1 Topic by mootej

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I'm reading your posts Reiner (or really, anybody with high speed video lighting experience) and it looks like you have been down the lighting rabbit hole.  Same application, golf swing and golf impact capture.  I have a couple of fairly sensitive cameras like the IDS UI3140CP-C, better, a Basler acA-1920-150um, I have a couple of acA2040-90um coming from ebay  and trying to get an IDS UI3060CP-M.

The acA1920 can also see the 850nm IR which is not very visible to the eye which helps keep the room dark enough to see a projector screen.

OK, the questions, where are you at with lighting.  <200usec exposure would be great.  Any IR lights work?  The ones I've tried (Univivi and Tendelux for security cameras outside) were surprisingly tiny, underpowered and did not help much.  Godox?  Well, any of your experience would be great...

I even was considering building something from these:
https://www.luminus.com/products/cobarr … inment-cob
...but the guy at their development lab said I would probably need a PhD in cooling to be able to use them. :-)

2 Reply by Reiner (edited by Reiner 2024-03-23 11:41:16)

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Looking on light topics, the spectral response and light intensity of each camera is important. It is not the manufacturer of the camera that makes the difference. Comparing the cameras you are mentioned, the cameras with the IMX174 sensor (Basler Aca1920-155um and IDS UI3060CP-M) will give the best results on low lights. The Python1300 sensor (IDS UI3140CP-C) I would not recommend so much. Especially the color version needs much more light. I always recommend the mono versions of each camera due to higher light intensity.
Always keep in mind that the price of the lenses for the 1/1.2" sensor (IMX174) is much higher than for the 1/2.9" sensor (IMX274). An aperture (F-value) below 2 is favorable.

Looking on the spectral responses of all of these sensors, the response at the area of IR-light is rather low. I tested it with some IR-lights and there wasn't a remarkable difference. So I did not went further with the IR-project.

Going below 200 microseconds will be difficult. Then you need a very, very high amount of flicker free light. I use between 300 and 500 microseconds shutter speed, using 2 x 200 Watt flicker free LEDs with an 1-10V dimmer (important to adjust to your need!) from the front (about 45° left and right from the golfers stand, mounted to the wall) and an Aputure Amaran spotlight 40Watt (25°) to lighten the ball directly from the top (mounted on the sealing).

The flicker free LEDs are the following:
AML® SQ-200 D – dimmbar,26.500lm, 200W, 4.000K, regularly used as hall-spots in the industry.

As you are always on the limit of visibility in low shutter speed applications like golf, I' using an automated post processing of the created videos using my scripting tool you may find on the golfsimulator forum.

3 Reply by mootej

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Thanks so much for the info, immensely helpful...

4 Reply by David

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Yeah Reiner, your expertise in cameras and light is unbelievable. I am looking forward to get my Basler aca1920 155um next week. Can’t wait to test it with the Kinovea software. From Basler I can get lenses that are not that expensive, between 70 and 190€. Reiner do you think they will not fit to the Camera. I worked with the lense calculator and it told me to pick up a 8mm 2/3“ C Mount lens and I got 9 different lenses to choose from. The price differs from 70 up to 800€ but I think I will try 2 or 3 between 70 and 200.

5 Reply by Reiner

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For Golf setup, I recommend a field of view (FOV) of 4500mm width and 2800mm height at the golfer level (not ball).
Using the th IMX174 sensor, your camera should be more than 3500mm away in faceon (FO) position to catch that FOV.
If you select the 2/3" lens, there might be some vignetting at the borders, especially the corners. However, you mostly do not need the full width of 1920 pixels. I use about 1400 pixels and have reduced the height to 1000 pixels, so vignetting should not be a concern. If the 8mm lens will fit (please double check the camera-object distance), I would recommend the C23-0816-2M-S f8mm for 70 Euro. It has an F-value of 1.6 which is pretty good. All other lenses in the recommendation list have a F-value above 2.0 and will more darken the image. The resolution of this lens is 2MB and should just fit your sensor.

6 Reply by David

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My maximum distance to the ball is 2500mm (3000-3200mm to the golfer). I planned width of 4000mm and height of 2500mm. Should I take a 6mm lense instead of 8mm. @Reiner do you have lenses you recommend for the imx 174 sensor?

7 Reply by David

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Is a 1“ lense better than a 2/3“ for my camera?

8 Reply by Reiner

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If your FO (face on) camera is not fixed to the wall, I would recommend the 6mm lens. Then you can play around with the distance to get it optimized. If you will increase the recording fps, you have to reduce the image height. Then you might go a little bit closer to the object to catch all of the swing. If the camera is fixed to the wall, a more detailed calculation of the geometry is recommended to find the optimal solution. However, there are only 6 and 8mm lenses available, nothing in between. So moving the camera to optimize the FOV is the best you can do.
These both lenses will fit perfectly to the IMX174 sensor camera:

GetCameras LCM-10MP-06MM-F1.8-1.1-ND1
Non-Distortion, Price 398,- Euro

Kowa, LM6HC, 6 mm, 1“, F1.8
Low-Distortion, Price 600,- Euro

I have two of the GetCameras - lenses and they are pretty solid. Didn’t find a better one at that price for the IMX174 sensor camera.

9 Reply by mootej (edited by mootej 2024-03-29 17:54:20)

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Going to try this for some slo-mo impact videos, a Godox SL300iii, 99,300Lux at 1m.  Picked up an open box on ebay...

10 Reply by mootej (edited by mootej 2024-03-29 18:15:00)

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https://photos.app.goo.gl/sGjFdttFFRmQh4KA8

11 Reply by mootej (edited by mootej 2024-03-29 19:59:46)

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https://photos.app.goo.gl/3ehSBCM4Gu3SagBU9

First light...the light is a beast!  At 40-50% light power, the acA1920-150um set at ~100usec, around 500fps...and it looks like the light is completely flicker-free.