Color shifting

[Tony]

First off many thanks to those for getting this forum back up and running.
And deepest appreciation to Colin for his time and effort over the years!!

Now let's try this baby out

I have been playing with shifting to red holograms this last weekend. I have not yet been able to get past orange yellow.

I am using less AmDi and I also increased the angle a bit.

Is there anything else I can do?

Many thanks,
Tony

[a_k]

Hello Tony

Factors in favour of red shift are:

- Composition of the film, less Amdi means redder results. Rallison's recipe for red holograms is: 3-30-200 (AmDi-gelatin-water)

- Light exposure: less light -> more red

- Composition of the first alcohol bath (ratio of alcohol : water) determines the direction of the colour shift, the amount of time in this bath the amount of shift.

Ahmet

[Joe Farina]

Hi Tony. I'm guessing that you're not using the succinic acid method that you developed earlier. Is there a problem with it? By the way, I was careful to make hard copies of your notes on this subject from the old forum.

[Tony]

Hi Guys,

Thanks for the replies.

Ahmet, can you tell me what that first bath should be. I have been using 50/50 as to keep it semi narrowband follow by a 70/30 and a dirty IPA.

Hey Joe, yes I still have those chems and have thought about using them. But I have some old Rollison (or at least his company's) DCGs and they had some really nice orange and red shifted holograms. I decided to see if I could do it. I mixed up a plate with pretty close to the formula that Ahmet refered to and they came out barely orange. Hence I'm here picking some brains.

Does the exposure angle need to change? I know Dave did this on his great three color mask holograms.

Thanks again

[a_k]

Hello Tony

I would try 60% or more IPA as the first alcohol bath. With 60% the result should still be quite narrow band. If the red shift is not sufficient, i would reprocess and leave the plate longer in the first bath. Btw., Rallison's paper about DCG processing contains useful information about colour tuning.

Ahmet

[holomaker]

Is there anything else I can do?

Many thanks,
Tony

Exaggerate the red reference beam (multi-color dcg), as your holograms are coming in orange, you are almost there now.

[holomaker]

Is there anything else I can do?

Many thanks,
Tony

Exaggerate the red reference beam (multi-color dcg), as your holograms are coming in orange, you are almost there now.

Sorry about that !

Exaggerate the red reference angle (multi-color dcg), as your holograms are coming in orange, you are almost there now

[Tony]

Thank you agin.

So some of the Rollison DCG holograms I have are two color (some are more). For example, a grim reaper figure has a green head with red eyes. I am thinking it is two holograms glued together.

So if the green head let's say is shot at one reference angle and the red eyes at another, would you expect them to both be visible or equally bright at the same time? Meaning as I tilt the hologram would I not see the face bright at one angle then as I tilt the plate the eyes get brighter while the face gets dimmer?

Or is the light source I am using (hologen lamp) radiate at so many angles, it does not matter?

It is amazing these are from the 1980's and they are still very bright and as good as any DCG I have seen (with the exception of August Muth). Funny even after 30 years we have not been able to improve much from what the Rollison guys did.

Peace
Tony

[holomaker]

i want to post this to show you Tony the "red" is not that really red after all ...........

[Tony]

When I look at these there is no question that they are red.
As I tilt the hologram the red and the green background move together.
I would venture to say the ang;e in which they were shot were the same.
Am I missing something?