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-   -   Welding... as a DV subject, suggestions? (https://www.dvinfo.net/forum/canon-xl1s-xl1-watchdog/3667-welding-dv-subject-suggestions.html)

Christopher Keiser September 12th, 2002 09:52 PM

Welding... as a DV subject, suggestions?
 
I have a shoot coming up where the crux of the images will be TIG welding. Specifically the torch on metal. I will be constructing a shield (same material as a welders mask) to filter the light entering my XL1s. But I want to know if anyone else has shot footage of this tricky subject. I'm scared of burning my retinas most, but I'd like to keep my camera for the following gig too.
Thanks,
Christopher

Jeff Donald September 13th, 2002 06:49 AM

I've shot glass blowers, not quite the same, but still very bright. You'll need to wear welders goggles and shoot through the shield. I would also use -3db gain, and have the ND filter on. If you want to experiment, try different White Balances and maybe a polarizer.

Jeff

Ross Milligan September 13th, 2002 07:25 AM

How about using a field monitor - just in case - that is what I do when working with lasers.

Ross

Marcus Farrar September 13th, 2002 07:47 AM

Greetings

We have shot some welding on a bridge construction site. We had the ability to be a safe distance back and just zoom in. Not the best but safe for the camera. I would say no way around getting the eyeware to protect yourself. Will you be inside or outside, in an open area with plenty of work around space.

Christopher Keiser September 13th, 2002 12:17 PM

Welding responses.
 
I appreciate all responses. I love this sort community intercourse.

I will be shooting this for interest in the craftsmanship of the welding process. The subject is actually a custom bicycle builder. Shooting from a distance of maybe 3ft. I would like to shoot the arc, and then maybe ride the iris and tilt up to the reflection on the welders shield.

I appreciate the suggestion of using a field monitor, had already planned that.

Curious about the chap, marcuskf, who shot the welding of the bridge on the construction site. From your vantage, could you actually see the arc, or just the flax, and sparks? Did you shoot through a welders shield (in front of your camera, as a filter)?

Thanks,
Christopher

Adam Lawrence September 13th, 2002 12:26 PM

Ive shot footage of a metal saw baldem sawing into a metal rod,
in turn created a mass amount of flying debris and sparks,
I shot the footage from about 4 to 5 feet away and zoomed in, creating
a "micro photograph" of the saw and rod which in turn made a beautiful
effect.

Marcus Farrar September 13th, 2002 01:11 PM

Welcome to the world of too much Technology. When I shot at the bridge location was a project for North Carolina's first Polymere Bridge (some sort of plastic yes plastic bridge pannels. The support beams on the bridge were made of steel and the welder was putting on the dividers, to hold the pannels in place. So the welding was not my main focus. I mostly just the flax, and sparks. I was at a safe distance of about 10 feet off. I got some good angles because he had to do a lot of welding and being outside had plenty of space to move around. As long as you keep an eye out for the sides of the bridge. At that time no gaurdrails yet. I had no shield because I had no idea I would be shooting welding. No matter how many meetings you have clients sometimes still leave out that important info. I love video production!!!

Interesting, though off the subject that someone still makes custom bikes. Sounds like a cool project.

Marcus

John Klein September 22nd, 2002 01:13 AM

another thing about shooting outside is the rest of the subject area is lit better than inside. There, you'd shoot the scene more normally and the arc would just be brighter. But inside, it's the only light there is.

I was just chuckling to myself about doing a white balance....OK you hold this piece of paper....you fire up the torch, and I'm gonna set the white balance. It probably should be done, but it just sounds funny.

Keep in mind that you can get a "sunburn" should you decide to do this for a few hours in shorts, etc. .. cover all areas exposed by the light. Cotton's fine. Goggles aren't right for anything but oxyfuel welding. Get the helmet.

Saw a guy in a football jersey (with the vent holes) once in weldshop get a surprize "tan."

part of me really thinks the ND on and auto/ AE shift might be an interesting way to try it. It would be making some changes as soon as the torch was on/off.

Christopher Keiser September 25th, 2002 10:18 PM

Thanks for your suggestions.
 
Naturally the shoot got postponed. I will try to make a clip of the welding available on my website once it gets done. I will post notice here.

Bill Ravens September 26th, 2002 01:14 PM

Take care of sparks. The molten metal that flies off is sufficient to melt silicon glass and embed itself in the glass surface. This applies to sparks from a metal grinder wheel, as well.

John Klein September 26th, 2002 09:35 PM

I just saw someone else's welding footage and it appears to be lit by the room lights, and they let the arc go hot. The footage looked good. I just assumed that the arc would throw enough light to be the primary light. I think that's possibly wrong now.

Ken Tanaka September 26th, 2002 10:03 PM

This same topic came up last spring. Here's the thread. Perhaps it will provide a bit more info.

http://www.dvinfo.net/conf/showthread.php?s=&threadid=1182&highlight=welder

Andre De Clercq September 29th, 2002 04:07 AM

Long before CCD burn-in occurs the image would be spoiled by strong smear effects. I you use ND filters, high f-numbers (avoid short exposure times for welding scenes)) and you don't have excessive smear there is no burn-in risk at all. I would not advise shooting for hours with the focussed highlight(s) on the same position in the scene especially with single CCD cams. The (absorption based) color filters on the CCD are much more sensitive to degrade from heat and UV light strongly present in the (tanning) welding plasma's. A good UV filter is a must then. The red and near-infrared parts of the spectrum are the "heat generators" and are much stronger in the sum spectrum. Although CCD cams have IR filters build in, an extra infrared blocking filter would be advisable if one need to shoot straight in the sun focussed and zoomed all the way out (small spot). To get an idea how much stronger the sun's heatingpower is, just take a magnifier glass (this is mostly comparable to an F2 to F3 camera setting at full field exp. time) and focus it on your skin...do the same for a welding ark..


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