MIG, lies and videotape

I used an 8x11 a couple times. I used regular enlarging paper, calculated the exposure times, shot it, then developed. It of course was a paper negative and using a light box, made contact positives from it.

Surprisingly, it lost only a tiny bit of resolution.

Very cheap to shoot with. It also works with other formats, of course.

Gunner

Leftwingers are like pond scum. They are green, slimy, show up where they are not wanted, and interfere with the fishing.

Strider

No, not the welding filter. The camera lense. All I'm saying is that the camera lense *could* focus enough light/IR/UV to a small enough area that it damages the camera. You would be gathering much more light from a lense than the iris of your eye, and the camera might no like it too much.

I agree that a regular welding lense *should* work, but it might not, and welding lenses are inexpensive compaired to cameras. I think it's better to start with the darkest lense, and then go lighter. At least, that's what I'd do if it were my camera. Or, I'd just ask around on the astronomy groups, and find out if any one really knows.

About 1967 I worked with USN motion picture crew shooting training film for navy welding school in San Diego, California. We used equivalent to 200mm lens on 35mm camera to keep camera away from welding. Neutral density filter, UV filter were used with extension tubes that also reduced exposure. The 16mm film cameras we used were not easily damaged by bright light that would damage video camera. Didn't use a tripod but a pipe bracket that clamped onto handy 4" pipe stanchion and had mounting flange for 16mm tripod head. We did exposure tests and frame rate tests to get desired results. Shot slow motion of metal drops falling from TIG rod MIG wire into puddle. Enough history.

Welding arc produces light from UV to IR with visible light in the middle. Modern lenses are color corrected so visible light from blue to red in point white light source will all focus at the same point on the film plane. Only special expensive lenses are corrected for visible light through UV light. I don't know of any that are corrected for all light from UV to IR. So filter out UV and IR or get fuzzy picture. Welding filter will do this. I would try using auto darkening welding filter. They have great UV and IR filtration and let camera see before during and after weld.

Go ahead and try camera auto focus and exposure but manual settings will probably work better preventing strange auto hunting for right exposure cycles.

From experance learning to weld needs the weldors full attention and shooting videos of the person learning welding needs camera man's full attention. Shooting close up video that will show good or bad welding is hard for both the weldor and the videographer.

I've been intrigued by this thread, partly because I have shot a couple of welding pictures using my digital camera. This is an old camera that I wouldn't mind replacing, so I didn't take any special precautions -- I set it back a ways, using full zoom, put it on the timer, and struck the rod. Took one picture without the flash, and it is pretty hard to see very much. Took another picture with forced-flash, and it came out much better. I did

*not* use any sort of filter whatsoever, but on the other hand I wasn't trying to get a closeup of the puddle -- just a general shot that showed me making some sparks. (One of these days I'm going to put together a website, and use that as an introductory picture -- one of these days ...!)

Andy

Simple camera auto exposer assumes light in picture is reflected from medium gray surface or all reflected light averages to what would reflect from medium gray. Bright welding arc light in picture is telling camera to use shorter exposure time and/or smaller lens opening to get proper exposure of subject. But your subject is the weldor which will be under exposed unless fill flash is used or exposure correction factor lets more light pass through lens and/or longer exposure time. You can manually put in correction factor but fill flash helps lower contrast between highlights and shadows often giving better results. You can compensate for over/under exposure during printing but much of the details in dark shadows and bright highlights are lost for good.

To add to that, we have seen many a person that uses flash in places that it won't light up the surface. It is opening up the lens and holding it open longer. Normally the lens on flash must stay open for 1/30 or 1/50th of a second for the flash to be 'seen'. So the fast lens doing 1/10,000 in sun is slowed down and the small child by a tree back lit by a shinny lake.... is shown nicely. Likewise faking out the camera on a welding shot - a hot spot in the camera might shut it down very fast.

Martin (former AFRS news photo guy. Since later Nam days AFRTS is the new acro

- added TV! )

You mean like, through the window of a jetliner?

Hey, easy on them folks -- it looks cool at a game when 4,000 flashes go off like a bunch of fire flies ... Oh, you mean they actually think they will get a "flash picture" ?? On the other hand, some people know how to take a flash picture at a distance -- check this one out (paste the url back together ... yes, that is a REAL train at night !!

mikey

You call that a flash? THIS is a flash:

:)

That looks like an interesting Engineering class to take. 6933 that is. Martin

You win !! That is a flash (and would even work at the football game to get the action ... from the top seat !! -- of course the teams would stumble around for the next half hour). I remember years ago (30+ ??) seeing an old Popular Science (I think) that had a picture of an even bigger flash tube than the one on your page (same purpose though -- high level flash photography recon during WWII ). Seems to me it had about 3 or 4 turns of a flash tube enclosed inside a container that was something like 3 feet long.

Some years ago, on Nova or some such, there was a 1 hour special on Edgerton and all his experiments. Really very interesting. Have not seen it for several years though. He did lots of work with strobes and stop action stuff.

mikey