Film exposed from base side -- development suggestions?

[Donald Qualls]

I discovered today that I exposed two sheets of old TXT through the base side, which I've understood will cost me about five stops.

Yes, I know, the sane thing to do would be to go back and reshoot (the scene is less than a block from home), but for my interest, in case this comes up again (as seems likely, given the frequency with with other LF shooters report similar errors), I'm wondering what I might be able to do to this poor, abused film to get whatever image might be there into the mid-tone densities.

Available to me, I have HC-110, Diafine, Dektol, coffee, vitamin C powder, hydroquinone, potassium iodide, sodium carbonate, borax, and ammonium hydroxide.

The best looking strategy I've found so far has been to dilute some Dektol 1+9, add enough HC-110 syrup to make it Dilution B equivalent, and add 4g/L of the vitamin C powder (plus a teaspoon per liter of sodium carbonate to counter the acidity of the vitamin C), then develop for fifteen minutes at 68 F; this should pull out everything that's in there (I think).

The other option I've considered is using HC-110 Dilution G and just putting the tube on the counter for about an hour, no agitation after the first minute, but this method doesn't have a reputation for increasing contrast in the low zones, so I don't think it's likely to gain much.

Since I have two sheets exposed identically, I'll at least get a second chance if the first is completely useless -- and no, I have no expectation of getting anything worth printing, I'm just interested, at this point, in seeing if I can get anything back from Zone 1.

Has anyone else recovered images from similarly underexposed film, possibly via seriously exotic treatments (latensification, peroxide vapor, perborate bath, etc.)? Latensification might be an option, if I can improvise a suitable light, and I can get 3% peroxide easily enough if peroxide vapor or perborate looks like the way to go, but all of those processes are said to be worth, at most, about one stop above a traditional push, and aren't reported as being additive.

I suppose there's also the possibility of bleaching (I can make a bleach; I have potassium ferricyanide solution for cyanotype) and redeveloping with coffee, possibly multiple times, to intensify the negative via staining (I have a coffee developer formula available that produces little if any general stain, but still some imagewise staining); hydroquinone can also be used to make a simple staining developer.

 

[noseoil]

Er, Donald, meaning no disrespect. I think your time might be better spent in re-shooting. If you have a five stop underexposure, I think there may be a bit too much contrast if there is an image which can print. You have effectively placed zone V on zone 0-I at best, so film speed is astronomical and results are questionable. By all means, have a go at it, but it seems the shot would be better served with a proper exposure. It would also be very time consuming, but who knows, it might work out well and make a decent print. tim

 

[David A. Goldfarb]

If this is just for the sake of experimentation, you could cut one sheet into strips to try a few different approaches, and if any of them work, use that for the other sheet.

 

[Soeren]

Next time, bracket five stops :rolleyes:
Søren

 

[titrisol]

Have you tried adding Vitamin C to your HC110?
This just might be a good chance to do that.

 

[Claire Senft]

If you want to try latensify a sheet and if being exposed from the backside is equal to 4-5 stops of light reduction...I do not know how much light reduction happens from being exposed thru the base but lets use that, then I would leave it in the holder with the base facing outward and place it 6 feet from a night llight with a 7 watt bulb which has a number 11 or 58 wratten filter over its face using black tape to seal off any light that leaks around the filter. I would expose 1 sheet this way for 30 minutes. Then I would develop it for 2-3 times as much you normally would have developed it if you had not made this mistake. If your darkroom room has flourescent lights make sure that they have been off for 15 minutes or more before starting the latensification. If flourescent lights are within a few feet of the film and have just been turned off before starting the latensification you may be getting more fog from the afterglow of the flourescent light than from the latensifying device.

Examine your negative. If the latensification has been nearly correct then the fb+f should be around perhaps twice of what would be normal. Because you have given the negative very vigorous development some of this will be chemical fog. Make your best guess on how to process the second sheet and give it a go.

Then I would recommend going back and rephotographing the same subject in similar light with 2 sheets of film. 1 sheet expose as you would normally.
I am guessing that you expose TXP at an EI of 200-250. Mark this holder so you know it has been normally exposed. Expose the second sheet at twice the manufactuers recommended film speed..640. Mark this holder.
When you get home latensify the sheet exposed at 640. Since your latensifying light is not being reduced by 4 -5 stops from passing thru the film base, expose and develop a sheet of film so that it has an overall density of approximately 1.5 or alternately move the latensifying light to a distance of 24 to 30 feet from the film. { DO NOT TRY REDUCING YOUR LATENSIFYING TIME BY A FACTOR OF 16 OR MORE. Latensification requires a minimum of 15 minutes to work. } Tape this in front of your latensifying light to simulate the
light reduction caused by passing thru the film base from the beginning example.

I believe that the latensified negative will have at least a good of shadow detail but will show less contrast that could have been restored by an approximate additional 10% of developing time.

So, if you do this you will have learned quite a bit and will have turned misfortune into knowledge.

I am wishing you good negatives.

Claire

 

[Donald Qualls]

Er, Donald, meaning no disrespect. I think your time might be better spent in re-shooting.

Oh, without question, in terms of getting the image to a print -- I can lug the bag and tripod back down there and reshoot in well under an hour, and probably will (if not today, then next week).

My interest was in what approach was most likely to yield a usable (or at least not completely blank) negative if this should occur again in the future with an image I can't easily reshoot.

Pablo, adding C to HC-110 is part of what I had planned as "best looking option" above -- mixing Dektol, HC-110, and vitamin C to make the "hottest" brew I've got the materials to make, and then let it soak as long as will do any good. Later post-process intensification is dependent on having *some* silver in the negative after the first process.

And no, I don't honestly expect to get much of anything useful out of Zone 0-I exposures; no pushing method I'm familiar with will gain more than about one stop in that exposure range, which would bring Zone I up to Zone II, and might do less than that for Zone 0 (which is, by definition, indistinguishable from the background fog). It's just an experiment.

However -- the scene (in direct, late morning sun) had a good range of brightness, and lots of texture; there should be small details scattered through much of the image that would have been above Zone VI had the film been right way in; what I'm hoping is that these, now in Zones I 1/2 to II 1/2, about, will get pushed up the slope into mid-tones that can be further enhanced by printing very hard. In the end, I might well wind up with an interesting woodcut or engraving sort of look in a scene with an artificially expanded tonal range.

So, off to the darkroom with me, to attempt the impossible. No expectations, but the hope I might discover something interesting.

 

[titrisol]

Also wouldn;t that be like having no-anti halation?

I'd try to develop in in diluted HC-110 with added ascorbate for 1 hour or so agitating every 5 minutes

 

[Donald Qualls]

Well, just after my last post I was in fact in the darkroom, developing in daylight tubes, which I treat as small tank (agitate by inversion, filled so they can stand when not being agitated). I made up Dektol 1+9, the six ounces a one-sheet tube requires, added a scant 1/4 tsp of vitamin C powder (approximately a gram) and 1/2 tsp of washing soda (to counter the acidity), then squirted in 6 ml of HC-110 syrup to make equivalent of Dilution B. The solution was warmed to 70 F, and I developed fifteen minutes with vigorous agitation (7 inversions in 5 seconds) every 30 seconds, after continuous agitation the first minute -- being after maximum contrast, this seemed best compared to my usual high dilution, low-agitation scheme that allows long development without excessive contrast.

The result is quite a lot better than I expected. The negative has significant fog, but only the thinnest areas are devoid of detail and there is still separation of clouds from blue sky (which didn't scan, but I can probably get it in printing); best I can figure this development should have been about a 3 stop push, perhaps 3 1/2 (that being about all one can reasonably get from TXT), so I can only presume that the antihalation backing on this film is less dense than some.