Never miss a chance.
It is no secret that the former Chicago Theological Seminary building is a favorite subject of mine. So it should come as no surprise that, while in Chicago for a wedding the weekend last, I made a few images in the old place. It now houses the Milton Friedman Institute. Many quips about how holy Friedman's ideas are to the University of Chicago have undoubtedly been made during the transition. The interior spaces within the building are cartoonishly beautiful and, in light of recent modifications made to the building, I am particularly glad to have had the chance to photograph here over the past years. At the time, I felt like I was sticking a little close to the beaten path of my previous work, specifically I worried with such limited time if I was using it to its fullest. Knowing now that this place is changing dramatically for the first time in ages, I feel like I unwittingly used the opportunity to its well. Don't miss a chance even if the subject be one well covered.
My relationship with religion and religious buildings.
I won't mince words. Religious thought as a method for understanding our objective world has been obsolete for centuries. We have shown what some of our ancestors must have long suspected: that scripture contains little if any objective truth. Scientific study of religion, religious peoples and religious culture, I believe, remains a fertile ground for understanding human psychology, etc. If I can point to any one remnant of the religious edifice as remaining highly valuable artistically and culturally, it is just that - the buildings. I'm a sucker for great (especially Gothic and neo-Gothic) architecture and, over the last few centuries, religious institutions along with the academy have been our sole source thereof. Secularists should be able to separate the culturally valuable remnants of religion from any adherence to dogma or belief in mythology. I found it very sad, then, to learn that in its purchase and renovation of the Chicago Theological Seminary's building, the University of Chicago, finding the beautiful glass panels throughout the chapels "inappropriate" for the buildings new use, removed all but a few of these works of art in the name of propriety. I remember these richly colored stained glass panels and, as no fan of religion, I can safely say they were quite beautiful. So, while I still think a University fit to be the steward of an architecturally triumphant religious building, I worry that poor decisions can be and are being made with regard to the value of the building's decoration.
The first image on this post and the following two were taking in the Hilton Chapel on the southern end of the building. To get there, one takes the corridor on the right of the photograph above. Past the weary, gray steps are the columns and entrance to what, I've read, the AIA Guide to Chicago calls a "tiny gem," the Hilton Chapel. A tiny gem this place is indeed. The entryway is stunning, two columns and a small portico with arched windows and (formerly) leaded stained glass guarded the entry into the chapel proper (scroll to the end of this post to see what this shot looks like without HDR). I could lose myself for hours poking my head into doorways and hallways, trying to find new angles on the intricate and highly decorated Gothic buildings throughout the City Gray. Whenever I find a new spot it is like meeting an old friend for the first time. The theme, the mood, the feelings may be the same, but that a place at once so old but so new to me is opened up is one of the principle joys of carrying a heavy camera around tight hallways and up stone steps.
The inside of the chapel is tiny indeed, but beautiful. In my mind, this is the little church in which Romeo and Juliet were wed. It isn't unusual for me to find students studying away in all the nooks and crannies of these many buildings, wrapped up in a scarf and a thick coat, nose buried in Marx or Plato, but here I was surprised to find no one at all. What a wonderful little spot this would be to grab a book and find some quiet time! Here the loss of those stained glass icons is plain to see. The room is flooded with light, but the cold white of the windows is a reminder of what beautiful colors once played there. What a wonderful spot this would make for a very small wedding!
My time in the chapel was short but I had to take an image of the ornate light fixtures before leaving. Because the scale of this room is so small (the image above was taken with the camera about two feet off the ground), I could get my camera very close to the hanging lamps to grab the frame of the Hilton Chapels wooden ceiling and bright, warm lamps at the top of this post. I decided it might be fun for me to take some screenshots and post them here so you can see how I took the image above from tonemapped HDR image to the final edit.
Step-by-step processing tutorial
This little walkthrough is going to take you from this tonemapped image (a bit of a disaster):
We are going to begin this tutorial in Photoshop with the tonemapped image and four other individual exposures stacked as layers. I am, therefore, going to assume that you know your way through processing the RAW files into a tonemapped "HDR" image and how to stack images in Photoshop as layers (I am using CS4 here, but any recent version will do). If not, I recommend starting with my online tutorial (there are two screencast videos near the very bottom of the page). In the screen grab below you can see that I have five layers. If I were to name the images according to the exposure compensation of the camera, (i.e. a "normally" exposed image were 0 EV and the under exposed images were -2EV, -1EV, etc) then you can see that I have the layers ordered from under to over exposed, top to bottom with the tonemapped HDR sandwiched in the middle. That tonemapped image (our starting point above) is "Layer 0" - it is the glue that is going to help us blend all our exposures together into something better.
Here is a close up of the layer order - the top layer is the -2 EV shot, the next is the 0 EV capture, followed by the tonemapped, +1 EV and + 3 EV images, respectively.
We are going to start by making layer masks for the top two layers. In the "Layers" palette, select the top layer and then navigate to "Layers->Layer Mask->Hide all," repeat for the layer underneath. Doing this will hide all the pixels from the top layers, revealing the tonemapped HDR image underneath.
Now our job is to use the layer masks we created to "paint in" the pixels from the top layers over the tonemapped image. Specifically, I am bothered by the "gray" tone of the windows. It was a bright day outside and the light was really pouring in through the windows (sadly robbed of their stained glass). So what I do is to select the black layer mask to the right of the thumbnail for the top layer (in the layers palette) and then select the paintbrush tool, set the color to white, flow to 100% and opacity to 30%. My brush is a circle of about 100-500 pixels with 0% hardness. Of course, at all points, you want to be sure you are painting white over the mask and not the image - to be sure have a look at the layers palette - you should see that the mask to the right of the image thumbnail is selected. Once ready, I paint in over the windows to reveal the -2 EV windows as seen below (compare below to above):
We are now going to do the same thing to the layer below, revealing the 0 EV image's ceiling, parts of the walls and windows as well. The point is to correct for all the muddiness that tonemapping an image introduces and to bring in some of the familiar, "normal" tones of a single-exposed image. After you've used the paintbrush to mask in the highlights and mask out the halos and "fix" the tonemapping artifacts to your satisfaction, we are now going to select the tonemapped image and create a new layer mask but this time you want to select "Reveal all" by navigating to "Layers->Layer Mask->Reveal all."
Now we are going to employ the opposite tack as before: use a black paintbrush with the settings listed above to "hide" all the portions of the tonemapped image you don't want and to reveal the portions of the overexposed bottom layers. The ceiling was very dark in the tonemapped image, and I worked to reveal just a little of the overexposed ceiling below.
You are going to finish by giving the layer underneath the tonemapped image (the +1EV image) the same kind of mask as the tonemapped image and, again, use the black paint brush to reveal parts of the +3 EV image underneath:
So what we have now is an HDR sandwich, where the layers above and below comprise the majority of the image itself and the tonemapped image is the glue that holes the blend together. To give you an idea of just how much the HDR is masked out I took a screenshot where I hid all the other layers. Notice how very little of the tonemapped, HDR image is showing (keep in mind that the underexposed images we masked in are hidden too - so the windows, etc that you see in the screen grab below are actually hidden our final treatment.
We are already a far cry from our starting point, tonemapped image, but we have a long way to go. One of the tricks to good HDR, in my opinion, is to get reversals (what is sometimes called the "HDR effect") without halos. Reversals are places where the image has been treated so that very bright objects are as dark or darker than very dimly lit objects. For example, the windows are very bright, but we also want the ceiling and stones and lamps to be nearly as bright (or, in some cases, brighter). One of the failings of HDR straight out of programs that produce tonemapped images is that it can be difficult to produce those reversals without also producing halos. Photoshop Shadows/Highlights to the rescue. Shadows/Highlights is an adjustment to be found in the "Image->Adjustments->Shadows/Highlights" menu of CS4 (and CS5, probably CS3 and even earlier versions as well). It does what it says on the tin: adjusts shadows and highlights. Specifically, it makes dark things bright and bright things dark. Applied too heavily it will also produce the halos and dullness of a bad HDR, but used in combination, sparingly it works wonders.
Starting with the layered image we have above, I flatten the image (Layers->Flatten image) and then duplicate that flattened layer (Layers->Duplicate layer). With the top layer selected, navigate to "Image->Adjustments->Shadows/Highlights":
You will get the dialog box shown below. Now it's just a game of adjusting the sliders. The first slider is how heavily the effect is applied, the second defines how dark or light a pixel need be to be modified and the third defines across how large a radius the effect should be calculated. At the bottom of the dialog there is a slider to correct for color shift and one to add contrast to the pixels in the middle of the range. Every image demands an individual treatment - play around.
Here's the image with the adjustment applied. I suggest playing around with the opacity of this new layer a little or masking out portions you don't like should the adjustment have produced any problem spots in the image. Here it looks pretty good so I've left it be.
Flatten the image again and now we are going to apply a favorite effect of mine to the image. With your newly flattened image, duplicate the layer and then navigate to "Filters->Blur->Gaussian Blur," and adjust the filter until you see no details left in the image (I use about 35 pixels for a 12 megapixel image). Here's what it should look like:
Now what we are going to do is use this blurred image to modify the pixels underneath. On the layers palette there is a pull-down menu that defines the "blending mode" of the selected layer. Normal is the default and it simply displays the pixels as they are. We are going to select "Overlay," this is where the magic happens:
You might have too much magic on your photo now - things will look a little funny. Some things will get way too dark, others will be too soft looking. What we are going to do now is to adjust how our overlay layer modifies pixels beneath. To do this we are going to change the blending options by right-clicking->Blending options or by double clicking on the layer.:
Now you are going to see a dialog box that has all sorts of options, menus and sliders. We only really care about two sliders for this effect. The first is the opacity - lower this a bit if you want to decrease the strength of the effect. The other slider we need to work with is in the box titled "Blend if Gray" and it is the top one labeled "This layer." What you are going to do with this slider is allow the detail in the bottom later to bleed through the overlay effect of the top layer. To do this without generating harsh lines where the effect begins and ends, you want to only more the right half of the black slider as shown in the screen capture below. To do this on an Apple computer, hold the option button, click the slider and drag it to the right. My guess is that the "Alt" key on a PC will do the same thing, but I'll have to punt to the windows experts out there. You should now see something like this:
Our image is almost there, but there are a few bits of clean-up we need to do. First, the colors of the image are now a bit muddled from having been through the camera, Lightroom, Photomatix, and now Photoshop. This image in particular has a greenish hue to the yellows - especially around the walls of the chapel. Create a new adjustment layer by clicking the symbol that looks like a Yin-Yang at the bottom of the Layers palette and then select "Hue and Saturation." Select "Master" in the adjustments palette and adjust the hue slightly to remove the green cast. This will, inevitably, mess with the portions of the image where the hue is just fine. Therefore, you want to hide the adjustment layer with a layer mask as we did before and "paint in" the mask over the portions of the image where you want to apply the correction.
To finish up I am going to apply two curves layers - one to adjust the colors and one to adjust the contrast. Both adjustment layers are made as before, the first is set to "Colors" in the drop-down menu in the adjustments palette and the curves themselves are set using the "Auto" button and then adjusted manually. This step is very important, color has to be nailed just right to make itself worthwhile in these images. Color has an enormous emotional component, be very aware how you apply a color cast to your images - shift blue for one emotion or red for another. The second curves layer is set to "Luminosity" and adjusted by hand - here I used a pretty standard S-shaped curve to boost contrast:
Finally, I'm going to give those Shadows/Highlights another tweak using the same technique as above to finalize the image and give it that last little bit of over-the-top HDR goodness. So there you have it - start to finish on the image in just a handful of relatively easy steps.
Of course, this kind of processing can be applied to any type of image, so I processed that photograph of the Hilton Chapel entrance using Photomatix Pro to generate an HDR, Bracketeer to produce what's called an enfused image and Lightroom to put out a single TIFF from one RAW file (in that order). Those of you who love HDR may be surprised to find out you can get nearly the same effect with a single image or using a non-tonemapping program; I also think it is interesting to compare the ability of these different techniques to hold-back highlights and to include shadow details. Personally, I think using Bracketeer or Enfuse to blend images retains the most information.