Monday, June 23, 2008

HVX vs EX1 vs XHA1: Analyzing the Specs (Part 1)

Now, in a PREVIOUS POST, I listed the specs of these three cameras with a promise to delve into the ramifications of what these actually mean. The HVX has 4:2:2 colorspace instead of 4:1:1? Is that a big deal? What for? 16 bit audio sampling? 24 bit? Ummm... Does it really matter how much the codec compresses my footage? Why? CMOS, shmee-moss...

Well, here's some of the specs again, with their real world applications included, with a couple reasonable conclusions.

CHIP SIZE

Half of an inch can be enough to impress the girls. Both the Panasonic HVX and the Canon XHA1 utilize three 1/3" CCD chips. The Sony EX1 uses three 1/2" CMOS chips. Does this 1/6 of an inch really make a difference?

Yes, it does. A one-half inch chip allows the videographer to achieve a shallower depth of field because it is a larger surface on which the image is being projected. Is the difference between 1/2" and 1/3" night and day? No, but it is noticeable. It is significant.

One should also keep in mind, though, that while the EX1 and HVX have 13-14x optical zoom lenses, the Canon goes up to 20x, allowing you to use the "back up and zoom in" trick to greater effect in achieving the appearance of a shallow depth of field.

Also, a larger chip means the ability to receive more light, and as a result, better low light performance and less grain. This can be especially noteworthy if you are combining your camera with a depth of field adaptor, which causes an additional loss of light (usually about one F-stop).

Using a depth of field adaptor makes the depth of field capabilities of a 1/2" chip vs. 1/3" somewhat less critical, but does highlight the great light receptiveness of the chip.

Winner: Sony EX1

CHIP TYPE: CCD and CMOS

This has been done to death, so I will refer you to a couple other posts (POST 1, POST 2) for the analysis on the topic, but suffice it to say that at this stage of chip design, a CMOS chip also means a rolling shutter.

One significant benefit of the CMOS chip is that it does not cause vertical banding when portions of the image are blown out by extreme brightness and high contrast, such as that achieved by a bright light bulb in the middle of a black background.

The cost for avoiding banding is fairly high, though, with horizontal skew on fast side pans, vertical stretching and compression on fast vertical pans, partial exposure with camera flashes and strobe lights, and the potential Jellocam wobbling in high vibration situations.

However, regarding his choice to work with the EX1, I did see the venerable Philip Bloom state somewhere that, at least for his purposes, he has gained more by avoiding CCD banding issues than he has lost by working with a rolling shutter.

The debate continues, and if you delve into the forums, you are likely to see a global vs. rolling shutter war zone. Make sure you bring your bulletproof vest and watch out for Sony and Panasonic die hard suicide bombers (comprised mostly, I would imagine, of quasi-professionals who can't bear to digest the idea that their five-to-six thousand dollars could possibly have been better or even equally-well spent on another camera).

Winner: Panasonic HVX and Canon XHA1

PRICE

Duh, by the time you buy the media necessary to shoot in HD on either the EX1 or the HVX, you will be able to buy two XHA1s for the same price (and record your footage to tape).

On price alone, XHA1 is the clear winner, since you could set two of them up for every shot and double your coverage. However, it has been said since time immemorial that "you get what you pay for."

Winner: Canon XHA1

1 comment:

Rina said...

Hello Jack,

I greatly appreciate all of your blog posts about the A1, and i love the footage you have gotten.

I have a few questions...

I was wondering if you have any experience calibrating a light meter with this camera. I am attempting to work out what the ISO rating is... I have heard 320, but at what gain level, I am unsure. I know that other factors are involved with equivalent ISO ratings (what the gamma is set at, etc).. but if you have any info on this it would be greatly appreciated.

In the guide I am using to calibrate my meter, it says to make sure the shutter is off on the camera. Is there some way that you know of to do this on the A1? Does it just mean to not be recording, or is their some "shutter off" button I am missing, that

Also, how much light do you lose using your Letus adapter, I have heard it is about 1/3 stop or so?

Thank you so much,
Rina