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Photography of Plasma and Glow Discharge

Posted: Sun Sep 08, 2019 12:08 am
by ian_krase
I have searched the forums for this in vain.

Plasmas can be a beautiful, even romantic thing. Unfortunately, in my experience I have never once succeeded in making a photograph of a plasma that really looked like the real thing -- the photograph is invariably either hugely undersaturated or overexposed to the point of opacity. I cannot capture that beautiful light.

This tends to make pictures of plasma rather formless, unless it's a plasma that has very vivid structure such as starmode, a bugle jet, or a sputtering magnetron discharge -- and even then one sees only the structure itself and not i.e. the glow emanating from the magnetron discharge.

I am curious as to whether anybody has a good procedure for taking actually good pictures of plasmas.

Re: Photography of Plasma and Glow Discharge

Posted: Sun Sep 08, 2019 12:24 am
by Trent Carter
As luck would have it my iPhone XS Max takes great pictures through the viewport.

GoPro (worthless, because the XRays and EM Noise make it go nuts. Maybe shielding?)
Fancy industrial camera (Crap) -> But maybe a better/different one would work if one was to keep trying
Cheap backup camera (works pretty good, just lower resolution, and gets "blown out" on a bright plasma)

iPhone Pic Example:
Glass_Cathode_IMG_5960_120x120sm2.jpg

Re: Photography of Plasma and Glow Discharge

Posted: Sun Sep 08, 2019 12:43 am
by Jerry Biehler
Get a chunk of leaded glass if you are having x-ray problems. For you and the camera.

Re: Photography of Plasma and Glow Discharge

Posted: Sun Sep 08, 2019 2:54 am
by ian_krase
I've been using my phone - maybe a better option exists?

Re: Photography of Plasma and Glow Discharge

Posted: Sun Sep 08, 2019 6:31 am
by Richard Hull
Much depends on the camera and what the folks making the software for your smart phone or whatever toy you are using thinks makes a good exposure under varying conditions. The only thing good about smart phones and the cheapo little video cameras is that their lens is microscopic and typically wide angle enough to shoot a full grid image through a tiny view port.

If one had a view post with 2 inches of glass in it, a good $2000 digital Nikon would place you in complete control of the image to begin with and then you can use software to massage it to what ever you think is pretty. A beautiful plasma image is a very artsy-craftsy thing and can stun and gratify the down-at-heel public at public exhibition. Scientifically, in the fusor biz, it contains no significant information related to the fusion process, nor is it a signature that fusion is even taking place! We now know that almost no fusion is taking place within it. It just a visible signature that electron orbitals are being messed with en-mass in their comings and goings in the level shift game.

Still, it is purdy....

Richard Hull

Re: Photography of Plasma and Glow Discharge

Posted: Sun Sep 08, 2019 8:41 am
by Frank Sanns
I have the distinction of having the first Archived image on the site. While my lattice grid added to the aesthetics of it, it was the photograph technique and conditions that had it published in various places including Wired, Maker, and a bunch others.

Room lights and all sources of reflections off the sight glass needs to be gone. Camera needs to be held securely and squarely against the sight glass, preferably with a tripod.

The camera should have excellent low light capability and have a manual setting. I guess you could use exposure compensation to get the exposure that you want but that will change shot to shot so I would not recommend that route. Manual exposure and focus is by far the best.

Next is the plasma itself. A chamber or fusor that is just starting up on air or deuterium will be hazy due to outgassing. Only a clean chamber that has been running a while even has the potential to get a good plasma picture with good color saturation and contrast.

I am skipping some fine points but next is the exposure. Use the widest angle lense you can find for wide field of view and depth of field. Use a medium aperture like f5.6 or f8 and adjust you exposure time to between some slightly longer exposure between 2 and 5 seconds. ISO should be 800 or preferably 200 or 400.

Lastly, adjust the plasma current to give the best visual appearance and exposure. Of course you can vary you camera settings to but they are all connected. Always keep you voltage below around 15kv when you are photographing so you do not have to deal with x Ray speckling in you photo and the totally unnecessary exposure to your body.