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Lightbridge first impressions

Discussion in 'DJI Lightbridge' started by markab, May 15, 2014.

  1. markab

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    Had my first couple of flights with Lightbridge last night overall reasonably impressed, hardware itself is fantastic and install was easy but I am reserving overall judgement for the time being.

    So firstly both flights rock solid control didn't notice any difference from a Futaba FAASST RX. The HD Video was crystal clear and did not have any drop outs or lock ups what so ever and the video looked very crisp however a lot of the time I was getting low frame rates on the screen resulting at times in a little jerky video.

    So in the manual it lists all the compatible input resolutions and frame rates up to 1080p60 in my case I had my GoPro running 1080p30 which is my usual standard. Also in the manual it lists the link quality settings HD distance/quality and Full HD distance/quality. In my case I was using HD Quality Priority which states it is 720p30 and is recommended, I am assuming the air end transcodes the input video resolution to the video link resolution on the fly in other words camera to Lightbridge is 1080p30 then is transcoded before Lightbridge to ground at 720p30.

    I thought about switching to Full HD Quality Priority so that the in video 1080p30 was already natively at the link resolution thinking that may improve frame rate by reducing transcoding however the link Full HD Quality Priority is actually 1080i30 not p30 so I assume still needs transcoded. Next flight I may try running the camera at 720p30 and the Link in HD quality Priority 720p30 this seems to be the only balance where the input and link is the same.

    So a couple of annoying things here, the manual is rubbish it needs to explain what the device is doing better so that users understand how to get the best from it, the maxium link resolution 1080i30 doesn't offer up much more quality over 720p30 in my mind this is not Full HD.

    To be honest for me 720p30 is fine for the video downlink (for me anyway) but it needs to be at a solid frame rate, if I have to start changing my camera resolution settings to get a usable downlink then the device is a fail, but I has to test further first to confirm this. (although does the GoPro HDMI out put at the recording settings or always 1080p60 regardless?)

    Only other thought was the Galaxy Note 3 was displaying at a low frame rate, but it has a fairly hefty quad core processor so should eat up 720p video easily, I guess I can test this by outputting to a standard HDMI monitor instead.

    Couple of other quick points of annoyance but are not really a fault with lightbridge, The GoPro in interval picture mode did not seem to out put video on the HDMI port so useless for framing shots (need to investigate further may have been something I messed up). Going to hook my Nikon D800 up to it tonight to see if I get different results to the GoPro.

    Is there anyway to switch the Futaba 14SG off with the trainer cord plugged in?
     
  2. sar104

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    I agree that the manual is not very clear on the operation of the air and ground units with respect to the video feed from the GoPro. The GoPro HDMI out is at the capture setting of the camera, and so it does appear that the air unit converts on the fly to the resolution chosen in the app. So far the video display on a mobile device looks fairly smooth, but not as good as straight HDMI out from the ground unit to a monitor.

    You don't actually need to switch on the Futaba at all - just plug in the trainer cable and it fires up in the appropriate (radio off) mode.
     
  3. markab

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    Ok so you are saying you are getting good frame rates on HDMI out but seeing minor issues with tablet/phone? (still have to try the HDMI out to compare)

    Yeah I get that about the Futaba, but I just want to leave the whole thing mounted and plugged in, would prefer to switch off with a switch rather than pulling a cable.
     
  4. sar104

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    I would prefer to be able just to switch it off too, but I haven't found any way to do that.
     
  5. markab

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    Interesting problem tonight, went out to fly, powered up ground, then powered up air side. Showed I had 100% video link but 0% control link however controls were working and video was blank.

    After numerous attempts at restarting both sides with no change I finally restarted the go pro and it all jumped into life. Would have been more helpful if it had indicated that video was the issue.
     
  6. sar104

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    I found that exact condition when the GoPro was set to a format incompatible with the LB. I agree that the indications did not aid the diagnosis.
     
  7. shartlza

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    Quick question for those of you using the lightbridge. Are you using it with the H3-3D? If so do you have the v1 H3-3D with the GoPro connector in the back or the v1.1 with the connection on the side. I guess if you are using a H3-2D it has the GoPro connection on the back as well. What I want to know is, does the LB work when the GoPro has the connection in the back??
     
  8. sar104

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    Mine is the original H3-3D with the regular connector on the back. That has the advantage of charging the camera when using HDMI. I haven't found any problems with it.
     
  9. damoncooper

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    But the HDMI out on the ground unit displays no telemetry, correct?
     
  10. sar104

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    Correct.
     
  11. markab

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    In my case the GoPro was running 1080p30 however the GoPro was powered before the LB, the reason I powered the GoPro first was I find that sometimes the GoPro will not power up with the HDMI connected, I have to disconnect, Power up the GoPro then connect again. I don't really want to damage the gimbal by doing that while the frame has power.
     
  12. markab

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    Do you get telemetry on the app but just no video when using hdmi? or does the app not function at all? (still not tried hooking up the HDMI out yet!!)
     
  13. markab

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    Yes because you connect the lightbridge with a light weight hdmi that hangs between the camera and lightbridge.
     
  14. damoncooper

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    I believe I read the USB and HDMI ports on the ground unit are mutually exclusive, but I could be mistaken.
     
  15. sar104

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    That is also correct.