Film Thickness

[dannybee]

If correctly coated my hologram would be gold colored, as it turns out it was gold on the thickest side, then green, then blue, then ultra blue and then clear ....

but doesn't this fly in the face of what I was orginally asking?
I have found the same thing only in how I watered down my formulation. The thicker version was indeed yellow while the thinner was green blue.

I could fix the heck out of it and barely shift it green. When I repocessed it shifted blue but was very dim

tony it depends what end your processing for thick end or thin end....and thats dependent on fixer and processing times... and ooo your mix too

[holomaker]

This is why i always preach (when i can ) about mold coating as its very easy to adjust/control thickness.......

Tony a possible reason for the dimness is there are layers that have shifted beyond blue .... (like over fixing)

[Tony]

Well if more water is added then the coating will dry thinner. Is this correct Tony?
After re-reading your question I think this agrees w/what you found

Yes exactly,
The orginal question was thick film results in narrow band while thinner was BB.
Your results indicate the opposite.
I found the same thing, I thicken up my film I observed more BB deeper yellow.
Adding more water (making the film thinner) I got a greener result that also was easier to reprocess to blue.

tony it depends what end your processing for thick end or thin end....and thats dependent on fixer and processing times... and ooo your mix too

yes true, I understand they are all linked. bath time bath temp etc.

But if you just look at Dave's results it would indicate thin film is narrower, assuming that gold yellow is a foam of BB.

[Tony]

Tony a possible reason for the dimness is there are layers that have shifted beyond blue .... (like over fixing

Very true Dave. When I reprocess from a very very bright yellow, it shifted too blue. So I added water to my reprocessing bath. It came out the correct angle but very dim.

I have seen bright yellow to green holos reprocess to narrow band the best but not in this case.

[holomaker]

Tony a possible reason for the dimness is there are layers that have shifted beyond blue .... (like over fixing

Very true Dave. When I reprocess from a very very bright yellow, it shifted too blue. So I added water to my reprocessing bath. It came out the correct angle but very dim.

I have seen bright yellow to green holos reprocess to narrow band the best but not in this case.

Reprocessing bath? Is that the first ALC bath? you can also start with a warm soapy bath to bring it back a little(works somtimes)

[Johnfp]

No, unfortunately I will not be going to the conference. You do not know how bad I wanted to meet everyone in person. Maybe another year.

[Tony]

Reprocessing bath? Is that the first ALC bath? you can also start with a warm soapy bath to bring it back a little(works somtimes)

Repossing is taking a hologram and shifting it blue. It's one of many ways of making a master.
The best way of coarse is when you can get the narrow band wavelength you want withour reprocessing.

I'm still not sure how thinkness plays a role.

[holomaker]

Repossing is taking a hologram and shifting it blue. It's one of many ways of making a master.
The best way of coarse is when you can get the narrow band wavelength you want withour reprocessing.

I'm still not sure how thinkness plays a role.

yes i know about the reprocessing part , but what bath did you add more water to? tha first ALC bath ?

Tony each layer is like a page in a book thin emultions has a few pages, thick has lots of pages. yes?

so its how each page is treated, BB hologram each page has a slightly different grating effect causing wide color range, NB hologram has a few pages all the same grating (replaying the same colors).

I know others have told me im wrong about this but i doubt it! They are not even sure about how the entire process works!

[Tony]

Sorry about the confusion Dave.
I add IPA to my reprossing bath only not my other baths.
I start with say 70% IPA if the imagine comes out on the green side, I add some IPA to shift it bluer. If it is too blue I add water. I think you taught me that.

Tony each layer is like a page in a book thin emultions has a few pages, thick has lots of pages. yes?

so its how each page is treated, BB hologram each page has a slightly different grating effect causing wide color range, NB hologram has a few pages all the same grating (replaying the same colors).

If I am reading this right then, then thinner films produce NB, while thick BB. This to me seems intuitive but I have heard the opposite.

[BobH]

In general, thicker material means narrower spectral bandwidth. That's true regardless of material. More thickness means more filtering. When the material is very thick, one might have the ability to chirp the fringes inside it by re-processing techniques like for DCG, but that's a different mechanism. No other recording materials offer the same manipulation.