Posted by CANbike on Wed, 16 Oct 2013

[Sony DSC-V3] Raw + Nightshot (IR) + NDX400

The Sony DSC-V3 in Nighshot mode captures infrared pictures. However, due to Sony imposed limitations it was intended only for night time. The shutter speed would be restricted to 1/30 or longer. If used during the day, the photos would be too overexposed.

A simple solution, was to attach a NDX400 (a 9-stop ND filter) to use the camera in broad daylight. See Infrared Bike Photos (10/10/13) and Infrared Bike Photos (10/12/13) for examples.

In jpeg mode, images produced are a monochrome green color. The camera retains the infrared data, and tosses the color information. With a bit of post-processing, either black & white infrared photos or false color infrared photos can be produced.

The Raw mode, however, retains all data captured. This includes infrared data, and visible spectrum data. This can result in some unique effects.

To access the Raw data in GIMP, the UFRaw plug-in was installed. UFRaw reads Raw images by using Dave Coffin’s Raw decoder DCRAW. Fortunately, the Sony DSC-V3 is listed as a supported camera.

Images Unprocessed

The jpeg is straight from the camera. The Raw image is a direct conversion without any additional processing.

DSC-V3 Infrared Unprocessed

JPEG Post Processing

Post processing is required for jpegs straight from the camera. A good base to start with is

  • Colors -> Hue-Saturation
    • Master saturation: 50
    • Adjust Hue for desired color
  • Colors -> Brightness-Contrast
    • Contrast: 15
  • Adjust Levels

DSC-V3 Infrared JPEG

Raw Post Processing

Raw images need to be converted and at least sharpened. There’s more flexibility but a typical procedure is

  • Open SRF file in GIMP
  • Adjust Exposure, Levels, and Denoise in UFRaw
  • Optionally Adjust Grayscale Mode in UFRaw
  • Click “OK” to convert and edit image in GIMP
  • Optionally Adjust Colors -> Components -> Channel Mixer
    • Swap Red and Blue Values
  • Optionally Adjust Colors -> Hue-Saturation
    • Adjust Hues for desired color
  • Optionally Adjust Colors -> Brightness-Contrast
  • Optionally Adjust Levels
  • Filters -> Enhance -> Unsharp Mask
    • Radius: 0.5
    • Amount: 1.0 – 2.0
    • Threshold: 1

DSC-V3 Infrared Raw

Sony DSC-V3 Raw IR Notes

  • Raw is set via Menu -> Mode > Raw
  • Nightshot can only be enabled in P or Auto mode
  • Both a JPEG file and Raw image file (SRF) will be saved
  • JPEG file is around 2.5MB
  • Raw file is around 15MB
  • JPEG image dimensions is 3072 × 2304
  • Raw image converted dimensions is 3109 × 2324
  • Raw images are noisy but have a nice grain texture
  • Shutter Speed is limited to 1/30 s
  • Metering Mode is limited to Center
  • White Balance is limited to Auto
  • ISO is adjustable

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