Not all the holograms you shoot will be perfect. The following table will help locate the problem when you encounter some fault with the holograms image.
|No Image.||A hologram without any image can be a very frustrating problem. Even though it might seem as if you don't have a starting point to begin evaluating the problem, you do. During development, did the hologram stay transparent or did it gain some density. If the holographic film stayed transparent in the developer it is severely underexposed. Increase exposure time. In the latter case, the most probable cause is that the film plate or model moved during exposure.|
|Parts of Hologram Missing.||If you are shooting a hologram that contains more than one object, each object must be secure. If an object moves even slightly during exposure, it will not develop a holographic image.|
|Dark Spots.||This is also caused by slight movement.|
|Image has Bands of Light and Dark.||The object moved slightly during exposure.|
|Image Faint.||A faint image can be caused by either overexposing or underexposing the film. If the plate went black almost immediately after being placed in the developer it is overexposed. If the plate doesn't gather density after two minutes of development it is underexposed.|
|Image is weak and fades.||This is a problem I encountered when I used green plastic filters for my homemade safelight. The safelight was fogging my film during set-up and development.|
Hints & Tips
1) In the illustrations the laser has been positioned on the isolation table. This is not necessary; you could move the laser off the table without any ill effects.
2) Never place the laser power supply on the isolation table. The 60 Hz hum from the step-down transformer may cause the table to vibrate making it impossible to produce a hologram.
3) After you successfully produce a few holograms, you may want to try batch processing. Here you expose a few plates, keeping them in a light-safe box and develop them all at once or one after another. The reason I don't advise doing this before you have successfully produced a hologram is if there is something wrong with the set-up, you'll be multiplying your errors with subsequent exposures.
4) Remember the chemicals used to develop holograms are poisonous, always wear rubber gloves when developing holograms.
There are many type of holographic set-ups that you canaccomplish with the equipment you have. Unfortunately we don't have time to try all of them out in this short article.