Seeing which of my pens go transparent under Infrared

January 6, 2022

Not all black/etc pens go clear under infrared photography, but here are the ones in my collection that do. With some on the side that have plastics that don't go clear at all that use plastic from around the same time period as the rest.

The oldest one in this grouping is the Sheaffer Triumph (1940s), and only the cap plastic goes clear on that, but not the barrel plastic. The Pilots and Montblancs are mostly from the 1960s to 1970s.

Five Views (4 on a Modified Camera, 5th reference on non-modified)

Infrared Only (850nm and up shown)

Infrared + Red Visible light (695nm and up)

Ultraviolet Only (no light above 400nm)

Full Spectrum (no blocking of Ultraviolet, Visible, or Infrared)

Visible Light Only (off a normal unmodified camera)

Some macro shots at 850nm+

Pilot Super 200 w/ 14K "Coarse" nib, can see the May 1966 date code under the plastic, tail end of the Pilot Super 250 above showing the switch filler.

Pilot Super 250, 14K Falcon, Montblanc 320, 14K EF, Montblanc 225, 14K XXF

Montblanc 221 (no transparency under IR), Montblanc 14 (faint translucence), Montblanc 225 (complete transparency thru grip and feed)

Sheaffer Snorkel Valiant and Statesman, The main plastic has no impact on IR light, but the grips do. Had I remembered to get a closer shot looking below, you could make out the snorkel tube when it's retracted.

Pelikan 400NN cap, and Sheaffer Triumph (1940s) Cap, the Body of the Sheaffer Triumph doesn't have any effect from viewing under IR. The cap seems to be a different black plastic than the body.

Pelikan 400NN, 14K Semiflex EF

Parker 45 w/ Accountant and XF Nib Unit , no impact at all, included because someone on reddit wanted to see if it would work.

January 7, 2022

Very interesting! Thanks for posting the photos.

So how do you get access to an infrared camera, and have you considered taking photos of pens in other colors as well?

Ruth Morrisson aka inkstainedruth

January 7, 2022

2 hours ago, inkstainedruth said:

Very interesting! Thanks for posting the photos.

So how do you get access to an infrared camera, and have you considered taking photos of pens in other colors as well?

Ruth Morrisson aka inkstainedruth

As shown in the image caption, the camera has to be modified to see it. Normally with the vast majority of consumer cameras, there's a piece of glass sitting in front of the sensor designed to block UV and Infrared light which can cause some undesirable appearances for normal photography.

My E-M5 Mk2 was sold off ebay already done with a "full spectrum" conversion (removal of the filter, and in place a clear one that allows everything thru that the camera is capable of seeing).

My previous camera that I still have but don't use was an E-M1 Mk1 (just like the one I have for regular photography), where the conversion was done by LifePixel to replace the glass with one called a "Super color" IR allowing light from 590nm and up thru (so some visible red, and infrared), which produced results like this, without using a filter in front of the lens :

You could put narrower filters in front of the lens to go deeper into IR without as much visible light, such as throwing on a Schott RG850 filter blocking all visible light and ending up with more of a high contrast monochrome look.

With a full spectrum conversion though, you pretty much have to use filters in front to narrow it down to the spectrum you wish to capture. Shooting all of it at once can be a bit 'soft' or out of focus looking when zoomed in, because Ultraviolet, Visible, and Infrared light focus different thru the lens, if you have the visible light focused, then the infrared that's visible is usually seen as sort of a halo effect because that part is out of focus.

In some unmodified cameras you can use the near infrared filters in front of the lens such as a B+W 092 (695nm+) or Hoya R72 (720nm+) , but would almost always need a tripod, or turn up the sensitivity to very high grain. So on unmodified especially if not out in the sun, the shutter speed usually has to be several seconds long with a wide open aperture. And some cameras block UV/IR much more effectively than others so then even the filters are useless.

"and have you considered taking photos of pens in other colors as well?"

Not sure what you mean by this question. What I selected from my trays were the pens that show up clear. None of my other pens be it of color or otherwise showed clear under infrared as you can see from the grey, green, and teal pens provided. Likewise ebonite, metal, and patterned celluloid block infrared light as well.