View Full Version : I don't understand Rodinol...
barnacle
6-Jul-2016, 12:29
When I develop Adox, the pre-dev wash comes out deep blue and the developer comes out red.
When I develop Agfa Green x-ray, the wash comes out pink and the developer comes out blue.
The Agfa film is pink before exposure and blue after it's developed...
I'm sure it's doing it just to annoy me!
Neil
Jac@stafford.net
6-Jul-2016, 13:16
This will seem counter-intuitive, but after a post-fixing rinse put it back into any developer, agitate well and wash. The tint left on the film should be gone.
X-Ray film?
Is different.
tmax - the developer looks like grape rush when you dump it out
I told my kid I develop film in grape crush and showed he when I dumped it out
she didn't buy it..but she knew to be wary of what I said by age 3
FredrickSummers
6-Jul-2016, 14:19
tmax - the developer looks like grape rush when you dump it out
I told my kid I develop film in grape crush and showed he when I dumped it out
she didn't buy it..but she knew to be wary of what I said by age 3
I think that's a Kodak thing. The Ektar and portra I have done c-41 all come out with the same color from the presoak.
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Bruce Watson
6-Jul-2016, 16:01
When I develop Adox, the pre-dev wash comes out deep blue and the developer comes out red.
When I develop Agfa Green x-ray, the wash comes out pink and the developer comes out blue.
The Agfa film is pink before exposure and blue after it's developed...
Mostly these are the sensitizing dyes. It's how you turn an orthochromatic emulsion into a panchromatic emulsion (https://en.wikipedia.org/wiki/Panchromatic_film).
If you do a prewash, it will carry a bunch of sensitizing dye with it when you pour it out. And you haven't even started to develop the film yet. When I do this with TMY-2, I get purple. At the end of processing the film is usually slightly purple-pink.
The color is basically meaningless. If you don't like your film color when you're done, give the film a few minutes in sunlight. The UV will generally kill off the color for you. But it's not necessary. You can print right through it in the darkroom (has no effect on the print). Similarly, you can scan right through it.
The color is basically meaningless. If you don't like your film color when you're done, give the film a few minutes in sunlight. The UV will generally kill off the color for you. But it's not necessary. You can print right through it in the darkroom (has no effect on the print). Similarly, you can scan right through it.
So it doesn't affect variable contrast paper?
Jim Noel
6-Jul-2016, 17:48
Mostly these are the sensitizing dyes. It's how you turn an orthochromatic emulsion into a panchromatic emulsion (https://en.wikipedia.org/wiki/Panchromatic_film).
If you do a prewash, it will carry a bunch of sensitizing dye with it when you pour it out. And you haven't even started to develop the film yet. When I do this with TMY-2, I get purple. At the end of processing the film is usually slightly purple-pink.
The color is basically meaningless. If you don't like your film color when you're done, give the film a few minutes in sunlight. The UV will generally kill off the color for you. But it's not necessary. You can print right through it in the darkroom (has no effect on the print). Similarly, you can scan right through it.
More likely the anti-halation backing in the pre-wash, and possibly that plus some sensitizing dye in the developer and afterward.
barnacle
6-Jul-2016, 22:40
The blue from Adox wash is the anti-halation layer; I've seen it still there on odd occasions when I've had a film stick to the bottom of the tray.
The blue on the x-ray looks to be part of the film substrate; it's constant irrespective of development times etc, completely uniform. Though no problem to scan through.
And I suspect that Bruce is right regarding sensitizing dyes; no reason for them to be the same colour between films or even at different stages in processing. The x-ray film is of course coated on both sides, so you can't see the substrate without removing some emulsion.
Neil
The blue on the x-ray looks to be part of the film substrate; it's constant irrespective of development times etc, completely uniform.
All x-ray film, AFAIK, is on a blue polyester substrate.
All x-ray film, AFAIK, is on a blue polyester substrate.
I think it started out as normal film on a clear base, but blue was chosen to ease eye strain for Medical types gazing at very important detail all day on bright light boxes.
It will not wash out, hence my earlier comment, 'X-Ray is different!"
StoneNYC
7-Jul-2016, 15:34
It's just the anti halation backing coming out... Some films have them, some don't, if you don't pre-wash long enough or dump and fill enough times with a few pre wash water bath then you're going to get different colors from different films, it's not any of the developers Rodinal or any other, it's the anti halation backing differences between films.
Jim Noel
7-Jul-2016, 15:37
The blue from Adox wash is the anti-halation layer; I've seen it still there on odd occasions when I've had a film stick to the bottom of the tray.
The blue on the x-ray looks to be part of the film substrate; it's constant irrespective of development times etc, completely uniform. Though no problem to scan through.
And I suspect that Bruce is right regarding sensitizing dyes; no reason for them to be the same colour between films or even at different stages in processing. The x-ray film is of course coated on both sides, so you can't see the substrate without removing some emulsion.
Neil
Not all x-ray film is coated on both sides. The film designed for mammography is usually single sided.
Bruce Watson
8-Jul-2016, 09:15
So it doesn't affect variable contrast paper?
When I called Kodak and asked that very question, they said no.
Rod Klukas
14-Feb-2020, 11:07
Just a late added note-I did not see anyone using a wash aid such as Edwin 4in1, Heico Permawash, or Orbit bath. Those are the ones I like in order. After fixing, I used to do a rinse of the sheet film basically in and out of water. Next into the wash aid for the time required and into the regular wash. Always clean negs with Tri-X and Tmax, and also Ilford Fp4, Hp5, for my many students and myself.
Hope this is helpful.
Louis Pacilla
14-Feb-2020, 11:31
Just a late added note-I did not see anyone using a wash aid such as Edwin 4in1, Heico Permawash, or Orbit bath. Those are the ones I like in order. After fixing, I used to do a rinse of the sheet film basically in and out of water. Next into the wash aid for the time required and into the regular wash. Always clean negs with Tri-X and Tmax, and also Ilford Fp4, Hp5, for my many students and myself.
Hope this is helpful.
Me Too Rod. I've always been a Heico Perma Wash guy. I would not feel comfortable with even an extended straight water wash (not saying that straight water wash won't get it done It's just my personal habits as I was introduced to wash aids by my 1st mentor 30+ years) . I use Perma Wash with film and prints and in particular when rinsing FB prints. Plus it cut WAY down on water usage.
Bertha DeCool
14-Feb-2020, 12:00
So it doesn't affect variable contrast paper?
Seems to me the only potential effect on VC paper would be if the color was a variation of magenta.
Yes it does... The contrast layer on MG is blue sensitive, so this allows more blue... (Magenta has blue in it, so adding it cuts green, but adds blue...)
X-ray prints contrasty for many users of MG due to blue base...
Early Tmax RF had a built in contrast filter for Kodak VC papers for it's screwy grade 2 3/4(ish) required filter to print normal... (The Kodak rep told me so in person when he came to the pro lab and I asked about it... ;-)
Steve K
It's just the anti halation backing coming out... Some films have them, some don't, if you don't pre-wash long enough or dump and fill enough times with a few pre wash water bath then you're going to get different colors from different films, it's not any of the developers Rodinal or any other, it's the anti halation backing differences between films.
Only Ektascan & other single-emulsion x-ray films have anti-halation backing. And they are all on blue polyester substrates.
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