Rose Bengal as a sensitizer?

[Nodda Duma]

I see little discussion about Rose Bengal as a sensitizer here. However, there is some discussion of it in photographic journals from the turn-of-the-century. It seems to provide for more orthochromatic sensitivity than does erythrosin. Is Rose Bengal a viable sensitizer? Why or why not?

 

[falotico]

Wall in "History of Three Color Photography" has a discussion of color-sensitizing gelatin emulsions. He mentions rose bengal, but says it is better at sensitizing to orange than red. The book is available online. Here is a link: https://archive.org/stream/historyofthreeco00ejwa#page/235/mode/1up/search/bengal

 

[Nodda Duma]

Okay. I understand it now. It sensitizes to orange. Thanks!

 

[Photo Engineer]

Give it a try. And you need a spectrosensitometer if you are going to do this stuff.

PE

 

[Nodda Duma]

Yes, I think so. And reading up on how to perform the measurements. Time to put my 50 free OSA articles / year to use!

 

[Photo Engineer]

We used Bausch and Lomb monocrhomaters and made quite good units. A stable uniform light source and you are all set.... Oh, you need an optical bench.

PE

 

[Nodda Duma]

We used Bausch and Lomb monocrhomaters and made quite good units. A stable uniform light source and you are all set.... Oh, you need an optical bench.

PE

My optical bench at the house is tied up with my interferometer and an MTF test station. Not sure why you'd need one in any case, unless there's some vibration-sensitive aspect of the alignment for the measurement?

 

[Photo Engineer]

If it is not constantly kept in alignment, the spectrum can shift slightly due to the offset.

I don't know how rigid it should be, but the ones I used were on a 2x3 ft plate of 1/2 inch steel.

PE

 

[Nodda Duma]

Gotcha. I kind of reasoned it out after asking the question. On the monochromators I've used in the past, the source was rigidly bolted to the monochromator assembly to maintain alignment. Hence my confusion. I don't recall the brand but it wasn't B&L. Maybe Lambda

 

[Photo Engineer]

I have a small hand held unit for viewing light sources that a friend gave me. It is quite handy and shows differences in light sources.

PE