Sunday, September 22, 2013

Auto Glass and Infrared Photography

I was on the Huron Parkway bridge waiting for the traffic light to change when I noticed some interesting clouds in the distance. The infrared camera (standard 720 nm conversion) with a 20 mm wide angle lens was on the seat beside me so I popped off the lens cap and shot a few frames at f/8 with matrix metering and auto focus. I did not use the viewfinder or LiveView because the camera was in front of my chin and pointed toward the left window of the car.   

Oops moment. Shooting IR photo through auto glass.
When I looked at the frames, I noticed that the side window was only partially down and the view through the window portion was exceedingly dark. It was one of those duh! – slap yourself on the forehead - moments. This experiment reminded me to lower the window completely because auto glass is treated to block infrared in order to reduce the heat load in the vehicle.
 
According to the U.S. Department of Energy, some 230 million vehicles in the U.S. consume 7 billion gallons of gas annually to power air conditioning (AC). By reflecting the sun’s heat and maintaining a cooler cabin temperature, IR reflective glass reduces AC power consumption up to 20 percent, increase miles-per-gallon by up to 5 percent, and lower emissions. By the 2014 model year, all new cars and trucks sold in California must have infrared-reflective glass under the California Greenhouse Gas Emission Reduction directive.

Information published by the Guardian Industries Corp. (Auburn Hills, Michigan, USA) indicates that IR reflective films block about 85% of the near IR light (about 3 f/stops) while reducing the visible light (what your meter sees) by 25% (half a stop). Grey tinted windows will reduce the visible light a little more. This means that the IR photographer who uses an IR-converted SLR camera will need to add at least 3 EVs of exposure compensation when shooting through auto glass. It also means that there will be about 3 stops less IR light in the vehicle when photographing interior objects with the windows closed. IR-converted mirrorless cameras will not have this difficulty because these cameras meter what the sensor sees.

The selective nature of the auto glass filtering – passing visible light and blocking IR – made me curious about the performance of the 590nm (SuperColor) conversion. The SuperColor IR filter passes some yellow, orange-yellow, and red visible light in addition to the IR wavelengths. To find out more, I took photographs through the partially lowered side window of a car (this time on purpose) towards a large photographic reflector. The reflector minimized any changes in luminosity due to the scene beyond the window (i.e., bright sky and dark foreground). All shots used a 20mm lens at f/8, with matrix metering, and focusing on the edge of the window. EV compensation was adjusted for each camera to balance the luminance values in the histogram. Cameras were placed on a tripod to assure the same field of view. My friend Vicki was kind enough to hold the reflector for me.

Effect of auto glass with different IR camreras
Effect of auto glass and different camera conversions
The composite photo shows the images captured with an unconverted D90 (VIS), a SuperColor (590) converted D90, standard infrared (720) converted D90, and a D90 with the deep infrared conversion (830). The visible light photograph shows very little darkening of the scene when viewing through the auto glass. The other images show significant darkening of the scene in the auto glass portions. While it is difficult to quantify the amount of near IR blockage, my visual assessment suggests that the 590 nm SuperColor conversion had the least IR attenuation of the three IR cameras and the 830nm deep infrared camera had the most.

Shooting IR photographs through auto glass will result require significant EV adjustments before one can obtain an acceptable photograph. This could be an advantage in extremely bright situations and when additional contrast is needed.

Friday, September 13, 2013

Five Remarkable Color IR Photographs

An important exercise for me as a photographer is to critically review the work of other artists. This examination helps me to determine what I like about their work so that I can incorporate some of those elements into my photos.  Trying to recreate these “pearls” is a learning process that improves my skills and helps me to grow as a photographer. I don’t slavishly reproduce the style of any photographer. My photographs have many influences but my style is unique.

Examining the work of others is especially important for color infrared photography because color IR requires more post-processing than visible light photographs. As you might expect, lighting, composition, sharpness, contrast, and tone are just as important for color IR as they are for visible light images. The additional element – the secret ingredient - is the post-processing.  This examination helps define my preferences as an artist and it shows me what is possible during post-processing. Some of these possibilities will fit my esthetic and workflow, some will not.
 
Fierce Defender. by Etownbeatdown
Fierce Defender by Justin Piercy
So with that introduction, I would like to introduce five remarkable color infrared photographs. The first photo is "Fierce Defender" by Justin Piercy. I love the composition of this photograph with the fence line leading your eye to the horizon. The diagonal cloud formations give an otherwise normal "vanishing point" scene a sense of tension and angular movement. The sharply focused post and chain in the foreground and the broken post provide visual interest. The colors are great. This type of coloration is often achieved when using a 720 nm IR filter and an accurate white balance.


"Sunset on Golden Pond" by KellyShipp
Sunset on Golden Pond by Kelly Shipp
Continuing with the red theme, we have the "Sunset on Golden Pond" by Kelly Shipp.This photo also appears to be taken with a 720 nm IR filter but this image features the more traditional white foliage. I really like the sunset behind the cabin and tree. The lighter band of sky accents the silhouette of the cabin. The light gradient on the pond and the darker land above create a wedge that draws my eye from left to right, toward the little puffy clouds. The curved shoreline at the far end of the pond nicely frames the cloud reflections. The tone and composition of this deceptively simple photograph are great.

Top Speed (Infrared) by 2121studio
Top Speed (Infrared) by 2121studio.com
Not all infrared photographs are landscapes and I wanted to review this one, "Top Speed (Infrared)" by Ali Shamsul Bahar of 2121studio.com.  This photo was taken in Negara, Jembrana, Bali, Indonesia. I love the lighting in this photograph and the sense of movement. This photo is a challenge for me because I don't quite know how it was captured. The animals and the wheels of the cart are in motion but the driver and the cart are sharp and motionless. Is this just great panning technique with a slower shutter speed? Maybe an off-camera flash with rear-curtain eposure? Could this be a composite image where the motionless driver is overlaid onto the moving cart? Whatever the technique, this is a stunning photograph in my estimation. 


Enchanted forest by David.Keochkerian 
Enchanted forest by David Keochkerian
The next remarkable color IR photograph is "Enchanted forest" by David Keochkerian. This is a lovely forest and water scene that also contains a woman with an umbrella. Can you find her? The image appears to be captured using a 590 nm IR filter and a channel swap was employed during post-processing. This approach produces blue skies and enhances the golden colors.The reflections are beautiful and the lighter trees downstream are framed by the arch of the trees. The arch and the brightness draw your eye into the photograph. I am not fond of the large dark branch in the upper left corner but this is still a lovely photograph.




Framed Reflection by McSnowHammer
Framed Reflection by Mattias Hammar
The final image, "Framed Reflection" comes from Sweden.The photographer is Mattias Hammar. This image appears to be captured with a 720 nm filter. Channel swap with color adjustments were problably employed to achieve the blue sky and the pink foliage. I really like the colors, the reflections, and the contrasts. The framing of this image is outstanding because it enhances rather than detracts from the far trees and the reflection. The black water is very nice. Black water occurs when you get reflections from a cloudless sky.  (A cloudless infrared sky is black.) This is a stunning photograph! The only thing I would do differently would be to remove the white leaf floating on the water just below the red tree reflections.

This is how I review images. Your methods will certainly be different.  I hesitated to include critical comments in this blog because I mean no disrespect to the photographers. These photos were featured because I thought they were outstanding.  I hope you do too.

Tuesday, September 10, 2013

Creative Infrared Photography - Chance Favors the Prepared Mind


Bald Eagle Sculpture - IR  Jesse Besser Museum, Alpena Michigan
Bald Eagle -IR  Jesse Besser Museum, Alpena Michigan
I was heading home from a visit “Up North” on Sunday evening when I noticed that the sky was begging for an infrared photography session.  The IR camera was in the back so I just needed to find an interesting foreground to make the shot work.  Fortunately, I was not far from the Jesse Besser Museum in Alpena Michigan. I pulled into the empty parking lot and got to work. 

Photo opportunities appear unexpectedly and when they do, I must be ready to capture them. There is nothing worse than a life full of regrets. 
To be ready, I must:   
1.   Be able to recognize the opportunity and understand which camera settings I should use to create the image. Aperture priority? Shutter priority? Manual? Matrix or spot metering?  Do I need higher ISO setting to achieve a faster shutter speed? Do I need to bracket for high dynamic range? Will I need a tripod? Flash?
2.   Have enough experience with my camera so that I don’t fumble to change settings, hunt through multiple menus, find and evaluate the histogram, and dial in EV changes. The technical operation of the camera must become second nature.
3.   Understand which compositional elements will help/hinder the photo. A church steeple, an architecturally distinctive building, or even a playground jungle gym could have provided an interesting foreground for these photos.
4.   Have some familiarity with the locale.  I try to scout out the areas I frequent.  I take note of where the sun sets and rises. What kind of light does it receive? Yes, I know these things are difficult to accomplish when you are in a new place, but in this case, I knew where the sculptures were and which way they faced. I also knew that there was enough open ground around them so that I could capture the sky and the statue foreground.
5.   Have my camera with me. None of the other points matter if I cannot take a picture.   

So, what did I do after I got to the museum?  First, I evaluated the eagle. The shiny metal on the sunlit side was far too bright and the detail would be blown out. I tried a couple of test shots with the sun behind the eagle but the bright sun created a detail-robbing haze that surrounded the beak. My flash did not have enough punch or spread to provide adequate fill lighting (the eagle was huge) so that approach was out. The angle shown here seemed to work but I was getting lens flare from the sun hitting the front lens element (the lens shade on the 20mm AFD f/2.8 lens is pretty shallow). Fortunately, the shutter speed (1/200 sec) was fast enough that I could hold the camera one-handed and shade the lens with my hand. I would have raised the ISO or used a tripod if the shutter speed was much lower. The test shot looked pretty close and I only had to dial in +0.67 EV to center the histogram. I also took a 3 shot bracket with 1 EV steps in case I had problems with the dynamic range in post. Electrons are cheap.

Unknown Soldker - IR Jesse Besser Museum, Alpena Michigan
Unknown Soldier - Jesse Besser Museum, Alpena Michigan
The soldier sculpture was easier to photograph because I had established the initial settings. I still had to move around to get the composition right and avoid some distracting elements in the background. The sun angle was slightly different with this photo so I did not have lens flare problems. I took some test shots and adjusted the EV. Shot a 3 image bracket just in case. I was able to get all the photos before the light changed appreciably.   

 I don’t have a pro-level of proficiency with items in the bullet list, but I am getting better. I clearly remember when I was so achingly slow with the camera that magic photographic moments faded away before I could do anything about it. How did I gain my current level of proficiency with the camera?  Practice, practice, practice.  I made mistakes, I took photographic risks, and I learned from the experience. 

In my future posts, I will describe my approach to gaining camera proficiency with a converted Nikon D90. I will also describe my “go-to” setups for different types of IR photography.

Sculpture Information:
Both sculptues were created by Tom Moran of Moran Iron Works in Onaway, Michigan.  The Bald Eagle sculpture was created in 2000 and the Unknown Soldier sculpture in 2007.  These sculptures can be seen at the Jesse Besser Museum in Alpena, Michigan.

Shooting Information:
Nikon D90 camera converted to Standard Infrared ( by LifePixel), Nikkor 20mm f/2.8 AFD, f/8.0, ISO 200.  The Eagle image was captured with a 1/200 sec shutter speed and the Soldier at 1/50 sec. Photos were taken on September 9 2013. 


Thursday, September 5, 2013

Creative Infrared Photography - Subject Isolation and Selective Focus

Traditional wisdom for infrared (IR) photography states that IR works well in the middle of the day, when the light is harsh and the contrasts are maximal. Traditional wisdom also insists that you should always use smaller apertures to compensate for any unexpected IR focus shifts, especially when shooting at the longer end of your telephoto range.  This traditional approach, as you might expect, provides a good starting point for a certain type of photography. That is, high contrast – get it all in focus landscape photography. Unfortunately, this approach does not work well if you want subject isolation, selective focus, or subtle color variations. Does that mean that infrared photography a one-trick pony? Not at all. To enhance the capabilities of your IR camera, you have to seek another type of wisdom.
IR Daisy - Taken in the Blue Hour
Daisy: IR selective focus.Taken in the Blue Hour
In her book, Digital Infrared Photography (Photo Workshop), Deborah Sandidge departs from the traditional approach by suggesting that IR photographers should shoot at the golden hour. The golden hour is the first and last hour of sunlight in the day – when the lighting is softer (more diffuse) and warmer in hue. Selective focus images and focus-based subject isolation usually require soft light.  Ms. Sandidge’s wisdom provides that soft light and I want to thank her for opening my eyes and moving me to a new place in my IR photography. In building upon Deborah’s wisdom, I found that soft IR lighting extends beyond the golden hour and well into the blue hour – that period of twilight before sunrise and after sunset. 

Photographing in the blue hour can be a challenge because your auto exposure system will freak out. It will call for ever longer shutter speeds when there is lots of IR light available. Switching to manual mode can solve this problem and extend your shooting time. The daisy photo shown here was shot in the blue hour with a shutter speed of 1/640 sec when the camera was calling for a half-second exposure. There is that much IR light available!
Stepping Out Tree - Subject Isolation
Stepping Out:  IR subject isolation. Blue Hour.
Selective focus also requires a larger aperture and accurate focusing – items that are mutually exclusive to the followers of the conventional wisdom, especially when using a zoom lens. LiveView and LiveView focusing really help with the focusing issues. As the light gets dimmer, LiveView with manual focusing also works well. Yes, I know LiveView focusing is slow, but your patience will be rewarded.

And finally, I would like to say something about subject isolation. The tree shown here was photographed well into the blue hour at f/2.8 and a shutter speed of 1/50 sec. The combination of soft light and large aperture made the tree stand out and gave it a three-dimensional look. 

Infrared photography is not a one-trick pony and I am convinced that IR approaches and subjects can be as diverse as those found in visible light photography.

Shooting Information:
Daisy:  Nikon D90 (720 nm), Nikkor 105mm f/2.8 VR, f/3.0, 1/640 sec, ISO 800.  No channel swap.
Stepping Out:  Nikon D90 (720nm), Nikkor 105mm f/2,8 VR, f/2.8, 1/50 sec, -1.33 EV, ISO 800. 
No channel swap.