What HoloWiki Provides About Dichromated Gelatin (DCG) Holography

Updated

HoloWiki covers dichromated gelatin holography in three distinct places: a basic introduction in the Dichromated Gelatin section, a historical timeline in History of Dichromate Holography, and a practical DCG Color Tuning guide compiled from the Holography Forum archives. Supporting material on the chemistry and recording materials sits in the Hologram Recording Materials section. If you are new to DCG, start with the basic section; if you are already coating plates and want to shift playback color, go straight to the color tuning guide.

The DCG-specific pages

Page What it covers Best for
Dichromated Gelatin Basic information about branching off into DCG holography Deciding whether DCG is the right process for you
History of Dichromate Holography A timeline of the people and technology in the advancement of DCG holography Understanding how the process and its key figures developed
DCG Color Tuning guide Derived from the Holography Forum archives; concerns adjusting the color response of DCG Troubleshooting or deliberately shifting the replay wavelength

The site describes the Dichromated Gelatin page as "basic information about branching off into the realm of DCG holography" — that phrasing matters. It is an entry point, not a complete coating manual. Expect orientation and pointers rather than a step-by-step lab protocol.

Where the chemistry and materials live

DCG is as much a chemistry problem as an optics problem, and HoloWiki does not isolate it entirely in the DCG section. Two other areas carry relevant content:

  • Hologram Recording Materials — how to get, make, and use recording materials, plus their chemistry.
  • Compilation of chemistry for holographic developers and bleaches, credited to Ed Wesly — useful when your DCG work overlaps with wet processing of other materials, or when you need to compare developer and bleach formulations.

If you are trying to source or mix dichromated gelatin itself, the recording materials section is the place to look before assuming the DCG page has it.

Related pages worth knowing about

A few other sections on the site support DCG work indirectly:

  • Holography Safety — flagged on the main page as "a must read." Dichromate is the obvious reason this matters for DCG practitioners.
  • Cold Water Processing article by Ed Wesly — relevant if you are working with processing schedules that avoid hot baths.
  • Experiment with albumen plates by Filipe Alves — a different sensitized-emulsion approach, useful as a comparison if you are weighing DCG against alternatives.
  • Holography Glossary and Abbreviations — worth a pass before reading the DCG material, since the terminology is dense.

How to use these pages in practice

  1. Read Dichromated Gelatin first to confirm DCG fits your setup and goals.
  2. Check Holography Safety before handling dichromate.
  3. Read Hologram Recording Materials for the chemistry side.
  4. Use the DCG Color Tuning guide once you have plates and want to control replay color.
  5. Consult History of Dichromate Holography if you need to trace a technique or attribution back to its source.

One caveat: the color tuning guide is described as derived from the Holography Forum archives, so it reflects forum discussion rather than a single authored reference. Treat it as a record of what practitioners tried, and cross-check against the recording materials page.

What HoloWiki is, in short

HoloWiki is the Holography Forum's wiki — "a Holography FAQ and Database for anyone who makes holograms." It is hosted by John Fisher, the site administrator, and the associated forum at holographyforum.org is where discussion happens. Browsing is open to guests, and the main page states that signing up as a full forum member costs nothing. The DCG content is one part of a broader structure that also includes a Beginner's Corner, an Experimenter's Corner, equipment pages, a gallery, and advanced theory.