a demo of their approach in action:

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Hi Trent
That seemed very successful. When it is all considered that is the only way you could get good resolution with software zoom. Thet video showed a big improvement and I bet the file size improved (increased) exponentially with it.
Cheers Bob

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Hi Bob,

I’d agree, there is always a tradeoff of some sort, in exchange for a PTZ effect that has no moving parts you pay in computing power and bandwidth increases.

Ultimately I think a proof of concept test will help us find the right balance, as the lathe won’t be a particularly large viewing area to cover perhaps a mixture of a moderate fixed zoom lens coupled with some software trickery may find the sweet spot.

I’ll defer to your camera experience as I’m still a novice with photography.
I think we’ve got a good spread of options already discussed and the right answer is probably among them.

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In the post-2020 cell phones, that is what they are doing. One can see 48 MP, 64 MP or 108 MP cameras and then lenses like Gollum’s eyes. They increase the lens diameter, with improved sensors, that do the pixel binning. Still the same 12 or 16 MP overall, but more pixels. The individual pixel sizes are smaller, the algorithm uses 4 or more of those pixels (binning) to get the value for 1 pixel. Thus, the resolution is better and can afford better zooming.

Fun fact about Logitech webcams: They can do face tracking. They can actually pan, when someone is in a video chat and move around.

Years ago I saw a video in an office set up, do not remember the camera make probably an in-built laptop one. The face tracking worked normally with a lighter skinned person, but did not track when the darker skinned colleague was in front of the camera. They were making fun of the camera being being discriminating. Hope they improved the algorithms. This was 7-8 years ago.

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Just to share what I read a few minutes ago: Bullseye does not support two cameras. Was bored and reading through the responses at Raspberrypi site and found a comment stating that.

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