thoughts and decisions for a creative edge

Controlling the shots

The HD7 is by far an achievement for pro-sumer video enthusiasts. It has created a a wave of excitement for the video enthusiasts being the first Full HD cam. But despite the claims, there are flaws which should have been fine tuned by JVC. I guess in the real world nothing is perfect, except for my mom’s cooking!

If you fall in the 80% of users who claim that the HD7 is not a good camera – then you are. There is nothing to change that scope of thought unless JVC themselves make the effort to address the existing weakness of the cam. It uses three 1/5-inch 16:9 progressive scan CCDs designed for HD use in a diagonally offset pixel configuration to generate the high resolution image for recording in full HD. There is only so much that 1/5 inch CCD can capture at one time. These are the figures released by Canon on their new CCDs performance :

Newly Developed Progressive Scan CCD Overview

Image size: 1/5” Diagonal
Aspect ratio: 16:9
Pixel size: 3.28 microns x 3.28 microns
Total number of pixels per CCD: 1016 x 558, approximately 570,000 pixels
Number of effective pixels per CCD: 976 x 548, approximately 530,000 pixels


HD7 + RøDE SVM with Dead Cat

For a camera that fits the size of your hand, that’s a lot of pixel crunching if you multiply that to do 30x in a second. And that’s just for one CCD. There’s 3 of them that needs to be interpolated to give you that final viewing you see. While its capturing and converting all those pixels, then comes the wall of a task that didn’t seem to have been worked out correctly by JVC. Image Stabilization.

Before we scrutinize this biggest weakness of the camera, lets go back to the derived design of the HD7. Idea came from broadcast cameras. How JVC has came about letting you carry those huge studio cameras in the palm of your hand is a feat on its own. Fujinon lens used in the JVC system is also used in broadcast HD video cameras. The incredible minimal F. No. is F1.8 wide open and F1.9 for telephoto. This is only made capable due to the indexed aspherical lens giving superior optical performance on the entire zoom range suited for an HD system. JVC designers can now keep the lens small and at no loss of light when you zoom in to your subject. To understand this, take your DSLR into AV priority mode with a zoom lens. The higher your zoom, you’ll see a significant drop in Aperture and thus the need to add gain – resulting in unwanted noise. This is not the case for the HD7 lens.

Now come the biggest grudge about this camcorder. JVC has this selection included in the OIS menu option, but many (including myself) would swear that we don’t see any change with this option turned ON or OFF. In fact I keep mine constantly on OFF mode since I now only shoot the camera with a monopod. But when I do come to situation where it has to be shot handheld, I will turn it on and try not to breathe – but hope! Why JVC has not addressed its HD7 users about this lousy claim of an IS is yet to be heard about. But knowing its normal not to have a built in stabilizer in broadcast camera has helped me to forgive the claim. But looking at JVC’s page advertizing its great IS Mode gets me fumed to have the camera returned at times. IT IS JUST NOT THERE JVC!! Their claim of the OIS meant for hand-held shots is highly not visible here. Even when I tuck my hands to my chest, I fail to get it stabilized. I guess I have minute parkinsons disease!

So I hear claims that the OIS works only while on a tripod or monopod. But come on JVC, that’d be the 1st I hear about Image stabilization. Maybe I deserve a T-Shirt too for buying myself a monopod. But that’s exactly what I did – an experiment and I’ll only let you guess the outcome.

PIxel Shift Tech
The Red and Blue imaging CCDs are shifted a half-pixel both horizontally and vertically relative to the Green imaging CCD. Because the pixel-shift system uses progressive scan CCDs, signals are processed first as 1920 x 1080p progressive signals, then converted to 1920 x 1080i interlace signals for recording. Thus it is progressive upon capture but when recorded, its interlaced. This explains the need to de-interlace the video when its being exported for playback.

As a result, JVC developed a new HD-specific processing circuit to process high-density interpolation signals for brightness and color. The circuit separates low frequency and high frequency components of the brightness signal to create an image with exceptional color reproduction and less moiré. The analog front end (AFD) uses 14-bit signal processing to produce HD high-quality resolution.

Continue to… LET’S SEE IT!


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