Tessive Time Filter - Holy Crap!

[Andy Jarosz]

Will do. I'll grab my Canon flash and do some quick tests. It'll probably be a couple of days, but that sounds like fun. I'll post the results to our website and let you know when they're ready.

Tony
www.tessive.com

Tony,

Do you foresee ever using a color LCD and creating an "infinite filter?" One where you can just dial in the color filter you want and the LCD acts like that filter?

 

[Dan Hudgins]

Stripes and dots

Stripes and dots

color LCD and creating an "infinite filter?"

If you use stripes or dots for the color pattern, then you get diffraction so it becomes a kind of diffusion filter if used in front of the camera lens. Its somewhat like the problem with PLZT light valve shutter glasses, the thin "wires" on the crystals block part of the light and alter its path a bit.

You could build a device with dichroic mirrors and use there LCD filters to do color mixing a little like the Bell and Howell additive light house mirrors array where white light is split then re-combined with three light valves, except you would use LCD light valves rather than the vanes.

Since the angle of view would be narrow, you would need it to be built like a snorkel lens where you put it on the camera and then mount the taking lens on its mount on its front.

The "dial a color" filter would be lower cost and easier to make just using two round crossed pola filters for each of the three light valves, the electronic light values are only needed where you want to program color changes frame-to-frame, otherwise you can use servo motors.

In fact you can replace the tensive light valve with one fixed pola and one rotating pola filter, where the rotating one rotates at the camera's frame rate, much smaller than a rotating ND disk, and gives a bell curve like light passing like the tensive filter in anti-motion-alias mode.

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With regard to the cost, its possible to wire a LCD 3D glasses filter to some simple electronics and pick up the HDSLR frame rate and sync the square wave or rectified sine wave to drive the filter, some of the glasses filters are large enough for use with some focal lengths of HDSLR lens, or maybe mount it behind the lens inside the camera mount because the rear element is smaller (even though to add some "plate effect" that way, the extra blur will decrease HDSLR aliasing maybe a bit). Such a thing can be put together for maybe two hundred in parts or less.

Likewise, if you use a fixed and motor rotated pola filter in front of the HDSLR, you can get a larger filter that pulsates and does not cost much, the cost of the motor would be low maybe $20 to $50, you can use a optical pickup to flag the PLL to sync the rotating pola to the camera's fps sync pulse.

 

[Tony Davis]

Welcome Tony!

Can you shoot and post a few test movs or avi movies (some format we can advance through one frame at a time) with camera flashguns, and emergency strobes? Would be great if it solved/reduced the one artifact that can be a deal killer when shooting with rolling shutter digital cameras compared with film.

Eric,

I ran a quick test today. I call the composition: "Random electronic equipment still life under various illumination."

Test 1: This is the RED ONE set to a 180-degree shutter without the Tessive filter. So this is the normal setup. I fired a Canon flash set to a 5 hertz repeat rate at the subject, and the results are what we would expect. The strobe often illuminates the sensor partway through the rolling shutter readout.

Test 2: Same setup, but with the RED ONE set to a 360-degree shutter and the Tessive filter set to produce a 180-degree shutter square wave exposure window function. You can see in the upper left of the image there is still a little discontinuity. The Tessive filter can't ever become 100% opaque, so a bit of the rolling shutter effect bleeds through. This may be problematic if the strobe were super-exposing the image, because that saturated light would blow right through the liquid crystal filter even when it's as opaque as it gets.

These images are very small, so I have full size jpegs included in the download .zip if you're interested, along with the two Quicktime movies out of Red Alert. The .zip file is 288 MB.

Strobe Test.zip

Let me know if that's the test you wanted to see.

Thanks,

Tony

 

[Dmitry Burenok]

Interesting. Once price drop I'll think about getting one. Technically is it possible to fix temporal aliasing on post (basically we have to film with high speed shutter like 1/1000 and up, than on post we can recreate motion blur using combination of different filters, etc. You can get pretty god result and it is fully controllable, especially with using EPIC 120 FPS feature temporal aliasing can be almost eliminated on post, but it is an extra time of course and quite complicated process), but results with this filter looks much better and you get it right away! Anyway, to me so far doesn't feel like $7K Sony has similar solution for topnotch F cameras - they incorporate mechanical shutter in front of the sensor, but this is more like to fix rolling shutter thing.

 

[Blair S. Paulsen]

Just picked up one of these about a week ago and have been torture testing it. I will post a report to the forum soon.

Cheers - #19

 

[Hrvoje Simic]

Folks here have noted the drawbacks of the system: light loss and price. This is a first-generation product. When we initially had the idea for a temporal antialiasing filter, nobody could tell us with any certainty if there would be any market for such a thing. We've found that there most definitely is, and now that some real cinematographers are getting their hands on it (rather than our engineering staff, who are well meaning but not pros) the results are even more spectacular.

The primary goal of the Time Filter is to correct temporal antialiasing (our website explains the details of this), but a side-effect is that it also corrects rolling shutter. Frankly, the rolling shutter in the RED ONE we use hasn't ever bothered me all that much, and it wasn't a design goal to fix it, but it does. We added in a normal 180-degree shutter into the filter control so that you can use it to correct rolling shutter without using the temporal antialiasing curve. The cameras that would most benefit from rolling shutter correction are DSLRs, and unfortunately we cannot synchronize with them.

You have a great product but are not stressing enough its greatest benefit, IMO.


The look of its motion blur.

 

[Martin Weiss]

Do I understand it correctly, that the usual scenario is that you put the camera on a 360 degree shutter, the time filter on 180 degree, and you lose 2 stops?

Since the camera usually would be on 180 degrees (unless you are Michael Bay), effectively you would only lose one stop, right?

 

[Patrick Grossien]

Really cool idea and it seems useful for certain applications, but $14,000 and a two-stop light loss? Plus you have additional glass in front of the lens, and an additional box hanging off the back. Not sure if that's worth it in average scenarios. It would be sweet if RED could build something like this right into the camera, but rather than a large filter in front of the lens, it would be a small filter right in front of the sensor.

Thanks for sharing, Andrew.

hehehe