Auto Video Level Correction?

Ray Musicbear · Post by **Ray Musicbear** » Wed Mar 23, 2005 9:45 am

Does VideoStudio 8 perform, automatic video, brightness/contrast correction?

After capturing my first video into VS8, I noticed that the light levels
were quite different than what I saw on my LCD, and on my TV screen
when I first previewd them.

Overall, the videos seemed much darker than they appeared in their
native format when I shot them and viewd them. As I view the video
clips in VS8, it almost seems like the lighting values change drastically.
At first, the lighting is fine, then the overall ligting seems to darken.
The video starts out bright and then darkens as it plays in VS8.

I captured my videos in DV-AVI format into VS8.

Any thoughts on this?

Gra · Post by **Gra** » Wed Mar 23, 2005 11:52 am

Hi Ray

I have a similar problem with light differences and also any shaking becomes more pronounced when viewed in VS8. I posted my question and it seems that the difference in viewing small screen LCD and larger screen is because the smaller screen condences things and any variations seem less pronounced until seen on large screen. I capture now to DV Type 1 as the percieved preference. Have you applied the light and colour balances filters? That can make a big difference but you need to play around a bit to get the right balance and contrast.

Having said that, I look forward as well to hearing from anyone that may have any other solutions.

Regards.
Gra

Ray Musicbear · Post by **Ray Musicbear** » Wed Mar 23, 2005 6:51 pm

Hi Gra,

Thanks for your reply.

You mention you capture to DV Type 1, is that VS8's default?

If so, it is the formati I've captured my video with, since for this
first time use, I went with all of the programs defaults.

It's funny, as I said above, I have not only viewed my video on
my LCD screen, I have also connected my cam to my TV, and
did not notice the darkened images I saw when viewing in VS8.
This is why I suspected auto image brightness correction.

As yet, I have NOT used any of the correction filters, that is next,
because right now, the overall image is way too dark.

Thanks

THoff · Post by **THoff** » Wed Mar 23, 2005 8:02 pm

UVS applies no default filters to captured video.

What you are experiencing are differences in the color and brightness of the display devices. Professionals always preview video on an attached monitor (not computer monitor).

UVS can be configured to send the preview to the Video Out of a dual-head video card, or even a DV device. If you have a camcorder that supports pass-through, you could send the video back to a TV. If you take your captured video and send it back out, it should in fact look identical to playing the video tape in the camcorder on your TV.

Post by **Ken Berry** » Wed Mar 23, 2005 9:40 pm

As a supplement to THoff's reply, you need also to be aware that the preview screen in Video Studio (and for that matter in most other editing programs) is not particularly good. But remember that it is no more than a preview screen -- only meant to give you a general idea of what is going on, what an effect looks like etc. Generally, it will look grainy and relatively dark compared to the original. As well as monitoring on an outside monitor, as THoff suggested, you could also (if that process is too difficult) try editing your video and then producing a video file and then burn it to an RW disc so that you don't waste a +/- R one if something goes wrong. This is what I always do. It is always my experience that the final burned video looks much better than it does on the preview screen. In fact, I sometimes have to pinch myself to STOP myself from applying the brightness/contrast filter which would make the video look better on the preview screen but too light in the final product.

Ray Musicbear · Post by **Ray Musicbear** » Wed Mar 23, 2005 10:07 pm

Thanks to all of you for your kind replies and helpful information.

I was concerned that perhaps I was applying some type of default filers, or that my camcorder was not functioning properly. You have cleared up my misconceptions about anything being "wrong" here.

I notice how much more grainy and dark the image is, as Ken Barry comments on in regard to the UVS preview screen giving a low qulaity image. It certainly does, doesn't it?

I also like Ken's suggestion of buring my preview to a DV-RW, and seeing what it looks like on my TV first. I am, of course, tempted to use the filters to brighten up the video, but as Ken suggested, restraint, because then the video will be too bright.

Thanks again for all of your helpful comments.

THoff · Post by **THoff** » Thu Mar 24, 2005 12:58 am

One terrible limitation of Videostudio is that the Preview window cannot be sized to match the project's output dimensions. Because of this, the video you see is always distorted and appears pixelated. Let's see if UVS V9 corrects this...

tomjscott · Post by **tomjscott** » Tue May 30, 2006 5:32 pm

I have a similar problem in VS7 and I have to disagree slightly with some of the comments here. Support from Ulead seems to indicate that there is no problem with the software, but I don't agree. My issue is that the rendering in the preview window shows the video at a very nice, bright level, but after it is done rendering, the final output is darkened considerably. I'm sorry, but if it shows the video bright when previewing and rendering in the Ulead preview window and then shows the rendered output darker in the same preview window, then something is wrong. I've had to apply a brightness filter to my videos to get the final render to match what I see in the preview window.

THoff · Post by **THoff** » Tue May 30, 2006 5:37 pm

It may be your video card and the driver for it -- not Videostudio -- that is doing a gamma adjustment of the hardware video overlay. The ForceWare drivers for NVIDIA GPUs for instance apply a default Saturation level of 114%, and other parameter adjustments are possible.

tomjscott · Post by **tomjscott** » Tue May 30, 2006 5:41 pm

I think you're missing an important point. The same preview window in Ulead shows the source video at a brighter level than the rendered output. How would the video card arbitrarily apply a brightness to the preview and not to the final output?

THoff · Post by **THoff** » Tue May 30, 2006 8:09 pm

You can't make any comparison between the Preview window, Windows Media Player, Media Player Classic, PowerDVD etc. unless you know exactly how different programs render.

Do they use the hardware overlay? If they do, do they use the Video Mixing Renderer? Do they apply proprietary video enhancement technology like CLEV-2? Does the program use hardware-assisted video playback?

The only way to get a good idea of what the final output will look like is to use the high-quality preview instead of instant preview (which does a render), and not use the Preview window -- output to a TV monitor through a DV device or a Dual Head device.

tomjscott · Post by **tomjscott** » Tue May 30, 2006 8:16 pm

You are still missing the point. I am not comparing the output to another program. I am talking about the SAME exact preview window in Ulead itself that is showing the source video bright and the rendered video dark. SAME window and SAME program.

However, I will try the high-quality preview that you suggest to see if that fixes the issue. I don't know what setting I curently have. This does bring up a point though. If the high-quality preview shows it dark and the quick preview shows it bright, then it still points to something odd going on in Ulead itself. Quality shouldn't affect the brightness/contrast levels in the preview window.

Post by **Ken Berry** » Tue May 30, 2006 10:11 pm

Tom -- sorry to jump in here, but to an extent, you are also missing an important point. In the more than 4 years I have been on this Board, yours is the very first time I have heard a complaint that the preview in VS is actually *brighter* than the final product. My first Ulead product was also VS7, and one of the first -- and discouraging at the time -- things I noticed about it was how dark and dull the preview was, but how much brighter and better it was when burned to disc. If indeed you are the only one with such a problem, then it sounds as though your problem is, as Torsten has already suggested, more likely to be linked to your computer's set-up than it is specifically to VS.

tomjscott · Post by **tomjscott** » Tue May 30, 2006 10:25 pm

Well, maybe no one has ever mentioned the problem before. I have had VS7 for a couple of years and although I've seen this problem since day one, I have never reported it. So perhaps there are many others out there that haven't said anything either. Also, I used to run this program on a completely different computer and had the same problem. I'm also an expert computer user with over 20 years experience. I can't imagine any possible way that this could be an issue with my setup. If it is, please explain to me how the following can occur:

1. Load source video file and preview in window. Witness nice, bright image.
2. Render to video file.
3. Play rendered output in same preview window and witness severe darkening of image.

Basically, we are talking about the same video card, same setup, same program, and same preview window. The only difference is source video versus rendered output. The computer isn't going to magically apply different video filters in one case and not the other.

Post by **Ken Berry** » Tue May 30, 2006 10:46 pm

It may very well be that there are people out there with a similar problem to yours. But the fact remains that I, at least, have never seen your specific problem mentioned before on this Board. If I am correct and this is the first time we have been confronted with the problem -- and moreover in a version which has been overtaken by 3 subsequent versions -- then we have never had to develop possible answers for it. None of us here work for Ulead. We handle problems as they are presented to us. Given that this may indeed be the first time we have heard about this particular problem with a 4 year old program, then it is only natural that we might think it is likely to be more particular to your computer (or computers) than the program itself.