Blackmagic Forum

Hi.

I know it's probably not the right forum to ask. But I thought i can find someone here who might tested the GH5 in comparison to the blackmagic pocket.

I have the blackmagic pocket for quite a while now and a friend of mine is considering getting the GH5 or blackmagic.
So we both had a look at the GH5 footage we could find online.
But we still couldn`t figure out if the GH5 can record 100% lossless compressed or uncompressed.

So we had a closer look at this footage:
(http://www.4kshooters.net/2017/01/13/do ... s-footage/)

The quality looks great, but when we had a closer look we could see quite a few artefacts...(waterfall is probably a good example)
So in fact, the blackmagic pocket gave us a much nicer cleaner result.

Does anyone know if that is just because this footage is already compressed, or is it the maximum quality you can get from the GH5?

If anyone know where to get uncompressed samplefootage for the GH5, i would be really interested to see

Thank you very much in advance
Jan

It's all compressed and far from mathematically lossless, but still decent quality.
If you want better source quality you need to use external recorder with GH5 over HDMI (record ProRes or DNxHR etc).

Neither camera records internally lossless or uncompressed, though the GH5 claims external is uncompressed. The BMPCC records in Prores HQ and raw, using intraframe compression. The GH5 records with either long gop interframe compression format, or intraframe like BMPCC. In my view, there is no point recording GH5 footage to an external source, given the limitations of the sensor.

Assuming the GH5 is set to use its intraframe codec, obvious differences in perceivable compression are unlikely, although you're far more likely to encounter moire with the BMPCC. But that's a different issue.

This 400Mbit I frame mode is not much better if at all than long GOP modes.
I frame option needs few times higher bitrate to compensate for lack of inter frames.

If someone wants the best of out GH5 external recorder still gives advantage.

Show me the advantage and I'll believe it. You'll never see it, with this camera.

If there is no "real world" difference then this is fine.
There will be "technical" (less compression- ProRes HQ is about 1000Mbit for UHD 30p) difference, but we know this is quite often meaningless in real world.

John Paines wrote:Neither camera records internally lossless or uncompressed, though the GH5 claims external is uncompressed. The BMPCC records in Prores HQ and raw, using intraframe compression. The GH5 records with either long gop interframe compression format, or intraframe like BMPCC. In my view, there is no point recording GH5 footage to an external source, given the limitations of the sensor.

Assuming the GH5 is set to use its intraframe codec, obvious differences in perceivable compression are unlikely, although you're far more likely to encounter moire with the BMPCC. But that's a different issue.

Could you explain " limitations of this sensor " I have the GH5 and like it very much and am considering getting the Atomos Ninja Inferno for one main reason to record UHD 60P in 10 bit not possible internally and thereby get a better file for editing. I can then record in VlogL or HLG at this frame rate. For information I have no interest in recording slow frame rates as I like the smooth motion of 60P.

Hmm interesting. That all gets quite technical to me and i might be wrong. But isn't the cinemaDNG format lossless? I mean it's compressed but just the filesize. The image quality should still keep uncompressed. So bit like a zip file, just that its unzipping when you play the clip.
That`s how i understood it at least...while recording in ProRes you will have at least a small amount of image compression.

I know that means probably looking for the details with a magnifier. And the image quality of the GH5 is great. I just try to understand, and when it comes to post-processing like keying, the image can`t be clean enough and the smallest artefacts can cause you trouble )

DNG from some BM cameras can be mathematically lossless (or not). More important is fact that BM cameras give you ability to record RAW. This is very different to already debayered/processed video.
RAW is "raw" data from the sensor (just stored as DNG files), so this is the best you can get from any camera.
Typical RAW recording is reserved for higher-end and expensive cameras.

SkierEvans wrote:

John Paines wrote:Neither camera records internally lossless or uncompressed, though the GH5 claims external is uncompressed. The BMPCC records in Prores HQ and raw, using intraframe compression. The GH5 records with either long gop interframe compression format, or intraframe like BMPCC. In my view, there is no point recording GH5 footage to an external source, given the limitations of the sensor.

Assuming the GH5 is set to use its intraframe codec, obvious differences in perceivable compression are unlikely, although you're far more likely to encounter moire with the BMPCC. But that's a different issue.

Could you explain " limitations of this sensor " I have the GH5 and like it very much and am considering getting the Atomos Ninja Inferno for one main reason to record UHD 60P in 10 bit not possible internally and thereby get a better file for editing. I can then record in VlogL or HLG at this frame rate. For information I have no interest in recording slow frame rates as I like the smooth motion of 60P.

Regardless of sensor "limitations" (GH5 sensor is decent) recording format is a 2nd and separate matter. You always want it as low compressed as possible or the best RAW. Definitely it's not fully pointless to record externally as there are modes which are not even 10bit internally (regardless how heavily they are compressed).
Ideally I would like to have RAW from GH5 to external recorder.
If you know that ProRes recording gives not enough advantage over internal recording then fair enough.

We have several GH5 cameras. Much of the time, the compressed format is great to work with. Sometimes, when the project is more critical or we want the 10-bit sampling for a chroma key, we use external recorders, in ProRes444. The Hyperdeck or video assist would probably do this fine. But we use Atomos Shogun Inferno with our GH5s. They play very well together.

Scott Smith wrote: Sometimes, when the project is more critical or we want the 10-bit sampling for a chroma key, we use external recorders, in ProRes444.

why ProRes 444? The GH5 HDMI out is only 10 bit 4:2:2 maximum!

Yep, you just wasting space. 444 is also same compression ratio as HQ, so there is 0 gain. ProRes XQ would make some sense for even lower compression ratio, but 444 is useless in this case.

My bad. You are correct, and we do record in ProRes422.