ideal temp and RH for working with DCG process

Dichromated Gelatin.
ahgu
Posts: 23
Joined: Tue Dec 08, 2015 11:30 am

ideal temp and RH for working with DCG process

Post by ahgu » Tue Mar 28, 2017 9:28 am

What is the ideal environment condition should I maintain when I go through the spin and exposure, and develop, sealing process?

My understanding is the too high RH is not good as it absorb moisture, but too dry is not good either, as it seal the top layer.

-Ahgu

Tony DCG
Posts: 147
Joined: Thu Jan 08, 2015 1:47 pm

Re: ideal temp and RH for working with DCG process

Post by Tony DCG » Wed Mar 29, 2017 11:30 am

Keep in mind that the best DCG holographers like Dinesh, August Muth and the company in Utah (that make DCG masters) all live in dry climates.
Dryer environments are good for DCG in that you can store your plates longer.
If you live in a high RH area you may want to look into Dave B's dip in shoot method which allows you to use plates before RH causes any issues.

ahgu
Posts: 23
Joined: Tue Dec 08, 2015 11:30 am

Re: ideal temp and RH for working with DCG process

Post by ahgu » Thu Mar 30, 2017 1:35 pm

what temp and humidity are we talking about? Logan Utah is actually pretty humid in winter, but dry in summer.

Ann Arbor, MI is pretty humid in the summer, What DCG place are you refering to in Utah?

https://weatherspark.com/averages/30726 ... ted-States

Tony DCG
Posts: 147
Joined: Thu Jan 08, 2015 1:47 pm

Re: ideal temp and RH for working with DCG process

Post by Tony DCG » Mon Apr 10, 2017 9:36 am

My understanding is heat and high RH decrease DCG film sensitivity. By how much I cannot say. But if you store your film in a dry cool location (say 40%RH and 70 degrees or lower) your film should be fine. Every location requires experimentation to find what is optimal for you. Here in my part of California the RH is higher (say 50%) and I can manage making DCG just fine.

Steven
Posts: 32
Joined: Sat Jan 31, 2015 8:14 pm
Location: Cornwall, UK

Re: ideal temp and RH for working with DCG process

Post by Steven » Sun Apr 16, 2017 6:14 pm

Hi Ahgu,

According to the wiki: http://holowiki.org/wiki/DCG_Variables

"Room Temp (exposure) - Warmer increased sensitivity.
Room Humidity (exposure) - More humid increased sensitivity."

I have exposed DCG with room a humidity from about 45% to 58% or more
with temperature ranges between 16 deg C and 23 deg C.

I live in the UK, so the humidity can swing about quite a bit.
http://nw3weather.co.uk/wx10.php
I don't use any environmental controls in the exposure room and the central heating
is turned off in the room.

I use dip and shoot and store the fresh sensitized plates in the exposure room to dry.
I usually leave them to dry for 24 hours or more before exposure.

HTH,
Steven.
Success through failure - the amateur DCG holographer's path to enlightenment.

ahgu
Posts: 23
Joined: Tue Dec 08, 2015 11:30 am

Re: ideal temp and RH for working with DCG process

Post by ahgu » Tue Jun 06, 2017 9:16 am

I divided the steps: I want to make the process consistent every time.

1. making emulsion: T&RH not important
2. spin coating: make sure no dust, is T&RH important?
3. exposure : T& RH important
4. develop: T & RH NOT important
5. sealing: T&RH important.

Which step is environment important? temperature and RH? I am guessing exposure and sealing? What is your opinion?
Is 21C/50% good number? or 24/60% ?

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