First DCG, Please, Help me find the problem.

This is a forum to share experiences and ideas about holography.
Locked
Dutchelm05

First DCG, Please, Help me find the problem.

Post by Dutchelm05 » Sun Feb 22, 2009 8:01 pm

Kiffdino wrote:It breaks my heart that it would make my newly acquired pizza-oven redundant.
What's wrong with using for pizza? :wink:
Although the chemicals residue is a little concerning...

Kiffdino

First DCG, Please, Help me find the problem.

Post by Kiffdino » Sun Feb 22, 2009 8:51 pm

yeah, id love to use it for pizza, but i guess beacuase of all that chemical residue that wouldnt be so smart.
your burn in is way stronger then mine.
so i definitely have to increase exposure times.

dave battin

First DCG, Please, Help me find the problem.

Post by dave battin » Mon Feb 23, 2009 3:33 am

Kiffdino wrote:By the way i just ordered some Tetenal Superfix Plus, the fixer many of you recomended.
It breaks my heart that it would make my newly acquired pizza-oven redundant.

So next session, there will be no oven and longer exposure times.

see thats a shame you wasted all the money and your energy on the system first,this is why the people who CAN make dcg holography suggest to initally use fixer w/hardner, then move over to the g307 system.there are many tips listed on this forum, the subjects can be easly found by using the search button above .......

you are almost there, if you can harden more will help to clear things up a bit, and what is the age of your film ?

Kiffdino

First DCG, Please, Help me find the problem.

Post by Kiffdino » Mon Feb 23, 2009 11:31 am

hi Dave,
age of the film was 12 hours.

can the g307 formulary be combined with chemical fixer ? So instead of putting the plate in the oven i would put it in the fixer bath?
Ive got to admit, i find the g307 quite practical cause i dont have to do the coating and drying under safelight. And since theres no dichromate involved in the coating, i can do it in the kitchen. space is limited...

Heres is a quote form the "Beginners Approach to DCG"
>> Processing the Plate<<
All temperatures can be at room temperature (70F). Take the plate and put it in Kodak Rapid Fixer with hardener. The Fixer should be mixed as per the instructions for the most dilute mixture (paper 1:7). Gently rock the tray until all yellow is gone then an additional 15 seconds. This should take anywhere from ½ minute to 2 minutes. I use a white tray to observe the yellow more easily. Once this is completed, place the plate in running water for 5 minutes ( a tray of water can be used if running water is not available)
by the way, i told you i started of with g307 because i couldnt find the kodak fixer.
i even contacted kodak and they told me their fixer wasnt available.
Only later on when i already purchased the oven you guys recomended tenetal Superfix plus. By then it was to late....

Joe Farina

First DCG, Please, Help me find the problem.

Post by Joe Farina » Mon Feb 23, 2009 11:47 am

It's not necessary to use G307 if the objective is to coat plates with gelatin and no dichromate. The coated gelatin plates can be soaked in a dichromate solution later. Also, fixer is not necessary when usuing regular DCG. A 100W light bulb can be used instead.

Kiffdino

First DCG, Please, Help me find the problem.

Post by Kiffdino » Tue Feb 24, 2009 10:31 pm

Ok just for me to get this correct.
I read the guides on the DCG-WIKI again and tried to work out the differences because i kinda got mixed up.
Correct me if im wrong.
There are three different ways to process DCG.

1. Joe Farina's way: [no fixer but with light bulb]

("A simple DCG recipe")
-start off with gelatin and dichromate only
-expose
-dark reaction
-rinsing
-lightbulb 100W halogen
-alcohol baths
-drying

2. John Precoras's way:[with fixer and lightbulb]

("A Beginners Approach to DCG")
-start off with gelatin and dichromate only
-expose
-dark reaction
-rapid fixer bath
-rinsing
-lighbulb 100W halogen
-alcohol baths
-drying

3. Jeff Blyth's way: [with oven, but no fixer and no lightbulb]
("G307 DCG formulary")
-start off with gelatin, dichromate, glycerin and alluminum sulfat
-expose
-dark reaction
-oven
-rinsing
-alcohol baths
-drying

So just for clarification.
The fixer and the light bulb work only if i use gelatin and dichromate only.
But when I use the G307 DCG formulary I have to stick to the oven and cannot use a fixer nor a lightbulb ?

dave battin

First DCG, Please, Help me find the problem.

Post by dave battin » Wed Feb 25, 2009 12:27 am

All you need is to apply dichromate and gelatin to glass wait several hours (3-12)
process as follows;

Kodak rapid fixer with hardner (high strength for plates) for @ 30 seconds

Wash in water for 60 seconds

Wash in water with two drops of soap or photo flow, enough to see the water NOT beading on films surface, wash for 60 sec.

Place in 70% ISO ALC bath 30 seconds

Place in 90% ISO ALC bath 30 seconds

Place in 99% ISO ALC bath untill images begin to appear, continue washing for 15 seconds more(this is the ONLY bath that requires heating) heat to 60C or so ............

Remove and dry heat as hard as possible, watch image appear across plate!


im not sure where the "light " plays a part of the process as the fixer should do enought hardening ............

Joe Farina

First DCG, Please, Help me find the problem.

Post by Joe Farina » Wed Feb 25, 2009 12:03 pm

I see the light bulb as an alternative to the fixer. Rallison describes this in "Notes and considerations for the dichromated gelatin (DCG) holographer." From page 87:

"Developing is simply a process of reducing the remaining chromate ions and thereby uniformly hardening the gelatin. Too much hardening will give a clean, clear but weak and green result. Too little hardening will leave the hologram milky and weak and reddish or yellowish. Development is done either optically or chemically using fluorescent or incandescent lamps or any suitable reducing agent or tanning solution."

Rallison used either Kodak fixer, or a 100W lamp at 6 inches from the hologram, for time periods of between 5 and 15 seconds. But he was also exposing at 441nm which would do a much better job than 532nm. By the way, I use the light bulb immediately after the dark reaction (before swelling with any water). I've used Knox gelatin with exposure at 457nm, and this is usually hard enough by itself to require neither fixer nor light bulb.

JohnFP

First DCG, Please, Help me find the problem.

Post by JohnFP » Wed Feb 25, 2009 1:58 pm

Sorry for the confusion KIffdino but you are incorrect in my proceedures. The quartz halogen light is not used for hardening at all. What I state in that write up is to turn on the quarts halogen light at the spot where you will eventully blow dry the hologram in the final step. This is mainly to add visual lighting to the area to obsever an image in the last bath, and you don't want to be reaching for a light switch after you take the hologram out of the last alcohol bath. You want to immediately start blow drying it. The quarts spotlight allows you to see the image come out when your are blow drying.

I hope this is clearer.

All temperatures can be at room temperature (70F). Take the plate and put it in Kodak Rapid Fixer with hardener. The Fixer should be mixed as per the instructions for the most dilute mixture (paper 1:7). Gently rock the tray until all yellow is gone then an additional 15 seconds. This should take anywhere from ½ minute to 2 minutes. I use a white tray to observe the yellow more easily. Once this is completed, place the plate in running water for 5 minutes ( a tray of water can be used if running water is not available). I now turn on a quartz halogen light that shines on the spot where I will lean the hologram to blow it dry. Then take the plate and place it in 35% alcohol for 15 seconds. Then 70% alcohol for 15 seconds, then 91% alcohol for 15 seconds then finally 100% alcohol until diffraction is visible (anywhere from 15 seconds to two minutes or longer). As soon as diffraction (colors) is seen allow another 15 seconds in that bath. Then take the plate out and lean it against the wall in the overhead light. With practice you will find which angle the diffraction is seen in the light and which way that relates to the visibility of the hologram when blow drying it. As soon as you lean the plate against the wall begin blow drying it with a hair dryer set on its hottest and strongest settings. Blow dry very close to the plate. Start at the center and in a circular motion move to the outside of the plate and repeat often. If the plate is leaning the right way the diffraction and image should start to get really bright. Continue drying until hologram in completely dry. You cannot over dry but you can under dry. This usually takes me 5 minutes minimum.

Kiffdino

First DCG, Please, Help me find the problem.

Post by Kiffdino » Wed Feb 25, 2009 8:45 pm

ok gonna try all the three processes as soon as the fixer arrives.

i got a very powerful halogen light, thats gonna do the trick
with the light bulb method im gonna do 1min and 2 min exposures

with Johns method, 40 and 80 seconds.

on g307 im going to prolong the expusure time from 20 sec i tried last time to 30 seconds and 40 seconds. while keeping the baking time constant at about 1min45sec

im excited, but a bit worried aswell about the long exposure times cause this is still an apartment and even though i built quite a sturdy setup, its very vulnerable to vibration

Locked