I need some JVC GY-HM750 SDI capture advice

[Simon Denny]

I'm looking for a cheap shoulder mount camera for some rough outdoor gigs and have been using the GY-HM750 recently. I'm wondering if I can get 4.2.2 50mbps out of the the SDI output to a Nano or some device.

Can anyone advise me on wether this is possible?

[Don Bloom]

Simon, even though I have a 700 I've never done it so I went to B&H and re-read the description and it states that with the SDI out you can get 4:2:2 @35mbps BUT IIRC, the Nano can be set to record at a higher rate. Up to 200mbps I think.
Perhaps check with Tim Dashwood or Dan from Nano just to be sure.

[Simon Denny]

Thanks Don, I also read the same info and seems odd that you can get 4.2.2 but not a higher bit rate.

Cheers

[Shaun Roemich]

Originally Posted by Don Bloom

it states that with the SDI out you can get 4:2:2 @35mbps

SDI out is uncompressed so it isn't 4:2:2 at 35mbps but 4:2:2 at 1.5Gbps (1500 mbps).

[Simon Denny]

So that means using a Nano I can get uncompressed 4.2.2 and a higher bit rate, lets say 50, 100 etc....

This might be a great option for what I need.

[Don Bloom]

Hey Shaun, I must have mis-read the description. Actually it's the Product Highlights and it is a bit misleading. 4th line down! ;-) In any case I knew I had read somewhere that the higher bitrates were possible.
Thanks for clearing that up.

Product Highlights (from B&H)
•1/3" Progressive 3CCDs
•Shoulder Mount Form Factor
•Bayonet Lens Mount
•4:2:2 Color Space, Up to 35Mbps Bitrate
•1080i/p, 720p, 480i Multi-scan
•Native MOV, MP4, AVI Capture
•Dual SD/SDHC Simultaneous Recording
•Variable Frame Rates
•68-pin Chassis Connector
•HD/SD-SDI, FireWire Output

[Mike Squires]

Yeah, HD-SDI out is uncompressed. You can use something like the Blackmagic Hyperdeck Shuttle to capture uncompressed, Prores (220Mbps), or DNxHD (220Mbps).

[Shaun Roemich]

Hey Don... that's interesting since XDCamEX at 35mbps is only capable of 4:2:0. To get 4:2:2 in XDCamEX you need 50mbps like the new PMW200 can do on UDF SxS cards. The HDMI and HD-SDI out on the HM750 are 4:2:2 uncompressed (1.5Gbps)

Wonder if Craig has seen that yet...

[Simon Denny]

I've been shooting with the JVC at a live event for the last two weeks to a big screen. I'm on the shoulder with a RF system attached to the camera which is then fed through a switcher etc... and then to the big screen. I'm amazed how good the image holds up although in camera recording to cards I find is very noisy with massive amounts of chromatic aberration which I'm attributing to the Canon stock lens. I'll try and get a Nano etc... and do some test while I have the use of the camera.

[Mike Squires]

Yeah, getting uncompressed out of HD-SDI blows away the 35Mbps MPEG2. In our studio, we capture using MJPEG (~100Mbps), and it's a LOT better than capturing to the cards. Getting a Hyperdeck Shuttle soon, to capture in DNxHD.

[Simon Denny]

Do I need a Hyperdeck Shuttle to record HD-SDI uncompressed or can I use another device: Nano, Samurai etc...

[Shaun Roemich]

If you want to shoot UNCOMPRESSED, I believe the HyperDeck is the only (reasonably) portable/affordable game in town.

If you want to shoot a less compressed digital intermediate file (ProRes or DNxHD) from an uncompressed HD-SDI source, you have options.

[Simon Denny]

Thanks Shaun.

Cheers

[Svein Rune Skilnand]

Simon.

If I read your post correctly, it seems you are looking to record to a less compressed format than XDCam EX. Have you looked at the Atomos Samura? It records to Pro Res, which can be set to different bitrates. Pro Res LT for instance is around 100mbps and should be sufficient in most cases.

My Samurai came with a D- Tap adaptor enabling me to power the unit directly from V- Lock batteries like Swit or the D-Tap output from the HM750.

I believe this would be a good solution as the Samurai uses SSD and should cause no problems running around. The stock Canon 14X lens has it problems with CA, unfortunately. Good lighting may compensate for some of it.

[Simon Denny]

Hi Svein, yes the Atomos Samura is a product that I have been looking at and might work. The CA on the Canon is very bad but i could live with this as the production is basic.
Cheers