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-   -   Can the split screen problem be fixed in post? (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/55128-can-split-screen-problem-fixed-post.html)

Bill Edmunds November 28th, 2005 09:21 AM

Can the split screen problem be fixed in post?
 
Obviously adjusting the video level of one side of the screen would be easy for most editing apps, but does it work satisfactorily? Is anyone doing it?

Michael Maier November 28th, 2005 09:28 AM

Bill, the best thing is to learn how to work around the split effect. It's not really difficult and with a little of basic video and cinematography knowledge you can easily do so. I have been shooting with the camera for a while now and I haven't yet found a situation where I couldn't get around SSE.

Bill Edmunds November 28th, 2005 09:31 AM

Quote:

Originally Posted by Michael Maier
Bill, the best thing is to learn how to work around the split effect. It's not really difficult and with a little of basic video and cinematography knowledge you can easily do so. I have been shooting with the camera for a while now and I haven't yet found a situation where I couldn't get around SSE.

I believe the issue occurs on low light where the gain is boosted to 9db and above (?). The problem is that I often shoot events where you cannot use supplemental lighting and therefore have to use a gain boost. Any suggestions? Do you try to keep gain at below 9db and use supplemental lighting?

Michael Maier November 28th, 2005 09:40 AM

That's one of the things, but SSE doesn't only show up with gain or in low light.
Sometimes it goes away or lowers substantially after the camera is warm. Sometimes it goes away if you play around with the iris. Other times if you just slightly move the camera or change the angle in relation to your key light will affect it too.
But honestly, if you need a stealth type of camera for shooting extreme low light stuff where a nightvision would be more useful than a camcorder, the HD100 is not your camera. You will be better off with a PD170.

Tim Dashwood November 28th, 2005 10:56 AM

Quote:

Originally Posted by Bill Edmunds
Can the split screen problem be fixed in post?

Short answer: yes.

Luckily it happens exactly at the 50% across the frame, so it is easy to duplicate the clip onto a new video layer, apply a 50% crop and then slightly adjust the black levels until it looks the same. Under some conditions if preset white balance was used, one side may have a slight magenta tint to it. This is also very easy to compensate for in most NLE colour correctors.

The only complication is when it "flickers" in and out in under some conditions. This would complicate things.

However, because of the conditions it seems to present itself, I find it much easier just to crush all the blacks a little bit - which is what I would normally do anyway. I hate milky blacks.

Bill Edmunds November 28th, 2005 11:05 AM

Quote:

Originally Posted by Tim Dashwood
The only complication is when it "flickers" in and out in under some conditions. This would complicate things.

Ugh. I'm now wondering if the camera is more trouble than it's worth? Or does it happen rarely? I can't believe JVC hasn't come up with a solution to this.
Quote:

Originally Posted by Tim Dashwood
However, because of the conditions it seems to present itself, I find it much easier just to crush all the blacks a little bit - which is what I would normally do anyway. I hate milky blacks.

Do you mean you crush the blacks in-camera or in post? Does this eliminate the issue altogether?

Michael Maier November 28th, 2005 11:08 AM

Quote:

Originally Posted by Bill Edmunds
I can't believe JVC hasn't come up with a solution to this.

The only solution JVC could come up with was to give the HD100 no native 720p CCDs, meaning a lower resolution chip with pixel shift(yack).
Otherwise, no technology currently exists.

Tim Dashwood November 28th, 2005 11:14 AM

Well look. For all practical purposes the SSE will never show up. The only time I can make it show up is on a flat wall, stopped down so that the resultant exposure is under 10 IRE.
Nate Weaver and I (and I'm sure others) have been successfully using the camera for paid gigs and the SSE has never been a problem - even in low light. I am always on the lookout for it, but it is quite easy to spot in the viewfinder, so it never worries me.

If you want to be able to run & gun shoot and not think about it, then the camera probably isn't for you. In that case you should stick to a prosumer camera with some auto features and never look back.
If you want the next best thing to the look and style of shooting super-16, then the HD100 is right for you.

If you don't believe that the camera is capable of shooting in low-light on 0db, then just check out Nate's latest music video. His only sources were a couple 2x4 kinoflos and the shutter speed was never brought down below 1/48. (I think the foot stomping was 1/100)
http://www.dvinfo.net/conf/showthread.php?t=55111

Bill Edmunds November 28th, 2005 11:28 AM

Quote:

Originally Posted by Tim Dashwood
Nate Weaver and I (and I'm sure others) have been successfully using the camera for paid gigs and the SSE has never been a problem - even in low light. I am always on the lookout for it, but it is quite easy to spot in the viewfinder, so it never worries me... check out Nate's latest music video. His only sources were a couple 2x4 kinoflos and the shutter speed was never brought down below 1/48.

That is very cool. So exactly when does the split screen effect happen? Can you predict it? The reason I'm worried is that I tested the camera at a dealer's shop and, sure enough, I saw it clearly. But like you said, it was against a flat wall. Does adding some "texture" to the image effectively get rid of it? In other words, if there was a person in the frame, would that have made it go away?

Tim Dashwood November 28th, 2005 12:11 PM

Quote:

Originally Posted by Bill Edmunds
That is very cool. So exactly when does the split screen effect happen? Can you predict it? The reason I'm worried is that I tested the camera at a dealer's shop and, sure enough, I saw it clearly. But like you said, it was against a flat wall. Does adding some "texture" to the image effectively get rid of it? In other words, if there was a person in the frame, would that have made it go away?

It is completely predictable. It isn't just flat walls, it can be flat anything and you will see it. Put the lens cap on and crank the gain and you will see it eventually. Go outside on a completely clear or completely overcast day, point the camera at the sky, turn the ND filters on, and then stop down until everything is dark gray and you may see it.

If by "adding texture," you mean a stucco wall, then no that won't make a difference if the pattern is consistent. However, use a cookie to break up the flat light, or stick a subject in the frame and it may just magically go away.

I forgot to mention before that I found on my camera if I set the master black to -3 I can't prod it into showing up at 0 to +6dB. I'm not sure if Nate crushed his master black on that music video, but I'm pretty sure he crushed some black on the final colour correct. I saw some of Nate's original shots in HD before colour correction and there wasn't a sign of SSE.

Bill Edmunds November 28th, 2005 12:14 PM

Quote:

Originally Posted by Tim Dashwood
It is completely predictable. It isn't just flat walls, it can be flat anything and you will see it. Put the lens cap on and crank the gain and you will see it eventually. Go outside on a completely clear or completely overcast day, point the camera at the sky, turn the ND filters on, and then stop down until everything is dark gray and you may see it.

But the key is "flat" and "dark"? If you stopped it down, pointed it at a clear blue sky and then panned over to some sky with puffy clouds, it is likely to go away when the clouds enter the picture?

Tim Dashwood November 28th, 2005 12:38 PM

Quote:

Originally Posted by Bill Edmunds
But the key is "flat" and "dark"? If you stopped it down, pointed it at a clear blue sky and then panned over to some sky with puffy clouds, it is likely to go away when the clouds enter the picture?

Good question. I've never tested that particular type of shot on a sky so I can't difinitively say yes - but likely. If the sky was properly exposed it wouldn't be there in the first place.

Huiy Tang November 29th, 2005 03:47 PM

Fixing one frame is one thing. I took dashwoods advic and tried shifting the blacks and correcting the split screen. It does help improve, but not necessairily eliminate the Split Screen entirely. One frame took me a several minutes of tinkering with the perimerters. Imagine doing several hundred frames if the Split screen is up for several seconds. For me it isn't worth the trouble of correcting something that shouldn't even be there in the first place.

Michael Maier November 29th, 2005 04:01 PM

Quote:

Originally Posted by Huiy Tang
Fixing one frame is one thing. I took dashwoods advic and tried shifting the blacks and correcting the split screen. It does help improve, but not necessairily eliminate the Split Screen entirely. One frame took me a several minutes of tinkering with the perimerters. Imagine doing several hundred frames if the Split screen is up for several seconds.

Another alternative is buying the camera with a professional D.P. in the package.

Steve Mullen November 29th, 2005 05:33 PM

Quote:

Originally Posted by Huiy Tang
Fixing one frame is one thing.

The should be no problem for someone to write a simple Black level and White level control routine that gives you controls for both halves of the image or a balance control for both halves.

If it was one parameter (Black level) it could be key-framable.

Likewise, it seems to be red that may differ -- so a red balance control would be a natural. Also could be key frameable.

Could do RGB, too.

This is a near trivial routine.

A smart routine would find black and white objects that cross the split and compute the correction.


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