Managing gross overexposure - how to develop?

[pdeeh]

Today is Remembrance Sunday in the UK, when 2 minutes silence is observed at 11am in memory of those who have served in the Armed Forces, and a short service is held at the 50,000+ War Memorials across the UK.

At the very last minute, it occurred to me to make a 2 minute exposure on film at 11am, during the service at my nearby Memorial. The slowest system I had to hand was a pinhole camera loaded with Acros 100 (120 format), so I picked it up and just went. No time for thinking.

The f/stop of the pinhole is approx f/138, the focal length 50mm; I took a reflective meter reading of the scene after the event which, for a value of ISO100, gave an exposure time of ~1/15s for f/22. According to my pinhole exposure calculator, this means the correct exposure should have been ~3s.

Thus, the scene is really grossly over-exposed by a factor of ~40; If however I can get anything at all off that film, I'll be very happy. If I can't, well, it'll be a little bit of a shame, but not the end of the world. There's always next year, and I've now got a whole 12 months to plan how to do it properly.

The only commercial developer I've got on hand is Rodinal, but I have many common photographic chemicals if a particular developer needs making up.

The exposure I'd like to save is at the beginning of the roll, so I could make some further exposures for clip testing, if that is going to help me.

So, the question is, what the "safest" development regime will be to rescue what I can?

 

[PeterB]

My quick calculations result in about 5 and a bit stops of over exposure. Have a look at the HD curve for Acros to see how many stops it can record and if the films shoulder is shown on the curve then get back to us.

I recently over exposed HP5+ by four stops and at face value it appears to have turned out ok.

I'll write more about dev time when you get the information I requested.

 

[Jim Noel]

If you have metol and sodium sulfite mix up some D-23 and use it.

 

[Bill Burk]

pdeeh,

As you consider your options, keep in mind that you should "probably" develop the film normally, because exposure does not affect contrast... You are about 5 stops overexposed... Your negative will take a very long time to print... but if you can stand long printing times, the print itself might be identical to a properly exposed negative.

From the horse's mouth, take a look at page 13...

https://archive.org/details/secretofexposure00fraprich

The statment of the case in the words of Mr. Vero C. Driffield* may be of assistance.

"I have in my possession two negatives of the same subject taken upon the same plate and
developed together for the same length of time, but the latitude of the plate used was such as to permit
of one negative being exposed for ten times as long as the other. While one of the negatives has every
indication of a perfect exposure, the other gives to the eye the impression of heavily fogged overexposure;
yet they yield identical prints..."

*The Photo-Miniature, No. 56, page 385.

 

[desertrat]

Ferrous oxalate was a developer used at the beginning of the 20th century for dry plates. It required 2 stops more exposure than the usual alkaline organic developers. The original formulae were much too strong for modern films, but someone posted here a few years ago about experiments with a more dilute version. It might help with strongly overexposed films. Here is an old post:

(there was a url link here which no longer exists)

You might try mixing up a small amount of the old recipe and diluting it considerably before use, maybe 1:3. You could shoot another roll with the same amount of overexposure for testing purposes.

 

[MattKing]

Rodinal isn't exactly a speed enhancing developer, so that helps a bit.

What was the light like (flat, contrasty, ??)?

 

[removed account4]

hi pdeeh

you have some great suggestions here !
my somewhat crazy suggestion is just process the film in caffenol C
whichever the plain-jane / normal version is ( cl ? )

just develop as normally

i often times over expose film by 5 sometimes 6 stops
and stand develop in cl ( or whatever it is called ) with 15cc / 1L (spent print dev / caffenol)
and let stand for 30-35 mins it comes out fine ..
usually a little dense, .. but thats ok, it prints like a charm.

good luck!
john

 

[NedL]

Bill's point about contrast is probably right, but here's another idea. I once was playing around with an old Kodak duaflex. I had it loaded with 120 Tri-X ( after sanding off the ends of the spool so it would fit.. the duaflex is a 620 camera ) but near the end of the roll I realized I had the shutter control set incorrectly. Instead of "snapshots" it was on the setting that simply opens the shutter for as long as you press the shutter release. Some of the shots were probably almost as overexposed as yours. I developed it in HC-110 dilution "M' which is 1:250. 4 Inversions then stand for 90 minutes. The negatives were printable and a couple were actually pretty nice!

 

[Gerald C Koch]

Develop and then uses a reducer.

 

[pdeeh]

Ah this is when I like APUG best! A wealth of interesting & helpful responses, amongst which are things I don't quite understand (which means I have a nice chance to learn a bit more).

So .. thank you to all who have offered responses so far. I wasn't thinking quite clearly enough, but of course once I started counting stops off on my fingers, yes it's "only" a bit over 5 stops over box.

@MattKing : the Sun was at about 40° above the horizon, from a clear blue sky. The foreground was partial shadow, fairly deep butnot black, and made up about 40% of the scene; the remainder was mostly clear pale blue sky, the balance being trees/tarmac in midtones. I would describe it overall as contrasty .

@Bill Burk: a different horse said,similarly, " ... it might be thought that if a film were over-exposed and so gave density very easily it should be developed for a shorter time than if it had received a correct exposure. This idea is quite wrong. What is wanted is not so much correct density, which only affects the time of printing, but correct contrast, and the contrast is controlled by the time of development ... Whatever the exposure, the best result will be obtained by the use of the normal time of development"
(I'll leave that unattributed for the moment in case anyone wants to have a bit of fun guessing where it's from)

So, As I don't have oxalate to hand, or HC110, or the characteristic curves for Acros (I think that is what is meant by "HD curves"?) I think I'll pop it into some Rodinal at 1:50 for 12 minutes. (Yes john I know caffenol would probably be wonderful too but Rodinal is so much simpler to make up )

Unless of course someone has a particularly strong argument for not doing so?

 

[MattKing]

I'd try your clip test idea first.

You have a subject with lots of potential contrast, so I'd suggest a shorter development time over a longer one. If you normally use Rodinal at 1:50 for 12 minutes for standard contrast, you might try 10 3/4 minutes instead.

 

[Bill Burk]

..(I'll leave that unattributed for the moment in case anyone wants to have a bit of fun guessing where it's from)

...or the characteristic curves for Acros (I think that is what is meant by "HD curves"?)

Not sure who but looking takes me back to the archives... thanks.

Characteristic curves are easy to find, yes they are the HD curves, the "D" of HD was my "horse"...

 

[pdeeh]

well, here's a clip test at 10' 45" (still wet)

With a certain serendipity I managed to clip exactly one frame in total darkness from a curly roll ...

this looks like it will print ok, and perhaps even scan ok (my scanner has a problem with very dense negatives)

The diagonal stripe in the sky at top right is a spreading contrail by the way, not uneven development