On the way to creating some more VJX-basics tutorials I have found myself distracted, hopelessly so, by the topic of feedback. Video feedback is of course a very common and simple “technique”, available in many forms, both hardware and software. However, in most incarnations the result is quite similar and recognizable. Not so with the VJX. The combination of 4 layers, per-layer blend modes and effects, and internal routing create a staggering range of possibilities. I’ve previously posted some examples, and now I’d like take apart and explain the most popular of those, the black and white mirror morph effect.

Vixid Advanced: Feedback Setup and Demo from Create Digital Media on Vimeo.

Input/Patch Setup

Camera or other source feed plugged in to Track 4. Select the appropriate input on Track 4.
Output 1: Connect via patch cable to input on Track 3. S-Video or Composite - Each will give different effects, as will using poor-quality cables, as noise in the patch cable will create more interference in the feedback loop.
Output 2: Connect via patch cable to input on track 2.
Output 3: Final Output - Connect to projector, screen, capture or preview.

The Setup

The VJX is in “Compositing” mode.
Outputs: All set to “Master 1″ (this is what builds the feedback, as the composited output is immediately routed back into tracks 2 and 3).

Track 4: Camera Input. Layer Order D (bottom). BCS (Brightness, Contrast, Saturation) Contrast on 255. Opacity at 100%. This effect works best with a moving, high-contrast, white on black source.
Track 3: First feedback layer. Input from Output 1. Blend Mode: Difference. Layer Order C (second from bottom). Opacity around 40%. Gain 255.
Track 2: Second feedback layer. Input from Output 2. Blend mode: Normal. Layer opacity 25%. Gain 220. Effects: Flip Horizontal, Negative.
Track 1: Not used (could be utilized as an additional feedback loop).

How it Works

The key to this effect is the Negative and Flip effects on track 2. Various combinations of a negative layer applied over a negative blend mode will give you other similar looks. Tweaking the opacity of tracks 2 and 3 will change the “bleed” speed, and depending on the brightness of your source input they may need to be tweaked up or down slightly.

I’m very pleased with this effect. It’s relatively simple to setup, and gives a beautiful, organic look. I’m not sure how well it would work on stage, but it has huge potential for post-production work.

While I’m in a sharing mood. I’ve been spending some time with Feedback effects in the VJX this week, as I was planning to do my next “advanced” tutorial on VJX feedback and effects. However, after losing several hours in experimenting with different blend modes, input and output routing - and creating a huge range of effects and looks - I came to the realization that feedback in the VJX is such a huge topic that we couldn’t hope to cover it properly in a single tutorial.

So instead I’m going to focus on some interesting effects I have discovered, and documenting the exact combination of layers, routing, effects, and other parameters are required to achieve them.

This one is rather complicated. Using the mixer in Battle mode it to isolate two layers as a “feedback loop”, it brings a camera input from track 4, over to the feedback loop on layers 1&2, and then composites them back over the camera input with layer 3. With Difference, Subtraction and Negative blend modes used, and an Inverse effect, I can’t really tell you what’s happening here, but it looks great. The entire effect is controlled with just the gain on the camera input, and tweaking this from 1-255 gives all of the various effects you see in the video.

This one is a little easier, and documented on the Vimeo page. The black/white butterfly effect is achieved by overlaying a Difference blend mode over a layer which is flipped horizontally and has Negative effect applied.

I’ll give proper instruction on creating these effects, and more, soon.

VJX owner Tiago Pereira (previously spotted on CDM) is fusing technology with tradition in the OMIRI A/V project.

With Vasco Ribeiro Casais on electronic bouzouki, nyckelharpa, flute, loops, beats, effects pedals, laptop and other enhancements, the sound is a complex mix of past, present and future, and - with the help of João Chaves - the visuals help build this into a consistent performance. The historical basis of these pieces is in dance, so the content is spot on, with dance from a huge range of cultures making an appearance.

OMIRI LIVE - Teatro da Luz - Xotiça Marmeleira from Tiago Pereira on Vimeo.

Being Vixid.Noisepages, this performance does indeed feature a VJX as the hub which glues the visual show together. There’s some fitting use of blend modes on display, but we need not forget that the VJX is a mixer at heart. You don’t need to use effects just because they’re there, and Tiago doesn’t fall into this trap.

The VJX16-4 controls aren’t outrageously different from a “traditional” video mixer, but there are a couple of initial concepts you need to master to get started. This Vixid101 video covers concepts from the left side of the mixer, the big ones being: Choosing inputs, routing outputs, previews, layer selection and ordering, and blend modes.

While these are the “basic” functions of the mixer, they also contain the core of what makes the VJX such a revolutionary tool. As you start to come to terms with these new capabilities, they will suggest to you whole new ways of working with video.

In the coming months I’ll be covering these new methods as I come up with them, as well as more of the basics. This site isn’t just about me though, there are plenty of other VJX users out there doing great things. If you have something you’d like to share, please get in touch.

These videos by Deepvisual have been previously posted to CreateDigitalMotion, but they’re a very useful initial look some of the functions which make the VJX16-4 different from other video mixers.

Selecting Inputs, Blend Modes, Effects, Keying

Blend Modes, Layer Ordering, Previews