[ANSWERED] Looking for affordable wired cameras for tracking

Fred

@kathmandale just to point out that the latency variation has little to do with the camera brand but more the design application. Both Sony and Panasonic make IMAG cameras, designed for live use that will have about a single video line latency from the lens to the SDI out. The series of cameras you seem to be testing with are designed for filming, most often the SDI output module sits after the debayering and encoding for the recording pipeline and is a bit of an afterthought, designed for non-latency critical applications like confidence monitoring. Most of the big camera manufacturers will make some cameras better designed for live use, they often don't have the capacity to record but have very little latency.

ioio

Hi, I bought one of those camera (usb mpeg fullHD infraRed with zoom and focus). it works smooth, you can add 40m of active usb. Its very cheap.

I used it to catch ir shadows with ir back light on a rear projection screen with no problem.

yoyo.

ioio

i forgot the link https://www.aliexpress.com/who...

Kathmandale

@fred

Thanks Fred. You're right, the old panasonic we were testing there was very much designed for filming and while it was a lovely camera to record with it was painfully slow to use in live work.

For live work now we use the Sony PMW-200 and on the last show hired some newer Sony PXW-X70. They seem to give a really good mix of speed and the functionality of decent film cameras. On the last show the cameras didn't go through a computer/server but straight to the projector via some ATEM switching. With that setup it was fast enough to look in-sync with live audio. I appreciate they're not going to be within all budget ranges but I'd really highly recommend them.

Incidentally, you can see that show, Night of the Living Dead: Remix on our website at the moment for free, or pay-what-you-want. I hadn't posted a link on here before as this one wasn't made with Isadora, although we did use Issy in rehearsal quite a lot. Because the show was all set to the timecode of the original film all video, camera switching, lighting, etc ran from a single video and synced up with timecode; once we'd finished making it to operate the show we pressed play then sat back to watch.

Gaspar

Hi everyone,

sorry for the delay in answering.

So based on all the information I've got from you, I'll probably stick on SDI CCTV with c-mount lenses, although I might have a look at the mini SDI cams @Kathmandale suggested

Two main questions remain open:
1. I'll possibly be using IR tracking. I planned to purchase IR LED washers and use an IR pass filter in front of the lense or between lens and sensor. @Fred You talke about a switchable IR cut filter. Does this mean that there are cameras with that include the filter as an option? is there any electronic way of "switching" the filter on or off or is it mechanical, by placing the filter in front of the sensor? I've seen a few CCTV cams that do have "night vision", but there's not much information about how it works, it looks like some of them just push up the ISO.
So. Any SDI CCTV cam with switchable IR pass lens? Or can I just buy "any" cam and place the IR pass filter in front of the lens or between lens and sensor?

2. The second question is reagarding the capture cards. As far as I understand I'll need an SDI to USB3 capture card or an SDI to HDMI converter plus HDMI to USB3 capture card (which are by far more common than SDI-USB3). Will Isadora deal with 2 capture cards? Any reccomendation? @Kathmandale suggested the Blackmagic Intensity card which allows analogue & HDMI input and in Europe is priced around 180 €.

I also had a look at @ioio's suggestion but being usb I more inclined to SDI wiring. The camera itself might be cheap, but 40m of active usb cable adds some cost and I'm afraid it is far more sensitive than a sturdy BNC.

I've found some scond hand Marschall cams, for 300€ each, and might go for them, but the Eyemax HD-SDI CCTV security Box camera suggested by @Fred is far cheaper and new (not sure about any significant differences bewteen brands) or specs between the cameras.

I'll keep on digging. Thanks a lot to everyone so far.

Fred

@gaspar

CCTV cameras have a night mode, this is selectable in a menu and uses a tiny solenoid to move the IR cut filter away (all cameras have an IR cut filter to filter out IR light as the sensor can receive it and it will have various effects on an image for normal light (especially in auto mode where the camera will adjust settings to incoming IR light that we cannot see)). Normally if you want to capture IR light with a normal camera you will have to open the camera and remove this filter.

To do good IR tracking it is good to have an IR pass filter as well (as well as setting the camera to "night mode" to move away the IR cut filter so IR light can pass), the IR pass filter will block light in the visible spectrum, so only IR light hits the sensor. This makes tracking and using IR lights for tracking a lot easier as you also don't have to deal with any visible lighting you are using. Another benefit is that you can track easily in front of video projection as VP uses visible light (obviously) and tracking software will pick up movements in the video, but with an IR pass filter the camera cannot see the projection, just whatever is lit up with IR light.

The cameras mentioned by @Kathmandale have better sensors and more control (at a much higher cost) but as they are standard cameras they all have built in IR blocking filters that make them very difficult to work with in IR tracking.

I use an IR pass filter from midwest optics, there are many choices and you need to match the IR wavelength of your lights and the IR sensitivity of your camera sensor to find the right match and then make sure you get one that covers the size of your lens - they have a simple screw mount system for adding filters to normal lenses.

https://midopt.com/filters/bandpass/

Also @Gaspar yes the different brands of cheap security cameras do make a difference, there are a lot but generally they only use one of 3 or 4 sensors and enable some slightly different features in each. Notably the way they handle 3ghz SDI (for 1080p50/60) may or may not comply with the SMPTE spec. Most listings will have a detailed specifications list as well as mentioning the exact sensor (and you can google that to check out the specs like pixel size and it sensitivity.

Fred

Gaspar

Thanks to everyone's help,

It seems quite hard to find SDI CCTV cameras here in Spain or in Germany (new CCTV standards as HD-CVI or HD-TVI have pushed away SDI, which is now "only" on professional cameras, but no longer on CCTV). In the US and on Aliexpress SDI CCTV cameras are still easy to find.

Regarding SDI capture cards, there aren't that many. There is the Blackmagic Design UltraStudio Mini Recorder for 155 € which has a Thunderbolt2 output (no USB3)

The other option is getting a SDI to HDMI converter for around 50 € (should have almost no penalty on signal quality or delay) and this way it is possible to use many of the avaliable capture cards feeding incoming HDMI to USB.

I'll try some stuff with my old camera and an old composite capture card. Later I will probably go for one of the above solutions.

----------------------------------

An update: No hardware yet, but I've had an Idea.

Since it is not easy to find (affordable) SDI cameras that allow manual settings, which is a must, I've been searching quite a lot.

SDI seems to have been dropped in the CCTV market. Actual CCTC cameras feature TVI, AHD, CVI or similar protocols, but almost all of them connect to a "box" (many are able to accept different protocols) that has an HDMI output to "monitor" several cameras. The box itself offers different split views (generally just one camera, 4, 8 or 16). So I'm thinking about using two cameras of whatever actual protocol (the cheaper ones right now are 2MP) and having the "box" putting out both views over one HDMI. Possibly I'll have to stick with a 4 split window, wasting half of the FHD outbput, but 1/4 FHD should be enough for motion tracking. I'm a bit concerned about the framerate, which probably also drops considerably, but being above 10 fps could be enough. Obviously I'll need to feed that into isadora using a capture card. I already got myself a blackmagic design intensity shuttle.
I think this is a cool solution to capture several cameras with just one capture card (4 cameras at 1/4 FHD is probably a reasonable quality for many applications and if it is not enough you can go 4K output) - Still the framerate issue needs to be clarified.

Cheers.

Fred

@gaspar yes I have only ever been able to order the SDI cctv cameras from China using eBay or AliExpress, but that should not stop you, you order wait and it arrives...as for the capture card if you need USB 3.0 for SDI you can use a magewell card (or again look for one on Ali express there are a lot of cheap copies of the magewell gear there that are actually great). This has been the normal way of getting gear for a long time, I cannot remember the last time I walked into a shop and bought a piece of equipment.

n.jones

@kathmandale Night of the Living Dead: Remix, that was a great show! I saw it at the Liverpool playhouse . I think might have quizzed you on what io you used !

Kathmandale

@n-jones Thank you, that's great to hear. The tour got cut short unfortunately but we loved our week in Liverpool. I do remember chatting about the setup after the show one night so nice to meet you again! Looking forward to next time.

Kathmandale

@gaspar glad you're getting a good plan together. Let us know how you get on.