Phantom HD / Panavision Genesis / Magic Lantern HD Framestore™

Earlier this year I had the opportunity to work with the Vision Research Phantom HD high speed camera as a Digital Imaging Technician. This particular project involved the Panavision Genesis as the 'A' Camera and the Phantom as a dedicated high speed camera. To round out our tool set we employed the Magic Lantern HD Framestore™ as an on-set HD reference tool and HD playback device.

The workflow was quite interesting . . . and more than a few mysteries about each of the cameras were clarified for me.

Since this commercial was one of the first HD outings for this client it became clear that maintaining client confidence was of tantamount importance. The D.P. Doug Koch wanted both the agency and the clients to see imagery that wowed them. Rather than simply feed the RAW output from the Genesis we opted to correct the image using the Panavision GDP (Genesis Display Processor).

In prep Doug and I developed the basic LUT looks using the GDP. Doug was very fluent with creating LUT's after having just completed the filming of The Bronx is Burning, an ESPN mini-series shot on Viper. In just a few minutes we familiarized ourselves with the GDP and setup some simple looks using the left to right - 'in to out' signal flow of the GDP Controller software version 1.44 as illustrated by the screen grabs below.

Although generating a look wasn't difficult, it turned out that properly saving the .gdf files and the corresponding LUT files, as well as the .acv curve files was slightly unintuitive. Care had to be taken to submit and save the pre- and post-gamma sections of the look. For safety we exported the LUT to the DaVinci file format using the File/Export requester and also saved the file to Luther Ascii foramt using the Lut/Create 3D LUT . . . file requester. In addition to the LUT files and Curve files it was all too easy to forget to save the main .gbf file! In future versions of the software it would be nice to be able see the name of the .gbf file that your are tweaking in a header just to help keep track of the files.

In order to keep the system intuitive we utilized the Magic Lantern HD Framestore™ to capture a still reference frame of the before and after for each look.

The Panavision Genesis signal was recorded to HDCamSR on-board. This is a simple single system recording in 4:4:4 to the on-board SRW-1 recorder. The Phantom, on the other hand involves a different approach. To preserve the Phantom footage, a time consuming transfer process was required. Once the footage is captured to on-board RAM(8 Gb max at that time) it then had to be transferred via Gigabit Ethernet to a PC laptop supplied with the camera. The laptop also acts as the controller for the Phantom settings and triggers the camera to start or stop recording. The specific model we used was the Phantom V10 which has no viewfinder or controls on the camera at all.

To be continued . . .

HVX200 CCD Alignment / Matte Box issues

Blake Desaulniers (http://rbdcreative.com) writes:

I recently mounted a Chroziel matte box on the 200, and encountered severe vignetting in the upper left of the frame when I inserted the 16 X 9 mask. We spent quite a bit of time at Lorne Lapham's (Vancouver) trying to remount and eliminate the problem, but in the end the only solution we could come up with was to shave the 16 X 9 insert down on the offending corner.

We tried everything, including switching rods and inserts, but to no avail. Brian (L.L.) suggested that it could be a chip alignment issue with the HVX. Any ideas?

______
CO: It doesn't make sense that chip alignment would cause the problem - many other issues (i.e. chromatic abberation, backfocus) would show up first if this were the problem. The question is should you return your HVX under warranty . . .

I will contact Steve Mahrer of Panasonic to ask him . . .

______
These responses came from the Creatve Cow Panasoniv HPX/HVX forum:


Name: Rennie
Date: Nov 6, 2007 at 9:58:14 pm
Subject: Re: HVX200 vignetting with Chrosziel mattebox


I would think any chip alignment would also give you out of focus problems. The lens and the chip set must be in alignment to get a proper image. Try shooting an alignment chart and blowing up the corners. I would think it more likely the matte box is out of alignment so maybe try another matte box or see if the mount is bent. You could also mount the matte box on a different HVX200 to see it it appears there.

---

Name: Noah Kadner
Date: Nov 6, 2007 at 11:13:21 pm
Subject: Re: HVX200 vignetting with Chrosziel mattebox


Definitely not a good idea- you would destroy the camera and still not solve the issue. Try a bigger matte box- Vocas could be a better fit.

Noah




An anonymous individual made this comment in reference to the HVX200 alignment issue.

Here is the comment:

Hi there, CCD alignment on the HVX is an issue i've recently tried to find more discussions about online but startlingly find it to be an uncommon point of interest. This thread is one of few i am posting on now to share the results of a test i did myself recently.

I started investigating when i was attaching a Redrock lens adaptor to the front of the HVX and found that the 'gate' at the back of the Redrock unit would dissapear from the edges of frame at different points of zooming with the HVX. I had hard mounted the Redrock using stepping rings and at first assumed it was a Redrock problem (much as you assume it is the fault of your matte box).

I steadily started removing variables from the equation until i was left with only the stepping rings screwed into the thread on the front of the hvx mount, and the edges of this too were not aligned centrally with the image.

This lead me to the certain conclusion that the center of the lens and the center of the CCD are out of alignment with each other.

I have so far tested around 10 HVX's and find the problem to be the same on all of them. The rings appear to be shifted to the right of frame, leaving vignetting on the left. (the same direction as your matte box problem)

I have also done this test with the sony Z1 and the old DVX and find the alignment on both of these cameras to be perfect.

On contacting Panasonic i was met first with denial, then with an excuse that "the HVX is not designed to be used with lens adaptors", which completely ignores the issue that ANY accessory attached via the lens thread is out of alignment with the image, and so what would be the point of any accessory? The final insult came when a friend of mine performed the same test demonstration in front of Panasonic reps at a Panasonic demo, to which they responded "your problem isn't CCD alignment, it's your budget - buy a better camera" (!!!!!!!)

I think it's about time Panasonic owned up to the fact that they have performed a massive and inexcusable cock-up in their manufacturing of the HVX and either offer to fix all affected cameras, or announce the problem and sell the cameras at discounted rates. Neither of which they have been forthcoming about doing.

If you own an HVX, please perform the same test to see for yourselves if you are affected, (because it may be just a bad batch made at one time) if is so, or if not, note the serial number and post it back here so we can begin cataloguing affected models.

Feedback welcome!!!


The preceding post was made by an anonymous individual .



Chris M. Oben