665nm opened
As shot and after conversion
IR processing
I took a series of photographs this morning using the 3-IR
filters available with the Sony A7r.
I've written previously that Life Pixel converted my A7r to shoot 665nm
IR. I'm also able to capture in the 720
and 830nm range using lens filters. The
7r gives me the ability to select 3-separate custom white balances and I've
taken advantage of that creating one for each IR filter range I'll be shooting.
The samples included here were all shot with the camera set
on the same tripod I use when I use my medium format technical camera so I know
it's rock solid. I attempted to keep the focal length the same on each
shot. What I've found is the 35mm marking on the barrel isn't as accurate as I'd
like. The first 2-shots; 665 and 720
were both captured at 31mm (I thought I was shooting 35) while the 830nm was
captured at 33mm (again I thought it was set for 35mm).
720nm opened
As shot and after conversion
IR processing
Once again I'm very pleased shooting a mirrorless camera as
what I see in the viewfinder (I rarely ever use the LCD) is exactly what the
sensor sees and will capture. F/stop,
shutter speed and ISO all immediately show the effects of their adjustments
thus it takes the mystery out of setting up the shot.
In the end the f/stop and shutter speed were all set the
same; f/8 and 1/125. The only setting
that varied was the ISO with me shooting at 50 for the 665 and 720 and bumping
it up to 225 for the 830nm filter. From
doing these and other tests I can tell that I'll be using the 665nm more than
the 720 and the 830nm when I want to shoot black and white. In the end it's nice having the choices;
almost like back in the film days.
830nm Opened
As shot and after conversion
IR processing
Silver Efex Pro
Each sample includes the file as it looked opening in
Photoshop CC or Capture One Pro. The
second file shows the actual image as shot by the camera and what it looks like
after running it through Sony Image Data Converter. The third image shows what the file is
capable of with a minor IR adjustment.
In the case of the 830nm file I've also added another sample showing
what it would like after processing through NIK Silver Efex Pro.
I'm looking forward to using this combination of camera,
lens and filters in the coming months as we visit Jackson Hole WY , Valley of Fire ,
NV Chaco Canyon NM
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