Bionically tinting B&W film for infrared

[joho]

Bionically tinting B&W film for infrared response to light with [chemi]** of plants.

I tried to tint normal Fomapan 200 sheetfilm with red beet chemos**-- used as wet plates to expose with Kenko R-72 filter and got a faint image???

anyone tried this ???

**the residue of the boiling of the red beet.

 

[koraks]

Sounds interesting. Did you compare with an untreated sheet? I'm kind of skeptical that it was the beet juice that did the trick. I suspect you're just seeing the effect of the trailing end of the spectral sensitivity of the film hit the trailing end of the filter transmission curve.

 

[joho]

Koraks, interesting is not the word. more later.
The kenko R-72 lets no visible range of wavelengths to which the eye is sensitive or normal film!!
On a project with a 6x6cm pinhole I had tried the R-72 on one roll 120 Foma 100asa with no image at all !!! not even a shadow mark of the 6x6 frame ? and with E_I_ 189sec exposure
-Here the use of a R-29 with filter factors in use at E_I_60sec exposure on the same roll came out great...

Please Note
E_I_was 1/60sec && 1/120sec NO filter factor in use !! and the film shows the clear the film holders with some light that has registered beyond - where there is bubbles from the beet, wet part of the plate we see the bubbles formation light imprint !!! !!!
developed on R09 1to 5 parts 30 Celsius 7 min

 

[koraks]

I'm still skeptical lacking a proper side by side comparison.
Whatever sensitization you're seeing may still as well be chemical fogging due to trace amounts of reducing agents present in beet juice.

 

[fgorga]

I am not entirely clear on what you have tried. I think that you dipped a sheet of film into an extract of beets and exposed this film while still wet through an R-72 filter. Is this correct?

If so, I would not expect that the beet juice will have any effect at all.

According to this reference (https://www.researchgate.net/figure...extracts-left-and-the-red-beet_fig3_230649504, the left hand graph is the relevant one), the only portion of the spectrum where beet pigments absorb light is in the area where the R-72 filter has already removed all of the light.

In other words, beet juice is red because it absorbs more-or-less the same wavelengths as the deep red R-72 filter. Since the filter is very efficient, there is no 'extra' light for the beet juice to absorb after the light has passed through the R-72 filter.

Additionally, your understanding of the R-72 filter is not entirely correct. R-72 filters have a very sharp transition between 740 nm and 760 nm. Thus, while no light below 740 nm is transmitted, there is some light transmitted between 740 and 760 nm. This light is certainly able to expose typical film. This is what @koraks is talking about in his statment about "trailing ends".

 

[Wolfram Malukker]

Also, Fomapan 200 is decently sensitive to near IR as is.

 

[JensH]

Hi,

hmm, as I understand it, to increase ir response of a film you would need a dye absorbing in the ir range.
So not a red dye but something greenish?

Jens

 

[Romanko]

I am completely lost as what you are trying to achieve here.

You can mix beetroot juice with vitamin C and washing soda to get a developer. Spinach and other vegetables and herbs were reported to work as well. And so is beer and wine. But why?

 

[joho]

fgorga
I am not entirely clear on what you have tried. I think that you dipped a sheet of film into an extract of beets and exposed this film while still wet through an R-72 filter. Is this correct? ----Yes
beet juice is red because it absorbs more-or-less the same wavelengths as the deep red R-72 filter. Since the filter is very efficient, there is no 'extra' light for the beet juice to absorb -----That was the experiment for the R-72 filter ----Some light came through SO what light was it ?????
no light below 740 nm is transmitted---------------------------------------------------------------------------------------------------------------------------------------------------------------------------Some light came through SO what light was it ?????
JansH
to increase ir response of a film you would need a dye absorbing in the ir range,not red dye but something greenish?-------------------------------------------------------------------------------That is part of the experiment. seeing if the red will transmit IR ?? of not ???
Romanko
You can mix beetroot juice with vitamin C and washing soda to get a developer,--------------------------------------------------------------------------------------------------------------------------Soooo did the beetroot help in the image developing [?]/have to try Spinach and other vegetables and herbs were - -reported to work as well
But why?----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Why Not!!!
Wolfram Malukker
Fomapan 200 is decently sensitive to near IR as is -----------------------------------------------------------------------------------------------------------------------------------------------------------R-72 _will not let it pick up an image. But ok for R-29 .....But Not R-72...
Koraks
Did you compare with an untreated sheet?--------------------------------------------------------------------------------------------------------------------------------------------------------------------a privious test was done R-29 ok! and then with filter R-72 no image !!

 

[koraks]

Some light came through SO what light was it ?????

I've told you before, so has @fgorga. Filters aren't perfect. Spectral sensitivity of film may also not be as clear-cut as the datasheet suggests.

This diagram shows the transmission of a Hoya R-72 filter (taken from here)
Overlayed in black is the spectral sensitivity as taken from the Fomapan 200 datasheet.

As you can see there's a small part of the spectrum between 700-720nm where the film has some trailing sensitivity and the filter passes some light. This is most likely the exposure that you're seeing.

I also mentioned before that a proper A/B test would tell you a little bit about what the beet root juice does. You mentioned having tested with Fomapan 100 and the IR filter, but if you look at the spectral sensitivity of Fomapan 100 and compare it to 200, you'll notice that there's a very significant difference especially in this regard:

Cyan = spectral sensitivity of Fomapan 200
Magenta = the same for Fomapan 100.

Evidently, the reason why you were getting a better image with the beetroot-treated Fomapan 200 than on the untreated Fomapan 100 is because the 200 had some trailing IR sensitivity to begin with. You could only conclude that the beetroot juice at least did not entirely remove this sensitivity.
Do the same test again, but now with two sheets of Fomapan 200: one treated, one untreated with beetroot juice. Expose and process identically. Then report back and let's see what you've got.

to increase ir response of a film you would need a dye absorbing in the ir range,not red dye but something greenish?-------------------------------------------------------------------------------That is part of the experiment. seeing if the red will transmit IR ?? of not ???

You don't seem to understand. In order to sensitize a silver halide to a certain frequency by adsorbing a dye to it, this dye will have to be able to absorb that frequency to begin with. It turns out that beetroot juice actually does not absorb IR by itself:

If you look at the source I took this from, you can see that absorption to a titanium-oxide photo anode does give some promising results. However, it's very far-fetched indeed to assume something similar would happen with beetroot juice adsorbing to silver halide grains.

So far, I'm afraid you're still at the "clutching at beets" stage. There needs to be a little more method to the madness in order for it to start making sense.

 

[joho]

Koraks
Thank you for the info !
and to all the response thanks!!!
the whole idea is [was] a what if ??? experiment. I will try it again, just have to find more beetroots.
P.S.
madness in order, dose not have to make sense.

 

[koraks]

just have to find more beetroots.

Shouldn't be too difficult. Coincidentally they're on sale in my local supermarket at the moment. We had beetroot salad yesterday.

the whole idea is [was] a what if ??? experiment.

Those are nice, but they're even more fun if there's a reasoning behind them. A good experiment starts with a theoretical expectation/hypothesis.
Throwing random stuff together is also nice of course, but most of the time it doesn't really do anything. I think that's what we're seeing here.

 

[joho]

Koraks,
“A good experiment starts with a theoretical expectation/hypothesis” —-I am well aware of it.

It started out of pure curiosity, I was using the boiled beetroot for color tint in my art. And a thought came to mind,[fuzzy Logic] as to infrared … What if…?? the idea from plants and like..having done some studies on this theme,
— I could give examples but you just deride.

Seeing as you take every thing Literally … with little humour.

 

[Romanko]

Thank you for the clarifications. It makes perfect sense now (when I stopped trying to find any sense in what we are doing).

May I suggest a correction to the title? It should probably be "botanically" rather than "bionically".

How about this? Make clear beetroot juice, pour it in a clear container and place it in front of your camera to act as a filter. Play with the concentration so that it is not too opaque. Shoot your black-and-white film through this filter and develop it in beetroot developer. Print the negative using a wet process and tint it with beetroot juice.

Serve chilled beetroot juice to the viewers of your photograph.

I vaguely remember that you need to add either acid (lemon juice) or an alkali (soda) to prevent oxidation (discoloration) of beetroot. Refer to your favourite cookbook for instructions.

 

[joho]

Next up, tomato juice & vodka. and if that does not work -well, just drink the developer.
cheers...