GH4 GH4 x BMD Video Assist

G

Graeme Meiklejohn

Member
Hey Everyone,
So I just got a BMD Video Assist to use as a monitor/recorder with my GH4 and Helix Jr. From everything I have read online the biggest gripe seems to be lack of HDMI REC trigger. After I got mine I updated to the firmware 1.1 and fired it up and REC trigger is working smoothly in both 4K downverted and 1080 60p in all Pro Res flavours. The bang for you buck with this new firmware update is absolutely outstanding in my eyes.
My GH4 setting:
Bit Mode : 4:2:2 10Bit
4K Downconvert- 1080p (auto seems to work also)
1080/30p set- 30p

Video Assist setting:
Trigger Rec- T/C Run
Source HDMI
Prores HQ (Or any seem to work)
 
Graeme Meiklejohn said:
Hey Everyone,
So I just got a BMD Video Assist to use as a monitor/recorder with my GH4 and Helix Jr. From everything I have read online the biggest gripe seems to be lack of HDMI REC trigger. After I got mine I updated to the firmware 1.1 and fired it up and REC trigger is working smoothly in both 4K downverted and 1080 60p in all Pro Res flavours. The bang for you buck with this new firmware update is absolutely outstanding in my eyes.
My GH4 setting:
Bit Mode : 4:2:2 10Bit
4K Downconvert- 1080p (auto seems to work also)
1080/30p set- 30p

Video Assist setting:
Trigger Rec- T/C Run
Source HDMI
Prores HQ (Or any seem to work)
Click to expand...

can you post a link to some footage captured with the pair?
 
To show the REC trigger functioning or to show some of the 10-bit Pros res in the two different capture formats? I may have some time tomorrow to grab a few shots but I am still working on what I want to do for power solution as finding a 2-pin Lemo from the helix to standard 12v is proving difficult.
 
I'm unable to use the Video Assist on my GH4 in PAL mode. Any ideas how I achieve this? New VA firmware shows NTSC in the top left, but I'm unable to change it. Worrying.
 
Have spoken with the UK Blackmagic technicial support. The Video Assist seems to be incompatible with the GH4 in PAL mode at the moment. I'm gutted about this and hope it gets looked into.
 
Dan Keeble said:
Have spoken with the UK Blackmagic technicial support. The Video Assist seems to be incompatible with the GH4 in PAL mode at the moment. I'm gutted about this and hope it gets looked into.
Click to expand...
That really sucks, I think it is a fantastic unit for 1080p delivery. Hopefully they can figure it out for you.
And to @RedChalice I'll see what I can do
 
Uh, so I can set my GH4 to 4K and downsample inside the BMD Assist? I know I won't be able to record internally at the same time if using 10bit but the live downsample seems like it make the 1080p inside the BMD Assist look amazing. Would it work to set the camera to 8bit 422 (hey, 8bit 422 is still better than 8bit 420) to be able to get internal 4K at the same time?
 
Graeme Meiklejohn said:
Hey Everyone,
So I just got a BMD Video Assist to use as a monitor/recorder with my GH4 and Helix Jr. From everything I have read online the biggest gripe seems to be lack of HDMI REC trigger. After I got mine I updated to the firmware 1.1 and fired it up and REC trigger is working smoothly in both 4K downverted and 1080 60p in all Pro Res flavours. The bang for you buck with this new firmware update is absolutely outstanding in my eyes.
My GH4 setting:
Bit Mode : 4:2:2 10Bit
4K Downconvert- 1080p (auto seems to work also)
1080/30p set- 30p

Video Assist setting:
Trigger Rec- T/C Run
Source HDMI
Prores HQ (Or any seem to work)
Click to expand...

Can you upload a few clips?
 
David Del Real said:
Uh, so I can set my GH4 to 4K and downsample inside the BMD Assist? I know I won't be able to record internally at the same time if using 10bit but the live downsample seems like it make the 1080p inside the BMD Assist look amazing. Would it work to set the camera to 8bit 422 (hey, 8bit 422 is still better than 8bit 420) to be able to get internal 4K at the same time?
Click to expand...

The VA only down samples from SDI, so no, you have to set the GH4 to down sample its output.
 
David Del Real said:
Uh, so I can set my GH4 to 4K and downsample inside the BMD Assist? I know I won't be able to record internally at the same time if using 10bit but the live downsample seems like it make the 1080p inside the BMD Assist look amazing. Would it work to set the camera to 8bit 422 (hey, 8bit 422 is still better than 8bit 420) to be able to get internal 4K at the same time?
Click to expand...

The Video Assist has a 4K to HD downsampling ability but only from the SDI input, the HDMI input only takes HD.

Luckily, the GH4 itself has that ability to downsample 4K to HD before sending to HDMI.

You can use the YAGH HDSDI output 4K 10bit 4:2:2 and have the VA downsample that to HD,

And you can get an external dedicated downscaler (cheap) that takes the 4K HDMI output and send it downscaled to the VA in HD.

Many options and we still need to know how they look and differ. Going for the highest end option of the YAGH might make a huge image difference and might look similar to the internally recorded 4K downsampled in-post.

Needs testing.

It's a shame the VA HDMI doesn't downsample 4K as this is what I expected, it would have been the device that gives the ability to take advantage of all those 4K HDMI cameras (A7s, NX1, A7rII, GH4, AX100, FS5, FS7, etc) without the enormous cost of 4K recorders (Shogun, Q7+)
 
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