Showing posts with label 311nm. Show all posts
Showing posts with label 311nm. Show all posts

Saturday, October 24, 2020

Reflected UV photography + videography using a MCP Amplified Camera System III

Today more about an experiment I have done, using a light amplification device in front of a normal visible light camera for recording reflected UV footage. This device uses a MCP (multi channel plate) with UV sensitive photocathode (approx. 190nm - 650nm), amplifies light by approx. 20-50.000 and shows the resulting image on a green phosphor screen. 

Using a suitable optical system, I relayed this image to my normal, visible light camera. UV filter used was a fully IR blocked (OD6) UV transmission filter (peak at 250nm). Target was a tea candle.

Using a f3.5/50mm quartz fluorite lens and an extension tube to get higher magnification.

1) Visible / IR light recorded w/o filter on full spectrum camera:

 

2) UV light recorded with a (fully blocked to 1100nm) 311nm filter on full spectrum camera: 

It gets rather obvious that the 311nm line is - as expected - quite intense on the visible left and right outsides of the candle, where the UV emission of the OH (hydroxyl) radicals happens.

3) UV light recorded with a (fully blocked to 1100nm) Baader-U (320-395nm) filter on full spectrum camera:

The reaction of the CH (hydrocarbon) radicals however emit UV around 385-395nm mostly on the top, which can be shown using the Baader-U UV transmitting filter (320-395nm).

I have written about this system doing still UV photography HERE.

I have done similar with a different amplified camera system before which did not allow to have an external camera attached, with just a TV output HERE

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Friday, December 23, 2016

Deep UV Ultraviolet Reflected Light Photography at UV-B and UV-C recording with candle light

Today another proof that reflected UV photography is doable at UV-B and UV-C using several special, up to NIR blocked, narrowband filters and a very different UV camera, an amplified 190-650nm MCP equipped video camera. Lens used was a CERCO f1.8/45mm quartz flourite lens. Light source was a candle flame.

[click on image to see a larger one]

This reveals, that the deeper one looks into UV, the area where the candle flame emits that UV moves from the top of the flame down to the sides of the flame. Pretty amazing how sensitive this type of camera is, as the needed amplification was still just in the lower 30% of the total available range.

I have a newer system HERE with a normal camera attached to the MCP amplification device.

I have previously written more about combustion and UV HERE.

Btw. Michael Faraday has in 1848 given six famous lectures about the chemical history of the candle, which may be read about HERE

Stay tuned, more will follow on that fascinating subject...