Godox BeamLight Max90 Reflector for KNOWLED MG2400Bi & MG1200Bi

I'd love to mount one of these to my camera (or mount the camera to the light!) for tracking nighttime rocket launches. Once the rocket rises 200' and exits the lighting around the pad all you can see is fire -- and not the rocket itself. Would be cool to keep the rocket lit for another 30 seconds for so until it gets out of range. They should send me a demo.:smile:
 
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Doug Jensen said:
I'd love to mount one of these to my camera (or mount the camera to the light!) for tracking nighttime rocket launches. Once the rocket rises 200' and exits the lighting around the pad all you can see is fire -- and not the rocket itself. Would be cool to keep the rocket lit for another 30 seconds for so until it gets out of range. They should send me a demo.:smile:
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That sounds cool but is it really going to make a dent in the exposure against the flame of the rocket?

Reminds me of another question I wanted to ask you. When you expose for rocket launches, do you have enough dynamic range on your cameras to have leeway with your exposure? Or do you really have to nail it precisely? And do you set exposure before the big moment based on past measurements? Or do you adjust exposure on all your cameras as the show starts?
 
ahalpert said:
That sounds cool but is it really going to make a dent in the exposure against the flame of the rocket?
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Actually, looking at a trig calculator, I guess that a 5-degree beam at 200' would only spread 17' wide. So it's definitely narrow enough to hit the rocket without wasting output. And I imagine that a 2400w COB would make a dent against the flame. But that flame must be awfully bright.
 
ahalpert said:
That sounds cool but is it really going to make a dent in the exposure against the flame of the rocket?

Reminds me of another question I wanted to ask you. When you expose for rocket launches, do you have enough dynamic range on your cameras to have leeway with your exposure? Or do you really have to nail it precisely? And do you set exposure before the big moment based on past measurements? Or do you adjust exposure on all your cameras as the show starts?
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You're right. I was just posting some wishful thinking about getting more light on rockets at night. I doubt the Godox would be powerful enough light up a rocket from a couple of miles away. Maybe an old WWII era carbon arc searchlight could do it, but that is never going to be allowed, nor is it practical.

The purpose of the light would not be to try to compete with the rocket exhaust, just to put some light on the rocket itself so it can be seen. After a rocket rises a couple hundred feet above the launch pad at night you cannot see it. All you can see is a ball of fire and nothing of the rocket itself.
 
ahalpert said:
Reminds me of another question I wanted to ask you. When you expose for rocket launches, do you have enough dynamic range on your cameras to have leeway with your exposure? Or do you really have to nail it precisely? And do you set exposure before the big moment based on past measurements? Or do you adjust exposure on all your cameras as the show starts?
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Good questions.

For both daytime and nighttime launches, I always set the expsoure by looking at zebras at the top of the rocket's nose cone (aka, fairing).

On most launches, no camera has enough dynamic range to capture both the rocket and the flames. That is especially true for SpaceX rockets. Their Merlin engines burn kerosene and the flames are super bright. Even in daytime the exhaust is going to burn out no matter what you do. So, I always expose for the rocket itself as it sits on the pad and let the flames do whatever they are doing to do when it launches. No exceptions. If the body of rocket is not correctly exposed then the shot won't be any good. If you tried to capture the flames with no clipping, then it would look like you shot it at midnight and nothing else would be visible except fire.

Reusing exposure settings from previous launches is no good because every launch is different and I never expose for the flames. The exposure is really dictated by the time of day, weather, angle of the sun, distance to the pad, etc. And it is changing all the time for daylight launches. In the final couple of minutes before launch I'm bouncing from camera to camera (like a guy spinning plates on sticks) fine-tuning the exposure on all of them to get it just right. As I said, I always set the expsoure by looking at zebras at the top of the rocket's nose cone and the flames can blowout as necessary.

For night launches, the pads are brightly lit with some really powerful flood lights, so once I set the exposure on the cameras I generally don't have to change them again. The floodlights on the pad are stationary and they don't follow the rocket when it moves, so once the rocket rises out of the floodlights, it becomes invisible and all you see is the flames. That's why I dream of having a powerful light that can track the rocket for a few more thousand feet into the sky.

An exception to all of this was the final Delta IV Heavy launch last week in daylight. Those engines use a different fuel, and because it was the middle of the day, the flames were hardly blown out at all. One of the best launches I've ever seen. Notice how the flames are clipped just a little bit, but you still see their full orange color.


Here's an example of how the same model of rocket just disappears into the night after it leaves the pad. I wish I had a light.
 
ahalpert said:
Actually, looking at a trig calculator, I guess that a 5-degree beam at 200' would only spread 17' wide. So it's definitely narrow enough to hit the rocket without wasting output. And I imagine that a 2400w COB would make a dent against the flame. But that flame must be awfully bright.
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Ha, ha, at 200' I'd literally be dead from the heat and sonic concussion. The closest anyone is ever allowed to be to a launch pad is 1.5 miles, and typically it is more like 2-3 miles.
 
Color from the 55 still looks damn good. Even though mine is pretty much just used for one particular show, today, I'm not getting rid of it. That camera was "lightning in a bottle" and IMO, the most un-Sony thing Sony has ever done. The Panasonic did stick out like a sore thumb, though.

The last few shots from the 750 looking almost straight up with the smoke are great.
 
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