How to make a Holographic Plate

1.Sub Glass Plate
LUCENTA CHROME ALUM SUB FOR GLASS AND GLAZED CERAMICS

Chrome alum is a gelatine hardener that makes emulsion stick to glass, preventing damage during processing. the LUCENTA formula below which I worked out back in 1980; is unrivalled for the purpose and keeps a lifetime. Chrome alum is not at this time listed as particularly toxic, but handle with discretion. FORMULA:

Distilled water 60 ml
ethyl alcohol 40 ml
glacial acetic acid 0.25 ml
flavorless food gelatine 0.5 grams
5 % chrome alum sol 2 ml

If in leaf form, cut gelatine in small pieces. Place with rest of mixture inside a glass jar with lid. Leave soaking for 30min, melt in a water bath at 50c, for 15-30 min. Stir occasionally until completely dissolved. Filter through paper,

Use top part of solution if solids sediment over the years. For larger quantities keep same proportions of ingredients.
To make a 5% chrome alum sol, dissolve 5 grams of it in 100 ml of water. (it keeps a lifetime)



2.Prepare Coating Table
For coating glass plates with photo emulsion; prepare a leveled glass table as shown in figure where on two wood strips AA, a window glass plate, B is leveled with the aid of a spirit leveler C

Insert pieces of carton D under wood trips to raise or lower glass B until it is perfectly leveled.

The liquid coated emulsion, due to the leveled plane will set with a layer of uniform thickness. The glass B can be a size of 8x10 inches (20x25cm) for holding 8 to 10 - 35 x 50mm negative glass plates.



3.liquefy emulsion
To keep liquefied emulsion at 35c for coating. Sit a larger dish inside water bath at 50c (122f) shown as A in figure. And on top of it, place the liquefied emulsion jar.

In this way emulsion will keep fluid for coating at around 30-35c (86-95 f) without ripening too much.

This will keep Lucenta rapid silver chloride emulsion which you have made yourself , from developing fog. Photo emulsion will be clean, as long as the same portion of emulsion is not heated more than 4 hours at this temperature.(35 c / 95 f )

To insure this, melt just enough emulsion for the job and coat it before 4 hours in this way also, thermostat settings of 50c, will not be disturbed to continue rapidly making more fresh and rapid batches of 250 ml (half pint) emulsions. Coating in next next step must be done in darkroom by red or orange light.



4.Coat with Emulsion

In darkroom position red or orange safelight in a manner that you can see the coating table.

Place a few uncoated subbed glass plates on the leveled glass shown as A in figure with the subbed side facing up.

with photo emulsion liquefied at 30-35c / 86-95f; with a 1 ml dropper shown as B draw 0.75 ml of liquid emulsion and gently discharge it on center of glass plate as shown in C and spread it with dropper or fingers so it covers all its surface.



5.Dry the Plates
After your coated home made photo emulsion has set into a firm solid on the glass plate;

have a razor blade nearby to lift it off the coating table in case it has stuck to the leveled glass due to some emulsion spilling on the back of the coated plate.

Hold coated plate firmly (slippery) when you do this. Handle coated plates wet or dry only by the edges.

Wipe off any spilling on the back of the coated plate using a moist sponge.

To dry them, stand them on the wood plate holder as shown in figure and position the plate holder in front of a current of cold air coming from a fan.

All small plates size 35 x 50mm should be dry to the touch in 1.5 to 3 hours.



6.Pack Plates
Following cold air drying, if coated emulsion feels a little sticky to the touch, It is due to emulsion attracting humidity from air. Before packing, apply warm air to emulsion on the plate with blow gun as shown as A in fig above, (care with light flash on igniting gun) until coat no longer feels sticky

and while the plate is still warm; pack each plate or object immediately inside plastic bag shown as B (or wrap in cellophane ) so it will not absorb more humidity from air. If packed without heating, plate will stick to plastic packing material)

Pack each coated object or plate individually as in C so they will not damage each other or stick together.
Store packed plates in total darkness. Under refrigeration at 5c / 41f or under, they will keep for months without change of speed or fog.