MIG, lies and videotape

Hi,

I'm just getting started with MIG welding and I was wondering if I could videotape what I'm doing so I can go back and review my technique? I'm worried about a) damaging the camcorder and b) whether I'll actually be able to see anything? Anybody tried this?

Rob

Reply to
Rob
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I haven't done this, but see no reason that you couldn't video tape it. I would take the pictures through a filter so it would not be overloaded with light. And drape something over it to make sure no spatter hits the camera. Also figure out where you can mount the camera so it won't get knocked over. Standard tripod mount is a 1/4

-20 thread so you could make your own " tripod " that clamps to your welding table.

Dan

Reply to
dcaster

Some of the Sony camcorders have an INFRARED mode. Video it in IR and I

*think* you'll be able to see more than just with natural light. It'll probably also read through the smoke - and be less affected by other lighting such as back lighting (when not welding).

DO NOT have anyone monitor the camera while welding is in progress. Sit it up, turn it on and do your welding. There *may* be a possibility of welder burn just looking through the eye piece. I don't see this as a problem when viewing the film / digital results.

Just a thought.

==========

Rob wrote:

Reply to
Al Patrick

Reply to
Robert Ball

Rob wrote: (clip) I was wondering if I could videotape what I'm doing so I can go back and reviemy technique? ^^^^^^^^^^^^ It has the additional advantage that you can show the technique to someone else for help.

Reply to
Leo Lichtman

Having dealt with video equipment enough in my earlier years, I'd have to say that this fear is completely unfounded. The tiny little viewscreen in the eyepiece can only generate so much light; that amount would be the equivalent of turning up the brightness as far as it would go and pointing the lens at a well lit piece of white paper, or a sheet. It simply can't get any brighter, because the viewfinder is capable of only generating so much light given the amount of energy you're putting into it to power it. You could just as easily stare at the sun through the viewfinder and not sustain any damage to your eye, and you can rest assured that the manufacturer of a device that will be pressed up against your eye isn't going to engineer it to have enough optical energy output to damage your eye. Once the eyepiece reaches its maximum white output, that's it and it can't get any brighter regardless of the brightness of the input source.

Now, the CCD chip(s) inside the camera that record the image would be a different story. I could see those being damaged by sustained exposure to an arc, especially after the light is gathered through a lens and focused down to a tiny point. You'd be filming through a filter anyhow so that you could actually see what you were doing instead of having a videotape filled with a bunch of white spots, so that should solve that problem.

Reply to
The Hurdy Gurdy Man

Thanks to everyone for the advice. I think I'll get a second welding helmet and put the camera behind that. That should protect the camera and provide the best view of the arc.

Rob.

Reply to
Rob

Reply to
Robert Ball

Try using a lighter shade for the camera filter than you would for your own viewing. This should allow the iris on the camera to close down and give you a better depth of field. This will make focusing less critical. It's hard to say how auto-focus and auto-iris will work in this application so you might have to switch to manual.

Cheers,

Kelley

Reply to
Kelley Mascher

I think I vaguely remember that they use a #10 lense for solar photography1, so maybe that would be dark enough. But I'd try a the darkest shade I could get, and then go lighter from there... You're gathering a lot more light just from the extra width of the lense focusing it down to a smaller area. You could easily destroy your camera.

This is just a guess, but I'd think you could find out a lot more from an astronomy group, as it's a lot like taking pictures of the sun.

Reply to
jpolaski

wrote : (clip) You're gathering a lot more light just from the extra width of the lense focusing it down to a smaller area. (clip) ^^^^^^^^^^^^^^^^ No. The welding window does not gather light and focus it. It acts just like a photographic filter, reducing the light by some factor. If you can look through the welding hood comfortably with your eyes, chances are the light level will be well within the range of the cam-corder.

Reply to
Leo Lichtman

Reply to
Robert Ball

"Robert Ball" wrote: The camera lens focuses the light onto a small chip in the video camera. (clip) ^^^^^^^^^^^^^^^ Same as your eye. If the welding filter reduces the arc brightness enough to look at, it should also reduce it enough to suit the camera lens/chip combination. Welding filters are required by law to reduce the UV to harmless levels. I thought Jpolaski was saying the welding filter area was gathering and concentrating the light, and that's what I was responding to.

Reply to
Leo Lichtman

simply get one of the bigger welding lens from the supply store and tape it to the front of the lens.

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

Reply to
Gunner

"Gunner" wrote: Rob. simply get one of the bigger welding lens from the supply store and tape it to the front of the lens. ^^^^^^^^^^^^ The only reason I didn't suggest that is that you might end up with weld splatter hitting the front of the camcorder. Mounting the camera inside a helmet ought to protect it better.

Reply to
Leo Lichtman

tape the lens to the front of a card board box big enough to enclose the camera, punch a hole in the bottom for the tripod screw and close it up.

Gunner, one time professional industrial photographer.

Rule #35 "That which does not kill you, has made a huge tactical error"

Reply to
Gunner

I am surprised no one has said anything about protecting the auto-focus mechanism. The old camcorders used to have an infared window on the bottom front, below the lens. I don't know if the newer cameras use through the lens or external like the older ones. I am pretty sure and arc has enough infared in it to burn out that little photodiode in there.

None the less, I like what Gunner says about putting it all in a box.

Thor

Reply to
Thor

"Thor" wrote: (clip) None the less, I like what Gunner says about putting it all in a box. ^^^^^^^^^^^^^ So do I, but if the camcorder does have an IR cell below the lens, placing the setup in a box, with just the lens looking out through a hole would mess that up, wouldn't it?

Reply to
Leo Lichtman

Hum -

Was once a AFR (no TV then) Photographer - largest camera I used - 11"x14" View Camera that was stored in the closet since used post WWII. Getting film for the monster was tough - used 8x10. Never even thought of using the tripod - It was 36' tall! It was a post battle documentation and beautiful wood camera. I re-stored it there before returning back to the states.

Martin

Reply to
Martin H. Eastburn

Hi Rob,

My status as a welder is fledgling novice however my day job is videographer/editor for a couple of city governments including producing informational and training videos. Prior to that I ran the video studio for the local community college. As a result I've shot thousands of feet of tape in some strange situations, not the least of which was from the back of the cage in the dog catchers truck complete with dogs. A lot of the things had to be essentially no or low budget.

Now to your problem. Northern Tool had an observers mask for about $3 which is nothing more than Oxy/Acet goggles with a shield attached to the goggles and a #10 flip up lens, part number 164561 if they still carry it. I put the camera lens up against the inside and the head strap around the camera. Worked fairly well. I sat the camera back a little and zoomed in to the shots I needed.

If spatter is a problem, just about anything that will ward it off will work. Harbor Freight has a small welding curtain that could be laid over any exposed parts of the camera and tripod.

Welding replacement lenses can be purchased at a welding supply in various strengths to fine tune the image (assuming no manual iris control for your camera.) Grainger had them for $1.95 each.

If you have a filter screw in mount on your camera lens then stacking neutral density filters would be an option but more expenseve. ND filters for my camera run about $18 a pop.

Any IR or ultrasonic autofocus on consumer cameras would be essentially useless due to being covered for protection or reflected back from behind a protective lens.

The key to getting a good shot will be getting the iris closed down enough to get a decent depth of field. It wouldn't have to be much but a wide open iris and a bit of a zoom will leave you with a depth of field as little as 2 inches front to back. Manually closing the iris just a little will increase the depth of field quite a lot. (This is the reason for stacking lighter lenses on non-manual iris control). The short time it takes the iris to stop down during the initial arc strike won't affect the CCD (single chip camera). I don't want to get into a whole lecture on CCD structure and prism light splitting on multiple chip cameras- this ain't the place.

Hope this helps you out.

Mike H.

P.S. Ernie, I'm just north of you a little in Snohomish. If you need some help putting some video together shoot me an email. I can probably be had for beer and pizza for a good cause.

Mike

Reply to
Mike H.

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