A second work from “The Clear Light,” at the 2017 National Prize Show of the Cambridge Art Association

I got the news yesterday that, for the second year in a row, a picture from this series was juried into the National Prize Show of the Cambridge Art Association. I’m especially pleased because it’s nice to reconnect with that community again even though, as was true last year, I’m an out of stater.  The National Prize show is not limited to artists in the Boston–Cambridge area, so I can still participate at times even though I now live in New Mexico.

This year’s picture is The Very Large Array.

The Very Large Array, or as it’s known around here, the VLA, is a radio telescope installation in western New Mexico.  For those wondering, “very large array of what?” it is a a set of radio telescope antennas laid out on a Y shaped set of tracks:

Radio telescopes like the VLA work on a principle that is not hard to explain if you are used to thinking about lenses.  I used to know the math to prove it all, but that was back in school 40+ years ago.  The array of telescopes on their tracks forms a giant lens.  The lens has the same resolution as a solid lens or mirror with the same huge diameter as the Y-shaped array; resolution is a function of diameter.  So, its ability to focus on fine detail is the same as that imaginary giant lens.  It does not have the same light-gathering ability as the huge lens, because there’s just the set of light-gathering spots—the individual antennas—not a solid surface gathering photons.  Fewer photons per unit time. However, since you can take your time gathering photons for most celestial objects, the VLA can be used to observe and record a wide range of things in space, from black holes to radio galaxies.  (There is also an even more titanic Very Long Baseline Array, with antennas like these placed on a line with the Virgin Islands at one end and Hawaii at the other end.)

Not only is the array huge, but so are the individual antennas.  You approach the array and see it from a long way off, as in the picture above.  The arms of the Y are each 13 miles long, so the antennas can be spread out that far, and you see them from a long way off.

When you get close to one, you appreciate how large a 25-meter telescope is.  Everyone stands and gapes at it—the one that is sitting at the visitor’s area of the control facility. For me, it usually is about the people.  The knot of tourists at the lower left of the above picture looked like my kind of thing, with the adults all transfixed by what they’re seeing and the little boy not paying attention.  He puts me in mind of my time as a public school teacher.  You have to get kids interested in stuff.  They find their own things to focus on, but those are not always what adults want or would predict.

So, there I had the clear light, all over the place.  There were all those antennas getting it, and I was getting some in a different but still unusual range of wavelengths, with an infrared digital camera. I moved over to the other side of the group.  Close—you want to be close.  As with other pictures in this series, this black-and-white rendition has even more contrast than you would expect for something taken in a sunny desert.   Shadows, for example, are very black: the sky does not fill in shadows with infrared light, and for the same reason, the sky itself is fairly black because air molecules don’t scatter infrared rays as they do visible, blue rays.  

However, the picture is still about the kid.  Sometimes the infrared makes things clearer. My friend Ed Friedman was always challenging me to shoot things that were “not just about the infrared,” which I strive to do.  

For those who are into gear

You can’t buy ready-made infrared cameras.  In the film days, you used special infrared film, which was not a pleasant substance to work with.  It was ultra-slow, usually very grainy, and more finicky to develop than regular film.  Of the film experiences I miss, IR is not one of them.   I have a couple of series of infrared film pictures, some of which I think are wonderful, but all of which are technically terrible.

These days, you get an infrared camera by having someone convert a regular camera to IR.  It is a task for a skilled technician, but it’s straightforward.  Digital sensors are naturally sensitive to IR as well as to visible wavelengths, and they have a clear glass filter cover, to filter out the infrared light that would mess up your normal color photograph. Without the cover, your color photos would have some strange properties, like artificial black fabrics, which fluoresce a bit in the infrared, coming out looking purplish.  

The technician removes that clear glass, and immediately you have a camera that can record all wavelengths including the infrared!  Then, one way or another, you filter out the visible light, or some colors of visible light, and there you have it. Qualitatively, the infrared camera and its lenses are as good as they were before you did the conversion—fantastically better than in the bad old days of grainy infrared film.  The infrared digital camera is as “fast” (light sensitive) as the original unconverted machine.

This is a really excellent thing to do with a slightly out of date digital camera body, after you buy a better body and for which you have a number of good lenses.  This particular body is a Panasonic DMC-G3, for which I have an assortment of high-quality Leica and Panasonic lenses.   (The Very Large Array was shot with the superb Panasonic 12–35 mm f/2.8 zoom, at 20mm.) After I upgraded from this old body to a new one, I had the G3 converted to infrared by LifePixel. Mine has the 590nm visible-light filter that LifePixel calls “supercolor”: the camera actually gives you a bizarre color picture, although I have so far always wanted to render mine as black and white.  

I have a second infrared camera, which is a Ricoh GXR 24–72mm zoom module.   It was not converted by LifePixel but by some sainted and anonymous Japanese person who evidently acquired a bunch of those lens units (maybe factory rejects, because mine has no serial number), converted them to IR, and sold them for dirt cheap on eBay, complete with an assortment of different visible light filters.  The Ricoh, which produces a surprisingly high quality image considering its point-and-shoot-sized sensor, is what I used for last year’s National Prize picture, The Muster.  

Several photographers have asked me, after seeing The Muster, where they could get one of those infrared GXRs.  I would say, if you don’t already have one, you can’t have one or you shouldn’t.  LifePixel would probably do it for you for a price, but I don’t see why you would do that when you could have them make your leftover Nikon or Canon DSLR into an infrared camera that used all those fantastic lenses.  Well actually, I do, because the Ricoh is a very compact system that I have with me almost all the time, which is  how The Muster happened.  So think about having LifePixel make you something out of a high-quality P&S, maybe.  That is basically what my Ricoh module is, in terms of sensor size and quality.

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