On Tue, Jun 27, 2017 at 12:51:40AM +0200, Nicolas Dandrimont wrote: > Hey all, > > I've spent an evening and a day working on video stuff last week-end, using > the > opportunity of a pair of lent cameras to do some work. I've put some pictures > up at https://krkr.eu/dcvideo/ > > Here's what I can report: > > Camera testing > -------------- > > I had both the Sony PXW-X70 and the JVC GY-HM200E set up. Both cameras are > largely similar in functionality and feature set, and they work just fine with > the vocto setup. > > I recorded to YouTube : https://youtu.be/BleLh5hXICY; at the beginning of the > video, the JVC is on the left, the Sony on the right; I switched them out at > 12 > minutes : most of the video has Sony on the left and JVC on the right. > > The differences I could notice were: > > - Low light behavior: using dawn and the blinds in the room allowed me to test > for crappy light conditions > > (reminder: at those timecodes, Left = Sony, Right = JVC) > test 1 : https://youtu.be/BleLh5hXICY?t=9282 > test 2 : https://youtu.be/BleLh5hXICY?t=10293 > > feel free to stroll through that video for more tests. > > What I noticed: > > The JVC high gain for low light setting is manual and fiddly; Sony has proper > automatic gain control. The JVC's auto white balance is slow, the Sony seems > to > do the right thing pretty fast even in very bad conditions (playing with > blinds, light switches, ...). The JVC also was very grainy when fully zoomed > in > and in low light (see the very beginning of the video).
In addition, the JVC's autofocus seems pretty bad, often requiring several seconds to be done; the Sony seems faster in that regard. Its grainyness is due to the larger sensor on the Sony; that's perfectly expected behaviour (and is why my friend suggested the Sony in the first place). I notice that the JVC seems to be able to zoom in further; is that a correct assessment? Given that it has a smaller sensor, this is also to be expected; but given that the Sony's sensor can do 4K and we only need 720p, we can probably get away with so-called "digital" zoom without that much quality loss (there will be some optical artifacts, but not really something you'd call showstoppers) Did you run a test on how far away you can get a close-up of someone? > - Size: the Sony is substantially smaller than the JVC and we should be able > to > fit two in a case the size of the ones we've been using for the dvswitch > laptops. That's good, yes :-) > - SDI connectivity: the Sony does SDI-6g (up to 4k) while the JVC does not > (AFAICT, pegging the SDI to 1080p). Not very useful for us, but who knows > what we'll do in the future... Right, but I doubt we'll ever want to do more than 1080p (if even that), so it shouldn't matter at all. > - Audio input setup: I only had batteries for the tests (no AC adapter) and I > noticed the Sony would lose audio input settings when rebooting. As it > defaulted to shoe mic it's not a showstopper. It is a bit annoying, and might be confusing. There is a slight risk of people switching off the camera and thereby losing settings, resulting in the recording not being the way it should be. I agree it's not a showstopper, but it is something we need to make sure we've got covered for volunteers; we should tell them never ever ever to switch off the camera, or have a cheat-sheet of "post-boot operations" with every camera. Probably best to do the latter, actually. > Also the silly stuff like phone remote control works... Heh. Cute :-) > IMO the Sony is superior to the JVC, mostly thanks to its smaller size and > better low light behavior. Happy to hear opinions. > > Streaming setup > --------------- > > I had a very productive chat with markvandenborre, member of the FOSDEM team. So am I ;-) > They use nginx with the RTMP module to get the feeds out of the rooms into > HLS, > then a bunch of nginx caching frontends to back video.fosdem.org. I think > that's a setup that we will be able to easily replicate. For streaming, this makes sense. FOSDEM also uses that setup for recording, with many woes. It makes some things easier, and in that light it does make sense for FOSDEM given the huge huge (*huge*) (no really, *HUGE*) amount of rooms they need to record, but I would recommend against doing the same for DebConf. You'll be sorry afterwards. [...] -- Could you people please use IRC like normal people?!? -- Amaya Rodrigo Sastre, trying to quiet down the buzz in the DebConf 2008 Hacklab _______________________________________________ Debconf-video mailing list Debconf-video@lists.debconf.org http://lists.debconf.org/mailman/listinfo/debconf-video