Week 24 - June 16, 2013
Bokeh
You're about to get a photo lesson that is part Japanese and part lens optic science. Bokeh (pronounced as the "Bow" in Bow and Arrow, and "Ke" as the Ke in Kettle) describes the blur, or the aesthetic quality of the blur in out-of-focus areas of an image. Bokeh has been defined as "the way the lens renders out-of-focus points of light". Shooting images that demonstrate the use of bokeh was the "assigned subject" for members of the Boise Camera Club this week. I decided to take the subject a bit further with the use of "patterned bokeh."
Because the shape of the out-of-focus light will take on the shape of the lens aperture, we often see the bokeh on "specular highlights" (the shiny spots of light in a photo), as hexagons or octagons, depending on the number and shape of the blades that compose the lens aperture. But, if we leave the lens wide open and instead place a shape in front of the lens, the bokeh will take on that shape.
So this is how I did it... I traced the filter from my Canon 70-200 lens on a piece of black cardboard, then cut out that circle. I cut the shape of a star, (about 1/4") in the center of that circle and then placed it on the end of the lens. Thus, my "aperture" was now star-shaped. To get good specular highlights, I crumpled up a piece of aluminum foil and took it out in the bright sunshine. I purposely turned off the autofocus so I could shoot the highlights out-of-focus and voila...got the star shaped highlights. Camera and lens settings are in the technical details below.
That gave me the background used in these photos, but I found I was not able to get a foreground object in focus while maintaining the background out of focus. (That is probably possible, but will take more experimenting.) For now, I used another technique. A few years ago, I had taken engagement photos of my daughter Megan and her at that time finacee, now husband Tyrel, on a green screen background. Using the software PhotoKey, I was able to drop out the green and replace it with the background of my choice, in this case the new Star Bokeh Background.
Not to be exclusive, I also had an enagement photo of my son Mark and his then fiancee (now wife), Brittany, this time shot in the green grass. The grass was green enough that it keyed well and with a little masking, was able to do the same for them.
So... some photo science mixed with some photos of my kids with their spouses - a nice set of subject for Week 24, which also was Father's Day!
You're about to get a photo lesson that is part Japanese and part lens optic science. Bokeh (pronounced as the "Bow" in Bow and Arrow, and "Ke" as the Ke in Kettle) describes the blur, or the aesthetic quality of the blur in out-of-focus areas of an image. Bokeh has been defined as "the way the lens renders out-of-focus points of light". Shooting images that demonstrate the use of bokeh was the "assigned subject" for members of the Boise Camera Club this week. I decided to take the subject a bit further with the use of "patterned bokeh."
Because the shape of the out-of-focus light will take on the shape of the lens aperture, we often see the bokeh on "specular highlights" (the shiny spots of light in a photo), as hexagons or octagons, depending on the number and shape of the blades that compose the lens aperture. But, if we leave the lens wide open and instead place a shape in front of the lens, the bokeh will take on that shape.
So this is how I did it... I traced the filter from my Canon 70-200 lens on a piece of black cardboard, then cut out that circle. I cut the shape of a star, (about 1/4") in the center of that circle and then placed it on the end of the lens. Thus, my "aperture" was now star-shaped. To get good specular highlights, I crumpled up a piece of aluminum foil and took it out in the bright sunshine. I purposely turned off the autofocus so I could shoot the highlights out-of-focus and voila...got the star shaped highlights. Camera and lens settings are in the technical details below.
That gave me the background used in these photos, but I found I was not able to get a foreground object in focus while maintaining the background out of focus. (That is probably possible, but will take more experimenting.) For now, I used another technique. A few years ago, I had taken engagement photos of my daughter Megan and her at that time finacee, now husband Tyrel, on a green screen background. Using the software PhotoKey, I was able to drop out the green and replace it with the background of my choice, in this case the new Star Bokeh Background.
Not to be exclusive, I also had an enagement photo of my son Mark and his then fiancee (now wife), Brittany, this time shot in the green grass. The grass was green enough that it keyed well and with a little masking, was able to do the same for them.
So... some photo science mixed with some photos of my kids with their spouses - a nice set of subject for Week 24, which also was Father's Day!
Technical Details
Camera - Canon 50D
Lens - Canon 70-200 f/2.8 L IS
Exposure - 1/40th sec. @ f/2.8 - ISO 200 - Manual Mode (this is for the background)
Software used - Green-screen work - FXHome PhotoKey
Additional image tuning - Corel Paintshop Pro X5
Lens - Canon 70-200 f/2.8 L IS
Exposure - 1/40th sec. @ f/2.8 - ISO 200 - Manual Mode (this is for the background)
Software used - Green-screen work - FXHome PhotoKey
Additional image tuning - Corel Paintshop Pro X5