Challenging Assignment in Small Chapel
I recently was asked to photograph a series of stained-glass windows adorning the prayer room at Lake Forest Hospital on Chicagos North Shore. The stained-glass was designed by my client and printed onto the window glass using a new technique hes developed called allusionism. It basically uses an enlarged high-resolution digital image in CMYK color space and prints it onto glass which is then sealed with a polymer coating that protects it from the elements and UVs.
The challenge presented to me was twofold; to capture the group of seven windows in one image (among other images) and to render accurate color in the images.
Capturing the entire seven windows was a challenge due to the small size of the prayer room, about 18 feet in diameter compounded by the circular shape of the room. Increasing the difficulty was that the most distant and optimal point from which to capture the seven windows together was off center from a position perpendicular to the center window. My best attempt was made with a 15mm lens capturing two separate images and later stitching them together in Adobe Lightroom. The first image was made utilizing six windows and then shifting the camera just enough to include the window to the far left which was not included on the first image. This little movement minimized the optical distortion that was similarly required on the first image.
The second challenge was the need to render accurate color to both the prayer room interior and the colors within the windows. A color meter reading indicated interior lighting at a color temperature of 2950K (Kelvin) and set my camera color temperature accordingly. A MacBeth color card was further used to ensure accurate color within the room. The problem was then to capture accurate color of the windows being lit by exterior lighting of 5100K but still compromised a bit by the overhead lights built into each windowsill.
Later in post-processing and after merging the two images to capture all of the windows, I opened the merged image in lightroom, and processed the image for the interior. I then created a duplicate copy of the merged image and processed just the window areas at 5100K. I then opened up the image processed at 2950K and the duplicate processed at 5100K together as layers in photoshop. With the 2950K image as the top layer, I created a mask and carefully brought through the lower layers windows with a brush tool painting black on the mask only in the areas of the windows. The top 2950K layer now had the window areas removed allowing the underlying layer (5100K layer) to show through the upper layer. After flattening the two layers I now had the correct colors rendered for both the interior lights and the exterior daylight illuminating the windows.All in a days work….make that three days.
Great results and a happy client. And thats what its all about.