Third try, dip-n-shoot DCG

manalokos · Post by **manalokos** » Fri Mar 05, 2010 5:38 am

Hello all,

Here is one "sucessfull" hologram finally,
done with the 215 30mw.

I had a lot of trouble because I was not drying the plates properly... (newbie's impatience)! =)
o I got many plates totally white. Today I bought a tiny oven following Dave's advice.
And things worked much better! I also had a lot of crystal problems...

I still have much trouble keeping the hologram from vanishing, I guess, would
it be the high humidity in a house, in a country where it has been raining non stop, for 4 months?
Usually the hologram looses it's diffraction in a couple of hours...

Thanks
Best regards
Filipe Alves

JohnFP · Post by **JohnFP** » Fri Mar 05, 2010 1:52 pm

Are you blow drying with a hair dryer very hot, on high, very close to emulsion and for a good while (for a 4x5... like 3 - 5 minutes)? The hologram will disapear after a while in high humidity, but i have had hologram in a high humidy environment (baltimore maryland in the middle of the summer after a few days of rain) and it took weeks and weeks for the hologram to disapear.

emf · Post by **emf** » Fri Mar 05, 2010 5:50 pm

I don't know what explains it, but I had similar problems with my early attempts at DCG. I was getting very dim holograms to start with, and within an hour or so there would be a noticable dimming and shift towards blue. By the next morning, it would be a deep blue and barely visible, so I took to making sure I had the cover plates and epoxy ready so I could seal it immediately after blow-drying. After I started getting brighter holograms, they stopped disappearing. Now my unsealed holograms have stayed visible and reasonably bright for weeks or months. My drying regime has stayed the same throughout, hair-dryer for a timed 5 minutes for 3x3".

Dutchelm05 · Post by **Dutchelm05** » Fri Mar 05, 2010 6:05 pm

Any progress is good progess.

It appears the green hologram is due to a lack of chripping. Is your 100% IPA warm?
How long did this dry the film for for?
Is your RH in you room above 60%?
How long was your fix time?
I cannot tell if you film is clear or cloudy? If it is clear you may have fixed it too much.

Best of luck, you are closer then you think.
\Tony

manalokos · Post by **manalokos** » Sat Mar 06, 2010 2:13 am

Hi,

Thank you for your advice!

Dutchelm05 wrote: It appears the green hologram is due to a lack of chripping. Is your 100% IPA warm?

I don't know what colour should the hologram be, is there a way to control the color?
I use farmaceutical Isopropylic alchohol heat in the microwave until it boils,and pour it
directly on the surfact of the plate, after the water/fixer/cold 50% IPA.

I keep getting milky results, so I have to focus on the emulsion, and to find a way
to get the humidity down, yesterday there was condensation on the windows, so
it must be very humid inside...

I reprocessed the coin hologram and sealed it with epoxy all over the surface,
and it seems that is not disappearing anymore. It is easier than I thought to seal the holograms.

Dutchelm05 · Post by **Dutchelm05** » Sat Mar 06, 2010 6:17 am

manalokos wrote:I don't know what colour should the hologram be, is there a way to control the color?
I use farmaceutical Isopropylic alchohol heat in the microwave until it boils,and pour it
directly on the surfact of the plate, after the water/fixer/cold 50% IPA.

Gee please be careful with that IPA my friend, 40-50C is fine.
You may only be using 91% IPA if it is a store bought and may not shrink the film enough. John did some work on this and found it worked as well as 100% but it is something to consider.
If the humidity is as bad as you say, store your film in a desiccant container and allow that film to dry well. Too much heat and humidity can kill your film and you’ll get dim holograms. It is odd that you are getting green holograms and white cloudy. If your film is too old normally you’ll get clear dim green holograms. What kind of fixer are you using again?
Another unknown is the wavelength; I would be interested what the DCG gurus have to say about this. I wonder how much of a shift you can achieve. I wonder if you can get that big of a shift.
Lastly, if you wish, comment on the lower left hand corner of your middle photo. Is there any small section in which the hologram looks good? The corner (and maybe it is the photo) looks gold or red. Perhaps we need to look at your film thickness. Too thin and it will be narrow band, if the corners look good (hence thicker) it will be more broadband. You should get a metallic look if everything works out well.
I am not sure how the dip in shoot method works entirely, but perhaps you should check with Dave regarding how long the film drys for before shooting.
Oh and yes there are ways to shift wavelength, review the great holowiki discription on what moves the wavelength, it will show just how many things you need to control to get consitant results.
There are many things that can cause this problem, work with us and we’ll get you through this.
Best of luck and keep it going!
Tony

manalokos · Post by **manalokos** » Tue Mar 09, 2010 3:51 am

Thanks all for the good advice.

My plates have been aging with a decent dessicant in the dark box,
following Dave's advice I baked them after exposure, which really confuses me,
because taking out the moisture from the plate just before dipping into water
doesn't make much sense, but in fact works!

Finally I got some un-milky holograms and others not so unmilky, but with stronger colors,
I managed to get some more redish holograms, but the color depends on the point of view...

Here the best of the night.

The gears were quite risky to do, it is something left from a cucco clock, a wooden frame with metal structure inside holding gears,
I just placed the plate over some gears and it turned out there was no movement... 20 min exposure.

The coin was exposed for something like 10 min. it is a big silver portuguese coin from the begining of the republic.

The watch was made over 3 screws and is away 1.5 cm. the image got a little blured I don't know why...
It had 15 min exposure. for a plate with 1.6cm. by 4 cm...

They are all very tiny plates cut from bad parts a batch, so now I know I can use the batch to make some bigger ones,
the laser cone was big enough for a 6x6cm plate so I can keep exposure times!

Best regards
Filipe Alves

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