Author Topic: Filming welding arc - filter necessary?  (Read 12747 times)

gyppor

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Filming welding arc - filter necessary?
« on: October 28, 2018, 10:48:21 AM »
Hi Kron Tech,

If I want to film the arc from a stick welder, should I use a welding shade in front of the lens? I'm concerned the brightness and UV radiation might damage the sensor. I would have the shutter at a very small angle but I realize since it's an electronic shutter, the sensor will still be exposed to the intense UV light the whole time.

Thanks!

G

Nikon1

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Re: Filming welding arc - filter necessary?
« Reply #1 on: October 28, 2018, 10:53:49 AM »
I filmed An CNC- Plasma Cutter and an -Laser Cutter on my Nikon J5 @ 1200 fps Without any special Filter. I used an Standard Clear Glass filter which i guess is an UV-Filter used in Photography, but just to prevent the Front of My lens from Hot Metal Stuff, since i was super close.
You will need to use VERY short Exposure time For that, since it is Realy bright.
I used Like f22 or even f44 for the Plasma and an bit of an faster Apperture on the Laser.
Didnt kill the Sensor for me.
But i cant gurantee for your case...
« Last Edit: October 28, 2018, 10:58:06 AM by Nikon1 »

jasonfish

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Re: Filming welding arc - filter necessary?
« Reply #2 on: October 28, 2018, 02:30:04 PM »

Sael

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Re: Filming welding arc - filter necessary?
« Reply #3 on: October 28, 2018, 04:26:03 PM »
A nice short article on the dangers of photographing bright objects over on PetaPixel: https://petapixel.com/2017/09/01/photos-cameras-lenses-got-destroyed-solar-eclipse/

If the light source you are directly filming is bright enough to burn things with just a magnifying glass it's best to look into protection, especially if you're expecting to be looking at it for a long period of time. I'd also think the near infrared radiation would be more of a hazard to the lens and camera than UV. Modern lenses usually have UV blocking coatings, as well as the glass itself being not very transmissive to UV. Near infrared on the otherhand will pass through and while the bandpass filter in front of the sensor will reflect most of it, it will heat anything it shines on.

Regular photographic ND filters are not designed to block near infrared, and as such are not suitable for solar photography. For this reason I wouldn't recommend using them for photographing welding either. A solar filter might work if you want more true colours, but I can't say how well they would work. Welding lenses are made for looking at welding arcs and are thus probably the best choice protection wise.

Welding shades are cheap insurance against lens and sensor damage, and not terrible to have extra of if you've got welding equipment already. A no.7 or 8 shade should be fine, it's about a 9-10 stop reduction and thus is approximately equivalent of going from F/2 to F/45 - F/64, or going from 1000μs to 2μs - 1μs exposure. If this is too dark for your needs a no.6 lens is a whole 3 stops faster, or 1000μs down to ~20μs.

gyppor

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Re: Filming welding arc - filter necessary?
« Reply #4 on: October 29, 2018, 11:16:26 PM »
Thanks, looks like I'll use a welding shade. I was hoping to film without the greenish tint of welding shades but I'd rather save my sensor!

Sael

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Re: Filming welding arc - filter necessary?
« Reply #5 on: October 30, 2018, 03:39:38 PM »
The green tint can be removed with some colour correction, there are plenty of articles around describing how:

https://www.diyphotography.net/use-welding-glass-as-10-stops-nd-filter/

I might look into if it's possible to do it with the in-camera white balance...

BondEric2

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Re: Filming welding arc - filter necessary?
« Reply #6 on: December 23, 2020, 02:51:39 PM »
I guess there is not even such a filter that would actually be able to protect the sensors actually. Just like the guy said above, I guess Standard Clear Glass filter  would actually be a great choice. You could try to use a certain filter which are made for solar photography, however I am not sure at all that it ill work out. I mean, the welding light is a totally different thing. Surely there can be a certain solution for this, I guess you can try and get the lens from a welding helmet. In order to get the best one, you can read the best welding helmets reviews and see which one is have the best lens.
« Last Edit: December 28, 2020, 10:45:42 AM by BondEric2 »

Nikon1

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Re: Filming welding arc - filter necessary?
« Reply #7 on: December 23, 2020, 03:48:11 PM »
I guess there is not even such a filter that would actually be able to protect the sensors actually. Just like the guy said above, I guess Standard Clear Glass filter  would actually be a great choice.
Not too sure about if that is true...?
 Old topic, but as people allready pointed out, there are propper percision Bandpass-Filters available for Visible Light only, and people use them For Solar Photography, aka. Pointing a Highly Magnifying Lens / Mirror assembly (filling the Frame with the Incredibly bright sun) directly to the sun and even focusing on it, which would easily destroy the sensor and actually melt the Camera behind it and can even Start fires (has happened bevore to some people) without propper filters made for it. Given the use of High apperture Telescopes in combination with the Brightness of the Sun, there is WAY more power involved in solar photography than in your usual welding (dont know about some Extreme Indusrial applications, but for most other welding stuff and electric arcs this should hold true) with an common lens.
 .
 those solar filters can sometimes be rather expensive, but they are very effective and have prooven themselves well over time, to be working very well, if you know what you are doing and get the Correct filter.
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 Now i am no specialist about those Sensors at this, but from what i have seen and heard, they are way less delicate in terms of damage by non-visual Light in general compared to human eyes. As i said in my first reply, i shot Plasma Cutting (which can be watched by bare eyes but is still uncomftably bright and proppably also not good to look at for long time, a Second or so is fine however) and even CNC-Laser Cutting (dont know exactly which type of laser that was, but a invisible one, that could easily make you blind from the Smallest of reflection, and at that place i had to wear special Eye-Protection Glasses made for that Laser Wave-Length at all time the laser was running, shot that Laser for like 30-60 Min as a Closeup of the Actuall cutting from like 20cm distance for some Troubleshooting which they couldnt do propperly by themselves, because the Machine was just moving way to fast to propperly see what was even going on on the Cutting Head. Industrial Laser, with scary power.) without any protection besides some Clear glass filters to avoid the crazy hot Splashing of Metal beads hitting the Fontlens and also keeping all the Dust out of there, again, sometimes from Pretty close up. So as for usual Welding, i would expect, that as long as you can watch it by eyes, aka. from behind Welding Shades, it should be very save for a Camera sensor. As Long as not too much power and Heat is involved (like from some Crazy industrial Arc Lamps/ -furnace or industrial Welding), it might even be fine to shoot without any additional protection at smaller appertures, not too sure about Very fast lenses though. Back then for the Laser i just risked it, cause it was like a 400€ camera body only anyways, but wouldnt be sure if i would just go and try that with an Chronos again (without having tested with an cheap camera bevore, to know its save), as i completely expected to loose that camera on that day when shooting the Laser. But did survive just fine.
 .
 If gyppor allready tried whatever he was shooting back then, maybe he could share what worked out for him as protection (if any at all).

Faraam

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Re: Filming welding arc - filter necessary?
« Reply #8 on: July 13, 2021, 12:31:46 AM »
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« Last Edit: July 15, 2021, 04:53:27 AM by Faraam »