Bit Rate HD/4K
2679 10 2017-6-29
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D-DWL
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I'm doing some work for Channel 5 (well, a production comany making a documentary for Channel 5) and they are interogating the output options of the Zenmuse X5. They have suggested that the quality of the video files will be better if shot in HD rather than 4K. This is what they said:-

"The  X5 can only record QTs (rather than RAW or ProRes). Both 4K and HD  shoot at 60 Mbits files. Normal cameras would increase the bit rate to  accommodate the bigger resolution.  This recorder does not, therefore in our post experience you are losing  a lot of detail and producing more artefacts when recording 4K."

Is this statement correct? I'd prefer to shoot in 4k as it gives me options to crop/rotate etc.

2017-6-29
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Insieme Agency
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Record in 4K because maybe the bitrate is the same BUT the image quality is NOT!
2017-6-29
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D-DWL
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Insieme Agency Posted at 2017-6-29 08:08
Record in 4K because maybe the bitrate is the same BUT the image quality is NOT!

Cheers, I was also told JPEG artefacts would be more visible at 4K, any opinions on that?
2017-6-30
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dancopter
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I have heard that tv companies are happy with 1080p. Plenty for broadcast. 4K is apparently overkill.
2017-6-30
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dancopter
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Insieme Agency Posted at 2017-6-29 08:08
Record in 4K because maybe the bitrate is the same BUT the image quality is NOT!

The customer is always right.
2017-6-30
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DroneAlps
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"Both 4K and HD  shoot at 60 Mbits files"
This is incorrect. HD (1080P) is 25 Mbits and 4K is 60 Mbits. Shoot in 4K to maximise bitrate. It makes a small, but noticeable difference. However, if the TV company demand HD then just bow down to them and forget about it.

http://www.dji.com/zenmuse-x5/info#specs
60Mbps@4096x2160(23.98p)
60Mbps@3840x2160(29.97/23.98p)
45Mbps@2704x1520(30/25p)
40Mbps@1920x1080(59.94p)
25Mbps@1920x1080(29.97p)

2017-7-1
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AEROKAMERA
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Hi,
Notice 1080p50 ~40Mb/s and 1080p25 ~25Mb/s => @4Kp25 should be ~100Mb/s or better.
They are right because probably broadcasts in 1080 format. Converting 4K to HD is time-consuming and result is not satisfied because of processing h.264 codec (decompressing, scaling and compressing).
Beleve me I tested it. 60Mb/s @4K is insufficient for further processing, pro camcorders uses >100Mb/s and better codecs.
2017-7-1
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D-DWL
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DroneAlps Posted at 2017-7-1 01:15
"Both 4K and HD  shoot at 60 Mbits files"
This is incorrect. HD (1080P) is 25 Mbits and 4K is 60 Mbits. Shoot in 4K to maximise bitrate. It makes a small, but noticeable different. However, if the TV company demand HD then just bow down to them and forget about it.

You're correct. Just checked the .MOV details and it confirms what you say
2017-7-2
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DroneAlps
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AEROKAMERA Posted at 2017-7-1 01:44
Hi,
Notice 1080p50 ~40Mb/s and 1080p25 ~25Mb/s => @4Kp25 should be ~100Mb/s or better.
They are right because probably broadcasts in 1080 format. Converting 4K to HD is time-consuming and result is not satisfied because of processing h.264 codec (decompressing, scaling and compressing).

Yes but they will have to grade the footage whatever you shoot it in, so then 4K @ 60Mb is better than HD @ 25 Mb no?
2017-7-3
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D-DWL
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DroneAlps Posted at 2017-7-3 10:00
Yes but they will have to grade the footage whatever you shoot it in, so then 4K @ 60Mb is better than HD @ 25 Mb no?

I would have thought so. I don't think the production company really know what they're talking about!!
2017-7-3
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AEROKAMERA
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D-DWL Posted at 2017-7-3 23:42
I would have thought so. I don't think the production company really know what they're talking about!!

Did you do tests? My experinces are different.
4k@60Mb looks great if you watch it in 4k on your monitor.
If downconvert it to HD or SD looks worse then 1080@40Mb without converting.
2017-7-5
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