Tim Kolb
Forum Replies Created
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Yes…it’s due to the development cycle. AJA’s retail drivers can be updated as AJA wishes and they can just keep moving…for third party vendors like CineForm, having to constantly chase each incremental update can doom a third party vendor to perpetual beta…
The OEM drivers are designed to give third party vendors…Avid, Media 100, CineForm, etc, a non-moving target for some period.
TimK,
Director, Consultant
Kolb Productions, -
I assume you’re having enough issues with CineForm that you don’t want that?
I’ve also had good luck with ProRes files…You can’t encode a master to ProRes, but you can edit it on a PC without much fuss.
…it would run better than uncompressed…even Y’CbCr.
TimK,
Director, Consultant
Kolb Productions, -
A polarizer, when properly utilized, shouldn’t shift colors, it removes glare.
To oversimplify this somewhat…coins can only go through a coin slot in one angle…it’s a slot. Coins pushed at the slot that are rotated so they won’t go through can’t pass. Light waves tend to modulate at all sorts of angles…a polarizer is like introducing a coin slot.
The effect is usually most pronounced with shiny, reflective surfaces at, or around a 30 degree angle to the camera…rotating the polarizer will take a massive specular glare off a new car, or allow you to see through the store window by removing the reflection of the street behind you.
The color shifts can happen when you use a linear polarizer on a 3 chip camera. There is a system of reflective/transparent surfaces that separate the light into the proper wavelengths to pass to the proper sensor. These surfaces are themselves a sort of polarizer.
When you take two sets of polarized sunglasses (or two polarizer filters for that matter) and look through both of them while turning them in opposite directions, you’ll see that when they are at a 90 degree angle to each other, they’re opaque. They block all light.
When a linear polarizer does it’s thing and passes the polarized light to the prism in the camera, the angle of the polarizer combining with the angles of one or more of the camera’s internal mirror surfaces will act like a multiple polarizer, and since the surfaces that allow or reflect light to each sensor are at different angles, the angle of the polarizer will interact with different wavelengths, therefore different sensors, therefore different colors…creating color shifts as the wavelengths of light will vary in strength from one sensor to another.
A circular polarizer is not named for its roundness. A circular polarizer takes the polarized light and sends it to the camera “twisting” like a corkscrew. Even though the light is still polarized, since it’s angle is now rotating onto the sensor/prism assembly, no imbalance in color strength is created.
As far as Infra Red…that’s a Ex1/Ex3 thing that has little to do with polarization. The camera is simply sensitive to IR and does create some reddish hues in the blacks. Tiffen has an IR filter developed specifically for the purpose of neutralizing this issue.
TimK,
Director, Consultant
Kolb Productions, -
Yes…I’m familiar with the meaning behind the numbers.
ProRes 4:4:4:4 can support both per Apple, but since Y’CbCr carries so much of the image material in the Y channel, it’s very unusual to see anyone use full sample for it. You CAN of course…but what you’d actually gain over 4:2:2:4, is pretty slight. Typically a full 4:4:4 sample is RGB.
In your case, I suspect that movie inspector could look at your clip and tell you what you have…then you’d know.
TimK,
Director, Consultant
Kolb Productions, -
[Tom Wolsky] “If I remember correctly DVCPRO HD is not 1920×1080, but 1440×1080.”
Indeed. It’s 1440×1080 at 25fps, and 1280×1080 at 29.97fps.
…and of course, it’s 960×720 at 720p.
TimK,
Director, Consultant
Kolb Productions, -
I am preparing to reconfigure for Windows 7…and actually use 64 bit, so my setup will be migrating…
BUT, I’ve typically been a Prospect user…HD, then 2K (now Prospect is in 4K). First Light adds a whole new set of tools to the system… I’ve worked with the SI camera workflow and really liked it.
My system right now has a Xena LH card and I have it dual boot. One boot is the AJA OEM drivers that use the card for CineForm, and the other boot is AJA’s retail drivers so I can use the AJA edit settings. I use both. My third boot was going to be Vista 64…but I could never quite get it the display drivers right to light up all four of my monitors. That will now be wiped off the system and hopefully Windows 7 will solve all my problems and run flawlessly with all my software.
🙂
On the hardware side, I’m pondering what I might do for system monitoring in the near future…possibly Display Port for SpeedGrade monitor-HDMI for output…DreamColor?, I might even consider one of the larger LED backlit LCD panels for client monitoring…which would cause me to really look at moving to a Xena LHi card.
All delayed substantially by our economic rut…but, what I have works, so I keep plugging along.
TimK,
Director, Consultant
Kolb Productions, -
By chance, have you tried to install CS3 on the new system with the old drivers to see if you could make frame rate?
TimK,
Director, Consultant
Kolb Productions, -
CineForm has a 4:4:4 RGB codec that actually tests out slightly batter than HDcamSR…
The question is what the material is destined for… RGB 4:4:4 is not television color space (the material was likely shot for theatrical release?), and you will have some illegal colors for Rec 709.
I would opt for CineForm Y’CbCr 4:2:2 myself…
As Eric stated, you’re in array territory…BIG array territory with 4:4:4 RGB uncompressed (8 bit RGBA or 10 bit RGB). You’ll need to make about 260 MegaBYTES (over 2 Gigabits/s…HDV is 25 Megabits/s) per second throughput with no effects or color correction…that’s one stream.
An hour will take about 900 GBytes of storage…and with data this huge and drive speed being this critical, you’ll need an array you can keep under 2/3rds full to ensure that fragmentation doesn’t torpedo your data rate.
TimK,
Director, Consultant
Kolb Productions, -
[Cliff Elliott] “I have heard that the Apple version of Premiere is suposed to be a lot more stable thus the reason for the original question.”
This has not been my anecdotal experience…It seems as if the problems are simply different.
Your license won’t transfer, I’m fairly certain of that.
are you on a Windows XP machine?
TimK,
Director, Consultant
Kolb Productions, -
ProRes 4444 is an RGB codec…not a Y’CbCr codec.
(Most “4:4:4” codecs are RGB, there are very few Y’CbCr schemes that run a full sample on all color channels.)
As with most RGB video…the color gamut is really meant for compositing or non-television video workflows (as in film or feature post production).
Most RGB codecs operate with values that are illegal in Y’CbCr color space (the space you are measuring in with your external WFM and Vectorscope), just as Y’CbCr generates values that are illegal in most RGB color gamuts.
TimK,
Director, Consultant
Kolb Productions,