dr_phil_physics | The Long And Short (Reply)

Wavelengths, that is.

I've been meaning to do this for a long time. I have two sibling camera setups. The Nikon D100R (a D100 converted to infrared use) with a 28-80mm f3.5-5.6D (New) AF-NIKKOR and a regular D100 with a 28-80mm f3.3-5.6G AF-NIKKOR. And I wanted to shoot them essentially side-by-side or rather serially, so I can see the same image in visible and IR.

Last Sunday was a chance to do it with bright sunshine and snow and ice. The IR shots were all done with the same false color settings on Ulead PhotoImpact 5.0 (Hue = +45, Saturation = -30), though with brightness and contrast adjustments they came out with different shades. Both cameras were set for ISO 200, so there were similar exposure settings.

The view SE of our garage in infrared. (Click on photo for larger.)
©2014 Dr. Philip Edward Kaldon (All Rights Reserved)

And the beautiful blue sky. (Click on photo for larger.)
©2014 Dr. Philip Edward Kaldon (All Rights Reserved)

This all should have taken ten minutes, but after the first IR picture the D100R locked up its mirror and gave Err on the top LCD panel. This happened when I first received it -- there's a procedure in the manual. So I came inside, looked it up. You have to remove & replace the battery, then put a small pencil in a reset hole. I took out a small Swiss Army Memory knife, but the blade didn't fit. So I brought it in and rummaged around for a tool with a longer, narrower point. Finally it reset.

The manual suggests static buildup, critical given that the D100 uses a CCD charge coupled device sensor and not CMOS. I suspect that the change of the IR cutoff filter to an IR pass filter makes the D100R a bit more sensitive.

Okay, so my ten minute estimate was wildly optimistic.

South down the driveway. Notice the lens flare. While the 28-80mmD has both a lens hood and a Nikon 52mm NC filter, the NIC anti-reflective multicoatings are optimized for visible, not IR. (Click on photo for larger.)
©2014 Dr. Philip Edward Kaldon (All Rights Reserved)

With the dark trees. Didn't adjust the exposures on any of these -- just using center weighted metering and aperture preferred automatic A on both cameras. (Click on photo for larger.)
©2014 Dr. Philip Edward Kaldon (All Rights Reserved)

Southwest into the sun. Strong lens flare is a fact of life in IR photography. (Click on photo for larger.)
©2014 Dr. Philip Edward Kaldon (All Rights Reserved)

Bright sun and backlight. Notice the complete lack of lens flare -- optimized lens coatings work. (Click on photo for larger.)
©2014 Dr. Philip Edward Kaldon (All Rights Reserved)