Monday, August 11, 2008

Petroff 4x4 Mattebox on Sony EX-3

I've been too busy enjoying my new Sony PMW-EX3 even to post!

There has been some chatter on the discussion forums that the Sony EX1, EX3 and indeed even Red exhibit an unfortunate trait common to CMOS cameras-- poor rejection of the IR spectrum. This could potentially result in color shifts or inaccurate reproduction of colors.

I'll be testing both for this site as well as for a future article on the EX-3 the IR rejection capabilities of the B+W True-Cut 750 IR filter. This new filter is touted by Schneider Optics to be superior to its earlier 486 and 489 IR cutting filters, reducing the potential for a greenish tinge which could potentially occur with the 486 and 489.

The IR 750 is currently only available in a 4x4 filter and that meant using a mattebox.

The Petroff 4x4 has long been my favorite and courtesy of Petroff, you see a Petroff 4x4 mounted to the EX3 using a lens mounting ring which Petroff developed for the EX1. Petroff had not yet tested the EX3 but I was convinced that there would be no issue with fit since the lenses are identical other than the interchangeable feature of the EX3. I was right.

The unit I am testing here is a two stage 4x4 model with optional side wings and a French flag. It is mounted with the Zacuto baseplate and rod system, my unqualified favorite plate and worth every penny.

Why do I like this product so much?

It is sturdy yet lightweight. The mattebox is made from a combination of metal and virtually-indestructable polymide. It has flexibilty while also being able to bend without feeling that you are permanently bending metal.

It is modular and can be assembled/disassembled without tools. You can add or remove stages, insert/remove filters, assemble/disassemble the mattebox and not have the need of a screwdriver.

Each stage can rotate or be locked in place. In the case of the IR 750 filter, I would not want to rotate the stage. A 4x4 polarizer would be an entirely different manner. Those same thumbscrews over which the lock fits are also the screws you would loosen to remove the filter holder. Then it is a simply matter to drop the filter in the holder and return to the mattebox, tightening the screw.

Note one concern with the design of the EX1/EX3. That infernal (and, in my opinion useless) built-in mike protrudes too far forward. It does partially block the thumbscrew in the stage closest to the camera. It is not a major issue but a bit of an annoyance requiring deft small fingers or a needle-nose plier to operate the screw. I suspect it might be possible to design a donut to extend the entire assembly slightly. Petroff does manufacture a "universal" mattebox designed for Sony HDV cameras where the built-in mike constitutes a more significant issue. EX owners might want to consider this universal model.



In this shot, note how tightly the mattebox components fit together and how securely the lens adapter, large lens mount screw and rod attachment both hold the mattebox together as well as secure it to the Zacuto baseplate.

No light leaks, no wobbling, secure snap in filter holders give the user of this mattebox complete confidence that it is doing what a mattebox is supposed to do-- light control, hold filters, and fit securely to the supporting rods.


The Petroff mattebox accomplishes all of these tasks and then some.

The P44 two stage as shown lists at $1370. Follow-focus is also available.

Check out the full product specs and product line at www.petroff.ws

Check out the baseplate, rods and tons of other related accessories at www.zacuto.com. Conveniently enough, Zacuto is also a Petroff dealer.

That's the mattebox part of this installment. Will start shooting with the filter in the coming days to determine whether the IR problem is pervasive or just infrequent.

Friday, May 2, 2008

Quick Update on Ultimate Raid

Highpoint Technology has updated the firmware for the RocketRaid 3522 to allow booting from Mac OS X 10.5. Now, this is not quite as significant to the video editor since we would not be capturing to a startup volume, but it is a significant advance in the evolution of the RocketRaid card for those users who require large start-up volumes.

This is one impressive raid card. Bootable (for those whose applications need bootable raids), easily updated via firmware patches, ethernet port for remote control of raid and computer functions, multiple raid levels, optional battery backup, but most importantly its Intel IOP 81341 on-board processor. It is a true hardware raid controller with all of the speed, security and management capabilities that any editing installation would demand.

Friday, April 11, 2008

Work In Progress— The Ultimate Raid

I've been writing quite a bit about storage over the past couple of years going all the way back to this first roll your own raid article to a more recent review of an 8-drive array from Dulce Systems with more general storage articles (check all of the out on www.dv.com).

Currently waiting for publication is a review of the 3Ware Sidecar.

This time I wanted to build an ultimate raid. But just what does an editor need? Well, what I needed was a single workstation unit with lots of capacity, with redundancy and with the speed to handle capture and playback of 10 bit uncompressed HD. 2K capabilities would be a nice bonus but I really only see myself working in 2K just in technology demo rather than production at the moment.

I had built a Raid 1+0 based upon the CalDigit eSata card for my MacPro and a Sonnet card in my PowerMac G5, connecting to a 5 enclosure port-multiplier box I bought from CoolDrives.com.

The CalDigit and Sonnet cards are software based, utilizing port multiplier chips from Silicon Image but with the raid itself configured and managed through the OS (in my case, MacOS X) and SoftRaid, a superb management utility.

I wanted to go the hardware route this time, so I chose to create a solution based upon Highpoint Technology's RocketRaid 3522 card (note-- this is the Mac page, but it works as well with XP and Vista-based PC's) and and the Enhance Technology E8 MS enclosure.

The Highpoint RocketRaid card is hardware based with an onboard Intel IOP 81341 processor with 2 external mini-SAS ports, each capable of supporting 4 drives in Raid 0, 1, 3, 5, 6, 10, 50 and JBOD. It is a PCIe 8x card which works as well in a 4x PCIe slot and includes browser-based raid management. It will work with any enclosure and with SAS or SATA drives.

An added bonus with the Highpoint card is an ethernet port which allows remote access to the card to configure the raid or even initiate rebuilding remotely in the event of failure.

Hardware raid means, in brief, that all processing is performed by the card's processor taking load off the computer's processors. Hardware raid level 5 represents a good compromise between speed, capacity and redundancy. Effectively, parity is spread across all drives and the raid capacity is reduced by the size of one drive. Raid 5 allows for the failure of one drive, while raid 6 allows for two drive failures.

The Enhance E8 MS enclosure allows easy mounting and removal of drives and has two miniSAS connectors. It will accept either SAS or SATA I/II drives.

I have been testing with 8 Seagate 7200.11 1 tb drives as well as with 8 1 tb Samsung F1 drives. Stay tuned for the detailed comparison of these drives but catch a sneak preview below.

Preliminary testing is very favorable with some amazing speeds, 3-4 layers of 10 bit uncompressed HD without rendering and seemless playback of 7 layers of 10 bit uncompressed. This can be attributed not just to the quantity of fast drives but in great measure to the Highpoint card.

One problem so far-- my MacPro (early 2008) dual 3.2 will not recognize the RocketRaid card in Slot 2 (the 16x slot). In fact, it will not recognize any card in Slot 2 other than a 16x video card. I suspect there are some issues with this machine on Apple's end and I look forward to solutions from Apple. I suspect that I will obtain even faster results once the card works in the 16x slot. Hurry up and fix the incompatibility, Apple.

Meanwhile, here are some AJA System Test results for both the Seagate (first graphic) and Samsung drives.





Not bad, eh?

Oh, and the cost to create all of this: About $550 for RocketRaid 3522; $650 for Enhance E8 MS; $250 each for 1 TB Seagate or Samsung drives. Total-- around $3200. Compare that to pre-configured 8 tb turnkey systems costing over $8000.

The upside-- you save money. The downside-- assembly required (but a lot easier than your kid's bicycle), configuration required and no unified support. There remains a great deal to be said for buying a turnkey system from a storage vendor like Dulce Systems, Sonnet or CalDigit (just to name three which I have evaluated recently). Roll your own, though, does have its place in the market.

Stay tuned.. more coming on this site and eventually in print.

Rolling Shutter Effect In Sony EX-1

In the April, 2008 issue of DV Magazine I reviewed Sony's EX-1 camera.

I love the camera, warts and all, and it is high on my post-NAB purchase list. This is coming, you understand, from an unabashed user of the Panasonic HVX200 and long-GOP skeptic.

But one of the concerns that many users have raised about the EX-1 is its CMOS "rolling shutter" which effectively scans the entire image progressively rather than buffers the image as does a CCD-based device.

This rolling shutter effect can produced partially-exposed frames under certain conditions, primary among them being strobing or flash photography.

I was able to reproduce this in my testing subsequent to the article. I'm shooting at night at the Rockefeller Center ice rink using existing light (those half-inch chips really do well in low light situations). Of course, every parent needs to snap their kid doing multiple axils.

Take a look first at a single frame before the flash.








Now, the next two frames contain the flash.





Can you see the rolling shutter effect? Look at "The Concourse..." You can see that the area is normally exposed in frame 1 and brighter in frame 2. So, the flash effectively "rolled" from the bottom of the frame to the top.

But does it really make any difference in this scenario?

Take a look at a 4 second clip shot 720p24 at 60 fps for a slow-mo effect. The flash occurs about 3 seconds into the clip.


video

The flash is certainly visible but even when played at full HD resolution the shot still holds together.

I'll keep trying to break the rolling shutter. Stay tuned...