Sunday, September 28, 2014

My Ideal Infrared Camera (Revised)

Many people who want to get into infrared photography convert one of their older camera bodies to IR. This makes some sense for the beginner IR photographer because he/she already owns the camera and the only real expense is the cost of the conversion and the shipping. After all, why should they spend a lot of money when they may not enjoy the experience? Other beginning IR photographers will purchase a gently used older camera for conversion. This may be a better approach if your older camera does not have LiveView.

What about those individuals who are committed IR photographers? What camera characteristics would be best? Like all camera choices, the right answer depends upon the photographer and what they intend to do with their IR camera. Most infrared photographers shoot landscapes and weddings. Yes, you can do much more than that with an IR camera, but those are the main IR shooting styles I’ve found while perusing the internet.

If performance, not cost, is the deciding factor in your IR camera choice, one would assume that the most expensive, pro-level cameras would be the ideal choice for conversion.  This logic has some merit but there are performance drawbacks. The Nikon pro camera bodies have an IR LED inside the camera body that is used to monitor shutter performance. This isn’t an issue when shooting at low ISO values (Issues and Solutions page

The Ability to Set a White Balance

White Balance (WB) is a much misunderstood process with IR photographers. In visible light photography, WB settings are used to remove unrealistic color casts so that objects which appear white in person are rendered white in your photo. In IR photography, WB is used to transform the invisible IR spectrum to a visible spectrum we can perceive and manipulate. This transformed spectrum is important for color IR post-processing and strangely enough, for black and white post-processing.  A proper white balance will also minimize red-channel clipping that occurs when the camera attempts to jam all the visual image information into the red channel. 

Most Nikon cameras have difficulty setting an in-camera white balance and the Nikon IR photographer often has to make these adjustments with software. You can learn more about White Balance and Nikon cameras by reading the white balance article on this site. My preferred IR camera would have the ability to establish an in-camera white balance, thereby saving time during post-processing. I know there is an acceptable workaround with software, but we are talking about the ideal IR camera.

Good Low-Light Capabilities

This is a camera characteristic I personally would like to see because I tend to shoot IR photos in a lot of challenging situations. The infrared photographer who never has to increase their ISO above base levels doesn’t have need this capability quite as much as I do.

The underlying problem is that the camera is designed to handle the entire visible light spectrum.  When you block all the visible light above 590 nm (SuperColor Conversion), the spectral irradiance of a daylight scene is reduced about 45%. Blocking all the light down to 720nm (Standard Conversion) will decrease the spectral irradiance by about 70%. The Deep Infrared (830 nm) conversion will reduce the spectral irradiance by 88%. These numbers assume that all your filters, lenses, and other optical components have perfect transmittance. Long story, short, an IR converted camera has to work harder to capture and render the IR spectrum because there are fewer microwatts of light hitting the sensor.

We can combat low-light conditions by increasing the sensitivity of the sensor (increased ISO values) but increased ISO levels will increase noise levels. A converted camera designed to handle higher ISO settings without noise is an advantage to me. Another way to address this problem is to install a filter that lets more light into the camera. By using a SuperColor filter, the camera has about 25% more microwatts to create an image than a 720 nm (Standard IR) filter.

An Electronic Viewfinder

Yes, I know that most Nikon digital cameras have LiveView.  But have you ever tried to use LiveView in bright sunlight?  Good luck with that. An electronic viewfinder that shows me what the sensor sees is a real advantage for infrared photographers. Imagine looking into the viewfinder and seeing an image as it will be captured - white leaves, dark skies, and other IR effects. Image pressing the EV button and being able to evaluate the exposure value while looking at the viewfinder image. 

Sensor-based Focus and Exposure

Better yet, what if the focus engine was based upon what the sensor sees? What if the focusing capabilities were a lot faster than our current LiveView capabilities?  Lens calibrations would be a thing of the past and we could use both ends of our zoom range with the same level of focus accuracy. We would also be able to use our lenses wide open for subject isolation without worrying that IR focus shift is going to soften the image.  Further, we could manually adjust the focus to get the perfect focus point.  Yes, we can do the last two items with LiveView and yes, LiveView allows us to zoom in on the focus point to make sure it really is in focus.  However, LiveView can be a pain when it is very bright outside.  Some of us compensate by using an LCD viewfinder or hood, but my ideal camera wouldn’t need one.

Other Nice-to-Have Features

  • FX sensor for more DOF control.
  • Ability to use my existing Nikon lenses
  • Smaller footprint. For many casual IR shooters, the IR camera is the second camera in their bag. This camera would get more use if they didn’t have to lug two large cameras. For the pro IR shooter, this isn’t such a big deal. 
  • 12 megapixel or greater sensor.  Dedicated landscape photographers will want more megapixels. I’m not sure what the right level would be for wedding photographers.
What does this all mean?
For the dedicated enthusiast and for some pros, the best Nikon camera available today for IR conversion may well be the Nikon 1 V3.  It is small, fast, and it handles low light situations better than the Nikon 1 V1. The ideal pro-level IR camera body probably doesn’t exist yet. 

Edited 7/9/2015.  I just got a note from a reader who had problems with a converted Nikon 1 V3.  She had her camera converted to the 830nm IR filter by LifePixel.  When she got the camera back, she noticed that the images had grid lines on them.  According to Daniel at LifePixel, all Nikon CX sensors have visible grid lines on them the but they don't show up due to the anti-aliasing filter. Daniel also told her that they haven't had problems with the J series or the V1 cameras but hers was the first V3 they converted.  Unfortunately, the only way to remove the grid lines is with post-processing.  I don't know if this is a filter-thing (830 nm deep infrared vs. 720 standard or 590 supercolor) or a V3 thing, but I am very disappointed.  I had every expectation that this would work well.   I was looking for a gently used V3 to convert...

Nikon 1 V3 Conversion: Pros

  • Decent resolution
  • Good dynamic range
  • On-chip focus is so much faster than LiveView.
  • On-chip exposure monitoring makes shooting very easy (Expeed 4A image processor)
  • Fewer problems with white balance
  • Changes in EV are reflected in the viewfinder
  • Eliminates IR focus shift compensation
  • The FT1 mount adapter allows you to use almost all your Nikon lenses. Your AF-S lenses will autofocus
  • DOF can be evaluated in the viewfinder
  • Handles low light situations better than the V1
  • Small, relatively light weight a (compared with a full-sized DSLR)
  • Viewfinder allows you to see the actual image, not the visible light analog you see in a converted DSLR camera viewfinder.
  • The smaller sensor gives you more apparent “reach” with your lenses.
  • Control layout is better for IR photography.
Nikon V3 Conversion: Cons
  • Small sensor presents some challenges when trying to isolate subjects.
  • Not sure how the electronic viewfinder will fare when banging around in my camera bag.
  • One reader reported image problems after the conversion (see above)

NOTE for those of you considering converting a Nikon 1 V1, my converted V1 (720nm Standard Conversion) works well for general IR photography, but it has some noise issues when the light is dim. I keep the ISO under 400 at all times. If you want to go this route, I suggest getting the SuperColor (590 nm) conversion. This will allow more light to reach the sensor and reduce the potential for generating noise.

Saturday, September 27, 2014

3 IR Channel Swaps - Comparing Photoshop Channel Mixer, CNX2 Hue Swap, & Photoshop LAB Color

In my previous post, I demonstrated how to perform a LAB color channel swap and discussed some of the workflow advantages associated with this approach. However, the unresolved question is whether the LAB color channel swap provides a different photographic output than the better-known channel swap procedures.  

For this post, I will take the same TIFF image through the Photoshop channel mixer swap, the Nikon Capture NX2 (CNX2) hue shift, and the LAB color channel swap using the Curves function.  
Image 1. Starting Point - Out of camera TIFF image.
Image 1 is the out-of-camera image.  It was taken into CNX2 honor the camera settings and to set the WB. The image was then converted to a 16-bit TIFF to standardize all the inputs. Photoshop handles NEF files differently than CNX2 so this levels the playing field. All of the channel swaps started with this image.
Image 2.  Photoshop Channel Mixer Channel Swap.

Image 2 shows the standard channel swap procedure in Photoshop. This procedure uses the Photoshop channel mixer to swap the red and blue channels. The resulting image was saved as a JPG and displayed here. No other manipulations were performed. The image has a teal-like hue to the sky and the water and the upper foliage has a magenta cast.

Image 3.  Hue shift using Nikon Capture NX2.
Image 3 shows the hue shift from CNX2. The sky and water are blue in this image and the foliage has a green-yellow cast.

Image 4 shows the LAB color swap output.  This image most closely resembles the Nikon CNX2 hue shift output. The colors in this image appear to be darker or more saturated than the CNX2 output, but the difference is minimal.  

Image 4. LAB color swap with Curves.
To the purist, the CNX2 resemblance may indicate that the LAB color swap might not be a true channel swap.  As a pragmatic photographer, I really don't care whether the channel swap is "true" or not.  I just want the sky to be blue and to generate an image I can work with. After all, all IR colors are false colors and it really doesn't matter how we get to the final image. The true power of IR photography is that there is no "right" and "wrong" way to approach or depict an IR scene.  We are free to follow our artistic inclinations.

Sunday, September 21, 2014

Creating a Blue Sky with LAB Color and Curves

My tutorial on performing a LAB color channel swap can be found on YouTube.

If you like creating color infrared photographs, you already know how to perform a channel swap. The classic channel swap using the Photoshop Channel Mixer usually generates a blue sky that is the hallmark of “traditional” color infrared photos. Unfortunately, the channel mixer is a rather crude implement. When I use the channel mixer, I am often left with residual blue and grey areas (in clouds and concrete) that require extensive hue and white balance adjustments. As I make more and more adjustments to remove these colors, I end up generating color noise and halos that are frustrating to remove.

Enter the LAB color channel swap. In its simplest iteration, this procedure can produce a good quality channel swap in seconds. The procedure for the simplified channel swap is shown below. The simplified channel swap provides a good starting point for generating a blue sky for most color IR photos.  With a little more work, I can efficiently generate a blue (or green) sky, adjust the colors in defined areas of the image, and improve the contrast - all in one workspace. The LAB color process also minimizes color noise. The video link at the top of this post will take you to a video tutorial on how to do the LAB channel swap. The tutorial will also show you how to efficiently improve color and contrast by using LAB color curves. 

When I talk about LAB color, most photographer's eyes start to glaze over. For most us, the LAB color space is a “Never Never Land” - a poorly understood place that doesn't play nice with printers and plug-in programs. However, the infrared photographer is, by definition, an extremist who needs extreme tools to manipulate the data generated by their camera’s image processor. LAB color, with its wide gamut and the ability to manipulate luminance independently of the color information, is becoming, for me at least, the workspace of choice for processing color and black and white IR photographs.

Simplifed Channel Swap - LAB Color

Simplified Channel Swap Method
Change to Lab Color:  
   Image > Mode >Lab Color
Select Channels > A channel 
Click the “eyeball” next to Lab (at the top)
Image > Adjustments > Invert
Select B channel
Image> Adjustments > Invert
Image >Mode >RGB

If you want to follow along with the tutorial, you can download the lake image from the following website: 

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