QUESTIONS & ANSWERS
Can you describe the general three-step process?
1. Part one: Photography:
The general process begins with capturing the person, or object, using your 35mm camera in 8 separate frames onto a film such as Kodak's TMAX100. This film is then "reverse processed" . . . which means instead of winding up with negatives, you wind up with positives. They are the same as standard "slides" when finished, except that they are black and white. To get the 8 frames, you move your camera along a straight line from left to right, keeping it facing forward, and capture that person, or object, onto the film with 8 equally-spaced exposures. You will see the person, or object, move from one side of your viewfinder to the other during these exposures. When processed, the film will show the person, or object, moving from one side of the frame to the other, mirroring what you saw when taking the shots.
2. Part two: Master Hologram:
A laser transmission hologram is made from the 8 individual frames. The master hologram contains 8 individual slits cut into cards that are placed over the plate, one slit at a time, with each slit corresponding to its associated 35mm film frame. The yet-unexposed master plate faces the ground glass, and each individual film frame, one exposure at a time, is rear-illuminated with diverging laser light, rear-projected onto ground glass, and exposed onto the master holographic plate. Each individual slit of the master hologram "sees" each corresponding frame projection. During each exposure, the rest of the plate is covered by the slit card's solid area so that no exposure takes place on the rest of the hologram. When one exposure is done, another frame is loaded, and another slit placed over the master plate. This process continues for the entire 8 frames, so you must make 8 separate exposures per hologram. As you will see, each individual slit "moves" from one slit location to the other, side-by-side. When all 8 slits have been exposed, individually, the 8 slit areas have exposed the entire master plate.
3. Part three: Reflection Copy:
This is a stadard H1 to H2 transfer . . . from the master laser transmission hologram, to the white-light reflection display copy. It is the easiest of the three steps, with step #2 above being the most challenging. Once set up, this copy process can take place very rapidly -- transferring many holograms per hour.
How did all of this come about?
Stereogram holography (or also known as integral and multiplex) has been in the literature for years. And when I say years, I mean going back to the 1960's. In fact, most of what you see today can be traced back to the original DeBitetto paper published in 1969. It was one of the first papers regarding holography that I was exposed to at an early age. In the early to mid-90's, I was doing very early drum-scanning, digital editing and color separations. This led to an interest in photographic portraiture. I began to extract information from many sources once again on holographic portraiture -- mainly stereogram methods -- and began adding my own steps to match what equipment I had to work with in my own lab at the time. By the mid 90's or so, I had worked out the process to the point of it giving me the results that I was looking for. So, in essence, it borrows from the foundation of stereogram holography, yet also contains a lot of steps that would be considered more in the realm of offset-printing, plate-making, and registration. Determining the absolute minimum amount of exposures to give the maximum amount of dimensionality, along with designing specific table geometry/component relationships and distances also removed many of the complex optical requirements usually associated with stereogram/multiplex/integral production.
Do I have to make a reflection copy?
No, not at all. You can illuminate the laser transmission master with laser light and view the three dimensional image as you look through all eight slits at one time. If done properly and carefully, these master images are even more impressive than the reflection copies -- which laser transmission holograms usually are. The drawback however is that you need a laser, it can only be viewed by one person at a time looking through the plate, and cannot be framed and displayed on a wall. But it is impressive indeed.
How good is the quaility of these images?
The main trade-off in quality compared to similar commercially produced holographic stereogram portraits is the viewing angle and parallax. However viewing angle and parallax is not totally missing either . . . and, in fact, it's only slightly less than the SONY system mentioned below, and is a much larger image as well. There's certainly enough there to give a rock-solid, three dimensional image. That being said, I will also state that if done properly, carefully, and precisely, following good procedures throughout each step, the resulting image will rival any similar stereogram (35mm film-based capture/silver-halide hologram) out there for image quality, per se . . . brightness, contrast, and dimensionality.
How long does the process take from start to finsh?
Starting from scratch, and once the set-up phase for each step is complete, figure on approx. an hour to do the 35mm photography and develop the film. Approx. an hour or so for the 8-slit master and development, and approx. a half-hour for the reflection transfer and development. A good way to do a project, assuming set-up is needed for each step, is to do photography in the morning, the mastering in the afternoon, and the transfer in the evening. You will find speed increases with experience . . . in the beginning, this will seem like a long, drawn-out process.
Once you've got things rolling, it's good to schedule your photography sittings back-to-back, then also do all of your mastering back-to-back, then move on to knocking out the reflection transfers. In this situation, several holograms can be produced in one day.
Can people do their own photography and send the film to me?
This is an excellent concept in theory, but I've been there, done that, and I do not recommend this at all -- unless you have several good photographers sending you the film that have been trained properly. Garbage in will always be garbage out, and you cannot improve the final hologram if this very first step is not up to quality. Look at any persons typical photos that they take to see just what you will be up against. With supplied photography from the general public, take my advice and stay away. Do your own photography, or train someone else to do it properly for you in the field.
What type of laser should I use?
Whatever laser you've already been working with, are comfortable with, and gives you already-known results. Now is not the time to switch or change any variable in your system. You can do these with as little power as 5mW if you have a good, stable system and environment . . . so it's your choice when it comes to HeNe or even a laser pointer, as this techniques does not require any more laser power than a typical 4 x 5 hologram. If you're already using a HeNe, laser pointer or diode system, and are getting good results, stick with it by all means.
Is this done with the Shoebox Holography system?
No. Not at all. You will need a standard holographic vibration isolation table to do this work, such as a sand table or flat-top table on inner tubes. The table must be large enough to set up your optics according to the recording geometries. It must be stable enough for moderate exposure times working with split-beam set-ups. If you are just starting out however, Shoebox Holography will give you 14 learning modules that will get some experience and background under your wings . . . especially exposure time and processing techniques without many system variables for early learning. But it has nothing to do with hologram portraits at all. After Shoebox, I'd recommend moving on to either the Holography Handbook or Practical Holography (or better yet, both) to begin learning about, and getting experience with, laser transmission holograms, mastering, and reflection transfers.
Why 8 exposures?
I have found that 8 is the minimum amount of exposures that will still give great results, with the least amount of time spent during production (since it's all done by hand and not automated), and also not requiring expensive (or difficult to build at best, i.e. liquid-filled lenses) "corrective" optics. You could do 800 exposures, but you will still not increase the dimensional quality, nor would you want to hand-register 800 frames or expose 800 slits by hand. For image quality and dimensionality, I will put these 8 exposure hologram portraits up against any other 35mm captured, silver-halide stereograms . . . regardless of how many exposures they have (come to the Meet & Greet in Phila. in Oct. 2004 to see side-by-side comparisons).
Once again, holograms from the SONY automated system below do not show any more DIMENSION with 298 exposures as these do with eight. More exposures would only serve to provide the realization of motion, and more "time" for that motion, and the ability to show more parallax in this situation as well. These 8 exposure hologram portraits, for all practical purposes, are static, rock-solid, three-dimensional images. You CAN however, have the person smile (i.e. not smile for the first 4 exposures, then smile for the remaining 4 exposures). When you view the hologram, and move past it, the person will smile at you . . . or wink (i.e. first two exposures no wink, next four exposures wink, last two exposures no wink), etc., so you can have LITTLE things like that with 8 exposures that work nicely in the final hologram.
Can this be automated?
Definately . . . once you have the technique down, it is not that difficult to envision capturing the master information with a digital camera in one room, sending to a PC running a script to auto-register the images, and then send the information to two LCD's on your holography table in another room . . . 1 LCD dedicated to the digital photography frames, and the other placed in front of the master plate which synchronizes the slit movement with the images. Of course, this adds quite a bit of complexity, and only addresses the laser transmission master.
For all practical purposes however, I've put this process together so that if you are already doing split-beam holograms, you should already have very much of everything that you need to get started creating these portraits.
As far as automation goes, SONY has had a one-step reflection hologram portrait system for several years now, utilizing an LCD panel which they term a "light modulator" in lieu of the 35mm photography. The camera tracks on a rail, sends the digital information to the LCD, and the hologram is made on the spot in one step (on photopolymer material). By replacing the H1 master with the LCD, and then projecting those images into the plane of the reflection H2 copy, similar results are achieved as with the H1 to H2 method -- although requiring more complex optical set-ups, mechanical transports and synchronization. Several years ago, I visited the SONY studios in New York when a prototype was being demonstrated. A web page for that is Here.
What will be covered in this area of the web site?
It is well beyond my ability and scope of this area to provide instruction to the point of being a complete step-by-step, highly detailed set of tutorials -- although I would love nothing more than to be able to have the time to do that. What will be provided is the fundamental elements -- along with the assumption that you know how to make holograms to begin with. This should not be undertaken by someone who is preparing to make their first hologram. You should already be getting good results in your own lab first. And also have experience making laser transmission holograms and reflection hologram transfers from laser transmission masters. If not, then get that experience under your belt first. Of course, there will be those who have the ability to jump right in and get results, and if you're one of them, congratulations. But everything must be done properly along all steps here -- from the quality of the 35mm film capture, to mastering, to transfers and all associated processing. It brings everything together. I don't want to sound discouraging in any way. But I also do not want someone frustrated either -- from poor or even nonexistent results. Yes . . . it does work. And it gives excellent results. But troubleshooting along the way will be needed, and this is where you will have to call on your own past experience. If that experience is not there, you can easily see where this will wind up for you.
Can this really work out?
Yes, it can. Remember, you're dealing with the most powerful selling feature of all time: Vanity. Holograms of bunny rabbits are really neat. However, no hologram will ever have the impact and appeal of one that is of a person, a pet, or new baby, or marriage, or graduation, or job promotion, or a car, a house, or boat. It's just human nature. Always was and always will be.
What are the most important points?
The most important points are as follows:
1. KEEP IT SIMPLE: the focus of this entire project is simplicity and very low cost -- yet resulting in high-quality results. I have tried to break down complex issues and make their execution in the lab as easy as possible. I already know all about the more complex ways of doing this. I already know all about how it can be automated. At this stage of the game, we are making hand-crafted hologram portraits, using common and inexpensive materials, and simple, straight-forward table geometries. By hand.
2. Make sure your photography results in quality images, with good brightness and contrast, and maintaining both shadow and highlight detail. Be consistent from frame-to-frame as you move from left to right. Learn about lighting techniques for portraits. Maintain good focus of image.
3. Make sure your slit cards are cut accurately, so that the exposed areas just touch one another on the master plate when finished. They should neither overlap, nor be spaced apart.
4. Be accruate with registering your transparancies with one another during mastering. The image will jump around if this does not take place. It should be rock-solid, and "grounded" in the resulting hologram.
5. Pay attention to what you're doing. The master hologram must be removed from the plateholder so that each slit card can be replaced over it. Do not forget how the plate was oriented and then replace it incorrectly.
6. Remember which image goes with which slit. Exposing the #3 image with the #7 slit will not work.
7. Be accurate with beam ratios and exposure times.
8. Process both the master and reflection hologram carefully.
9. Get a signed release form stating that you are permitted to use the images/holograms captured in any promotional efforts. I failed to do this, and I am left with many, many master plates that I cannot copy, photograph, and put on a public web site -- although at the time back then there were no web sites to put them on. Think ahead.
10. And so on . . . and so forth.
I will attempt to point out these areas along the way. However, if you do this correctly and accurately from start-to-finish, you will be astonished at what you will achieve in the finished display hologram portrait.
If you're ready, let's begin:
Module One: INTRODUCTION -- GO