Adventures in enlarging negative by reversal

[Raphael]

Adventures in enlarging negative by reversal
============================================

Hi all,

I procrastinate this for months, even years, and profited of the last holidays to bit the bullet and give it a try.

So, I tried to get first as much inputs as I could, on APUG forums or not, but my direction of work comes mainly from Liam Lawless' article, which can be found in PDF here (there was a url link here which no longer exists)


I was stockpiling required chemicals since a long time, and I have a box of Macophot Ortho sheet-film handy, in an odd size 8x10cm (not inches !), but it was perfect for testing.

I describe here my experiences, in chronological order, with all the mistake I made. So, it's going to be long, sorry. The people which could be irritated by my inconsequent babbling and english mistakes can jump directly to the end (if ever interested ). Maybe the reversal subject was beaten to death, but I hope just this progression story along a learning curve will be useful for someone.



First day test :
****************

Okay, I just bought a few supplementary small trays in the local home depot store (intended for plaster or masonry), so let's start, following Liam Lawless guideline :

I prepared my processing chain as follow :

1st tray : First developer is, as read here on APUG, 300ml of Rodinal (or Fomadon R09 equivalent) in dilution 1+50

2nd tray : Stop bath, using acetic acid two time the usual concentration I use for paper of film (i.e 20ml of 60% Acid for 1l water)

3rd tray : Bleach, using the Permanganate version described by Lawless : 1L concentrate made with demineralized water, 50g Permanganate, and sulfuric acid (with 32% acid, diluted with appropriate amount to get the equivalent given by the recipe), this concentrate solution then diluted 1+9 with dem water before use.

4th tray : wash water

5th tray : Clearing bath, with 50g Sodium Metabisulfite disolved for 1L of water, putting a hundred of ml in the tray.

I started with no negative in the enlarger, just making a serie of strip exposure under enlarger lens.
Hmm, as this sheet film is supposed to be Orthochromatic, I can theorically work under safe red light, but... Wait, it's worth a test, and it's not too long to do, and let it a minute under red light before plunging it in dev.

Result : well, either this film is not really orthochromatic, or my safelight is too much powerful or not perfectly safe, unexposed part of sheet is showing slight fog in the developer.

So, it's better to proceed with first step in total darkness, or at least under a very dimmed redlight.

Then, making progressive exposures of a sheet under enlarger, with a black sheet of paper under, using both a very stopped down lens, and dimming the multigrade head lightflow.
Now in successive baths :
- 1st dev for about 5 minutes
- transfering sheet to Stop bath, waiting a few tens of secondes, lighting up the room (white light)
Hmmm, that's very dark, but that's expected.
- Putting it in dark soup of bleach bath : I shake the tray gently, and pull it up time to time to see what's happening. Strange, apart turning to gray, and the weird tint, that's doing no so much... at least after the time described by Lawless (1 minute), waiting a minute more. What I'm supposed to see ? I understand that the neg should going white, but when ?
Okay, the time specified is passed for long, I'm afraid to mess it completely, so, now, I pull it from Bleach to put in wash bath... Changing water a few times to remove the purple.

- now, in the clearing bath ; hurrah, sheet is whitening !! Waiting 3 minutes, still shaking slightly the tray, as specified.

- a quick rinse under the tap, and now, back in first tray for second development.

- the sheet I put in start going grey... then black... starting from edges. I shaked gently the tray to ease the process, and... emulsion started to desintegrate.. and accelerating as it was striked by Daleks' death ray or something !!!

I took it quickly to a wash tray... but too late, I finished with a total mess of emulsion goo and fully transparent base sheets of film... The three sheets I tried to reverse this night ended up with the same fate. I believed first that the culprit was insufficiant bleaching, so I prolonged the bleaching a few minute more... Disintegration of this last, in second dev, was even quickier than the others !

Okay, it's now 3am, and I'll have to work tomorrow, so I think it's time to put an end to the battle.
But I don't think that all this night session was lost, as I also determined the correct base exposure for an actual neg, with making test strip, bringing it just through the first development stage.

So, all wasn't lost, and some others hints learned :
- use of print tong, even only for the first dev, is a waaaay less pratical than just using gloved hand.
- a cool way of exposing the sheet film, and keeping it flat is using a sheet film holder (a 4x5" is a cool fit for my 10cm long sheet). However, holder's borders
will be visible on final enlarged negative.
- permanganate bleach *stains hands*, and this is somewhat durable ! Wasn't careful enough using latex gloves...
- Sodium metabisulfite...well, it smells strong !



Second Test Day :
*****************

Well, as a debriefing, time to browse, read, and re-read all online documentation to understand what I done wrong.
Amongst other, I read a lot of APUG threads, and there is a consensus around two points, related to reversal and
emulsion peeling off :
- Permanganate bleach is generally used with 2g/L concentration *max*, often 1g/L
- Process temperature should be cool, well under 20°c

I obviously failed for these two points :
- my darkroom is in the basement, rather cold in winter, and I use generally an homemade tray warmer for paper developer, and a Kaiser one for fixer. I used the last for bleach bath, but at low heath. Maybe the second developer bath was too hot for a fragilized emulsion.
- With the formula given by Lawless, with a dilution 1+9, if I understand well I'm at 5g/L
Rather making again the Bleach from bulk chemical (Permanganate is hard to get, and don't want to spill it), I decided to dilute 5 times the 1+9 working solution (I call it dilution I), adding 325ml demineralized water to 100 ml of dilution I. To keep acid proportion, I added 75ml of 32% Sulfuric acid.

Working in IT, I should have abide to the unofficial law of problem solving : NEVER change two parameters at once ! But time to time, there is the exeption to the rule : when in hurry, change anything you can, in order to get it working, you will narrow the solution later...

Let's go for another session :

Setup :
-------
1st tray: First developer is Paper developer Tetenal (in dilution 1+9) : another departure from the first session's basics,
but with tray warmer greatly reduced (18°C approx)
2nd Tray : no change
3rd tray : Bleach, but with Dilution II, as stated above, i.e. 1g/L of Potassium Permanaganate (no warmer eiter, ambiant temp).
4th tray : wash water as previously
5th tray : fresh clear bath, unchanged

I added a 6th tray, with same Paper developper as in #1, at ambiant temp, just in case peeling off was caused by thermal shock the other day...

Testing sheets film exposed with a real negative this time, with the exposure determined with my setup the other day : Tbase=10s at f/11.

I used a Fidelity holder for exposing the sheet, and checked focus with a focus magnifier upon a previous test sheet. As a copy source, I choose, rather arbitrarly, a shot on Kentmere 400 35mm film.

Now, First test : exposure (no Flash exposure for the first) 1st dev (in complete darkness), stop bath for 60s, transfering it in bleach (lighting up)
Okay, shaking gently, removing the sheet from cold bleach with handed glove time to time : the sheet is turning paler, becaming grayish.
Waiting the advised time, and transfering to wash bath. I decided to change the water bath a few time, before clearing. Waiting 3 min while shaking the tray gently.

It's all white... Now, after a quick wash under the tap, with an agonizing feeling of suspense, in the 2nd developer tray (#6).
Sheet film is darkening, blackening... waiting very looong minutes... And it's not peeling off !!! Hurrah !!!!

Made several other tests this night, but adding a flash exposure, well, the emulsion peeling seems to be tamed...However, I haven't any enlarged negative to show either, rather a pile of less or more dark greyish sheet films.

Wee... A little discouraged, now. What and when I made wrong ???

A few days later, debriefing the session :

Giving the processed sheets another looks,in some case, the grey seems to be even darker, nearly opaque : there is something like solid black on sheet back.

Was the Flash exposure too short ? Is chemicals suffer from exhaustion of some sort ?
Another point I maybe passed over too quickly : after bleaching wash : In Lawless' document,
he advises several minutes washing before clearing, thing I haven't done.

Third Test Day
**************

A few changes from the last day chemical trays setup :

Excepted the fresh developer (Variospeed W again) in 1st dev tray, and fresh bleach (in dilution II, again) in 3rd.
As temperature issue seems to be cleared, I planned to use the first tray for redevelopment.

The first process stages as usual :
1st dev, stop bath

Now the bleaching, with constant agitation with a gloved hand of the sheet film, and monitoring progress...
This is where I discovered that previously, when checking progress, stupidly, I didn't checked the *BACK* of the sheet film, where the image is still showing in dark grey...

So, now, I'm agitating the film until even the back of film is bleached. It brings my current bleach dilution time around 4 min, more than expected.

Another change : I washed the sheet film on continuous tap water during a few minutes before clearing.

Clearing for the Lawless recommended time, three minutes.

I recognize now that, during my previous tests, I wasn't very careful with respecting this time, some sheets rested a few minutes more in clearing bath. AS I read somewhere, Metabisulfite is a silver solvent, and silver image can be attacked if resting too long. Maybe that's explaining what I obtained on certain sheets.

- A quick rinse under the tap, and now, back in the 1st developer.
Sheet is turning grey, darkening from the edge to the center. I'm slightly rocking the tray, until completion. Still no peeling off, thanksfully.

At first glance, after 5 minutes, in the tray, it seems a sheet of the same solid grey I got on Day 2. But when I took it to see the light through...

I see... a negative... in big !!! Hurrah !!!

Here are the results :

Left sheet is a test while increasing exposure strips, both with base exposure and flash exposure.
It moved slightly during successive base exposures, hence the obvious blurring.

So, finally I got something which looks like a negative, probably too dense for using in alt-process, but that's a begining, and probably a matter of tuning Base exposure and flash exposure.

To be continued...

 

[Molli]

Thank you for taking the time to write up your process in full. I must say, you're a very patient being. I'm certain I'd have been discouraged and called it quits well before getting any results. You are very persistent!
Like you, I am guilty of changing many parameters at once when experimenting. You did really well to so quickly identify and fix the problems you were having. These are very encouraging results and you've provided a wealth of useful information for those of us interested in making enlarged negatives in the darkroom.
Thank you again for taking the time to write up your progress in detail.

 

[jvo]

Raphael, I sure hope someone versed in the reversal process responds and comments - with all the darkroom time, and documetation, I want to see how this ends!!!

 

[SMBooth]

Try this as a basis.

 

[MartinP]

Regarding use of latex gloves -- they are certainly water-resistant, but not necessarily proof against darkroom chemicals as these slowly absorb through the glove. I suggest that you find some nitrile gloves, sold as 'nitrile examination gloves', from a pharmacist. They are stretchy so, if you prefer a non-stretchy type of glove, look for thin PVC safety gloves from a chemical-safety materials supplier. Always check that the class of protection is appropriate for the substances you will be handling.

 

[Raphael]

Hi all,

@Molli , @jvo , @all, many thanks for your interest, kind words and encouragement.

Shane (@SMBooth), many thanks also for this document, I didn't know it. I will study it more closely to pick guideline and hints. However, as many, it uses Potassium Dichromate as bleach bath. It seems to be the "royal" way in this process. However I choose (maybe I'm a little stubborn, here ) the Permanganate bath, not only for less toxicity, but mainly because Dichromate is harder and harder to get here (I have it handy, but only a small 30g - I wish to keep it for alt process where it's not replaceable). It seems also, maybe it's a false impression, permanganate bleach way are a little less documented around the net. I'm not afraid of experimenting !!!

@MartinP : you are absolutely right. I had latex gloves handy but wasn't confident with it, especially while handling acids. Since theses first days, I switched to blue nitrile gloves.

BTW, since I started to wrote the first post of thread, I made further progress in my process, I need to write it done.

So, stay tuned

 

[Raphael]

Adventures in enlarging negatives, (Episode II)
====================================

Well, it's time to tell the next episode (yeah, that's rather pretentious) of the story.

As I supposed earlier, the enlarged negative I got has too much density to be usable for cyanotype.
I can scan it, even do a contact print with it, but I got a blank square on sensitized paper when exposing through a reasonable amount of time (with a BL exposing box)

During the following days (or nights in the darkroom), I perfected the workflow, trying to change
a few parameters at once.

For example, I read that original negative with a weak contrast aren't advised for. The first negative I tried, is indeed, not very contrasty. So, I tested different source negatives, you can see a few sample of the results here :

Process seems now to be well driven, however, I still get too dense negatives for alt-process.
I tried to change a few parameters :

- I introduced a plain water tray, for prewet, before first development. I let in sheets two minutes with sporadic agitation. No impact intended on density, rather about even development.

- Next, I changed Developer, from Variospeed W to Eukobrom (still Tetenal). I read that warmtone developer aren't advised for this process, don't know exactly why.

I noticed that the change affected general tonality, which is rather sepia with Variospeed (that's somewhat good logic...), to more neutral. However I cannot say that's actually affecting density or not...


Another question I raised to myself is about the Ortho film I used until now. I bought the box long ago (it has an expiry date of 2009), and it was stored in coolness, but not into the fridge.

So, how a certain amount of "aging" fog renders when reversing negative through this process ?
I would guess intuitively that it induces a less dense negative, but is this right ?

Then, the thought came to me that I have indeed another Ortho film in stock, hopefully fresher. I bought a few weeks ago a box of Wephota F05 film, in 4x5, just by the sake of curiosity rather on purpose. Not much technical data are provided, I only know it's orthochromatic.

Let's start exposing a test view with this. I loaded a Fidelity holder with one sheet, and exposed the same time I already used for the Maco Ortho. Now, handling a 4x5" sheet through the different trays, first in total darkness, is not a common thing, even it's still a "small" format. The sheets seems heavy, slippery and fragile. I truly got the feeling things are going serious !

With the same exposure time, I got a nice, rather detailed negative, in 4x5", but still too dense.

After a few days, I decided to "print" another test sheet, with a few secondes increase of Flash exposure. I loaded the holder, exposed it, put it in pre-wet bath, and... What the heck ??? Why this sheet seems a lot more physically thinner than the first time ??? And more and more strange, later in the process, sheet is almost completely blank when in bleaching bath... It turn almost completely black, after 2nd development. So logic ! Since first 4x5" try, I only slightly increased flash exposure. The completely black sheet result means that it was very under-exposed. I was going to bed completely puzzled, and wasn't able to find a plausible explanation the following day.

First possibility that came to mind, I loaded two sheets sticked together in the holder the first time. But, then, why the second attempt seems a way lot less exposed ???


In the evening, I decided to look carefully to two sheets of resulting negs side to side. Ahem...It hits me in the eye : outside the thickness, notch codes aren't the same, that obviously not the same film !

The revelation stroke me : I mixed boxes of films when loading my first 4x5" sheet in holder. On my lab bench I have also an opened box of Kodak Portra 160 VC color film. In total darkness, I mixed the boxes, and I loaded the holder with a color film instead of an Ortho one ! Stupid me ! I confirmed the culprit looking at a color negative I had.

Still no exploitable negative for alt process, but I demonstrated at least one thing, by accident : it's possible to use color negative film to enlarge a B&W negative I understand roughly why, as color films are indeed on a B&W basis, but what about the pigments ? But maybe one of our photochemical experts would add further explanation.

Thanks for reading until here

To be continued...

 

[LAG]

So, how a certain amount of "aging" fog renders when reversing negative through this process ?
I would guess intuitively that it induces a less dense negative, but is this right ?

Not enough to be worried about! But of course, as you said above, it'd be much better to have all the parameters "as fresh" as possible.

it's possible to use color negative film to enlarge a B&W negative I understand roughly why, as color films are indeed on a B&W basis, but what about the pigments ?

Washed away!

As for the adventure: I can appreciate too many altered variables (some disorder to be honest) in your explanations, which makes the results so difficult for you to analyze, as you admit youself. As long as you do not have everything controlled, what I would do would be to stick to the smallest possible changes, and with the same and fresh (as much as possible) chemicals at least (In my case, the bleaching is with Potassium Dichromate) After the clearing bath I wash for at least 1 full minute with constant agitation. In fact, between developers (I do not use acid stop bath) all my (time+agitation) stages are the same (3+constant).

I agree with the glove tips and chemical precautions mentioned above

Thanks for sharing & congrats!
Best of luck!

 

[pdeeh]

Washed away!

Not sure what this is supposed to mean.
Colour film developed in black and white chemistry retains the couplers/DIRS even after fixing.
(The pigments are formed by the reaction of the oxidation products of the CD with the couplers/DIRS in normal colour developing.)
There are no pigments dyes "washed away" in any black & white process as they haven't been formed yet.
(it is possible to recover colour from colour negatives developed in black & white by means of a rehal bleach and redevelopment in a CD)

This is not really germane to Raphael's thread, but it's important not to let misleading information stand uncorrected.

 

[LAG]

...but it's important not to let misleading information stand uncorrected.

This is not a black & white "standard" chemical process, and there is no CD involved either.

 

[pdeeh]

I didn't say there was a cd involved, and this is a reversal process that utilises commonplace b&W processes.

I stand entirely by my comments: it is entirely incorrect to state "the pigments are washed away".

No pigments dyes are ever created in the process Raphael is pursuing.

 

[jeffreyg]

I can appreciate that you like to "experiment" and that finally reaching the goal is rewarding but for those who would just like to make an enlarged negative the analog way consider x-ray duplicating film. Simple chemistry and technique. I have used it to enlarge negatives for pt/pd printing. There is a short learning curve to get used to somewhat long exposure times and doing the opposite of positive printing when it comes to burning and dodging.

http://www.jeffreyglasser.com/

 

[LAG]

No pigments are even created.

I agree with this

 

[chrisaisenbrey]

Well indeed: one of the most challenging problems of subtractive color photography was to prevent the color couplers from washing away.

I’m enlarging negative by reversal with fomapan 200 and documol 1+4 as developer. This gives relatively hard negatives.

I wonder why you don’t like the dense enlarged negatives. It simply means longer exposure time for the final alternative process (Print trough the fog). I’m afraid that if you try to make less dense negatives you are using the toe of the characteristic curve.

I’ve attached the characteristic curve I’ve measured once for my film/developer combination.

 

[Raphael]

@chrisaisenbrey : Thanks for contributing It's interesting you used non Ortho film with good result !
About dense neg, that's not a matter of taste, I just cannot print cyanotypes with these too dense sheets without excessive long exposures. At least with my setup, either my emulsion isn't sensible enough or my UV box not enough powerful. I don't want exposing for more than 1 hour, but maybe I should persevere.

I'm interested in your characteristic curve. How did you draw it ? Have a you a densitometer, or had used a scanner ? I know there is a lot of ressource here on APUG or anywhere on the net, but I would appreciate a link to a simple, understandable website and method, if you have one.
@jeffreyg :Thanks. Use of X-ray film is in fact in my next test list, it will be described in a incoming post

As for the adventure: I can appreciate too many altered variables (some disorder to be honest) in your explanations, which makes the results so difficult for you to analyze, as you admit youself. As long as you do not have everything controlled, what I would do would be to stick to the smallest possible changes,

Hi LAG,
Many thanks for reading and comments. Yes, I'm somewhat a disorderly person (some people even think 'deranged'), however, maybe my perfectible English narration is more messy than reality

After a lot experimenting, I think I have now a stable, rather reproducible process. To summarize :
In total darkness :
1°) Base exposure of source negative onto enlarging sheet
2°) Flash exposure under enlarger, without negative in carrier.
3°) Prewet for 2minutes in plain water tray, sporadic agitation
4°) 1st developer (Tetenal Eukobrom 1+9), for 5 minutes. Continuous agitation of tray for 1st minute, 10s every minutes after that. Tray warmer around 20°C setting.
5°) Acid stop bath tray for 1 minute
Red light on (maybe unecessary), to check if all is OK, and for immersing the sheet in Bleach tray
White light on
6°) Bleach bath (Permanganate bleach, dilution II see episode I) to completion, while shaking the sheet with gloves. It takes from 2 to 4 minutes depending on exhaustion.
7°) Wash tray for a few tens of secondes, then throw tinted water and puting the ray under the tap (cold running water), for 5 minutes.
8°) Clearing bath, for 3 minutes, continuous agitation.
9°) A quick rinse under the cold water tap.
10°) 2nd development, back in tray of 4°) for 5 minutes
Wash as a print under running water or with frequent water bath change.
Then, I use a bath of Color E6 stabilizer, for 1 minute, before hanging the sheet for drying.

I'm currently writing another episode relating my last sessions, I will post it in the next days.
Thanks to all for you interest.

 

[chrisaisenbrey]

@chrisaisenbrey : Thanks for contributing It's interesting you used non Ortho film with good result !
About dense neg, that's not a matter of taste, I just cannot print cyanotypes with these too dense sheets without excessive long exposures. At least with my setup, either my emulsion isn't sensible enough or my UV box not enough powerful. I don't want exposing for more than 1 hour, but maybe I should persevere.

I'm interested in your characteristic curve. How did you draw it ? Have a you a densitometer, or had used a scanner ? I know there is a lot of ressource here on APUG or anywhere on the net, but I would appreciate a link to a simple, understandable website and method, if you have one.

Yes, I used a densitometer, but it also works with a scanner.

There is no big magic in creation of these curves:

First I enlarged a stouffer transmission step wedge, and simply measured the densities. That is the curve.

Before I got the densitometer I’ve used a scanner for density measurements. I used the transmission step wedge as a reference, but this is always some fiddling.

I know the problem of too dense negatives. I tried for some time to reduce the density with farmer, but the results were never even. At the end I’ve accepted the long exposure times. I’m in the range of 40 min for carbon printing.

Perhaps the silver solvents (Potassium thiocyanate or Hypo) used in the first developer in many description of the reversal process can reduce the density without reducing too much the contrast.

Btw, I’m trying to create color extracts from C41 films, so I need panchromatic film and very reproducible results. And I’m still fighting with some details. ;-)

 

[Raphael]

Adventures in enlarging negatives, (Episode III)
================================================

Holidays are supposed to be a time when you have a lot of for yourself, but the ones I was living last days aren't that way. Children are such a pest !!!!

So, I have however made progress since last episode, but didn't managed to write it down until now.

As I told earlier, i think I arrived to define a straight process, regarding its chemical steps.
However, I still had to find right exposures combinaison to get enough contrasty negative, but not too dense.

In the precedent épisode, I tried (and failed) with a different film, the Wephota Ortho WP05, because I confused film boxes. This incident indeed made me discover Wephota film is a lot less sensible than the (mistakenly) Kodak Portra 160 (this explained the greatly underexposed sheet), and from that, same thing in regard of Maco Ortho.

I had to adapt my exposure times for the Wephota 4x5" film. A lot less sensible film means also longer exposures time, and then a lot more exposure latitude and control, both in base and flash.

Base exposure guessing, as stated by Lawless, should be made by "printing" source negative on target sheet film, and after stop bath, then judging the right exposure with the positive image obtained. The choosen time should be factored 4x, less or more, depending the source negative contrast.

However, determining the right exposure from positive image after stop bath is rather hard, in regards of the black background of "print".

So, I decided to change my exposure determination method, using a Stouffer 21 step tablet. I exposed a sheet of film through the step tablet, for a guessed time, and process the sheet as usual.

I refined this time with a few more tests. The main difficulty is estimating if a negative got correct exposure while holding, a fresh, fully processed, wet sheet onto the light. Indeed, I discover that a negative can seem, at the first glance through the wet sheet, too thin, but come later as a suitable negative for cyanotype printing. And, maybe it's false impression, it seems going denser after washing+stabilizer.

Here is my first "exploitable" result, from, the shot #34 on 35mm negative.

Another point is, with my setup at least (light output of enlarger) , the relatively great impact of a small variation of exposure time (1 or 2 secondes) on contrast and printability of resulting negative.

Here you can see a few examples, will only a small variation, from 1s to 2s of flash exposure (two negatives from the lower row, they got same base exposure).

Well, it's time to show here what I got while cyanotyping.

Negative #1, 40min exposure on Canson Montval paper.

Negative #2, 40min exposure on Fabriano Aquarello :

This paper it's a first try for me. Obviously not the better paper for cyanotyping (blue is often turning pale/greyish after drying), but its mottling can offer interesting effects.
Thanks you for reading patiently until here

BTW, I'm currently working the next step for me : enlarged negatives on 13x18cm X-ray film !!!

See you soon !