Author Topic: Insanely high speed slit scan method?  (Read 58 times)

PaulBryanTV

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Insanely high speed slit scan method?
« on: October 21, 2017, 08:47:08 AM »
Hi David and others!
Just wondering after reading a lot of articles online about photo finishes, is it possible to make the Chronos read out a 1x720px image at even higher speeds for stuff such as high velocity weapons etc? So we could create high res 'frozen in time' style images from the footage using something like Slit Cam?

As the bullet or projectile would travel through the horizontal axis creating a full image of itself, so we only need the vertical resolution?
Would this make the camera be able to record insanely high speeds?
Is it even possible? Just an idea.

tesla500

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Re: Insanely high speed slit scan method?
« Reply #1 on: October 21, 2017, 11:15:47 AM »
This could be done, yes. The limitation right now is that the video encoder doesn't support resolutions below 96 pixels height. To get around that, we can add black bars to the video to remain within the encoder limitation. Once Raw/uncompressed saving is done, this won't be a problem at all.

There's also a frame rate limit above which the camera becomes export controlled, I believe the number is 200,000fps but I have to check. But the image sensor itself is capable of well above that when running at 1 pixel height.

David

PaulBryanTV

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Re: Insanely high speed slit scan method?
« Reply #2 on: October 21, 2017, 11:30:41 AM »
Does it support width of less than 96px? As a vertical pixel strip of maximum resolution height with a 1px width is what most would use.
For example a side profile shot of a bullet in mid air from left to right.

If you can incorporate this in some manner I think it would be awesome. Especially for content creators and photographers in the high speed niche.
Theoretically whats the maximum fps the sensor could handle? I think if you can put even a basic test feature of this in, you'd REALLY turn some heads in the industry.
Something like a 500K fps slitscan would lead to some INCREDIBLE images being made, particularly for ballistics / explosives.
« Last Edit: October 21, 2017, 11:36:33 AM by PaulBryanTV »

gyppor

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Re: Insanely high speed slit scan method?
« Reply #3 on: October 21, 2017, 01:23:26 PM »

There's also a frame rate limit above which the camera becomes export controlled, I believe the number is 200,000fps but I have to check. But the image sensor itself is capable of well above that when running at 1 pixel height.

David

It seems that as of 2011,  cameras capable of >1,000,000fps or <1us exposure AND >125fps were subject to controls. I can't seem to find a more recent version of the document:

http://www.international.gc.ca/controls-controles/about-a_propos/expor/guide-2011.aspx?lang=eng


From the document, on the list of controlled items:

1-6.A.3.a. Instrumentation cameras and specially designed components therefor, as follows:

[...]

4. Electronic framing cameras having a speed exceeding 1,000,000 frames/s;
5. Electronic cameras having all of the following:

    An electronic shutter speed (gating capability) of less than 1 μs per full frame; and
    A read out time allowing a framing rate of more than 125 full frames per second;



On another note... Is the new firmware going to include the black stripes top and bottom for higher frame rates? :-p

PaulBryanTV

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Re: Insanely high speed slit scan method?
« Reply #4 on: Today at 05:20:19 AM »
Pretty sure all of that would be EXTREMELY easy to get around with Open Sourcing stuff with easy implementation methods / software?

BiduleOhm

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Re: Insanely high speed slit scan method?
« Reply #5 on: Today at 05:39:13 AM »
Yep, software limit it to whatever the export limit is and then those who want to go higher just need to change a value or two in a config/header/whatever file and maybe re-compile the thing if the change isn't in a config file.