(Page 2 of 2 pages for this article  <  1 2)

Filed under: Cameras •Post Production •Production •Tips •Visual Effects •

Tiffen DFX 2 Digital Filters

There aren’t a lot of controls in the typical Tiffen DFX filter, which is fine by me. The filters themselves are specific enough that you don’t need too many controls: the optical properties of each filter type are built in to the filter, so instead of constructing a look you are only finessing the strength, color, or where it’s applied.

I picked the “Glow” filter as a generic example. Here’s the original image:

This looks pretty nice, but it could look better. There are some small skin blemishes that could use some cleanup and the skin texture could be smoother. This kind of adjustment isn’t a “make or break” tweak, but it will definitely take this shot to a level beyond what I could capture with an inexpensive camera on a low budget.

Here’s what happens when I add the “glow” filter without any tweaking:

This is a bit heavier than I’m going for, but it gives me a coarse idea of what the filter will do. Let’s do a little tweaking with the filter controls:

The checkbox next to “Glow” enables or disables the filter’s effect. This is what I like the most about packages like DFX 2 or Magic Bullet Looks: you don’t need to leave Final Cut Pro to do your color grade the way you do in Apple’s Color. Everything is done in the timeline, which (after rendering) allows me to not only immediately see the new look in the context of the edit and the audio, but also allows me to quickly turn the effect off, or adjust it, if it doesn’t work as intended. Shots rarely stand alone and must be viewed, and graded, in context with the shots that occur around them. A professional colorist might be able to grade a completed project in one pass, but I tend to tinker and play with looks and it helps me to do this without leaving FCP.

Filters can be stacked and it’s simple to turn them on and off to see what combinations may work for the scene. Every change results in rendering time before the clip can be seen in motion, but results can be seen in still form immediately.

The “View” option determines what we see while tweaking the filter controls. The three options are “output”, which shows the image with the filter applied; “original”, which shows us the original image, or “selection”, which drops us into a black-and-white mode that helps us isolate specific parts of the image where the filter will be applied. More on this shortly.

“Blend” is a fairly powerful tool. The “add” option simply adds the bright glow effect to the image without much discrimination. This setting would work well if there weren’t many bright highlights in the shot already, as “Glow” would create them. IN this case, as I already have highlights in the image, the alternate option, “screen”, preserves the highlights and offers a higher degree of subtlety. For this image “screen” is the blending mode that we’ll use for the final look.

The “Brightness”, “Horizontal Blur” and “Vertical Blur” sliders that appear beneath the “Blend” pulldown menu only affect the areas to which “Glow” has been applied. That can be the entire image, or it can be portions of the image that we’ll select below. “Gang blur” syncs the horizontal and vertical blur sliders so they travel together, although if you’re going for an anamorphic look you could uncheck that box and increase the amount of horizontal blur without affecting the vertical blur.

“Color” determines what color the “Glow” filter highlights will be. That’s pretty handy. If you want the highlights to glow white, as they would when using white diffusion, then you’d leave this alone. If you wanted the look of a flesh-colored nylon stocking behind the lens you might want to change this. We’ll do that below.

The six options below “Color Correct” apply to the entire image. Sometimes applying a filter overall will dramatically change the image in some way, so this section allows you to do an overall compensation for the filter’s effect. For example, if you wanted to apply “Glow” to the entire image but the blacks became very milky then you’d be able to compensate overall by manipulating “contrast”, “gamma” and “brightness” here.

“Selection” is probably the most useful tool here. “Position” and “range”, however, aren’t the most intuitive labels for these controls, so let me try to explain what they do in better terms:

When using the “position” tool we need to change the “View” pulldown menu at the top to “selection”. DFX shows us this black-and-white image:

“Position” divides the image into bands of brightness, and by moving the “Position” slider I can select a range of highlights, mid-tones or shadows. The bright areas in the selection preview are what “Glow” will be applied to, while the dark areas will be ignored. Right now “Glow” will be applied to nearly everything in the shot to some degree because there’s very little that’s truly black (“unselected”) in this image. I want to isolate the flesh tone highlights, primarily on the legs, so I’m going to move the “position” slider until those highlights are the brightest things in the image:

You can see that I’ve still got too much of the image selected, but I’ve made the flesh tone highlights on the legs as bright as they can be. I’ve used “position” to determine which slice of luminance values I want to affect the most, and now I’ll slide “range” down to reduce that slice to just what I need:

I’ve retained the bright areas of flesh tone as selections while eliminating most of the folder and clothing. The martini glass will still get a little bit of glow but I’m good with that.

Here’s what the controls look like afterward:

There are a couple of things to notice here:

The color of the glow has changed. I used the eyedropper tool to sample the darker flesh tones and add that color to the filter effect. This gives the flesh tone highlights a bronzed effect.

I’ve changed the “Blend” option to “screen”, so instead of adding glowing highlights to already bright highlights and taking them way past clipping, the glow effect will be blended in a way that preserves the highlights that already exist without blowing them out.

You can see the new “position” and “range” settings. “Position” is set a bit lower than it was initially, and “range” is set dramatically lower in order to isolate a narrow swathe of brightness levels. (It might help to thing of brightness as a pie, with “position” selecting a slice and “range” determining how big that slice is.) I didn’t use the “blur” slider as that feathers the selected area and I wasn’t really interested in doing that. I’m being very specific as to what portions of the image I want to affect.

“Force 16-bit processing” is a neat trick: it takes your footage, which in this case is 8-bit DVCProHD, into a 16-bit color space for manipulation. After the effect has been applied the result is transferred back into 8-bit space on your timeline. This can help smooth over some odd artifacts that can creep in when manipulating 8-bit data, such as banding due to rounding errors. If you have a fast enough machine that the render times don’t become prohibitive, I recommend turning this on.

“Mix” affects the opacity of the effect. In this case I want it full up, so that’s about where it is. Adjusting this slider changes the filter’s transparency, with 0 totally eliminating the effect and 100 being completely opaque.

Here’s the result:

It’s a subtle effect, but then the best ones usually are. I don’t want to telegraph that I used special filtration, I just want the audience to respond to the look. I think you’ll agree that this is a silkier, smoother look than the original. Here’s the difference:

One thing that I’m not showing, due to my making the control panel as big as possible, is that every aspect of this filter can be key framed. Every adjustment can be set to change over the course of the shot. You can’t do that very easily with a glass filter.

Tiffen DFX 2 contains digital versions of popular Tiffen diffusion filters as well as a host of other effects that could prove handy. One of my favorites is “Halo”, which emulates the “diffusion in the telecine path” look. For those of you who weren’t around in the 80’s, putting diffusion in the telecine was quite popular: by putting a diffusion filter in the optical path while scanning color negative film the diffusion effect was reversed, so instead of causing highlights to glow the shadows bled into the highlight areas. It’s a very interesting effect. Give it a try in Photoshop by inverting an image, applying the “diffuse glow” filter, and then inverting it back to normal.

I’ve got the Final Cut Pro DFX plugin, but you can get it in a stand-alone version as well as in plugin form for Photoshop, Photoshop Elements, After Effects, Autodesk Combustion, and several flavors of Avid.

Art Adams is a DP who positively glows about post color correction. His web site is at www.artadams.net.

(Page 2 of 2 pages for this article  <  1 2)

                   

 

NAB 2012: Assorted Snapshots Adam Wilt | 05/08 A few cool things I saw at the show that didn’t fit into any other articles. NAB is too big a show in too short a time to see more than a fraction of it. I’ve covered a few things in some depth (as have other PVC folks), but there’s plenty more that slips by without proper coverage. Here, I have a few photos…

Color Correction Practice Game Steve Hullfish | 05/05 Test your skills, improve your eye I found a very cool little site that tests your ability to match a specific color based on hue, saturation and brightness. At first, I thought it was just kind of cute,…

NAB 2012: SpectraCal Scott Simmons | 04/28 This may be one of the most affordable monitor color calibration systems. One little booth I happened to come by as I walked the NAB show floor was SpectraCal. A bright red screen with a little…

You must be registered to comment. This is an effort to reduce spam. Please REGISTER HERE.

Art,
Thanks again for sharing these tips.  The before and afters are terrific examples.
 
Everything I read about in regards to color correction and effects discourages the use of FCP due to the limited bit depth workspace.
When working with HVX-200 media, are you staying in DVCPRO 8bit or are you working in Pro-Res 10bit?

Posted by .(JavaScript must be enabled to view this email address)  on  05/08  at  10:43 AM

---

Hi Adams, this is a very nice blog..it give a good information on Dfx v2 multiple masking and layering features .. great blog..thanks for sharing

Posted by joe  on  07/02  at  12:02 AM

---

Name:

Email:

Location:

URL:

Smileys

Remember my personal information

Notify me of follow-up comments?

Submit the word you see below: