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Author Topic: 8-bit Video in a 10-bit Wrapper  (Read 27882 times)

JB Rasor

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8-bit Video in a 10-bit Wrapper
« on: April 11, 2014, 01:52:55 AM »

With the Sony A7s vs. Panasonic GH4 debate gearing up, I wanted to get some guidance from the members about a particular quirk...oversight, or however you'd like to phrase it, with regards to the A7s.
I am pretty new to the video world, so forgive my basic inquiry, but I've searched the hell out of this question and can't seem to get a solid answer.

The A7s outputs an 8-bit 4:2:2 signal (hoping this is the correct terminology) via mHDMI. Ideally one would be running the new Atomos Shogun recorder, which records in either 10-bit 4:2:2 ProRes or Cinema DNG raw. So what flexibility or advantage have you gained by recording in a 10-bit 4:2:2 codec, but only outputting 8-bit from the camera? Essentially 8-bit video in a 10-bit wrapper.   

Is it like it was natively recorded at that bit rate? No difference at all?

I know the details of the process are pretty technical, but hell, it's a photography forum so bring it on :)

Thanks everyone for your help. Have a great weekend!!

JB
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Sareesh Sudhakaran

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #1 on: April 11, 2014, 08:11:30 AM »

The A7s outputs an 8-bit 4:2:2 signal (hoping this is the correct terminology) via mHDMI. Ideally one would be running the new Atomos Shogun recorder, which records in either 10-bit 4:2:2 ProRes or Cinema DNG raw. So what flexibility or advantage have you gained by recording in a 10-bit 4:2:2 codec, but only outputting 8-bit from the camera? Essentially 8-bit video in a 10-bit wrapper.   


None whatsover. The same applies to a camera that records to 4:2:0 internally but sends out a 4:2:2 signal.
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michael

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #2 on: April 11, 2014, 08:27:51 AM »

The advantage that you gain is indirect. It's like loading a 12 or 14 bit stills image into a 16 bit workspace. You aren't increasing the bit depth, but you are enclosing it in a larger container. This has some (small) advantages when it come to grading as the data is not constrained by the boundaries of a smaller space.

Michael


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JB Rasor

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #3 on: April 11, 2014, 05:48:09 PM »

Thanks guys. With the rumored price tag of the Sony A7s I think my descision got a lot easier. I love the capability of the GH4 but I've never used M43'rds before and was a little nervous about getting into it head on. But that may just be my move.

JB
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JB Rasor

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #4 on: April 17, 2014, 02:39:43 PM »

I have a question Michael...and other members into video tech as well.
The Atomos Shogun records Cinema DNG raw. Does the camera also need to be able to shoot raw video, in order to record Cinema DNG to the Atomos, or can you record raw data from any camera onto the Atomos? I'm assuming the former is the case but I wasn't sure.


  
« Last Edit: April 17, 2014, 02:42:37 PM by JB Rasor »
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michael

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #5 on: April 17, 2014, 04:00:43 PM »

I have a question Michael...and other members into video tech as well.
The Atomos Shogun records Cinema DNG raw. Does the camera also need to be able to shoot raw video, in order to record Cinema DNG to the Atomos, or can you record raw data from any camera onto the Atomos? I'm assuming the former is the case but I wasn't sure.


No, the camera itself has to output raw. The Panasonic GH4, for example, can output 10 bit 4:2:2:, which is still photography terms is like outputting a 14 bit TIFF. Tons of detail, little lost, but still not raw.

Funny thing is, many people with raw capable video cameras are using them with Prores, because raw video workflow is still a bit of a horror.

Michael
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JB Rasor

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #6 on: April 18, 2014, 12:08:37 AM »

Thanks Michael! That was what I thought but wasn't entirely certain. I guess the storage issues associated with raw are tough.

Unfortunately the 10-bit 4:2:2 output of the GH4 can only be recorded externally. But that's part of the trade off. Still a great camera by all accounts.

Thanks again,
JB
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paul ross jones

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #7 on: July 06, 2014, 05:24:17 AM »

The advantage that you gain is indirect. It's like loading a 12 or 14 bit stills image into a 16 bit workspace. You aren't increasing the bit depth, but you are enclosing it in a larger container. This has some (small) advantages when it come to grading as the data is not constrained by the boundaries of a smaller space.

Michael




i have been able to grade heavier when hit with a grading problem with a 8 bit tiff when i convert it to 16 bit (like banded sky). a retoucher told me he thinks that photoshop makes up gradients to fill the bit depth, not sure if it does, but it does work. obviously not nearly as well as working off a native 16 bit tiff.

paul
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bcooter

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #8 on: July 11, 2014, 01:30:06 PM »

Raw or baked in, I guess it depends on the project.

Me . . . I want our dailies to have the closest look possible to finish and I love it when we have to produce dailies and proxy's from the RED vs. any baked in look.

The RED's with the Red Rocket and the newest cinex make a great workflow for us, using Cinex or Resolve to set a file, copy the look, paste it onto a bunch of files and let it rip.

But I love Resolve, especially with the Rocket card because it runs real time or faster.  

I did this in Resolve, from dailies to proxy's to finish (minus the flash which was in the NLE) and the client didn't have to make a leap and ask what is it going to look like.



For file size, well, all files today are big, though nothing is larger than 442 pro ress as in 2k it's almost as big (may be larger) than a RED 4k raw file.

I think a lot of people fail to recognize that everyone works differently, everyone rolls their own in workflow and style.

Red catches a lot of heat . . .  some they deserve, most the don't, but their business model allowed me to buy three real cinema cameras for less price than one Arri and btw I think Arri makes a very nice camera.

IMO

BC

PS.  Speaking of large file sizes I had a European ad agency request a long clip in uncompressed proress, the file was huge even in 2k, and we have fast load times in our London space and it still took 12 hours for it to go up probably about 4 to 5 hours to download, which was funny because the final video they edited was for mobile only.
« Last Edit: July 11, 2014, 01:33:30 PM by bcooter »
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adrjork

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #9 on: October 05, 2015, 10:47:10 PM »

[JB Rasor: So what flexibility or advantage have you gained by recording in a 10-bit 4:2:2 codec, but only outputting 8-bit from the camera? Essentially 8-bit video in a 10-bit wrapper.]
None whatsover. The same applies to a camera that records to 4:2:0 internally but sends out a 4:2:2 signal.
I know this is an old topic, but it's perfect for my doubts: if I understand correctly, the 10bit 4:2:2 HDMI output from GH4 is not a native 10bit 4:2:2, but a 8bit 4:2:0 in a 10bit 4:2:2 wrapper? Is it so?
If that's right, that means that the only 2 benefits of recording with Atomos are:
1. more bitrate (less artifacts)
2. slightly easier to grade in post (8bit in a 10bit wrapper)
But if I'm right, well... when FCPX trascodes the footage in HQ Proress during import, it does - more or less - the same thing! (With the difference that FCPX re-encodes a file, while Atomos records directly. Actually a little difference in comparison with 2000$ for an external recorder!!!)
Please, give me an answer guys. Thanks 
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fredjeang2

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #10 on: October 06, 2015, 05:10:06 AM »

What is lost in capture is lost forever.
Regardless of how many gazillion of bits or color sample it is
Wrapped later.

This is the reason why I don't get the entusiasm
I often read in this forum on the GH line, when
There is BM who brings with the same mount,
At about the same price and small factor, raw video and
Prores HQ.
Actually, my BM rigged with a metal shell is still smaller
Than a GH and files are from another league when it
Comes to post-prod.
With the GH it was constantly a dilemma  with artifacts
If you didn't nail it in capture. Specially working with
Minimalist imagery.

I remember that we did some testings with Rainer in
Octocopter and the sky was banding like hell in his
Files and same story with my footage in interiors with
White walls.

I know it is a photographer's forum and that the GH does
Picture still also. But so do the cell phones.

In motion, capture has to be recorded with
Maximum information otherwise post will NOT solve
The sins.
And even, you don"t have to make mistakes. In a perfectly
Exposed image, artifacts can happen according to the
Subject, plained colors  etc...without talking about
Green screen etc etc...

When we see in YouTube the endless video sagas like
The GH4 vs EPIC...and people "wao" the Panasonic because
It looks identical, what those videos aren't showing is
The post production area...
When things get nasty and when there is no room to
Play with.
Comparing a GH to Red or Arri like I saw many times
Is completely ridiculous, pointless, a complete scam.

So the little difference with the external recorder is
Actually a true advantage. Because it records more information from capture. Worth the extra cost?
No!
Not at all...because adding and adding extras you end
Buying a real camera, as Morgan pointed many times.
And that's the point of those DSLR cameras: they cost in the end the same or almost the same as much better devices.

But the illusion remains in the sense that as we do fragmentated purchases, it looks cheaper. But it's not.
And no way the performances of a GH4 with external recorder is going to match a Raw profesional camera.
Not even an Alexa setted to Prores only (wich is generaly what Arri owners shoot).

People will pay MORE FOR LESS buying those GH, Sony stuff 
because you'll change them every 2 years or so
when the next 5K illusion will be available
and to make them work well you need to invest at least the doble, ending with cableries, external devices everywhere,
and your Little camera soon occupates the space and weight of a R1 more or less.
Completly absurd, completly paradoxal but still...it Works for Panasonic and Sony. They know how to market those stuff.

Actually: no R1 or almost none are available on the used market. Why? Because people are still using them.
Make calculations...

Look, this morning I woke-up with a newsletter from
A prod company who was offering an Ursa kit, complete
In its pelican case, for less than5000 euros...
New. with:
1 BODY URSA BLACKMAGIC
1 URSA Shoulder Mount Kit
1 URSA VLock Battery Plate
1 card Cfast 64GB
1 tripod shoe
4 Batteries Vlock
1 Battery charger Sony BC-L100CE V-Lock Mount Broadcast
1 Pelican case for the al kit.

Replace the Ursa for one of those BM Little cameras and you have a less than 3000 euros kit
featuring a much better imagery with no hassles in post,
that you'll still shoot with it in 5 years.

And I'll even go further: I want to see the proofs that a 5000 euros cine lens delivers a much better image
on those devices than a 200 euros Panasonic pancake. I'm not even sure those equipment are capable
to record the subtle differences. I suspect that their sensors and-or electronics, codecs aren't powerfull enough to use the full potential of
profesional cine primes.
On the super16 sensor of the BM, the differences between a very expensive cine prime and a good vintage c-mount
are very difficult to picture and completly no-visible for any audience.
I even have some russian cinema lenses that if I did a blind test I doubt trained people will always picture wich is the expensive lens.
So I'd like to see real proofs that those cameras are indeed capable to record the full potential of profesional glasses...
If not, why people are mounting 5000 euros lenses on a 2000 rigged GH? I don't have the answer but I more than suspect something.


Thanks to Dave who cleared this concept in another thread. I copy-paste his words here: [i]"When it comes to grading, bit depth is more important, especially if you have to push the image around very much. Banding will rear its head pretty quickly with 8-bit video. 4:4:4 is more important for compositing, where software has to discern edges between colors. And it's important for subjects where fine color detail is important--like some fabrics or mosaics--where low-resolution color will actually blend adjacent colors into their average. No amount of grading will get those colors back"
[/i]


It seems to me much more important to have a recorded image that does not fall appart instead of 4K or 150000000000000000000000000000000 stops DR.
Ironicaly, I could grab a Bond image scan of 1 fotogram and to my enormous surprise, the footage stands still every LUT, every grade, no banding, nothing...and we are talking about an old film technology with almost no DR compared to now.
I same applied the exact same color corrections from an Hacked GH2 to 250mB/sec and it falled appart completly!! Choose your camp.

Hope this helps.

Gosh!! Have you seen this thread? 15000+ visitors.
« Last Edit: October 06, 2015, 09:25:18 AM by fredjeang2 »
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Morgan_Moore

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #11 on: October 06, 2015, 12:48:03 PM »

I think it is worth understanding the Gh4.

AFAIK the 10bit output is a 10bit output.

Ive recorded it (I have a yagh box and SDi pro res recorder)

It certainly feels a lot more flexible file than the onboard.

The 4k onboard is however sharper than gh 1080 and needs no wires or crap hanging off the camera

I would be very interested to see a GH4 and Ody do some recording..

S
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adrjork

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #12 on: October 06, 2015, 01:15:21 PM »

My first observation: I've seen a video in which Dave Dugdale recovers colors from an A7S' overexposed sky highlights (8bit). I've not yet seen a video (at 10 or even 12bit) in which someone tried to recover colors from noisy lowlights.
My second observation: could be possible that, after converting footage from 8bit to 10(or more)bit, a video grading software (like After Effects or Davinci or even FCPX) fill the bitdepth with gradients? like in paul ross jones example:
i have been able to grade heavier when hit with a grading problem with a 8 bit tiff when i convert it to 16 bit (like banded sky). a retoucher told me he thinks that photoshop makes up gradients to fill the bit depth, not sure if it does, but it does work. obviously not nearly as well as working off a native 16 bit tiff.

So, here my questions: is it better to grade an 8bit clear footage, or a 10bit noisy footage?

And about paul ross jones example: the difference between working on 10bit "native" fooage or on 8-to-10bit converted footage are so huge to justify an external recorder?

Thanks a lot
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eronald

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #13 on: October 06, 2015, 07:10:19 PM »

I think it is worth understanding the Gh4.

AFAIK the 10bit output is a 10bit output.

Ive recorded it (I have a yagh box and SDi pro res recorder)

It certainly feels a lot more flexible file than the onboard.

The 4k onboard is however sharper than gh 1080 and needs no wires or crap hanging off the camera

I would be very interested to see a GH4 and Ody do some recording..

S

I too believe the 10 bit external GH4 HDMI is *real*, and probably worth using if you can be bothered with an external recorder.

I tried going to a dealer and using an Odyssey, as I wanted one anyway as a focus aid, but setting it up proved a real hassle (we failed).  Your mileage may vary, if you're better than me with wires, software and menus, but people have reported that the connection is fragile, things need to be switched on every time in the right order.

There is now a Vlog codec released as an option for $99 for the GH4, and this might (or not) be a good reason to use an external recorder/monitor  especially if it can do LUTs. Also, GH4 video will kill just about any notebook (mine is an SSD MBP bought in Jan), but maybe ProRes from a recorder is more digestible.

I got the GH4 partly because it looks like a no-fuss cheap consumer compact, and allows me to be discrete, low key, while doing interviews, so I'm not complaining.

Edmund
« Last Edit: October 06, 2015, 07:17:41 PM by eronald »
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adrjork

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #14 on: October 06, 2015, 09:18:17 PM »

After seeing some GH4 owner's tests, it seems to me that V-LogL follows the "vocation" of the camera: to be a really smart camera under certain conditions. V-LogL seems simply to give no benefits in low light conditions. GH4 surely gives many advantages in terms of controls, touchscreen, focus, and some "pro" features like 10bit from HDMI and the new V-LogL, but all this smartness starts working when you have extra light, extra recorder, extra SpeedBooster, extra fast lenses, and anyway curfew after 4 p.m. (or extra noise reduction to add some extra softness)! Well, I love m43 smart philosophy, and I'd go for it (mainly for that tempting 10bit!) but I can't spend a lot of money (for all m43 system: cam + recorder + lenses...) fearing about shooting in the evening!

So my question remains: what is preferable, grading a clear 8bit or a noisy 10bit?

Ten bit, or not ten bit, that is the question:
Whether 'tis noisier an old kind of shutter
The things that allow advantageous AF tune,
Or to take Atomos and solve all troubles...
« Last Edit: October 06, 2015, 09:25:48 PM by adrjork »
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D Fuller

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #15 on: October 06, 2015, 09:29:17 PM »


So my question remains: what is preferable, grading a clear 8bit or a noisy 10bit?


I don't think you're asking the right question. I think the answer is: which ever of them is properly exposed.

And my guess would be that the noisy one is noisy because it is not properly exposed.
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adrjork

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #16 on: October 07, 2015, 05:59:41 AM »

Sorry but no, my question is different:
Let's say you are a color artist and delivery asks for a heavy color manipulation. You can choose one take between two similar to work with: the first is dark and noisy but at 10bit, the second is clear and clean but at 8bit. Which is preferable for you? Working with the first or the second?
(It's very important for me to get an idea about this.)
Thanks
« Last Edit: October 07, 2015, 06:03:01 AM by adrjork »
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bcooter

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #17 on: October 07, 2015, 09:48:51 AM »


(It's very important for me to get an idea about this.)
Thanks

Actually D fuller did answer your question, given the fact he or none of us have any visual reference to what you trying to shoot.

But if you want an answer, just rent.  A gh4 and one zoom lens is about $160 for the week, a good 10 bit recorder another $124 so for under $300 and shooting in the scenarios that are personal to you, you'll know.

Even resolve 12 is free (with limited functions).

Not to be hard, but in reality the gh4 is a good camera, will work to a little over 800 asa, 8 bit or 10 bit with that camera makes little difference.

$300 will answer a lot of questions.

If you don't want to light and work in very dim situations, then you'll need very fast lenses, or a different camera like the Sony A7SII, which is $3,000, or a $16,000 Canon C300II.

But once again, I have no idea what your trying to produce.

IMO

BC

« Last Edit: October 07, 2015, 12:26:44 PM by bcooter »
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adrjork

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #18 on: October 07, 2015, 01:57:33 PM »

Thanks for your answer.
Here were I live is not so easy to rent exactly that kind of devices.
As I said, my field of study orients me toward video-art. Video-art means all and nothing, but we can clumsily say all that kind of video installations you can find in a modern art gallery: from Nam June Paik to Bill Viola, Stan Brackhage, pixel art, generative video synthesis, 3D animation and so on. As I said: all and nothing. What do I plan to do? Well, I'm going to start on two fronts: on one side SHARUNAS_BARTAS' style, and on the other side TACHIGUISHI-RETSUDEN's style, so natural-light hieratic documentary language on one hand, and stills-based animation and compositing on the other hand. So I need a camera for stills and video: stills for animation and compositing, and video for natural-light-docu style.
Said this, both kinds of file will require a lot of post: cropping/filtering/keying/rotoscoping for stills, and grading for videos.
As you can see, both stills and videos require ideally as many bits as possible... in a reasonable compromise, of course!
Reasonable compromise - for me - means working in a practical way, so the least rigging as possible (as I'm a one-man-crew).
What is my ideal camera? A practical little cam that can do big stills (to crop in post), can handle natural-light without problems, can do videos with good bits for grading. Simply it doesn't exist. But compromises do exist. I'm only trying to understand which is the best one for me. For example: A7S is a tiny cam, it's good for every amount of light (expecially A7SII), but for stills-to-crop-in-post A7RII is better, and for bitdepth BMCC is the king. If GH4 had better managed low-light, I would have considered it as the best compromise (tiny cam, 16MP stills, 10bit) but it lacks just a big feature: low light. A camera that forces a one-man-crew to bring lights and reflectors with him, that gives its best only in specific conditions, only when the sun shines, only with fast-fast lenses+adapter at widest&softest aperture that means no-damned stabilization that implies a tripod... well, this "smart" cam lacks another big features: it's not a practical cam at all!
In this compromises match, Sony seems to be a good solution (A7RII or A7SII), but lacks 10bit, and this is not good at all thinking that I will surely heavely grade in post.
If you say, guys, that 8bit or 10bit from GH4 is not a big difference for grading purpose, then simply I will go for the Sony.
This was the meaning of the question of my last post: what does a color artist think could give a better result with grading: dark&noisy 10bit GH4 evening footage, or clean&clear 8bit A7S evening footage? (Please, let's image to be that color artist, and to have this couple of evening takes, and simply try to anticipate which take will work better.)
Thanks a lot for your patience.
« Last Edit: October 07, 2015, 06:00:24 PM by adrjork »
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Morgan_Moore

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Re: 8-bit Video in a 10-bit Wrapper
« Reply #19 on: October 07, 2015, 06:21:52 PM »

I too believe the 10 bit external GH4 HDMI is *real*, and probably worth using if you can be bothered with an external recorder.

I tried going to a dealer and using an Odyssey, as I wanted one anyway as a focus aid, but setting it up proved a real hassle (we failed).  Your mileage may vary, if you're better than me with wires, software and menus, but people have reported that the connection is fragile, things need to be switched on every time in the right order.


I have the Gh4 and yag box running to a BMC recorder by Sdi long cable - unlike other 'dslrs' that Sdi is unique so I can get 10bit with a good connection.

My typical use would be to have the camera stuck on car window and the recorder sitting on the seat - not a compact set up - a specialist one.

the BMC recorder does not have a menu - just a record button - which being on the recorder acts as a 'remote' so the camera can be on a the hood/bonnet. The recorder also has HDMI and SDI out for 2 monitors!

S
« Last Edit: October 07, 2015, 06:24:17 PM by Morgan_Moore »
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