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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Red One genlock tests for 3D....

3D Sync error

3D Sync error

What we would also need to understood is

- What is the source, length, routing and material of the Genlock cable used to feed the two cameras.

- Was Shutter Phase used to adjust either one of these shutters or not ?

- Were the cameras in a Master / Slave ( USB cable interconnect) setup ?
 
Hmmm!

After doing that little bit of maths above I noticed something.

Whilst working out the numbers at first I used 24fps instead of 23.98fps.

I realised this didn't fit Pedro's test so I did it again correctly but it got me thinking, what if somewhere along the genlock chain (user,sync source,camera) a similar error had occurred how long would it take to knock two cameras out to produce the 10º fan blade offset?

The answer is about 45-50 frames (assuming 1000rpm fan) if there is a "mix up" between 24fps and 23.98fps sync!

So is it possible that this sync problem maybe something as simple as a 24/23.98fps mix up? (which could be a user error/incorrectly set sync source/firmware issue)

Possibly...

JohnF
 
Stuart English said:
What we would also need to understood is

- What is the source, length, routing and material of the Genlock cable used to feed the two cameras.

- Was Shutter Phase used to adjust either one of these shutters or not ?

- Were the cameras in a Master / Slave ( USB cable interconnect) setup ?
Click to expand...

Source: I did most of the tests with an AJA Gen10 with switches in 1-2-7 position.

Additionally I used a deneke just for comparison. Results were the same.

Length: I used verified(tested and built by Pacific Radio in Burbank) equal length cables. Same cables I used to test the Sony.

Phase: I adjusted only 1 camera for phase changes. In the pictures posted above no phase changes were made. I can post 1 degree phase change results once I get back into town.

Mode: The cameras were not in master/slave mode (usb). I my field experience I have had too many problems using that cable (camera lockups) so I never use it anymore.

I can certainly do another quik retest with the cameras in M/S mode.

I'm out of town shooting 3D, I can do it as soon as I get back.

JOHN- I also did the tests @ 23.98 and 24 - Same results
 
Pedro Guimaraes said:
Goal: To fully test weather the RED one will achieve a perfect lock at various frame rates/timebases.
Main result: It never truly locks.


I want better.

If sony and others can do it, I’m sure RED can do it.

If RED is serious about 3D then need to address this issue. Perfectly locked cameras are just mandatory for 3D if you ask me. But since it’s not that perceptible we’ve been skating by without it.

So RED and others? What you think?
Click to expand...

The gen-lock feature was invented for live editing and mixing.
It is a playback or play monitor feature and does not control the timing of the image sensor virtual shutter (CCD charging) timing.

To get perfect sync one must use single camera rig with stereoscopic adapter.
Mathew Orman

For state of the art stereoscopic vision systems with: eyestrain free, distortion free and realistic immersion stereoscopic experience contact me
at:
http://www.tyrell-innovations-usa.com/
 
icester said:
To get perfect sync one must use single camera rig with stereoscopic adapter.
Click to expand...

I know the history of genlock as do most reading this post. I know what it does on many cameras. The RED is not doing that properly.

Your statement is not true. Stereo adaptors have numerous issues as well. There is no perfect 3D system.


I applaud your developement of stereoscopic devices, but please, instead of just blatantly plugging your still camera adapter business how about you add some valuable information to the post?
 
Pedro Guimaraes said:
I know the history of genlock as do most reading this post. I know what it does on many cameras. The RED is not doing that properly.

Your statement is not true. Stereo adaptors have numerous issues as well. There is no perfect 3D system.


I applaud your developement of stereoscopic devices, but please, instead of just blatantly plugging your still camera adapter business how about you add some valuable information to the post?
Click to expand...

Ones again:
the gen-lock is not design to sync shutters.
One camera can point at apples and the other at oranges and the Red camera gen lock will make perfect frame alignment so one can now mix apples with oranges.
It is only coincidental that on some Sony cameras the delay on shutter action is constant.

Mathew Orman

For state of the art stereoscopic vision systems with: eyestrain free, distortion free and realistic immersion stereoscopic experience contact me
at:
http://www.tyrell-innovations-usa.com/

p.s.What kind of numerous issues Stereo adapters have?
 
Ones again: the gen-lock is not design to sync shutters.
Click to expand...

Matthew, that may be true on other cameras, but it's not true on RED ONE.

For us, the PRIMARY purpose of genlock is to sync shutters, the SECONDARY purpose is to sync HD-SDI.


So with regard to Pedro's comments, we still need to understand why it is that he sees the results he reports.
 
Stuart English said:
Thanks..

What did you use for timecode btw?
Click to expand...

I also used the Deneke TC/sync gen device to make sure it wasn't the AJA. In that case I used deneke to give me tc signal.

With the aja, I would sync the slate into the camera using the lemo connector from the deneke slate to the camera. Then I would jam the left camera to the right camera with same cable. This way the the cameras always feeding TC to the other and that way even if they drift from the slate they always match each other.

I do usually jam the "master" camera often troughout the day (during productions) to insure TC is as close as possible to the slate or recorder.
 
Stuart English said:
Matthew, that may be true on other cameras, but it's not true on RED ONE.

For us, the PRIMARY purpose of genlock is to sync shutters, the SECONDARY purpose is to sync HD-SDI.


So with regard to Pedro's comments, we still need to understand why it is that he sees the results he reports.
Click to expand...

Are you sure?
If you are an optoelectronic engineer then it is great news.
One thing puzzles me though, how do the cameras communicate the shutter speed?
Also I would like to build a true stereoscopic rig with off-axis convergence
and shutter sync.
Is the a cad drawing of a RED camera which I could import to my SolidWorks?

Mathew Orman

For state of the art stereoscopic vision systems with: eyestrain free, distortion free and realistic immersion stereoscopic experience contact me
at:
http://www.tyrell-innovations-usa.com/
 
If the Gen10 only creates trilevel sync for 1080P and 720P, that's one potential mismatch because red one is 4k and the timing is different, right?
 
Regarding Mike's above post:

Can someone please clarify what should be the correct camera and sync source settings/signal specification (tri-level I presume) of the sync signal required for shooting 4k at 23.98/24/25/30 etc using multiple genlocked/synced RED1's?

I remember in the earlier days of genlocking SD equipment that some gear was more prone than others to "reflections" within the sync cabling itself. Appropriate cable and connector specifications were very important (plus kinks in the cable were a no-no). Are there any hardware (cable type/length/connectors etc) issues that may apply here?

Cheers

JohnF
 
3D Sync error

3D Sync error

Are you sure? If you are an optoelectronic engineer then it is great news.
One thing puzzles me though, how do the cameras communicate the shutter speed?
Click to expand...

Yes I am sure. Genlock may be used to provide each camera a shutter start time reference.

The (master) camera communicates shutter speed (to the slave camera) via the USB cable interconnect.
 
Tri-level Sync

Tri-level Sync

If the Gen10 only creates trilevel sync for 1080P and 720P, that's one potential mismatch because red one is 4k and the timing is different, right?
Click to expand...

Nope, its the frame rate that is important, so normally you would use 1080p @ 23.98 fps ( or 25.00 fps ) Tri-Level Sync...
 
Stuart English said:
Nope, its the frame rate that is important, so normally you would use 1080p @ 23.98 fps ( or 25.00 fps ) Tri-Level Sync...
Click to expand...
Then, where's the technical issue coming from?
 
So, what can RED do in order to address the problem?
 
Genlock

Genlock

What can RED do about what which problem?

Not nitpicking, just want to make sure which question to answer.
 
Stuart English said:
What can RED do about what which problem?

Not nitpicking, just want to make sure which question to answer.
Click to expand...
If the sync doesn't lock with fast frame rates and narrower speed shutter...

Being in the cue for more than 2 Scarlets (2 x 2/3" + 2 x S35 + 2 x FF35 more exactly) in the next future, I'd like to know how this can be solved.

Tests in Lisbon have faced the same trouble. I've been aware of this (and this thread as well) by the hand of one of my collaborators. He's just the most prolific 3D expert in my native country. Sony's man for 3D as well. His advice is Silicon Imaging and their inventive system (the best option for low budget digital cinema in his opinion -- he is an unbiased shooter too ;-)

http://www.siliconimaging.com/DigitalCinema/SI3D_KeyFeatures.html

Despite to be an admirer of Ari (Presler) and David Newman as much as I am of Jim, Jarred, Graeme and Co, I am a RED customer, I don't want to buy from anywhere else only for 3D production.

As matter of fact, I've been in the way trying to sell the Scarlet route to this professional nowadays. But it hasn't been easy once he has an important 3D shooting for next months. These issues and no release date concerning Scarlet don't help either.
 
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