Last Saturday (30 March 2013), I was in Bellevue visiting the
Temple built by the
Church of Jesus Christ of Latter-Day Saints. I enjoy opportunities photographing this structure, since the landscaping changes often, and it does not move. On very sunny days (like last Saturday), the most difficult part of the structure is the golden angel statue atop the spire; the reflections are unbelievably bright:
The details are completely washed out, and although you can tell that this is indeed a statue of a man with a trumpet, it looks terrible. Additionally, the building is very white, and bright sunlight creates exceedingly harsh shadows when the scene is properly exposed. In essence, three photos are necessary to obtain a desired final product that (hopefully) looks good.
Photo 1 - A good exposure of the stature, with minimal glare, and reasonable detail.
Photo 2 - A good exposure of the sky and daffodil foreground that is rich with color and details.
Photo 3 - A good exposure of the building, that minimizes the harshness of the shadows created by the hard sunlight without washing all the detail from the white surfaces
I am using a Nikon D300s with a Nikon 14-24 mm lens, attached to a Manfrotto Ballhead atop a Manfrotto Tripod. Setting the camera to ISO 200, I find that Photo 1 is good at a shutter speed of 1/500 at f11. Photo 2 is 1/250, and Photo 3 is 1/125. All images are in Nikon RAW (NEF) format. I use iPhoto as my primary organizing and preliminary editing tool.
My plan is to use GIMP to manually blend the portions of the three photos together into a single composite image, then do the final adjustments for color, saturation, sharpness, etc. on the completed product. Let's see how that works out.
In iPhoto, the only changes I make before exporting are to images 1 and 3. For image 1, I fully recover all highlight details in the RAW image, and subsequently fully darken the highlights. This produces acceptable detail and depth to the statue. For image 3, I also fully recover all highlight details, and darken the highlights about 60%. This reduces the overexposed portions of the white building to more acceptable levels, and does not darken the shadows much at all. Here are the three images side by side (in iPhoto):
Yeah, you can't see much like this, but hey, it's a blog. Oh well.
Anyway, time to bring these images into GIMP and see what I can do to combine them. I use an AppleScript I designed myself to "export" them as linked files, so that I do not have to burn up more hard disk space. The link is set to the JPG files that iPhoto creates after I do the mini-manipulations, so it is those JPGs that I will open up in GIMP. Magically, GIMP has a nifty command entitled Open as Layers:
I then select the three files, and each file is placed in its own layer:
I renamed each layer to correspond to the photo numbers I defined earlier. All I want from Photo 1 is the statue, so I put that at the bottom of the stack to act as the background layer. I will need to mask out the statue in both upper layers so that the statue from the bottom is fully visible. Of course, I also need to mask out the sky and daffodils in Photo 3 as well, so that only the building from Photo 3 is visible.
First, we just need to create a layer mask, starting with Photo 3, the uppermost layer. To quickly get rid of the sky, and preserve the building, I start with the Fuzzy Select Tool, and set the threshold to 35. (I got that with a lot of experimenting to see how well the edges of building were selected.)
The selection was not perfect, but it is close enough to start with, since we can edit the mask manually later on. Now, the tricky part; the selection has to both be inverted AND converted to a layer mask. With the selection still active, I click on Layer --> Add Layer Mask... Then, check both the Selection and Invert mask boxes:
Boom! Not perfect, but now we can edit the mask directly with a paintbrush. First, it is necessary to click onto the mask portion of the layer, to be sure that it is highlighted. It is also a reasonable idea to make sure that Edit Layer Mask is checked, indicating that you are actually about to edit the mask, not the image:
I want a hard brush, so that I can make a nice (freehand) mask edge along the left side of the building:
I painted everything black, so that the mask completely blocked it out, allowing Photo 2's sky to be visible throughout, including over the statue atop the steeple. I went back with white, and then grey over the evergreens along the left so that they were visible as depicted in Photo 3. I still want the daffodils to be from Photo 2, but I don't want to use the hard edge brush for that, so I select a brush with a hard center, and very soft radius (the one just above the hard brush) and do the entire daffodil section.
The big problem is on the right side, where the tree branches were not all selected as part of the mask. Holy cow, what a mess!! That is going to be time consuming to try to repair.
For the statue on Photo 2, I just created a layer mask, and blacked out the brightest portions. That worked as well as trying to select the thing precisely and completely mask it to allow Photo 3 to be visible.
And, here is the finished product (with the iPhoto spread for comparison), except for all that annoying stuff on the right, in the branch/sky mixture. I have removed all the spots from the sky, but I still have not done any color saturation, sharpening, or noise reduction: