Arc Welding Photography Advice.

I'm interested in photgraphing arc welding. I know about the safety

of the photographer during the session as well as protecting the

camera from the welding itself but what about the CCD sensor. I have

read that the arc can actually cause dead pixels to appear in the

sensor. I have the FZ-30 and no dead or hot pixels and I don't want

to end up with any dead or hot pixels.

 

Any advice?

With film you'd have to overexpose and under-develop. With digital is tricky and the dynamic range of your camera's sensor will be one of the main limitations. Shooting RAW is a must.

 

You could also use strobes to reduce the difference between the arc and ambient which would in turn put less dyn. range requirement on the sensor. It depends also on the look you want to achieve. If you place the arc at 2-3 stops above *its* own metered point you'll get one look. If place the arc at 1 stop above you'll get a different look. Additionally, should you use fill strobes with either exposure you'll get different looks yet.

 

I don't know about the effect of the arc on the sensor. But, you'll be far away (!) so, I don't see what the problem would be.

With my 5D (a full frame camera) I'd probably shoot the scene in a tight crop with a 200mm or even 300mm telephoto, around f/4 to get some DOF while blurring the visible background.

 

Again, it's a matter of requirements and/or taste.

Shoot through a welding helmet, or perhaps just the glass. The arc will provide all the light you need. Make sure you are protected, both eyes and skin. Arc welding can cause nasty sunburn - make sure you are completely covered. If you observe the arc with your eyes unprotected for more than a few seconds, you will wake up in agony the next morning - it's as though your eyelids stick to your eyes.

 

If you are shooting a more environmental type of scene, you may not need a really dark filter. Just make sure the arc is not directly visible to the camera. It is virtually a point source, so you will still get the effect of "welding" if any small object blocks direct view.

 

Watch for spatter ("splatter" to the uninformed). It stings and can burn holes in clothing and start fires in combustibles. Needless to say, an lens would be ruined - use a protective filter or two. OSHA and fire rules demand a trained fire watcher be present or at least to inspect and approve the area. Play around with exposure times to get the streaming effect of spatter. Welders don't move very fast - at least the good ones.

I would use a RM72 infra-red filter. I would also keep a stack of ND filters handy incase the RM72 was too strong. Lens/filter flare could be a problem with such an intense and small light source. Wear sunscreen.

Use a film camera.

I used a Wratten 87, Infra Red filter, to shoot a partial eclipse with success although for a moment the camera and I had a fright as we coped with the bright light through the EVF.

Exposure was 1/4000 at f/8 even with the 87 which passes no visual light as far as humans are concerned. The camera is mildly IR capable with exposures of 1 second at f/2.8 in bright sunlight.

 

As an occasional arc welder I would imagine the sun is a little bit brighter than the weld since I do my welding through a filter I can see a little bit. Perhaps get yourself a welders lens/glass for the camera, only a few dollars. To overcome the excessive contrast perhaps take two shots, one without a strike and one with, and blend in editing?

use the welding glass as a slot in filter use a tripod and a cable release (solely to keep you

out of the way as a welding flash is way to sore - think pins or hot sand in the eyes) - you

will also need a fairly short exposure as there is a lot of movement in welding.

<p>After reading the advice here, I was better prepared for a welding shoot and came away satisfied with the results. The welder was very helpful in faking the shot in order to get the sparks flying however I asked him. He changed rods and the direction of the welding plate to modify intensity and angle. <br /><br />I used two Lowel Omni tungsten lights (500w) with barndoors for fill behind the welder's mask and lower right, checking exposure first without the welding. Shooting with a Nikon DSLR, I used a 50mm lens (1.5 crop factor) at f5.0 and a shutter speed between 1/10 and 1/20 of a second, ISO 160. I didn't use a filter other than a UV, no sensor damage. The camera was on a tripod. I used a welder's helmet for protection--you can't see anything but the arc and spatter, so I just kept my finger on the shutter and would fire about ten shots for each go-round until I was confident we had enough variety and proper exposures.</p>