Real Lens Flares
Schmutz (rhymes with “puts”) is the most complex Real Lens Flares core projection yet. At its simplest, Schmutz mimics the dust, debris, or smudging on a lens. When light hits such lens gunk, it produces artifacts like sparkling or defocusing. Aperture configuration and lens type will also impact these artifact characteristics.
As shown in the above image, Real Lens Flares currently ships with 12 Schmutz textures. (Taxonomy reminder: These textures should not be confused with presets, which are a broader collection of characteristics. For example, if you pull up the Holodeck preset from within the Dream State lens flare preset collection, you’ll see that its Schmutz core projection incorporates the Smudges texture.) As their names imply, each of these textures aims to emulate a different sort of lens debris effect. To illustrate, the images below all use the same Holodeck preset and control values; only the schmutz textures have changed.
While there is no way (yet) to alter and save a schmutz texture, you can change the orientation and appearance of how these textures manifest in flares. Many of the schmutz properties you’ll find in the Inspector Pane are identical to those found in other core projections and don’t need repeating here. Rather, we’ll detail the properties unique to the Schmutz core projection.
Tip: If you’re only going to work with one schmutz texture on a project and would prefer to hide the other textures, click on the small icon showing four squares located below the texture preview thumbnail, close to the Inspector Pane’s top-right corner. Click the four-square icon again to bring the textures menu back into view.
The Mirror control can quickly change the schmutz position so that its displayed orientation changes between scenes. For example, if you take a camera to the beach and capture two clips at two different times, the sand texture on the lens may change. Mirroring the schmutz along the horizontal and/or vertical axes can subtly convey this change.
The Defocus control applies a given amount of blurring to schmutz based on combining the aperture and schmutz images in conjunction with a blur percentage. You could say that the blur is seeded by the aperture, because schmutz shape will change based on aperture shape. You’ll see this manifest in reflection ghosts. Defocus values can range from 1% to 100 percent.
In the left image below, you can see how the Dirty Water texture appears with almost no defocusing. Note the crispness of the lens debris at 1 percent. You would never see this kind of schmutz clarity from a real lens image, but being able to simulate it in Real Lens Flares might come in handy — when trying to emulate shooting through a dirty glass window, for example.
The Holodeck preset with the Dirty Water texture set to 1% defocusing (left) and 100% defocusing (right).
The F-Stop Affects Defocus checkbox does just what it says. Enabling this option will affect schmutz brightness, depending on the aperture size, but it also impacts defocusing. The more open the f-stop, the blurrier schmutz will appear. Conversely, a smaller f-stop will yield sharper schmutz. Try saying "sharper schmutz" five times fast.
The Illumination From Light Source/Background controls (Size, Exposure, Chromaticity, etc.) work just like those controls in other core projections. Keep in mind that these controls affect the schmutz, not the underlying lens flare.
The Light Source Illumination and Background Illumination check boxes let you decide whether to process illumination from the Real Lens Flares light source, luminous areas of your background image layer, or both to illuminate your schmutz. Just to make sure we avoid confusion, keep in mind that a Schmutz core projection exhibits its own illumination. As you see in the following image, we've turned off every core projection except Schmutz, yet there's still illumination of the schmutz and a center control point for the effect from which that illumination emits.
Let's examine the impacts of Light Source and Background Illumination on Schmutz in the following images. Note that we increased Exposure to 4.00 in both parameter groups to make the effect more apparent.
We'll start with the Chainsaw Sunset RLF preset and Dirty Water schmutz added. In the following comparison, we've enabled both illumination options. In the right image, though, we've disabled every core projection except for Schmutz, so you can see how overexposed schmutz appears on its own.
Now, let's see the impact of only having Light Source Illumination (left) or Background Illumination (right) selected on its own.
With only Background Illumination selected, we only see the schmutz in close proximity to that lightbulb. If that's too subtle of an effect, here's the same image with settings of Spread: 100% and Exposure: 6.
Note that low-contrast background scenes can make it harder to spot schmutz effects from only Background Illumination. That's why we chose a lit bulb in a dark room for our example.
The Highlights Only control sets a threshold value for the level of luminosity in the background scene that will affect the schmutz. Consider the above pair of images. On the left, we set Highlights Only to 10%, meaning the bottom 10% of the scene's luminosity will not interact with the schmutz — and thus 90% will. That's why you see more schmutz in the left image than the right. In the right image, we increased Highlights Only to 90%, so only the 10% most luminous areas of the background (basically, just the brightest areas of the background scene) will illuminate the schmutz. Our red arrows highlight one of the more obvious differences, even with Exposure cranked to 4.40. This is a particularly subtle effect, but you can still see how lower Highlights Only values can reveal more schmutz from your source clip.
The Influence section also offers several controls.
Schmutz Zoom and Schmutz Offset only apply to schmutz’s impact on reflections, not directly to the schmutz.
In the image trio above, the top image shows the Schmutz core projection turned on and all Influence controls enabled. (We blew out the settings to make things more obvious.) In the center image, we disabled the Schmutz core projection, so you can compare the lens flare with and without schmutz. However, in the bottom image, we enabled the core projection but disabled Visible Schmutz. It’s almost impossible to see the difference at a small size, so here it is zoomed in and brightened by 50 percent:
Notice the speckling in the brighter, small heptagon (left arrow) and the darker choppiness in the area indicated by the right arrow. Even though schmutz isn’t visible, the effects of the schmutz are visible in lens reflections.
Note: What is “schmutz”? Our Oxford English Dictionary Compact Edition does not contain the word, but online dictionaries (e.g., Collins and Wiktionary) trace the word to Yiddish and Germanic origins. It’s likely related to “smudge” and “smut,” but it commonly means dirt, grime, or garbage.