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21
Software Dev / Re: Chronos V0.6.0 Full Release
« Last post by NiNeff on March 22, 2021, 12:24:37 AM »
The linked instructions say that special factory calibration files are no longer needed for both the 1.4 and the 2.1, while the first post here only mentions the 2.1 – can anyone please clear this up? Can the 1.4 generate it's calibration entirely on its own or is this limited to the 2.1?
Also, as the update currently cant be done "in place" but requires an SD-Card update, is the existing "factory" calibration data still relevant ion some way (like providing better results?)
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Chronos User Discussion / Re: Seeing a pellet in flight
« Last post by Nikon1 on March 20, 2021, 07:01:57 AM »
i assume the Line is from Changing Shutter speed /angle after the Black Calibration.
 To get rid of that line, make sure to set your Gain, Resolution, Framerate and Shutter Angle first, and after all settings are done and applied, do a Black Calibration.
 This should usually get rid of that line.
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Chronos User Discussion / Re: Seeing a pellet in flight
« Last post by WalterF on March 20, 2021, 06:57:08 AM »
I tried some of the techniques you mentioned this morning on a clear bright  morning. It helped a lot. Just nor sure why I have the red band at the top.

https://www.youtube.com/watch?v=drtRe8cwoWA
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Chronos User Discussion / Re: Seeing a pellet in flight
« Last post by Nikon1 on March 20, 2021, 01:11:57 AM »
As far as resolution goes, for this shot you could have easily choosen an wider Aspect ratio Image, as about the lower half of the Image as of now is "dead Space", where almost nothing is happenig anyways. So if you went with half the vertical resolution and reframed the shot to only see the now top part where the pellet is flying, you wouldnt really loose any detail from that, while increasing framerate by quite a bit. For Tracking things like those in Flight, a pretty Wide image is usually more usefull anyways than an close to Square one.
 .
 Another Trick to make the Projectile seem to move slower, i see often used with projectile Footage is, to not shoot at an 90° Angle from the Path of flight (Of course sometimes necessary to get an good view of front and back of target...), but to get closer to the Shooters Perspective or an more shallow angle, as now the same Space in Frame covers more real World Distance the Pellet will have to travel, meaning it will be in Frame for longer (and also moves seemingly slower).
 Of course not very usefull trick, if what you are going for is the typical 90° Side angle, but still worth thinking about sometimes.
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Chronos User Discussion / Re: Seeing a pellet in flight
« Last post by WalterF on March 19, 2021, 09:11:26 PM »
Thank you, the lens I am using is the computar 12.5-75 and I had to have the aperture wide open and the gain all the way up to even get an image, it was very cloudy today. I will try to clean up the background and shoot in more favorable lighting conditions.

I was shooting around 460 something by 360 something for pixel size, this gave me the 11500 fps. If I go up more it will be more pixelated.

I will wait and try again on a sunny day, using your suggestions.
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Chronos User Discussion / Re: Seeing a pellet in flight
« Last post by Nikon1 on March 19, 2021, 08:36:01 PM »
i dont know what lens you are using here, but there is a ton of Color Fringes going on in the image, which take away a lot of the Detail the Camera could have possibly captured here. So maybe stop down (use Smaller Apperture/ Iris Setting, this sometimes goes away or at least gets better with smaller Apperture Settings) your lens a bit or try to use a better lens.
 .
 Even more Important is the Lack of Seperation from the Background. Try filming the Pelet against the Sky, use some White Backdrop where you expect the Pellet to fly or use some Really bright light as a Backlight of the Pellet from the Oposite side of the Camera to give it a distinct outline (Nice Trick if you are low on light, use Heavy backlight to at least have Silhouettes clearly visible, so you sometimes can get away with an overally too dark image, while still beeing able to see whats going on). The Dark Pellet is just not very visible against the also rather Dark Grass.
 .
 Another thing to consider is Shutter angle and Framerate. As from the Motion blur visible and the (for gun stuff) rather low Framerate i assume you filmed this on an Cloudy day or with not too much light overall, which is understandable. But if you want slower, sharper Footage, you usually either need to up your Framerate or make your Shutterspeed / Shutter-Angle Smaller/Shorter (which will make your Frame a lot darker!). This means for some things like that you need to either add artificial Light to your Subject you are shooting or Shoot on bright and sunny days only.
 .
 Most general-Purpose (motion Picture Production and so on...) Highspeed-Video gets away with a lot less light (Still needs Plenty bright Environment to record anything worth showing), but especially gun stuff and Projectiles in Flight require A LOT of Light!
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Chronos User Discussion / Seeing a pellet in flight
« Last post by WalterF on March 19, 2021, 08:18:02 PM »
I just got my Chronos 1.4 and went out to shoot exploding golf balls with my air rifle. It is tuned to shoot the pellets at 800 feet per second. I am set up a little more than right angle to the subject. I set the cameras resolution to give me a frame rate of almost 11500 frames per second. When I processed the video I had to slow down the speed to 50 percent to be able to see the pellets trajectory. I know the feet per second of the air rifle because I use it in competition and use a chronograph to check the speeds.

How are people getting clear images of the pellet going to the target? What am I doing wrong?

I included the link to the video.



https://www.youtube.com/watch?v=ashdl61T3xc
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Software Dev / Re: API bugs
« Last post by rspears on March 17, 2021, 07:59:36 AM »
Another bug: Adjusting resolution - I can set the resolution to any supported value (incremented by 32 in the width, 2 in the height on the 2.1 camera I'm testing) via the camera interface. On the web interface and API, unless I set it to "standard" values - like 1920 x 1080, 1280 x 1024, etc. - I get blue lines or blue tint in the video. Even some of the common resolutions listed in the camera's datasheet exhibit these issues. Something is happening when I set it on the camera that is not happening when I set it via the API.
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Chronos User Discussion / Inexpensive Acoustic Trigger
« Last post by Jeff_Dawson on March 16, 2021, 12:44:37 PM »
I’ve found a way to acoustically trigger my Chronos 1.4 camera that is very inexpensive, accurate and easy to build.

The ‘sound detector’ board from SparkFun (SEN-14262 -- https://www.sparkfun.com/products/14262) is an analog audio sensing board that is able to output a TTL compatible pulse when it detects a sound.  This board is inexpensive ($12.50 CAD) and easy to hook up.  The board is easily powered by batteries (I use three AA batteries = 4.5 V).  If you connect the ‘gate’ output to your camera IO1 input then you can trigger your camera on a variety of acoustic events – claps, bangs, bird-tweets, stubbing your toe and cursing, etc.

The board also outputs an analog signal that is equivalent to the acoustic oscillogram and outputs an analog voltage that follows the envelope of the sound detected – so it’s quite a versatile board.  You can also change the microphone gain to make it more or less sensitive (it’s default is quite sensitive and worked well for me as delivered).

My plan is to incorporate this into a nice project case with BNC output so I can easily cable it to my camera in future.

I’ve attached a picture from my oscilloscope showing the output from the board.  You can find additional documentation about this board easily on-line.

I consider this a small work-around until the acoustic triggering features of the camera are implemented.

Please note that I do not work for SparkFun and I have not received compensation for this post in any way.  I’m just an absent minded professor-scientist.

Jeff.

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Chronos User Discussion / Re: Chronos 1.4 Footage Thread
« Last post by Buddlich on March 15, 2021, 02:48:31 PM »
https://youtu.be/7gZNjg7ppP8

I took a closer look at my daughters electric toothbrush.
Was quite suprised how the toothbrush can "suck" the water up to it's bristles. Are the the capillary forces of the water?

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