Thread: tips on shooting arc welding

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  1. #1 tips on shooting arc welding 
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    Hi guys, I have a question for you who have experience shooting welding scenes and not getting the sensor fried :)

    We are going to film with a Red dragon and a Sony a7s3 but I'm worried about damaging the sensors.
    We could've gone with a bmpcc 6k instead of renting a Red but I know it doesn't have an internal filter so I would definately get damaged?

    I would be greatfull for any tips..
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  2. #2  
    Senior Member Brian F Kobylarz's Avatar
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    Hello Emir - Have done this countless times over the years - everthing from arc welding to plasma to electron beam welding. In all those years, never fried or damaged a sensor. My best results with RED's were obtained when using a motion mount combined with ND filtration. I would also hit the area with a lot of light (typically HMI's). You are not going to overpower the arc - you are just bringing the rest of the frame closer to the exposure necessary. It is tempting to play with the shutter to achieve the right exposure but this will shorten the trails from the small pieces of molten metal ejected from the process. Better to use ND's.

    Of more concern is how close the camera is to the welding activity - the welding process can introduce very small particles of metal into the surrounding air. It is very easy to destroy the lens - I found small pits in the coating on the front element if I did not protect it by adding a clear filter in front. They cost a lot less than repairing a lens. Note that the glass filters in welding helmets becomes pitted with these small particles and that glass is designed for that environment. Of course, if you can keep the camera at least six feet away, the particles have a chance to cool enough so the will not embed themselves in the lens.

    The most important consideration when filming welding is one of personal safety. Looking thru a viewfinder will not damage your eyes - looking directly at an arc will. Going home with what is called "arc flash" is not a pleasant experience. It feels like someone dropped sand in your eyes and there is no way for you to do anything about it. Once is too many times. Since you don't have eyes in the back of your head, the best solution is using a monitor 180 degrees away from the shot to use as a viewfinder.
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  3. #3  
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    Thank you Brian, your advice is invaluable.

    I've learned a lot from you guys on this forum, thanks again..
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  4. #4  
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    Has anyone tried shooting through the clear glass of one of the new LCD shutter helmets mounted in front of the camera lens? Self-powered or battery-powered exchanges for conventional helmet glasses can be found on eBay. These clamp the light almost instantly. Rolling shutter might be an issue. I was examining them with a view to using one as a shutter for flash-scanning 16mm motion picture film on a Steenbeck flatbed editor.
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  5. #5  
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    Quote Originally Posted by Robert Hart View Post
    Has anyone tried shooting through the clear glass of one of the new LCD shutter helmets mounted in front of the camera lens? Self-powered or battery-powered exchanges for conventional helmet glasses can be found on eBay. These clamp the light almost instantly. Rolling shutter might be an issue. I was examining them with a view to using one as a shutter for flash-scanning 16mm motion picture film on a Steenbeck flatbed editor.
    correct me if I'm wrong but wouldn't that darken the image once the arc starts? It would be nice if your going for a welders POV shot..
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  6. #6  
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    Quote Originally Posted by Emir Aksay View Post
    correct me if I'm wrong but wouldn't that darken the image once the arc starts? It would be nice if your going for a welders POV shot..
    You are entirely correct. I may have missed what the original poster was aiming for.
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  7. #7  
    Quote Originally Posted by Brian F Kobylarz View Post
    Hello Emir - Have done this countless times over the years - everthing from arc welding to plasma to electron beam welding. In all those years, never fried or damaged a sensor. My best results with RED's were obtained when using a motion mount combined with ND filtration. I would also hit the area with a lot of light (typically HMI's). You are not going to overpower the arc - you are just bringing the rest of the frame closer to the exposure necessary. It is tempting to play with the shutter to achieve the right exposure but this will shorten the trails from the small pieces of molten metal ejected from the process. Better to use ND's.

    Of more concern is how close the camera is to the welding activity - the welding process can introduce very small particles of metal into the surrounding air. It is very easy to destroy the lens - I found small pits in the coating on the front element if I did not protect it by adding a clear filter in front. They cost a lot less than repairing a lens. Note that the glass filters in welding helmets becomes pitted with these small particles and that glass is designed for that environment. Of course, if you can keep the camera at least six feet away, the particles have a chance to cool enough so the will not embed themselves in the lens.

    The most important consideration when filming welding is one of personal safety. Looking thru a viewfinder will not damage your eyes - looking directly at an arc will. Going home with what is called "arc flash" is not a pleasant experience. It feels like someone dropped sand in your eyes and there is no way for you to do anything about it. Once is too many times. Since you don't have eyes in the back of your head, the best solution is using a monitor 180 degrees away from the shot to use as a viewfinder.
    Very nice piece of advice to a roockie.
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