diggin these ghostly / whispy vibes
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the new pcb works as intended, and gives very nice results!
I’ll check some values and test some more. if all is ok, I’ll start a order thread! 
current features:
- blur amount pot
- gain adjust pot (to match the dry signal to the blurred tint)
- blur range > 3way switch (blur/blurry/extreme smear)
- input jack
- CV over dry / wet signal
- output jack
trimpot for cv range (0-1v to 0-5v) with testpads
trimpot for gain adjust
jumper for blur to white or blur to black* more on this later
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To quote the band Blur…
Woohoo!
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@reverselandfill Martijn, in the demo video and stills, I’m seeing a horizontal blur but no vertical blur. So is that the way it is? I guess that’s just the way a low-pass filter works.
Rasters basically are drawn left to right, not up and down. You can’t create a vertical blur with an analog filter because you’d be going back in time or at least that would require a frame buffer.
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@rempesm Yeah, I understand all that. But riddle me this. How does an analog switcher generate a continuously variable soft edge to a wipe? And not just a line or a box wipe, but a circle? There’s no time travel involved there, at least as far as I know. So there must be much more sophisticated math and circuitry going on there.
And before anyone says “Your switcher must have a frame buffer”, I’m talking about legacy switchers that have no TBCs, only genlock. To run videotape into such a switcher, you need external TBCs and everything genlocked to house sync.
The type of wipes you’re talking about wouldn’t need a frame buffer at all! It is all happening in real time.
Maybe I’m misunderstanding what you mean by a vertical blur. Let’s consider this image from above which is blurring from left to right:
Are you talking about it being able to produce a directional blur like this?
Or like this?
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Actually what I would want is an isotropic blur… like camera bokeh. Equally blurred in all directions.
If that can happen on a circular wipe edge, without a frame buffer, it must be theoretically possible for a video signal.
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there are some possibilities with CV control.
if you use vertical bars as cv input, you can get this type of effect:
(source is a keyed diamond shape)
but it will depend on the blurred region / amount (range) where it can go.
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But that’s completely dependent on the shape. This is not really a vertical blur, and it only works because your source shape is a diamond. Fundamentally you’re filtering out the highest frequencies, higher than horizontal line rate. Right?
As I think about this, it seems like it’s not possible to create a vertical nor an isotropic blur with a low-pass filter. If the filter cutoff was high enough to create a vertical blur/delay, we would lose all of the detail in the horizontal dimension.
Which brings me back once again to the question, how does it work in a continuously variable soft wipe edge?
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Correct. This is the same case with any kind of analog filter in the video domain. If you want a blur to happen in all directions, the simplest way to do it outside of post-processing is to rescan your source image with a slightly defocused camera and composite it against your original source.
Let’s say this is our Key input to a soft keyer:
Background and foreground inputs can be whatever.
As you adjust the threshold of the keyer, it will follow the shape of the circle gradient that is already present across the full frame. It’s not going back in time to create this effect because the guide of the circle gradient as our key source is present at the time the keying operation happens.
With analog low pass filtering, you are removing upper frequencies at the time that they occur which gives the visual impression of a blur to the right. It can’t blur content that has already been displayed.
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yes, it is not vertical blur, but taking advantage of the shape and making the most out of it.
if the blur is extreme, you can get higher than the input shape
I’ll post some video later with some tricks. you can also get cool foreground / background type of effects.
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yes this!
sometimes it can be easy to get wrapped up in modules and hardware instead of real world solutions that are already available.
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yes, I use this method with a feedback camera setup regulary. rounded camera tunnel feedback spirals!
(instead of the usual rectangular shapes, or certain TV looks) >> slightly of totally unfocused works great!
patchtip: use the SNOW comparator output as a trigger to get disfocussed / “blurred” snowstorm / blizzard field of focus effects.
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Rescanning introduces many problems around registration, brightness, contrast, saturation etc. It also assumes a spare camera, monitor, blackout rig etc. It might not be possible to create isotropic blur with an analog circuit, but maybe that functionality could be built into a future TBC2 firmware revision.
Working with defocussed cameras is a great technique in general.
Interestingly, stacking a defocussed (inverted) image with a regular image was a method for sharpening an image when working with film in the photographic darkroom. It was called an unsharp mask and retains that name in Photoshop and other software. I’ve not tried it with video, yet.
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RGB with three BLUR modules can get crazy pretty fast!
here is a screenshot (I’ll post some proper captures later)
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Uuuu…
I’ll get three then :)))
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I am doing some patching with the BLUR now, it plays well with the Syntonie Frequency Doubler & Fox Priority Layering!
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it would be interesting to priority layer being used to show an original B&W channel with a freq doubled version of itself and a blur > freq doubled version as well!
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