New section: FAQ?

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Tony

New section: FAQ?

Post by Tony »

Suggestion for a new section in the forum: FAQ



In other words, frequenctly asked questions (by newbies).



Here's one example, which I would post immediately:



Why are DCG reflection holograms brighter and whiter when reconstructed with white light than silver reflection holograms?





Format would be one simple question get's asked, followed by ayone who knows the answer posting a response...
Colin Kaminski

New section: FAQ?

Post by Colin Kaminski »

I have tried many times to start this. Let's Use this thread and get some questions and answers started and I can make it more formal when I have some raw data.



What is a laser?

What are the requirements for a holography laser?

What laser colors can be used for holography?

What is a pulsed Laser?



What is a hologram?

What is a HOE?

How do you make computer generated holograms?

What is a multiplex hologram?

What is a dot matrix hologram?



What is the difference between a transmission hologram and a reflection hologram?

What is a H1 and H2 hologram?

Why can't I make a "Princess Leigha Hologram"?





Where can I buy film and chemicals?



What is a pseudoscopic image?

What is an orthoscopic image?



etc...
DJ Mathson

New section: FAQ?

Post by DJ Mathson »

I think this is a good idea. I have thought of starting a FAQ and a tutorial on holography now for 7 years but have not come up with anything so far.



I start with a few questions. Please make better suggestions or corrections on any erroneous facts or grammar. Maybe some kind of wiki could be benefitial so forum members could update the information.
DJ Mathson

New section: FAQ?

Post by DJ Mathson »

What are the basic components needed for starting with holography?



1. A laser

2. Holographic plates

3. Developer chemistry

4. A lens to spread the laser beam (not needed for a bare laser diode).

5. Vibration isolation

6. Object



1. The most basic laser is either a helium-neon (HeNe) laser or a low power red diode laser like those in a laser pointer. The power should be at least between 1 to 5 mW where the higher value is more preferable. The laser should be TEM00 and lineary polarized. (See laser questions).



2. The basic and most used holographic plates are of the silverhalide kind. There are either glass plates or plastic film covered with a photosensitive emulsion. It is easier to start experimenting with glass plates. The film is cheaper but needs to be clamped between glass sheets and are therefore more prone to move during exposure. Different kinds of emulsion are suited for different kinds of laser colors and holographic setups. The cheapest to start with are small 2.5x2.5" (63x63mm) plates.



3. There are several kinds of developers that are suited for different emulsions. Several companies have ready made kits.



4. A lens is needed to spread out the laser beam to cover the plate. This is not needed for a bare laser diode since the laser light from these are already spreading out. Either a positive or a negative lens with about 9 mm focal lenght is good. Actually any lens that spreads out the beam to cover the plate is good.



5. Vibration isolation can be a 10" pavement stone on a small inner tube or bubble pack. You can also have a litte cup or bucket with sand where you put your object and then lean the plate against the object.



6. The object should be bright, preferably white, and solid, like a pocelain cat or something similar. Metal objects can be a bit tricky since they have specular reflections.





Holography kits can be found at http://www.integraf.com.



Basic tutorials can be found at

http://www.integraf.com

http://www.buildcoolstuff.com/gallery/holograms.html

http://www.holography.ru/files/holpte.htm
DJ Mathson

New section: FAQ?

Post by DJ Mathson »

Where can I find tutorials on holography on the Internet?





Three Dimensional Imagery´s Hologram Production Lab

http://www.3dimagery.com



25 Holography Lessons at Holography.ru

http://www.holography.ru/techeng.htm



Amateur Holography--Simple & Low Budget

http://members.aol.com/gakall/holopg.html



Practical Holography by Christopher Outwater & Van Hamersveld

http://www.holo.com/holo/book/book.html



Hologram Basic Principles by Jason Sapan

http://www.holostudios.com/holohelper/index.html



Integraf´s Articles on Holography

http://www.holokits.com/newsarticles.htm



Making Holograms with an Inexpensive Laser Pointer

http://www.buildcoolstuff.com/gallery/holograms.html



Hand-made Hologram Portraits - An Amateur/Hobbyist Guide

http://www.holoworld.com/holoportraits/index.html
Colin Kaminski

New section: FAQ?

Post by Colin Kaminski »

Colin Kaminski wrote: What is a laser?
The word LASER is an achronym for Light Amplification by the Stimulated Emission of Radiation. It is a device that emits a light beam that has special qualities. Most lasers are a pure color and travel in a beam with out spreading.

What are the requirements for a holography laser?


For holography, the qualities we require are TEM00 mode, long coherence length (narrow linewidth) and high power. Tem00 means that the beam when spread with a lens illuminates the object evenly. Long coherence width effects the depth of scene we can make a hologram from. High power shortens our exposure times.
Colin Kaminski

New section: FAQ?

Post by Colin Kaminski »

How do I calculate exposure times?
edelbrp

New section: FAQ?

Post by edelbrp »

Colin Kaminski wrote:
Colin Kaminski wrote: What is a laser?
The word LASER is an achronym for Light Amplification by the Stimulated Emission of Radiation. It is a device that emits a light beam that has special qualities. Most lasers are a pure color and travel in a beam with out spreading.


The first thing I thought of when I read this: this is rather too technical and already getting off-topic as to what a newbie might ask when they want to make a hologram.



People starting are interested in the results, not the technical details. They're thinking, "How little money/bother do I need to make one?"



Or, "How much (little) do I need to spend to start?", "Are the chemicals dangerous?". "What sort of time commitment is there for making a hologram?", "When can I have the lights 'on' during the procedure of making a hologram?", "What are the different kinds of holograms and what are their relative (at a glance) differences in costs and difficulties to get started and to make a hologram?"



Keep the terms in the glossary. You could always link to the definitions from the FAQs.



Think of a hierarchy instead of linear FAQ so users can explore and get answers to things they are looking for and not have to waste time with things they either already know or don't yet want to know.



Lastly, and GET A WIKI GOING! ;') Get people involved in contributing and refining content for you.





-Phil
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