Gast
I have quite a few black-and-white negatives that are rather faint, either due to underexposure or underdevelopment.
In an old guidebook (*Dunkelkammerpraxis* by Heinrich Freytag), I found a description of how to enhance faint negatives. I have uploaded the relevant page.
It describes the preparation of certain chemicals for "enhancement", as well as noting that there are also tablets available to dissolve for this purpose.
I have the following questions:
What is the technical term for this "boosting" of black-and-white negatives? (I’ll have a googling for more info)
Where can I get hold of the chemicals mentioned? As I don’t want to mess about too much, I’d prefer ready-made solutions or the “tablets” mentioned
Where can I find more information on the lab process?
Many thanks,
Wolfgang[ATTACHMENT NOT FOUND]
Gast
Does nobody really know anything about this...?
Wolfgang
I have quite a few black-and-white negatives that are rather faint, either due to underexposure or underdevelopment.
In an old guidebook (‘Dunkelkammerpraxis’ by Heinrich Freytag), I found a description of how to enhance faint negatives. I’ve uploaded the relevant page.
It describes the preparation of certain chemicals for "enhancement", as well as noting that there are also tablets available to dissolve.
I have the following questions:
What is the technical term for this "boosting" of black-and-white negatives? (I’ll have a googling for more info)
Where can I get hold of the chemicals mentioned? As I don’t want to mess about too much, I’d prefer ready-made solutions or the “tablets” mentioned
Where can I find more information on the lab process?
Many thanks,
Wolfgang[ATTACHMENT NOT FOUND]
ChristianKolinski
Does nobody really know anything about this...?
You won’t find mercury amplifiers these days.
As far as I recall, selling mercury chloride to private individuals is no longer permitted – and that’s probably for the best.
WolfgangMoersch
A copper amplifier would be one option. But if there’s nothing there to begin with, it won’t do much good. Give it a go – it certainly won’t make things any worse.
Gast
Copper amplifiers are one option. But if there’s nothing there, it’s not much use. Let’s give it a go – it certainly won’t make things any worse.
Where can you get something like that ready-made...?
Wolfgang
WolfgangMoersch
From me, or from Impex – but it might take a few days.
Best regards
rmrts
Hello,
I once had some very faint negatives (many years ago). You could only see anything if the light came from a certain angle.
I then photographed these negatives using dark-field illumination.
That produced quite usable results, if I remember correctly.
However, it’s only worth the effort if the negatives are important.
Best regards,
Reinhold
Gast
Hello,
I once had some very faint negatives (many years ago). You could only just make them out if the light came from a certain angle.
I then photographed these negatives using dark-field illumination.
That produced quite usable results, if I remember correctly.
But it’s only worth the effort if the negatives are important.
Best regards,
Reinhold
Well, I’d already imagined a chemical solution...
How did you go about it with the dark-field illumination?
Wolfgang
rmrts
Hello,
How did you go about the dark-field illumination?
Wolfgang
- Cut a negative-sized section out of black card
- Mounted the negative behind it
- Lit it with two lights on the right and left so that the light hits the negative in the form of a streak.
- Used black card or, better still, fabric (completely matt black!) as a background
- Photographed the negative.
That was it.
Oh yes, the emulsion side of the negative facing the camera, if I remember correctly.
The visible image appears as a positive and is created by the scattered light.
If light falls on it from behind as transmitted light, the effect disappears completely or partially.
You can hold the negative up against a black background and tilt it; then you’ll see the effect.
As for chemical processes, I’m only familiar with the one using mercury sublimate. But I didn’t dare try that back then.
It is rather toxic, after all.
Best regards
Reinhold
Wolfgg
Hello Wolfgang!
If the negatives are important: just to be on the safe side, have them scanned first, so that the ‘enlargements’ can still be produced using an inkjet printer if necessary, in case anything goes wrong. That way, you can see straight away on the screen what the best possible result would be and whether it’s worth the effort. And: no enhancement technique will produce a negative that matches a correctly exposed/developed one; they merely ease the photographer’s pain somewhat. Enhancement is nothing more than a last resort when you can’t produce a usable image even with the toughest paper.
Generally speaking, the processes used by our ancestors – and now accessible only through raw chemistry – should be used exclusively by those with a firm grasp of chemistry. This is because they involve potent ingredients such as dichromates, catechol, hydrochloric acid, caustic soda, etc., meaning you have substances in the house that the uninitiated (children) must never get their hands on. For those who are only dealing with this ‘just once, quickly, and hopefully never again’, this is not a viable option. So the only options left are the product mentioned by wm and the dark-field process. Anyone who develops transparency films themselves could produce a steeper duplicate negative by significantly extending the initial development time. I would advise against copying twice onto steep negative film stock; it takes a lot of time and is nerve-wracking (dust problem), and the sharpness suffers too much.
Regards, Wolfgang
Gast
Thanks for the comments so far.
I’m slowly starting to rule out the chemical solution, even though that’s the one I would have preferred.
I don’t need that much of the solution, and a container like that costs 20–30 euros straight away… And it doesn’t help with underexposure anyway…
These are 6x9 negatives (and just a few 24x36 ones), but they’re important to me and some of them have quite a strong curl.
Furthermore, I only have a 35mm slide scanner, which isn’t particularly suitable for negatives – I’ve already had a go with it. I don’t have a flatbed scanner either, which would be necessary for 6x9. But I do have a 6x9 enlarger (Teufel) with a reproduction stage; perhaps I can make use of that...
I’d definitely like to give the dark-field illumination a go...
But as I said, since these are mainly 6x9 negatives, I reckon the dark-field illumination will only work if the negatives lie absolutely flat. To do that, I’d have to clamp the negative between two glass plates... I wonder if the side lighting would still work then?
Perhaps I really do need to play around with it a bit...
Perhaps someone else has some experience with this and can offer some tips...
Wolfgang
Wolfgg
Hi Wolfgang!
You don’t need a dedicated (and expensive) film scanner for 6x9 film; a much cheaper flatbed scanner with a transparency unit, such as the Epson 4870, 4990, V700 etc., will do just fine. Perhaps you could borrow one from a friend.
Best wishes, Wolfgang
Gast
Hi Wolfgang!
You don’t need a dedicated (and expensive) film scanner for 6x9 film; a much cheaper flatbed scanner with a transparency unit, such as the Epson 4870, 4990, V700 etc., will do just fine. Perhaps you could borrow one from a friend.
Regards, Wolfgang
Sure. That’s exactly the sort of transparency scanner I meant. My scanner doesn’t have a transparency unit and it won’t work without one – I’ve tried everything already...
But I didn’t want to buy a new scanner just for that reason... Unfortunately, nobody I know has one.
Wolfgang
Gast
I had a look at various flatbed scanners online anyway... they cost around 100 as well
Beef
Hi Wolfgang,
I’ve scanned a page from my enlarger manual for you here :lol:
It explains in detail how the dark-field illumination works.
There’s even a picture included. It’s really simple to set up.
On my enlarger, you can remove the slide where the negatives are clamped in.
Maybe you can do the same with yours and use it for this. Otherwise, you’ll have to come up with something... perhaps using a new CD case :rolleyes:
You can get the right distance from the floor, for example, by placing the whole thing on top of two tall books or something... you just have to improvise.
You can simply hold the camera above it using a standard camera tripod.
Here are the instructions:
[ATTACHMENT NOT FOUND]
Regards,
Andi
Gast
That looks good. In fact, my enlarger (Teufel VG 6x9) has a removable 6x9 film holder that contains two glass plates, between which the film is clamped.
I’ll have to experiment a bit to see how best I can light it up....
Many thanks for the comprehensive information
Regards
Wolfgang :rolleyes:
Beef
Hi Mausebä,
I don’t know if you’ve sorted out your problem yet, but I recently faced the same issue.
I was at a party and took loads of photos there. Unfortunately, I completely underdeveloped the film because my thermometer was broken. Instead of 20°C, I developed it at about 16°C (which makes a huge difference to the development time).
I couldn’t even salvage the pictures on the highest-grade paper with a gradient of 5. Then I remembered Tetenal Dokumol, which is supposed to bring out an extra gradient. I happened to have some at home because I’d ordered it for testing purposes, so I immediately set up a bath.
This developer is AMAZING!!! I was able to produce wonderful prints with the deepest blacks, the brightest whites and excellent grey gradients (combined with grade 5 paper). The images look as if they were printed from a perfectly developed film :)
It almost feels to me as if it delivers two extra gradients :lol:
I think the mix was 1+6. Normally, my paper takes about 1.5 minutes in any run-of-the-mill developer (e.g. Tetenal Eukobrom)... but here it takes about 3 minutes... so don’t be surprised if it takes longer. That’s probably just the nature of this developer.
Even if you have a film that develops well but is subject to underexposure, you can compensate for that (to a certain extent)... in this case, however, you’ll get higher contrast with fewer grey tones.
Just wanted to let you know...
Regards
Andi
Gast
Hi Andi,
No, I haven’t sorted out the problem yet and have actually put it on hold for a bit because I’ve had other things to do.
The fact is, though, that some of the negatives are so faint that you can only make out anything decent under dark-field illumination (see also above)....
So I doubt your method would work here, but I’d still get some of that Dokumol solution to give it a go. Which paper with which gradient did you use?
Regards
Wolfgang
Beef
Hi Wolfgang,
Well, my negatives are already extremely thin. But when I hold them up to a light as normal, I can still just about make out the darkest areas.
I used Fomaspeed V. 311 (multigrade paper) for this... with a contrast filter set to gradient 5. Of course, you could also use fixed-grade paper with G5.
The FOTOIMPEX description of the Dokumol here says ‘...but don’t expect miracles.’ I can say: ‘The developer works wonders’ :)
Now a few people here will get annoyed again, but: if nothing else helps, you could try reducing exposure for a shorter time and extending development for longer than usual...even if it takes several minutes, or even a quarter of an hour or half an hour :lol: That’s how I’ve managed to salvage quite a few shots, more or less.
And another tip: If you somehow manage to get a faint fog from the negative onto the paper, you can scan the print and carry out a tone/contrast correction (or adjust the contrast/brightness) on the computer. That’s worked for me too. The better the grey-scale gradation on the paper and the higher the dpi you scan at, the better your digitised image will be. Just make sure you disable the scanner software’s automatic sharpness and tone corrections... these functions usually make the scans worse :(
Scanning the dull negative with a negative scanner and then correcting it doesn’t really work... the scanner can’t properly distinguish the tonal values here... so you’ll need to boost the contrast a little beforehand using your G5 paper and the Dokumol.
Regards
Andi
Gast
Hi Andi,
Yes, I’d love to give that a go.
However, Dokumol is only available in 1-litre containers, which covers about 5 m²... But I only have a few small areas I want to use it on.
I read somewhere about 100 ml bottles, but they’re not available anywhere. Can anyone tell me where I can get hold of them in small quantities (in Munich if possible)?
Many thanks,
Best regards,
Wolfgang
