COVERING OUR TRACKS October 2005
by John
Mantzefield
copyright 2005
The
photo of PMUG’s General Meeting that was used in this
months cover was shot with a Nikon 8400. The primary
web site I used to check out the pros and cons of the
8400, and other digital cameras, was
steves-digicams.com. This site has many linked pages
that contain complete camera model details and they
offers a reviews of specific camera models as they are
compared to others in the same category. The Nikon 8400
is an 8Mp compact camera with a fixed lens (not an SLR
type with interchangeable lens). One of it’s unique
features is the lens focal length - it zooms from 24mm
to 85mm (35mm camera equiv.). It’s 1.8” pivoting color
LCD screen can be used to shoot and view your pictures.
The camera comes with a IR remote shutter release (for
time exposures or slow shutter speeds) that’s useful
for taking pictures from the top of a tall monopod.
Nikon offers add-on lens for the 8400 and I used their
18mm wide angle to shoot the cover photo.
During the general meeting I shot photos (camera was on a tripod) from three different angles. At each location I shot a series of widely varying exposures ranging from fairly short (1/250-F11) to time exposures of a couple of seconds long. This was done so that I would have perfectly exposed pictures of every part of the room. The shortest exposures captured good images of very bright areas like the overhead lights. The longer exposures got a clear shot of the computer projectors screen.
The design concept for this cover is found in this question, what kind of incongruous elements could I add to the background image to transform it into a scene of unexpected and/or out-of-place elements? To do this I opened the best exposure of the fully lit room in Photoshop CS v8 and then added more of the other exposures on additional PS Layers. To create the final background image of the meeting room I used Layer Masks (Click the Add Layer Mask button at bottom of Layers Palette, then the “B” key to select the Brush Tool) to remove the poorly exposed areas in various images of the room. To make Layer Mask painting easier press the “D” key to set the Background & Foreground colors to Black & White, then as you paint the Layer Masks use the “X” key to Toggle the Back-Foreground colors between black and white.
The final composited background image of the meeting hall is made up of 10 layers, which were Flattened into a single 4.8Mb 300Pi Photoshop file. Thirty five more Layers were then added over the background so that I could position the robots, the “Buck Rogers” style projector that the robots brought to the meeting and numerous other graphical elements like the pizza boxes and the image on the projection screen.
All of the robots and the big projector were modeled (the process of creating the outer shape of objects) in a 3D program called Cinema4D XL v8.5, distributed by Maxon Inc. The first thing I had to figure out was how to make the C4D lighting match the exiting lighting in the background image so that the 3D objects would look fairly real. The other element that needed to be added to make the 3D components blend into the background image is the addition of their shadows in the final composited scene.
Most of the ceiling mounted projectors parts were made from “Primitives”, which are basic 3D shapes like cubes, spheres and other fundamental geometric shapes. The cables that come out of the side of the projector and the large one that goes down to the front of the meeting hall near the podium were also modeled in C4D.
During the general meeting I shot photos (camera was on a tripod) from three different angles. At each location I shot a series of widely varying exposures ranging from fairly short (1/250-F11) to time exposures of a couple of seconds long. This was done so that I would have perfectly exposed pictures of every part of the room. The shortest exposures captured good images of very bright areas like the overhead lights. The longer exposures got a clear shot of the computer projectors screen.
The design concept for this cover is found in this question, what kind of incongruous elements could I add to the background image to transform it into a scene of unexpected and/or out-of-place elements? To do this I opened the best exposure of the fully lit room in Photoshop CS v8 and then added more of the other exposures on additional PS Layers. To create the final background image of the meeting room I used Layer Masks (Click the Add Layer Mask button at bottom of Layers Palette, then the “B” key to select the Brush Tool) to remove the poorly exposed areas in various images of the room. To make Layer Mask painting easier press the “D” key to set the Background & Foreground colors to Black & White, then as you paint the Layer Masks use the “X” key to Toggle the Back-Foreground colors between black and white.
The final composited background image of the meeting hall is made up of 10 layers, which were Flattened into a single 4.8Mb 300Pi Photoshop file. Thirty five more Layers were then added over the background so that I could position the robots, the “Buck Rogers” style projector that the robots brought to the meeting and numerous other graphical elements like the pizza boxes and the image on the projection screen.
All of the robots and the big projector were modeled (the process of creating the outer shape of objects) in a 3D program called Cinema4D XL v8.5, distributed by Maxon Inc. The first thing I had to figure out was how to make the C4D lighting match the exiting lighting in the background image so that the 3D objects would look fairly real. The other element that needed to be added to make the 3D components blend into the background image is the addition of their shadows in the final composited scene.
Most of the ceiling mounted projectors parts were made from “Primitives”, which are basic 3D shapes like cubes, spheres and other fundamental geometric shapes. The cables that come out of the side of the projector and the large one that goes down to the front of the meeting hall near the podium were also modeled in C4D.
To
do this I created the path that the cable would follow
and then added a diameter shape to make the cable
appear round. A Texture/Color map was assigned to the
cable object to make it appear realistic. The shadow
behind the big cable was added in Photoshop as a
semi-transparent painted element.
To make it easier to figure out what angle I needed to position the 3D robots, etc. in C4D so that they would look correct when they ware composited with the background (in Photoshop) I placed a low resolution copy of the background meeting room image on a flat plane (like a huge wall) behind the 3D characters in C4D’s workspace. This gave me a good reference whereby I could get the 3D objects positioned at the right angle like they would be seen by C4D’s virtual camera. Usually it only took two or three tries to get a usable rendered image. The final C4D images were rendered as 300Pi TIF files with an Alpha channel. The Alpha channel is a precise black mask that surrounds the 3D object and allows me to easily separate the object from the background once it’s in Photoshop.
A
great feature in C4D is it’s ability to make 3D objects
look real through it’s texturing and simulated dirt
features. The image to the left at “B” shows a robots
head as it appears with only the basic gray coloring
used during the modeling process. At “A-1” you can see
the Dirt effect turned up about half way and “A-2”
shows how Bump mapping can add an overall surface
texture to the object. Bump map textures can be set to
simulate a subtle surface details like cloth or as a
heavy pronounced surface like rough stone.
The
image to the left shows how shadows were added to
Layered image elements, where “A” points to the black
painted “Shadow”. In this image the main background
image has had it’s overall Opacity reduced to 40% and
the man’s Opacity is set to about 70% to make the
painted shadow stand out. In the image to the right the
shadow Layer is on top, but in the finished cover image
it’s below the man’s image Layer and has it’s opacity
lowered to 68%. Complex shadows were created using the
Polygonal Lasso Tool to form an outline for the shadow.
To fill the shadow’s selection set the Background color
to black, hold Com, then press Backspace to Fill the
selected area. All of the natural shadows in the main
background image are soft and diffused, so the edges of
painted shadow also needed to be softened. In some
cases I used the Select>feather command to soften
the edges or in others cases I used the
Filter>Blur>Gaussian Blur filter to soften the
shadow area.
To make it easier to figure out what angle I needed to position the 3D robots, etc. in C4D so that they would look correct when they ware composited with the background (in Photoshop) I placed a low resolution copy of the background meeting room image on a flat plane (like a huge wall) behind the 3D characters in C4D’s workspace. This gave me a good reference whereby I could get the 3D objects positioned at the right angle like they would be seen by C4D’s virtual camera. Usually it only took two or three tries to get a usable rendered image. The final C4D images were rendered as 300Pi TIF files with an Alpha channel. The Alpha channel is a precise black mask that surrounds the 3D object and allows me to easily separate the object from the background once it’s in Photoshop.
