Problems with GY-HD110 film shoot
 

hi all, I directed a 7min. screener for a series of short films for TV (real films, not TV movies) using by chance a JVC 110 (25p and Fujinon TH13x3.5 wide angle) as no XDCAM HD was available at the rental firm. Low-light conditions were prevalent. Settings were +6db gain, -3 black gamma, 0 black stretch .

We have frightful video noise in the grey areas and disturbing artefacts in deep red areas around spot-lit items on red background.

On the other side, we obtained a very satisfactory film look overall. The camera handled high-contrast areas really splendidly and produced sumptuous blacks. Lighting was film-style, high contrast.

the camera had a dead pixel, and since we used a Marshal 7-inch HDA monitor it went undetected. also it heated severely after several hours of shoot. Capturing the footage to FCP (on an mac-pro with latest FCP release) in 720 25p was a pure nightmare, even though there are no timecode breaks on the tapes.

in the end the result was splendid when screened on a standard-res Tv monitor or standard beamer (so we got the job for 26 short films) but on a full HD monitor and full-HD beamer the greys and reds are just too lousy.

I loved the overall film feel resulting from the 110 , I actually prefer it to HDCAM or XDCAM even though we'd have enough budget. So I'd like to continue with the JVC (250 ?) but we'd need to fix these video noise problems.

what went wrong ?
any suggestions ? thanks

The grays and reds are too lousy? Can you expand the explaination please. Did you do a channel separation and find the red channel and the luma channel were off on the vectorscope? Have you tried using any scene files available?

Hi, I know what you must have gone thru. I filmed my short film last summer on my HD 111E (new at the time) I got the camcorder like one day before we started shooting and we did do a lot of mistakes.

That are some things that I have found out that I MUST keep in mind when I'm shooting with the JVC HD Camcorder.

It is a HDV camcorder that meens 4.2.0 Color system. It is limited, It not very forgiving and the need to get the best quality on the shoot is very important.

That includes:

Nr: 1. Never shoot above +3db. Personaly I never shoot above 0db. Becoure you are gaining something up that is not there. for (exp. video noise in the grey areas.) I just us more lights.

Nr: 2 Lights, Lights Lights. This makes the picture perfect. (Ewen when doing Low-light conditions) Low lights Scene ar done with Lights, right. I is better to shoot the scene correctly and then take it done in post. That way you have someting to work with. (And Im not talking about over exposeing). You know what I meen.

Nr: 3 Did I say Lights ;o) (Sorry, I started out in tv/film-making, doing lights I like lights alot.)

Nr: 4 Remember it is HDV-420. So try to get as close to the look (in color) as you can when your are shooting, that meens less color correction in post. You can do that by Downloading some Scene files or Recipes.
(see link http://www.dvinfo.net/conf/showthread.php?t=62835 )

Nr: 5 Use A GOOD TRUE RES. HD MONITOR, and it is good to use a Waveform Monitor to measures the brightness of the video signal and a Vectorscope. I use DV Rack. for mesuring.
The Zebra on the camcorder can also be very helpful.

Nr: 6 Mind the Shutter-speed for exemple when shooting at 25p the shutter is set to 50 or more. But you know that :o)

About the Post:
on an mac-pro with latest FCP release I know it is a PURE NIGHTMARE!!!!!! ;o(
I realy hope that they have fixed this problem in FCP 6 that's just out.

Hope that helps some.

Keep on shooting. VIDEO I MEEN. :o)

Eric In Iceland.

Ps: sorry for my grammer not good ;oI

Claude, +6db is going to add alot of noise. You can avoid BG noise with two techniques. First have the camera correctly calibrated by using a WFM monitor and a DSC chart. The levels of blacks and gamma adjustment influence your latitude. Take a look at my settings at http://www.paolociccone.com and load the "TrueColor V.3" config and do some tests.
Second, avoid simingly uniform dark backgrounds. This is a problem for ma ny HDV cameras and it affects the JVC as well as the XDCAM. The problem is caused by the square sampling of 4:2:0 and the averaging that is happening. If you can break the BG with a pattern or slashes of light, even just a bit, you'll see noticeable improvement. Lastly, if you can use a good large HD monitor in the field it will help you check the noise before you go to tape. I captured a couple of problems in this way. I could not see the "buzz" in smaller monitors, including my PC with DVRack, you need a large screen or enough practice to isolate the problem spots.

Good luck.

+6 gain in HDV = bad news. Working in SD for 8 years I got spoiled using gain becuase you just couldn't see the noise.

Fast forward to now, I would never bump up the gain in HDV unless my life depended on it.

Claude- I guess you learned the hard way just like me!

This is a major enlightenment for me, which I'm sure to gain much from (ouch). Seriously, this helps me to understand why I had some very bad noise issues without gain. Large dark areas, but without pushing the camera - just exposing that way. It probably didn't help that I was trying to work with V3 settings on the HD200, but some other stuff came out great....

Sean, I would stick to the stock settings for the 200/250 until I get TrueColor ported to that camera. Without testing and verifying both the latitude and the colors, using an HD100 "recipe" is a shot in the dark.
Regardless, a solid wall in darknes will be always very challenging for any 4:2:0 cameras. As I mentioned, this affects also higher-end cameras like the XDCAM which has a 1/2" sensor and captures images at 1920x1080 (1440x1080). It's just the nature of the codec. Now, if you really need to get rid of the noise there is a possible solution, depending on how much time you can spend with it.
Go to http://www.silhouettefx.com and buy the Roto plugin. Get yourself a Wacom tablet and load the clip in AfterEffects or FCP. Rotoscope the area with the noise. Silhouette Roto makes this job much, much easier. Use the B-Splines instead of the Bezeier curves for faster work.
Apply a dose of blur and watch it blend!

I really agree with previous posters: try not to use the gain swith, and if you really must the max gain is +3 dB, that already results in grain and noise and overal soft look of the image.

As I shoot quite a number of events I don't always have perfect light and must live with whatever is available. I found out by now that this camera is not very well suited to low light situations. As long as you are aware of this you can anticipate on this during a shoot. Paolo Ciccone settings ar a must by the way.

Regards,
Erwin

Yep. What he said....

This is great advice for shooting HDV. This forum is a wealth of info.

Drew

Thank you Erwin. BTW, one thing that I have to mention that came up on several discussions: TrueColor has been calibrated to go from the darkest area of the FrontBox HD chart up to the brightest with perfect rendition of every step of the grayscale chart. This means that blacks are rendered evenly from 0% up to 100% in the WFM. I designed the same color configuration for the Canon A1 and the difference in latitude was obvious. The extra $2000 of the HD100 buy you, among other things, the extra latitude.
One thing that is not obvious though is that you get definition in the blacks even when it's not evident by naked eye when monitoring the shot. To see this in action you should run some test and then load the footage in your NLE and do some color correction. When using FCP, load the clip, add some Color Correction 3-Way to it and bring up the blacks 3 or 4 clicks. You should see more detail in the dark areas. This is the verification that the camera recorded the different tones of black. If the blacks were crushed you wouldn't see any additional detail. I see this happening all the time.
Even when you don't have the chance to control lighting, the use of the DSC chart for contolling the exposure can save your butt. If you place the chart in the critical area of the shot and you're able to see all the 11 grayscale steps then your exposure is correct. Verify the other end of the exposure it with zebras on for the white chips then you're all set.
Also, remember that the stock lens tend to loose light as you zoom in, if you're at the limit of available light try to go wider a bit, that will give you a bit more light reaching the CCD.

thank you all for the wonderful response.

- Stephen, enclosed is a screenshot regarding the greys. I don't have one for the reds but the artefact is this: instead of decreasing uniformly away from the light source (spotlight trained on an object on red background) the brightness decreases in visible steps, almost like circular gradients. No, we didn't vectorscope. We'll do that.

- Eric, unfortunately I could not add more lighting because we shot in a museum so a) some areas had total lux restrictions plus b) in some rooms (like the one in the screenshot ) I didn't have enough budget to bump up the overall level as this would have required 20-odd additional Dedolights and taken a full day - it was only a screener after all.

-Paolo: the blacks were actually very impressive, beautifully velvety with still enough detail. So, you are absolutely right about the camera's potential in the blacks. I loved that and it's important to me because I am very keen on night/dark scenes. I'm not sure HDCAM does soooo much better, at x-times the rental and post cost, of course, and HDCAM yields a more sterile, clinical image quality.
Thanks for the cleaning tip!

- Erwin, the JVC overall gave such a wonderfully "FILM" result that I would put up with a lot. Only noise and artefacts are not acceptable. Actually, it was my understanding that it is well suited to low-light because it has "only" 720 lines... so what's the general position on this ?

Claude

What you get from HDCAM is higher resolution and 2/3" chip which, objectively, will give you shallower DOF. Also, you get better selection of lenses like the E-Series and C-series Fujinon. Of course the cost of rental doesn't even come close but, for cinema-style work, it's hard to beat.
Kinda in the middle between the two there is the XDCAM. 1/2 the cost of renting an HDCAM, excellent use of lenses, shallower DOF than with a 1/3" chip and, at 35Mbps, amazing image quality even when recording straight to the optical disc. I actually mixed footage between the HD100 and the XDCAM and they work well together :)

Paolo, specifically for dark interior scenes, night scenes etc. or even more extreme: street scenes at night with little additional lighting but passing car headlights etc, how does this JVC series perform ? I do a lot of those, a lot more than shooting in bright sunlight where DOF could be a major issue.

Now, of course, for DOF , by the time I have a P&S adapter (which is noisy and ) and a set of prime lenses and follow-focus and and and... rental cost will be up there with a HDCAM :-(

I can be shooting standard def on 2/3" chips and still want a little more low-light capability. A 1/3" HD chip is trying to fit twice as many pixels in a quarter of the area. That just ain't happening without making some sacrifices.

Tell you the truth, I haven't done any of that but I might test it tomorrow night. I'll let you know.