Do Plug-Ins like Nattress Film Effects Degrade Image

A Cinematographer in the latest issue of American Cinematographer states that when manipulating the colors on a feature film shot in HD, that these changes degrade the captured footage. Is this true for any video? And what about applying plug-ins like the Nattress Film Effects? Will this also damage or degrade the image quality?

That's true for compressed processing (speciially with heavily compressed codecs like HDV), but not so for uncompressed timelines. In that case, there's minimum or no degradation.
There are also other things to consider. Sometimes when you use an effect to modify the look of an image, you're perhaps technically supressing information but getting a picture which is more pleasing to you in subjective terms (which is what really should matter, right?)



Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com

<<<uncompressed timelines. In that case, there's minimum or no degradation. >>>

There is always degradation. Even in uncompressed work, you only have 8 (or 10) bits to play with and if you do something as simple as making the picture very slightly brighter, there are pixels in the dark regions that need to be doubled up and pixels in the bright reagions that will be lost.

We have a standard definition commercial right now that has three overlayed special effects timelines running at the same time. We were forced to affect all those effects (so to speak) and we're hoping the degradation isn't too bad.

Certainly as the quality of the original work degrades, filters and tools damage the look much more. If you stop an HDV movie in real size on a glass monitor, you can see the damage and you haven't even applied any filters yet.

Koz

Greg: What you say is technologically correct, but a bit dangerous in the context of the question. What should matter is "noticeable degradation". Because Brent might get the idea" I better not touch anything". So, Brent, the idea is that in a production workflow some degradation will ocurr. Some of it you can and want to avoid (by your equipment and worfklow choice), and some of it can be done in a way nobody will really notice and actually allows for an image that looks better to you, other professionals and your mom.

As I said, in an uncompressed timeline, there is minimum or no degradation (because most sources are already 8 or 10 bit per channel with 4:2:2 sampling or less, so you're not really reducing information per se). If you to Marco Solorio's site, you'll see that there are codecs that actually produce a result which is a pixel by pixel clone of the source, ie, no degradation in the processing itself. If that's not enough Shake, After Effects 7, etc can process in 32 bit float and import/export 32 bit files where degradation could only be measured by mathematicians.

On the other hand, most color correction operation supresses some image information but still a well corrected image usually looks much better in subjective terms that the uncorrected one. That's what matters.



Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com

Adolfo & Greg

Thank You for your help. I am still somewhat confused. I know what a "Time-Line" is, at least I think do... unless there is another time-line other than the time-line I work in FCp up on the screen with my edits and so forth. But what do you mean by "uncompressed time line?" And what does Greg mean by "multiple time-lines?" I thought there was only one time-line.

So there is software that I can by that will correct or enhance the pixel rate? If so... i want one!!!

Man, I'm confussed.

Brent: I can understand your confusion.
Uncompressed timeline is a way in which us video geeks mean a Sequence which is set up to edit and process (if needed) images with an uncompressed codec.
If you use DV, for example, your sequence (timeline) is set up to work with DV codec, which is not uncompressed (the processing is not lossless, though pure editing and capturing is).
Multiple timelines... FCP and most contemporary professional editing software allow you to create several sequences (timelines) in a single project (to make it simple!). This allows for many things. For example, having two or more versions of an edited pieces, or using a sequence as if it was a clip inside another timeline (these are called nested sequences).
If you have these questions, which are completely understandable, I would say: don't worry about what you read, image degradation won't be as bad as you could imagine. People who are really envolved in really professional productions may have more strict needs.



Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com

Adolfo

Thank you for your time. It's too bad that I have been doing this off and on for better than ten years, started on the Media 100, and FCP two years ago, and didn't even know I could work with multiple time lines.

Whew, man.

I have a long way to go. I am working with Mini DV shot with an XL2. Even though it is only DV, I like to treat it like it were 35mm, wich is what i work with most. I want the best picture possible with whatever medium I work in. It scares me a bit to think that by applying filters and such that I am actually degrading the image some. I'll have to get over it.

One last question. You say that there is software that can help maximize the quality and integrity of my video? Can you fill me in a little more?

<<<I'll have to get over it.>>>

Not entirely. If you work in DV, the picture has been compressed so it takes up less room on the tape and in the Mac. The problem with editing with compressed material is the machine has to uncompress it to apply an effect and then recompress it again.

I think we said up there that each pass through compression/decompression exacts a toll on the image. Almost all video compression is slightly distructive. If you look really closely, you can see the area that you, for example performed a dissolve, the picture isn't quite as perfect as it it everywhere else.

You're a film person. Good. You know when you send to the lab to get a film dissolve, they have to be really careful to match the frames or you'll see the work. Or an older film where the dissolve portion has deteriorated and you can see it. The same thing happens in DV. If you mess with the image enough, you may start to see the picture deteriorate. You do have to pay attention to this.

You just don't have to lose sleep over it.

Unless you want to.

Koz

Brent: If it makes you feel better, I will say that some of the very best film editors I know barely know how to turn a computer on Of course it's a great thing learning the deep possibilities of software, but we are all different and each has his or her strategy to reach a creative potential.

Let me oversimplify things a bit.
DV compression is really nasty for people (like me unfortunately) who do very graphics/design/effects oriented work. But it works quite well as a camera codec. If you're doing narrative work, you don't have to worry that much. The effects you will want to use are probably not in the territory where DV stinks

To put things in perspective: three things where the DV codec really shows its limitations are chroma keying, secondary color correction (replacing certain hue in an image by another) and text animation. Is there a lot of those in your work? If there isn't, you will be just fine! (if you do need those, there are workarounds).

Yes, there is software out there which helps with DV's ugly side. The coincidence is... that one such tool comes with Nattess Film Effects! It's a plug-in called G Nicer. It's really good at reconstructing damage produced by DV's low color sampling, but you know what? It's completely useless if you go back to DV tape for your master: simply because you would be going then through DV compression again. Avoiding this requires devices which allow FCP to go out though uncompressed outputs to a non-DV deck (usually really expensive).



But as I said, don't get the idea that you really need all that. The DV workflow has been and will continue to be just fine for a lot of things, especially narrative work, and it's cost effective and easy to use. If some time down the road you really feel limited by DV (or HDV) we can have this discussion again
Meanwhile, trust your eyes. If it looks nice to you, it will probably look nice to others.
The XL2 produces beautiful images, by the way!
All the best



Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com