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JVC GY-HM 150 / 100 / 70 Series Camera Systems
GY-HM150, HM100, HM70 recording AVCHD MP4 & QuickTime .MOV to SDHC cards.

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Old September 10th, 2009, 07:44 AM   #1
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Help for a "Newbie?"

For the last 30 years I have lived in the audio world. Live sound for everything from business meetings to rock and roll festivals. Studio work from voice overs to full album productions.
With the economy going the way that it has, I have had so much work drop off to the point I was dying a slow death. I rolled the dice and am branching out into video. Less to carry, faster set up/breakdown and I figure can get more events into a day.
I took out a loan and bought the HM 100, lighting and new computer with Vegas 9. I have been shooting everything I could as an adjunct to the sound work that I have done, cooked the video down to an iPod touch (the most expensive business card I have ever had) and been showing the previous videos to anyone at the next show that might have a need.
First of all, any "rules of thumb" that anyone can offer to a newbie will be greatly appreciated! Things that you educated pros probably learned in the first week of class.
Now, I have my first paying video gig on September 30. I went down to the site to test the camera. Brought the video back to cook it in Vegas to look at it. The background is a brick wall in a comedy club. I was about 30 feet away. The moire' effect ( I think that is the proper term) is very disconcerting when I try to follow the performer across the stage and shoot his interaction with the audience.
This is the question: How can I lessen the effect so that It does not become so distracting as to take away from what's going on stage? Are there settings on the HM 100 that will help in this matter? I was shooting MP4, 1920 1080 60/30 HQ, on Full AUTO.
Any thoughts on this matter will help.
Thanks,
Tracy
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Old September 10th, 2009, 07:57 AM   #2
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well

Anything now would reduce the resolution of the video , however if you deinterlace the video it might lessen the effect moire. Also their are 3 rd party filters that are supposed to reduce this just look up some filters for fcp.

Doug

Also in the camera their is a detail menu so if you turn down the detail it will help somewhat.
Next time adjust that
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Old September 10th, 2009, 09:55 AM   #3
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Tracy, I would recommend shooting 720/60p. Contrary to what a lot of people will say on this site, this is the type of setting a lot of video guys use for shooting mountain bike, skate, snowboard and ski videos. You also might want to place the camera closer and use only wide setting. Unfortunately with HM100 there is no 1/20 shutter, so you have to use 1/100 and deal with bit of a funky look.
BTW turning detail off also helps. Avoid zooming at all cost, just leave the zoom alone. Just leave the lens wide and let the subject move across the shot.
Don't use auto, leave it as "emergency measure"- hook up your cam to your TV, put it on a tripod and learn how to operate it manually.
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Old September 10th, 2009, 12:04 PM   #4
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I'm assuming your moire effect is in HD and not your downconverted to DVD? That's a different question and answer.

Lower your detail settings in your camera. Shoot progressive. 24p or 60p. (another subject about 24p vs 30p vs 60p) but suffice to say 60p gives you the most options, but I don't like it because you need to keep your shutter speed higher (1/60th and 1/100th or higher), in some cases too high if you go to 24p timeline later. (again that's a different subject and lots of arguing on this forum) Try looking at your video and see where the WORSE moire effect is. It will be somewhere the worst for maybe 10% of the middle zoom range and not obvious for everything above and below. So if you need to cross that zoom range, do it with a person crossing so you won't notice or look at the video buzzing moire effect, or do it with a quicker zoom and pan.

Another thing you might try is to make sure your aperature is fairly wide, and your subjects are fairly far away from brick wall, and be sure to focus on the people, pan with them, probably be manual focus most of the time if you can, that way the brick wall will hopefully be out of focus a little so there will be less to make the moire effect.

The effect is because the built in computer of the camera is sharpening the CCD image. All cameras do this. All cameras (digital still and video) essentially apply a blur (think photoshop guassen blur) to hide the digital pixelation caused by recording of images on a CCD/CMOS chip, then the built in computer sharpens the image back a little. This usually makes a pretty good image. Chain link fences for example (or in your case brick walls) exposes this process, so you may have to dial down the sharpening a little.

Also something will probably help you out, I'm guessing for the testing all the lights where on, but durring the performance it will just be a spot light and some simple fills? In which case the bricks would be less noticable (we hope) and not be that much of a problem anyway. (we hope) .

Since you have time I would suggest heading back there on another night or day, or at least some place with similar bricks and try the following.

shoot 24p (1/48th shutter) and shoot 60p (1/60th and 1/100th shutter) and do the pans and zooms that you will likely use. Set your sharpness to normal and off and low. ( I don't have the HM100 so I can't tell you what it is. On the other JVC lines 10 is Normal, -10 is off.. -5 is you guessed it really +5 and +10 is really +20. So JVC calls 0 normal (in actuallity it's 10 above zero). So you will want a negative number, like OFF or MIN, and -5 and -3 and Normal (0) and keep notes, use a piece of paper or clap board to record what you are doing for each take so you can dial in what you need to do with your camera. I expect with -3 or -5 90% of the moire pattern will dissapear at all zooming ranges without much loss of percieved resolution in the rest of the footage. If you feel you need to sharpen anything up, you can do that in vegas or any NLE with filter and really control the look of your video. Many people here shoot sharpness at MIN and sharpen it back up in thier NLE with keyframes to have total control over that aspect. Not a bad way to go. I just don't have the paitence for that myself. So when I'm shooting around chain link fences I shoot at sharpness -3, and the rest of the time pretty much normal. For 95% of what I do that works.

hope that helps a little.
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Old September 10th, 2009, 02:18 PM   #5
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Thanks all. I have other opportunities to practice

Thanks to everyone. I will have other opportunities to go out and try all the settings before the gig. As you all know, this is a steep learning curve to climb for an old guy and the new technologies are a bit rough for a guy that still has scars on his fingers from editing audio tape with a razor and a block!!
Any other tips you can offer on the basics that one tends to learn and forget because it becomes "muscle memory" will be greatly appreciated.
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Old September 10th, 2009, 02:30 PM   #6
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Oh, one other thing

I know that I'm going to need a lot of homework on Vegas 9. Would I be well advised to get the Sony Media Vegas Pro 9 Seminar series DVDs as training tools? Is there a better place to start as far as self-help training?
Thanks again
Tracy
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Old September 10th, 2009, 04:56 PM   #7
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Edward Troxel has a series of newsletters that have a great deal of infformation about Vegas of all numbers, 3 to 8 for sure and I *think* there's one for 9.
www.jetdv.com :: Index

Simply register and then read ;-)

BTW, Edward is a Wrangler here in the Vegas board.

Also I have to ask. You still have fingers?! lol
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Old September 16th, 2009, 04:57 AM   #8
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The Saga Continues!!

OK, Went back to the comedy club (Twice more) to try many things in the way of settings and this is what I came up with. I need to know if there is a better (more elegant) way of doing this.

Problem: Moire' patterns showing up and being distracting from funnyman on stage.

What I did (in no particular order):


Re-aimed most of the lights on light bar to a more downward angle, off the brick wall.
Put red gels into the lights that were hitting only the brick wall.
Put Blue gels into lights that were hittng brick wall and the floor
Neutral Density switch in
Shutter Speed 1/60
F stop 1.8
Lowered Detail Level to -2

Shooting from about 30 feet (close in seats are money makers for the club)

It looks like the moire' is lessened because the wall is more out of focus.

Any additional thoughts that can assist? (I think I accurately reported settings)
Thanks, all.
PS Any other lessons anyone would care to share?
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Old September 16th, 2009, 06:25 AM   #9
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Quote:
Originally Posted by Tracy Foust View Post
OK, Went back to the comedy club.
Moire' patterns result from a fixed pattern (bricks, blinds, etc.) which send STRONG high-frequency information into a camera.

When you shoot with camera that uses interlace CCDs -- each line output from the CCDs is "sum" of two lines which acts as a low-pass filter which reduces vertical resolution. This reduces unwanted high-frequency information when you record interlace.

Moire' became a poblem when camcorders could switch to shooting progressive. When CCDs are switched to progressive, each line that is output is NOT a sum, so vertical resolution is not reduced -- and the unwanted information is recorded. To prevent this, a low-pass filter can be switched in. It helps prevent the unwanted high-frequency information from being recorded.

The HM100 has it's CCDs always running in progressive mode, hence in both interlace recording and progressive recording -- the unwanted information is recorded. (A low-pass filter my be switched ON when recording interlace.)

What can you do?

1) throw the background out of focus -- ND filter to allow iris to go to about f/2.8.

2) Move back and shoot Tele

3) Adjust the H/V to minimize vertical resolution and then adjust the Detail down.

4) Of course, filters that reduce sharpness can help. Keep the back darl.

I would also try several different monitors because Moire' is actually "created" for our eyes by the monitor.

PS: this has alll been simplified.
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Old September 16th, 2009, 06:55 AM   #10
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Steve,

Excellent advise - helped me too, 'cause it's very good hints for DOF issues - first time I REALLY understand the concept :-)

/peter
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