I share below my response to an emailed question from a reader of the diglloyd Guide to Digital Infrared Photography. I’m proud of my work in and of itself, but reader comments are always excellent feedback, and frequently yield the satisfaction of knowing I’ve helped others—thanks to everyone who’s written me.
Reduced-size version of the image from the Guide
Reader John T asks:
I have read through the "diglloyd Guide to Digital Infrared Photography " and found it to reinforce a lot of what I have learned over the years with My Sony F717 in Night shot mode.
Can I ask a question regarding the attached photo from the book.
I assume that you have set the custom white balance in the IR camera for the conditions on the day and you compensated for the IR exposure as well as using a middle of the road aperture (5.6 of 8.0).
The question is - Is the false colour in the attached image a result of the camera exposure or has some colour been applied. IE; is the image straight out of the camera and if so how is it that some other image do not show this false colour - straight out of the camera.
I intend making further investigation on this subject and wait for your reply.
The book is in my opinion the best that I have read for Digital Infrared Photography and does not include unnecessary text regarding film based IR as so do so many other. I certainly appreciate the advice about a dedicated IR camera (Conversion) after trying many other so called solutions.
Thanks again—John T
(Emphasis in bold above is editorial).
DIGLLOYD (slightly clarified from the email response):
Thanks for writing. No color has been “applied”, nor have the hues been altered from the original. See attached image in Nikon Capture NX; all “as shot”. 20mm @ f/11.
The white balance I use for the D70 and EOS 5D is fixed in the camera for all around good results; I haven't changed it for years. Sometimes I do “click around” in the RAW-file processor to alter the balance, but this particular image is more or less as shot, with contrast and saturation enhancement as is typically needed with any RAW image, but no alteration to the color relationships the camera produced. I originally processed it in Nikon Capture (pre-NX), but Capture no longer functions properly on Mac OS X for me so I cannot reproduce the exact processing, an irritating situation that should concern anyone shooting RAW.
My D70 internal filter is allegedly 815nm, but I suspect that it “leaks” quite a bit below that, because the false color effects are about as nice as I’ve seen from any camera, including 715nm ones. I'd really like a Nikon D3 that performs on a per-pixel basis like the D70, but it's very expensive, and its CMOS sensor might offer very different IR response--no way to tell without sacrificing a D3 to the cause of science.
A D70 is still one of the very best IR cameras out there—CCD with big pixels. Probably other models are as good, and the D70 controls are dated, but that rarely impedes me. (Lack of mirror lockup isn't helpful though).