DOF: Depth of Field Using 35mm Lenses Continued…
Take notice: We want to create this in a unique but informative way, recycling things you can find in your house. This is not a blueprint for a professional or sophisticated device.
The most difficult part of this project is going to be in turning or shaking the ground glass in order to eliminate the grain. Optometry lab devices and laser equipment may utilize a ground glass diffuser, but there are a number of inexpensive ways to accomplish this without those tools. But for us, we want to try to spend as little as possible, using things you can find laying around in your home. One thing you could try is using a clear CD and a turning mechanism found in a broken CD player to turn the CD.
By designing this first, with a computer, it can enable efficient work and minimal mistakes.
Items to acquire:
1. Macro lens (Closeup)
2. 35mm lens
3. Bottom of a lens cap
1. Broken CD player’s motor
2. Fake CD
1. Particle Boards
The measurements from the ground glass to the lens are extremely important, we need a flexible design that we can move until we come to the position we want. If not, the device made will not be able to be focused. Three boards holding the lens, macro lens, and CD, is what we decided to go with.
The first thing that should be done is to place the CD player’s broken motor onto a board. To create space between the board and the macro lens and lens, use large screws.
The fake CD will act as the ground glass. With optical uses, this clear plastic CD is a great inexpensive alternative. The rotating CD will help to make as little grain and scratches possible.
The image below illustrates the lens plate attached. In order to attach the lens you need to make a hole in the lens cap and glue it to the board. Acting like spacers the screws allow us to put enough distance between the two boards. The estimated measurement taken from an SLR is 50mm between boards. But the flexible design allows us to change the placement of the boards, so that we can find the position that we are able to focus the lens.
The macro lens will be attached by the third board. Like before, long screws are used in order for me to change the boards’ positions. The macro lens is important because that is the side we attach the video camera to. You then zoom in to focus the video camera on the CD (ground glass). Not having the macro lens, focusing on the CD (ground glass) is not a problem but you are not able to zoom. Therefore creating a vignette effect we do not want. All camera lenses creates a vignette effect around a round image. The camera crops out the vignetting to create a rectangular photo with no vignette effect.
The images below gives the perspective from the opposite side. Again, this structure gives us flexibility to change and find the best distance between the boards that we need.
This is the first model prototype and since the dimensions are unknown, an enclosure is not given any thought.