Thursday, January 23, 2014

Digital Workflow 1 – Camera Settings

I have received some requests to share my digital workflow and IR camera settings.  All of this information will not fit into a single post, so I am breaking it into chunks that are easier to download and digest. My general IR workflow is listed below. In this post, I will share my camera settings and discuss the importance of shooting RAW files.

General IR Workflow
  1.       Set up the camera
  2.       Shoot RAW files
  3.       Set White Balance (Nikon Capture NX2 or Nikon View NX2)
  4.       Auto Levels
  5.       Save as TIFF (Do not skip this step!!)
  6.       Noise Reduction
  7.       Black and White processing and/or Channel swap (Photoshop or CNX2)
 Camera Settings

 ISO:  I use base ISO whenever possible. A 720nm filter will exclude about 90% of the luminosity in most scenes so your sensor is in a low-light situation even when it is bright outside. Keeping the ISO as low as possible is helpful because it will decrease the noise in the image.That said, if you need to raise the ISO to get the shot, raise the ISO.  (Noise reduction programs can clean up some of this in post production.). A noisy photo is better than no photo.

White Balance:  I use the LifePixel preset on all my cameras. Only a few Nikon cameras will reliably accept a custom white balance after IR conversion (see below) so I don’t even try to set one. I adjust the WB in post.The next post will address white balance issues. 

Image Quality:  I shoot RAW images exclusively. This allows me to adjust the white balance in post-processing and gives me a lot of after-the-shot flexibility.

Picture Controls:  I use a modified picture control setting for all of my cameras. I start with the VIVID setting then add contrast (1 block to the right of center) and +6 sharpness (6th block from the left). I save this as a custom setting called Vivid&Sharp. 

You are probably wondering why I care about Picture Controls, especially when shooting RAW.  There are two reasons. First, these settings are applied to the image on the back LCD and a sharp contrasty image makes it easier to evaluate the exposure values and other camera settings. Second, I use Nikon Capture NX2 (CNX2) to adjust the white balance. CNX2 will apply the picture controls to the image (other programs don’t) and give me a good starting point for the white balance and channel swap processes. Picture controls do not matter as much if you do not use the Nikon programs to set the white balance. PhotoShop and other programs cannot access the Picture Control information in the NEF file and the images you bring into PotoShop may not  look like the images you see on the back of the camera. 

Please note that when you set the in-camera Picture Control to Monochrome, CNX2 to will present the image in monochrome. Monochrome images are often more difficult to modify in post. Fortunately, the NEF file still has all the color information and changing the Picture Control back to Vivid in CNX2 will give you an image that is easier to modify. If you shoot JPG images, you cannot make these adjustments.

Histogram:  My histogram settings are different from those described by many other IR photographers. First of all, I turn off the RGB histogram and shoot using only the highlight overexposure warning (blinkies) and luminescence graph. For my shooting, a balanced image is one where the luminance histogram is not bunched up on the left or right and there are no unexpected blinking areas (clipped highlights). 

Other IR photographers will tell you to watch the red channel histogram to make sure it does not get overloaded (really bunched up on the right). This does not apply when using most converted Nikon cameras because the best way to address an overloaded red channel is to adjust the white balance and I cannot do that in the camera. I have to rely on the RAW capture to collect all the color data and fix the WB (and red channel overload) in post. Watching for red channel overloading is important if you are shooting JPG or TIFF images because what you see is what you get and you have no way to recover lost image data. 

I use these settings on my 590nm SuperColor, 720nm Standard IR, and 830nm Deep Infrared camera conversions. All of these cameras (Nikon D90s) were converted by LifePixel.  

The following Nikon DSLR cameras can set a custom white balance after infrared conversion:

D40X      D80         D1
D50         D100       D1X
D70         D200       D2X


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