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Introduction

Vibrations

Processing

SB Transmission

Exposure

Recording

SB Reflection

MB Transmission

MB Reflection

Lighting

Hardcopy

Resources

Creating A Multi-Beam Reflection Display Hologram

You are now going to use the real image of your final transmission hologram plate from your multi-beam transmission setup as the object scene in this multi-beam white light reflection display hologram setup. You're also going to use your multi-beam transmission setup for this reflection hologram setup, with a few changes. Figure 21a illustrates the setup if you want to hang your hologram on a wall and use overhead ceiling lighting. Later, in Figure 21d, I'll show you the setup if you want to hang your hologram on a wall and use underneath table based lighting. Figure 21b shows a close-up of H1, H2, and the real image positions.

multi-beam reflection setup image
Figure 21a: Multi-beam white light reflection display hologram setup for overhead reconstruction.

close-up of H1 & H2 image
Figure 21b: Close-up of H1, H2, and real image.

There are a number of things that have changed in this setup from the multi-beam transmission setup, which we'll do in a moment:

Note: It is important in this reflection hologram setup that you do not move any of the components, at this time, in the new object beam path including the laser, mirror M1, and beamsplitter BS which are outside the object beam path. This will insure that the incident beam on transmission hologram H1 is exactly the same as it was when you made it, and this in turn, will guarantee that the projected real image is distortion free.

New Object Beam Changes

The first change is to remove the object scene OS from the optical table. The loss of weight on the optical table by removing the object scene OS and its mounts may cause the reconstructing object beam O to slightly shift its position at H1. We'll tweak this later.

The second change is to insert H1 in its plate holder and orientate the transmission hologram H1 so its projecting its real image. You're now ready to make changes to the new reference beam.

Setting Up the Components in the New Reference Beam

This section should be read through completely before implementing because you'll probably have to build and paint some more components.

Check the reference beam illumination again at H2 for uniform illumination and check that H1 is uniformly illuminated. You may have to move DL1 left or right and/or up or down to uniformly cover H1. Put your shutter in place. Go ahead with the recording procedure and processing. Check the density of your first recording and make exposure time corrections if needed. Make sure that when you put the plate in the H2 holder, the emulsion is facing H1. This means that when the hologram is illuminated as it hangs on a wall from overhead, the emulsion will face the viewer. This also allows the glass side of the bleached plate to be painted flat black for a much brighter image. Use the painting procedure described previously.

If you decide to place the image in H2 to be projected in front of the plate instead of straddling the plate, move H2 away from H1. If you want the image to be further behind the plate, move H2 closer to H1. Remember, though, that you can only move H2 so close to H1 without the reconstructing light for H1 hitting H2, which you don't want.

If you want your final white light reflection display hologram to be illuminated from underneath the plate with the illuminating light source on a table top, use the setup shown in Figure 21d.

multi-beam reflection setup image
Figure 21d: Multi-beam white light reflection display hologram setup for underneath reconstruction.

A reflection hologram produces a monochromatic colored image. Since this hologram will be viewed with a white light source described in the next section, the color reconstructed in the image will depend on two factors:

 

Revised 5/2/2017