XH A1 grain

[Jim Simpson]

hello,

i just got my xh a1 and can't seem to get the type of picture that i see samples of online. My picture is grainy. I have read on this forum about every thread i could find and have adjusted settings in manual and have gain down and i'm using some of the presets available here. It's definately better, but looks sd not hd. The colors just have so much grain to them. I have seen several threads started on this topic but i couldn't find a resolution.

Any help would be great i'm in a time crunch for shoot on friday.

jim

[Jim Simpson]

I am uploading two pics. They are a little skewed by my export but the picture looks the same.

This first one is in good lighting but look at the poor color, it's grainy.

http://shiftministries.org/vbs/Sequence%2001.bmp

This second one is in low lighting

http://shiftministries.org/vbs/Sequence%2002.bmp

Do i have a bad camera or am i missing something?

[Chris Hurd]

Hi Jim, are you certain that the AGC slide switch is set to the Off position?

[Jim Simpson]

Yes i just double checked. Can you see what i'm talking about in the samples?

[Benjamin Hill]

Jim, I would say that the pictures appear grainy to you because this camera needs more light than is available in either one of those shots. They don't appear grainy to me so much as dim. These Canon HDV cameras can produce extremely sharp and clear images if there is ample light to work with. Without enough light their video gets sorta dusty (for lack of a better word).

I was taping with the XL H1 recently and accidentally had the gain turned on- now THAT was some grainy video. These pictures, there's just not a lot of light.

[Jim Simpson]

i just keep seeing other shots that look so much smoother. There is one i saw last night in a thread here of a guys snake and it was dark, but looked great.

[Bogdan Tyburczy]

There are many factors involved. Light is fundamental, but there are also custom parameters in the camera that you can adjust to achieve best results in particular conditions. Take time to read other posts on the forum. There is tons of useful hints and tips here. Experiment with camera's settings and both noise reduction options.

[Daniel Browning]

Originally Posted by Jim Simpson

i just got my xh a1 and can't seem to get the type of picture that i see samples of online. My picture is grainy. I have read on this forum about every thread i could find and have adjusted settings in manual and have gain down

When you say you have gain "down", does that mean -3db?

Originally Posted by Jim Simpson

and i'm using some of the presets available here. It's definately better, but looks sd not hd.

Are you saying that the noise is obscuring so much detail in the image that it looks like standard definition? The frames you posted don't bear that out.

Originally Posted by Jim Simpson

The colors just have so much grain to them.

I don't see that much noise in your stills, although I hate to see interlaced. Noise can be caused by a warm sensor (30+ minutes of shooting), narrow spectrum light (tungsten), or dark scenes (low key). Your stills obviously had the latter two, and probably the former. If you want a dark image with low noise, it's best to shoot overexposed then burn it in post. If you shoot underexposed, you're reducing the signal ratio.

[Jim Simpson]

i shot at -3db and only shot each one briefly and hours apart. What do you mean by burn it at post. I use premiere CS2. What can i do there to correct some of the picture. Also what can i do about interlacing. Sorry for silly questions i'm just trying to learn.

thanks
jim

[Chris Soucy]

Hmm, well, can honestly say that's some of the worst A1 HD I've ever seen (heck, my XL1s takes better video than that!).

No idea what the banding I'm seeing is about (if that's what Daniel means by interlace) but yep, it's horrible alright.

I haven't shot a lot of A1 stuff in bad light, so can't really comment, but one test you really ought to do is:

Get a sunny day, go out when you've got blue sky, white and fluffies floating by, and shoot some of the most complicated stuff you can find @ -3 db. Forget all the presets and other stuff, just let the camera do what it can do on it's own.

Look at it on a REALLY good HD screen (straight off the camera - no NLE) and see if it looks anything like that stuff you posted. If it does, you have a serious camera problem. If it doesn't, you have a serious light/ presets/ other problem.

I normally shoot in really good light (hey, that's when everything looks so great) and can assure you that the picture from my A1 on a true HD screen just blows your socks off. Not a trace of grain or banding nor anything else whatsoever. And yes, I shoot 50i ,'cos it's cleaner(IMPO).

If you don't do that test, you have no benchmark against which to measure anything.

Just my 2 cents.


CS

[Paul Cronin]

I agree with Chris hook the camera up to a HD monitor and go through all the settings. This will give you the opportunity to see what combinations work and don’t work. Also it is a fun way to learn the camera and experiment with all the settings. Don’t be discouraged I went through the same process and now have great results with the A1.

[Don Palomaki]

To get a good shot you have to set-up a good shot, and that includes appropriate lighting for effect you want to achieve. How does the footage look on a TV? Hard to say what the deal is other than that the images are not great - with out knowing the full parameters of the shot, and keep in mind that stills from video will rarely look as good as stills from a real still camera.

What were the camcorder settings you used in the images?
What were the presets?
The lighting?
White balance?
What were the exposure parameters (you may be able to read them from the data code)?

Considering the gradient in the interlace artifacts, were these captured from a sequence that include both pan/tilt and zoom?

[Matthew Nayman]

To help out a bit, I de-interlaced Mr. Simpson's image. here it its. You should also correct the aspect ratio to 1.33 which is HDV 16:9 (for a 1440x1080 image)

http://www.notomatofilms.com/1.jpg


Doesn't look terrible to me. I am curious as to your settings? Are in 60i? 30i? 24f? DO you have noise reduction on? What gamma curve are you using? Do you have any gain turned on? Are you sure you're focused right? What's your f-stop? Shutter speed?

Need a full list of the facts before we can diagnose.

[Daniel Browning]

Originally Posted by Jim Simpson

What do you mean by burn it at post?

Darken with effects. Getting noise-free digital video in dark scenes is a bit of an art. The easy way out is to just use some noise reduction software like Noise Ninja. A higher quality solution is to overexpose without blowing highlights (that means the dynamic range of your lighting should be even smaller than the already small range of the camera), then darken it to the level you want in post.

Doing it that way gives the sensor a much higher signal-to-noise ratio, which yeilds far fewer noise pixels.

Originally Posted by Jim Simpson

Also what can i do about interlacing.

In the menu, change from 60i to 30F or 24F.

[Jim Simpson]

First of all i have a hd monitor that i have hooked the camera up to and played with. The images are sharp but the colors look grainy. Hope that helps some.

As far as settings.
In the first shot
i used the preset panavision
-3db gain
fstop unsure
shutter unsure
White Bal A
AGC off
AWB off
60i

On the second shot
i used the preset standard film
-3 db gain
fstop 1.6
shutter 1/100
White Bal A
AGC off
AWB off
60i

I just shot some outside footage and i'll load a pic in just a moment.

Hope this helps. I appreciate all of the helpful suggestions.

jim