- Joined
- Feb 3, 2015
- Messages
- 1,882
- Reaction score
- 734
X5 only 60mbps is this a big issue?
- Thread starter tdwragg
- Start date
That's the photos, we're talking of video here
Yes, and the files Romeo Durscher provided are not very useful to evaluate DR, as they are shot underexposed and into the sun, so shadows show very noisy. Tried to process in LR CC 2015 and was disappointed in the latitude of the files.
I've provided the feedback on bitrate to Eric Cheng @ DJI and he acknowledged it and was thankful for the feedback.
He did suggest we should probably reserve judgement until we see the actual results of the production X5 units, as we've been here before with the X3 "shaky gimbal" issue prior to I1 launch etc.
I think that's fair to ask.
Hopefully the feedback will be heard and possibly result in a FW update to bitrate. I think the X5 / R can be real game changers.
He did suggest we should probably reserve judgement until we see the actual results of the production X5 units, as we've been here before with the X3 "shaky gimbal" issue prior to I1 launch etc.
I think that's fair to ask.
Hopefully the feedback will be heard and possibly result in a FW update to bitrate. I think the X5 / R can be real game changers.
- Joined
- Aug 26, 2013
- Messages
- 840
- Reaction score
- 368
All very true but.....the C100 doesn't pretend to be a 4k camera (which of course it isn't) and the frame rate tops out at 30fps/60i. If we start shooting interlaced we are going to lose 30% horizontal resolution due to the Kell factor and nobody wants that with aerial footage
Like you, I want to see untouched files straight out of the X5 where I can examine them properly locked away in my man cave before I make any sort of credit card type decision.
I'm speaking of the C100 mk2, which shoots 60p at 35 mbps. Yes the image falls off when pushed too hard in color grading, but it is a much better image than a 5D or forum favorite reference-camera GH4.
- Joined
- Feb 8, 2015
- Messages
- 202
- Reaction score
- 124
- Age
- 47
- Location
- Sussex, England
- Website
- www.visualair.co.uk
There is a comprehensive review of current microsd cards and actual speed tests. The Sandisk extreme pro can write around 85MB/s and is one of the fastest cards.
Amazon
I ordered the X5. I hope the video quality will be a significant improvement over X3, and for 4 times the price of X3 it should be. The bigger sensor is going to help a lot.
Last edited:
Only at 1080 resolution, and these days 35Mbps is pretty low with most cameras of that level now offering 50Mbps 422 at 1080 resolutions. Now of course 4K is here and needs even higher bitrates.
Found a list of 4k bitrates. 60Mbps look way too low. As a matter of fact, even the Sony Action cam does 100Mbps for 4K.
Sports Camera | 4K Action Cam x1000v | Sony US
The X5 may have much better quality than X3 -- I surely hope so because I already ordered it -- but I think the low bitrate will be a point of contention for a lot of people. I would like to see DJI improve the bitrate -- preferably via a firmware update -- on the X5 as soon as possible. That would make the difference of being (barely) acceptable and being great considering the "Pro" moniker associated with the X5. Nobody would consider the Sony Action Cam as a "pro" camera and it does higher bitrate than X5 for 1/5 the cost. There is something very wrong with that.
Sports Camera | 4K Action Cam x1000v | Sony US
The X5 may have much better quality than X3 -- I surely hope so because I already ordered it -- but I think the low bitrate will be a point of contention for a lot of people. I would like to see DJI improve the bitrate -- preferably via a firmware update -- on the X5 as soon as possible. That would make the difference of being (barely) acceptable and being great considering the "Pro" moniker associated with the X5. Nobody would consider the Sony Action Cam as a "pro" camera and it does higher bitrate than X5 for 1/5 the cost. There is something very wrong with that.
- Joined
- Aug 26, 2013
- Messages
- 840
- Reaction score
- 368
Of course, I'm all for a higher bitrate. My point is just that bitrate is not everything and I would rather have a large sensor with a lower bitrate than a small sensor with a high bitrate.
Ultimately we'll have to wait and see!
Yeah, while I have no doubt it will look better...that is relative. When I have a client that says to me, "yeah, I wish the footage looked better, how can we make that happen?" and I say "it'll cost $2,300" (need that $99 vibration plate too right?!), and they say "Okay, I'll cover that!" then I'll say "you got it", X5 here I come! As a pro videographer I've never once had a client ask me for a better camera, or that's not good enough. Sure they may see a difference between a gh4 and HMC150 if its side by side, but in the end 99.9% of the time the x3 will be plenty good enough. Anyone wanting the x5 either has specific requirements that make it worth it, or just have the money and want the best image they can get even though it most likely won't be appreciated by anyone other than them or forum members!
A 4K equivalent bitrate to the 1080P @ 35Mb that the C100 Mark II shoots is 140Mb. UHD is twice the horizontal AND vertical resolution of 1080P, so it's four times as much data as 1080P.
For what it's worth the C100 Mark II only gets 35Mb when it's doing 1080P at 60fps. For 24 or 30fps, it records at 28Mb in AVCHD... which looks great... but you'd need 112Mb to get the same compression level at UHD/4K.
Going the other direction, 60Mb @ 4K is the 1080P equivalent of 15Mb. My old FS100 could record 17Mb 1080P in "FH" mode and I can tell you from experience with stuff shot that way that it was SIGNIFICANTLY degraded vs. stuff that was shot at 28Mb.
It's the same reason ProTune GoPro footage is terrible to grade vs. ProRes 422 out of a Ninja Star. A LOT of data is thrown away (especially dynamic range data) when you compress things heavily.
There's a reason you're FAR better off shooting 2.7K on your GoPro unless you need the 4K pixels for some reason. 60Mb is just simply too low for great-quality UHD much less DCI 4K.
For what it's worth the C100 Mark II only gets 35Mb when it's doing 1080P at 60fps. For 24 or 30fps, it records at 28Mb in AVCHD... which looks great... but you'd need 112Mb to get the same compression level at UHD/4K.
Going the other direction, 60Mb @ 4K is the 1080P equivalent of 15Mb. My old FS100 could record 17Mb 1080P in "FH" mode and I can tell you from experience with stuff shot that way that it was SIGNIFICANTLY degraded vs. stuff that was shot at 28Mb.
It's the same reason ProTune GoPro footage is terrible to grade vs. ProRes 422 out of a Ninja Star. A LOT of data is thrown away (especially dynamic range data) when you compress things heavily.
There's a reason you're FAR better off shooting 2.7K on your GoPro unless you need the 4K pixels for some reason. 60Mb is just simply too low for great-quality UHD much less DCI 4K.
- Joined
- Aug 26, 2013
- Messages
- 840
- Reaction score
- 368
Well 1080p60 @ 35 mbps would be equivalent to 4k30 at 70 mbps, according to your logic.
Practically speaking, who cares on numbers that are that close... I mean we all want the least compressed image possible, but if for some miraculous reason DJI released another version that was smack dab in between (let's say ProRes 422 at 145 mbps), I doubt many pros would notice much of a difference when presented with the two files side by side. When we go to push them in colour grading, that's when we'll run into issues, but I would argue the lack of bit depth (8-bit) will provide more problems than the bitrate.
I'd pony up for the recorder if it used commercially available memory (i.e. SD cards) and recorded ProRes 422 a la Atomos Ninja Blade. 1.7 gbps on a 4/3 sensor is overkill and necessitates an expensive and of course, proprietary 512 GB SSD and recorder. Probably why I won't be purchasing the 'R', and instead hoping for a firmware update unlocking some better bitrates and bit-depth on the basic version (which will probably never happen).
All I really care about is the 1080p video quality. By the time we are up with 4K from the post-production side of things (and our clients begin actually asking for 4K finals), there will undoubtedly be another, better camera on the market.
My original numbers are correct:
1920x1080 = 2,073,600 pixels for each frame
3840x2160 = 8,294,400 pixels for each frame
8,294,400 / 2,073,600 = 4
A UHD frame is essentially FOUR 1080P frames in a 2x2 grid.
UHD video takes FOUR TIMES as much data space per frame as 1080p so to get equivalent compression rates at UHD resolution, you need a bitrate four times higher than the equivalent at 1080P.
As for the rest... ProRes is a pretty poor acquisition codec all things considered. It's popular because the encoder chips are out there and it's quick to edit, but it's very inefficient when it comes to card space (ProRes 422 HQ @ UHD is 880Mb/s) compared to some of the more advanced inter-frame codecs like XAVC or higher-bitrate AVC/H.264 in an MP4 wrapper.
ProRes was (and is) intended as an EDITING codec. It's intraframe, so it plays nice in the NLE. I transcode pretty much all my H.264 stuff to ProRes as part of my ingest workflow because it makes the NLE run smoother.
The Ninja Blade doesn't use SD cards... it uses 2.5" laptop SSDs (I have one sitting on my desk right now). Recording 4K ProRes would require a guaranteed card write throughput in the 75MB/s range, which is do-able but only with the fastest SD available... and even then, that's getting pretty close to the 90MB/s max these cards are promising. That's why the high-end world is moving past SD to CFast and XQD (and SSD).
Last edited:
There is also a framerate difference, 4K @ 30 fps vs 1080p @ 60 fps. Gruvpix's calculation took that into the consideration.
Fair enough. But to compare image quality throwing in 60fps is just confusing the issue (because of the way H.264 compresses video, a higher frame rate doesn't hit your compression nearly as much as more pixels do. 35Mb/s 1080p60 from the C100 Mark II is roughly equivalent to 28Mb/s 1080p30... which is equivalent to 112Mb/s in UHD.
To explain it at a VERY high level: H.264 is an interframe codec... so if those frames are spaced tighter (higher framerate) each individual frame will have fewer pixels change. Interframe codecs only record the changes from frame to frame (between keyframes anyway), so there's less to record for each of those frames.
In any case, the point is at the same frame rate, 60Mb UHD is equivalent to 15Mb 1080P which is an insanely high compression ratio.
And for what it's worth, I too hope for a firmware update that has a higher bitrate for the X5. That camera at even 100Mb would be a must-buy for me... as it is now, I'm hoping for a miracle but guessing that the footage from the X5 vs. X3 isn't going to be revolutionary.
- Joined
- Aug 26, 2013
- Messages
- 840
- Reaction score
- 368
Absolutely, and yes I was taking frame rate into account.
Again, I'm probably in the minority here but I really don't care about 4k, thus why a ninja blade-like recorder would be handy. You are right SD cards recording prores or dnxhd is too much to ask, but a cfast would not be outside the realm of possibility.
I'd love nothing better than an X5 that recoded 200Mb H.264/MP4 to MicroSD.
I see what DJI was aiming for... they want the "good, better, best" three-segment product line that companies like Apple have used to great effect. The point is, very few need the high end and no one wants to think they bought the cheapest one, so most of the buyers end up in the middle even if they didn't need more than the low end.
The problem with that strategy as executed here is they've essentially created "good, good, best" by handicapping the middle camera with an incredibly low bitrate. There are two possibilities for why this happened... either DJI is trying to sell more of the X5Rs than they would if they had a more capable X5 or (more likely) there isn't a lot of video expertise on-staff at DJI and they figured "if it's good enough for the X3 and GoPro, it's fine."
I would have paid good money to upgrade my X3 to 100Mb before I'd want a bigger sensor and a swappable lens. The sensor in the X3 is capable of a LOT more than DJI (or GoPro) are getting out of it.
I'd have even paid the $2300 asking price if the X5 was Sony's 1" EXMOR (from the RX100 III and IV, RX10, etc.) with a 100Mb bitrate and fixed lens (with adjustable aperture).
100Mb 4K isn't exactly a huge stretch in a tiny camera... I think one of the Sony Action Cams even does it.
But the X5 as it sits is a whiff for me (and every other video-centric person I've talked to). We're all holding out hope they've done something miraculous with 60Mb, but we know what 60Mb 4K looks like (and grades like) and it ain't pretty.
I see what DJI was aiming for... they want the "good, better, best" three-segment product line that companies like Apple have used to great effect. The point is, very few need the high end and no one wants to think they bought the cheapest one, so most of the buyers end up in the middle even if they didn't need more than the low end.
The problem with that strategy as executed here is they've essentially created "good, good, best" by handicapping the middle camera with an incredibly low bitrate. There are two possibilities for why this happened... either DJI is trying to sell more of the X5Rs than they would if they had a more capable X5 or (more likely) there isn't a lot of video expertise on-staff at DJI and they figured "if it's good enough for the X3 and GoPro, it's fine."
I would have paid good money to upgrade my X3 to 100Mb before I'd want a bigger sensor and a swappable lens. The sensor in the X3 is capable of a LOT more than DJI (or GoPro) are getting out of it.
I'd have even paid the $2300 asking price if the X5 was Sony's 1" EXMOR (from the RX100 III and IV, RX10, etc.) with a 100Mb bitrate and fixed lens (with adjustable aperture).
100Mb 4K isn't exactly a huge stretch in a tiny camera... I think one of the Sony Action Cams even does it.
But the X5 as it sits is a whiff for me (and every other video-centric person I've talked to). We're all holding out hope they've done something miraculous with 60Mb, but we know what 60Mb 4K looks like (and grades like) and it ain't pretty.
