Dignan 2-bath color negative process, modification 1

[Alan Johnson]

It does appear that trying to match the printed chart is more difficult than matching a real scene [post 45].
It doesn't do the Dignan process any favors. But it does suggest that a simple red and blue adjustment is not likely to be satisfactory.
It would be interesting to know how use of a proprietary color checker might improve matters, thanks.

 

[Alan Johnson]

I posted 4 Ektar + Dignan scans without color correction.
IMO the impression is of some color negative film from earlier times.
Spots are my mistake, exhausted fixer silver deposits.

 

[pentaxuser]

The 1st Regatta one doesn't look bad at all apart from the shoreline red/magenta-ish look. What should this part have been?

Thanks

pentaxuser

 

[Alan Johnson]

The shoreline is a mud bank on the edge of this bird sanctuary.

The wetlands that Crossrail built

How Europe’s largest infrastructure project is helping to rewild the Essex coast

www.economist.com

Dignan is not too good at mud.

 

[pentaxuser]

Thanks for the reply, Alan

pentaxuser

 

[Alan Johnson]

Thanks for noting that.
A better result is obtained by decreasing red and removing the color cast:

 

[koraks]

and removing the color cast:

It did however not remove the crossover. You'd have to alter individual curve shapes for this; give it a try if you like. It would entail things like pushing the red curve downward at the top end of its scale and leaving it alone at the bottom end, or even lifting it.

My apologies btw for not yet following up on the inkjet color checker issue; I'll get back to this, promise!

 

[koraks]

@Alan Johnson my apologies, still haven't responded to the inkjet color checker issue. But I will now, at least in a preliminary way: having given it some thought yesterday, a decent printer should yield a decent enough color checker print that you could verify your film (prints) against. I still have some doubts about mismatching dye curves, but that's probably going to be small potatoes. To get in the ballpark, an inkjet color checker should be OK-ish. It won't be great due to issues such as reduced gamut (real-world objects do better here) and inherently low contrast (bracket a -2 and a +2 along with a neutral exposure to get around this), and evidently only with a perfectly calibrated workflow the colors you print will match up with global definitions (but this isn't really a concern if you just want to check against your printed chart). I still want to look into some more details regarding dye curves and comparing a typical inkjet curve set against a typical color negative spectral sensitivity, but good data is hard to find and I can't make it myself. If I find anything useful, I'll update.

 

[pentaxuser]

It did however not remove the crossover.

I wonder if I will ever see this thing called crossover. Can I ask where it is in the improved version of the regatta scene. Is this the slight green in the tops of the foreground small waves? If so, I had just assumed that as this was in shore or even an inland water and this shallow then this kind of greenness might be there anyway

In Alan's other picture of the Wetlands he mentions that Dignan doesn't do mud very well but had this one been in the gallerye I don't thinkl I'd have seen any issue with the mid or the scene in general so is there any crossover here and if so where?

Thanks

pentaxuser

 

[Murray Kelly]

Alan, I downloaded the first image (18 footer?) into my fav, Irfanview and went to image/color correction and clicked on a white deck to set that as white. Blue came up and red down- both just a little.
A nonauto scan treated this way might save you a lot of fiddling.

 

[koraks]

I wonder if I will ever see this thing called crossover. Can I ask where it is in the improved version of the regatta scene. Is this the slight green in the tops of the foreground small waves?

No, it doesn't quite work like that (and I agree that the water more or less has a color that's likely to be natural, at least to some extent). The problem with crossover manifests itself whenever you try to fix one part of the scene by adjusting the color balance there, and then other parts of the scene become skewed color-wise. If you'd have to pick one particular part where it's most apparent in the regatta picture, it would be the shadow underneath the boat which shows a strong cyan cast that's also present all across the image. It results in highly reduced saturation in the buoy (?) all the way to the left and the cap of the guy on the boat. Also note how the highlight on the deck is decidedly unclean, tending towards a peach hue. The fact that the cast is different here than elsewhere in the picture points at crossover: the color balance is askew in different areas of the picture and in different ways depending on overall luminosity.

In Alan's other picture of the Wetlands he mentions that Dignan doesn't do mud very well

You mean the image from the Economist website? That looks OK, albeit severely adjusted with heavy vignetting, contrast increase in both fore- and background and burning in of the skies. I assume it's a digital shot, but that's beside the issue. Color-balance wise it isn't particularly problematic, but it's also not really relevant since it bears no technical relation to the 2-bath C41 process.

I've seen you struggle with the crossover issue a couple of times now and although I'm pretty sure it's been said before, please keep in mind color vision is kind of personal. This is in many ways. For starters, color vision and in particular the ability to discern hues varies rather wildly across people. It's well-known that around 10% of the male population has some form of color blindness, but even the other 90% differ vastly in how well they are at distinguishing hues (and I have the distinct impression that women are generally significantly better at this overall). Then there's the psychological aspect of how we actually interpret colors; a scene that may look problematic (color-wise) to me, may be perfectly natural or even pleasing to you. Finally, there's the language issue - color is something we experience and can sometimes be hard to put into words. When you ask "where do I see this crossover you speak of?", it's kind of challenging for me to make it explicit and specific enough for you to make sense of it without resorting to the factually accurate, but probably not very helpful answer: "all over the place".

Whenever the crossover issue strikes, the main thing I notice myself is a sentiment of "wow, this here don't look right at all" and I've learned to distinguish it from the feeling associated with a simple color balance problem (not being crossover), which to me feels more like "hm, I think I'd printed this a bit warmer/cooler/greener/redder/etc." So for me it starts as very subjective, more as a feeling than as an analysis, and I then have to take that and try to figure out what's going on. If you do that a couple of thousand of times, at some point, you just 'know' you're looking at a crossover problem without immediately realizing how the problem is made up exactly. That's also the tricky bit of troubleshooting crossover issues in real-world scenes; it's very hard (at least for me) to get past the "doesn't feel right" stage and put into words exactly what's wrong. Color checker charts are far easier for this because you immediately see which patches are skewed in which direction(s).

The conclusion you might draw from this is that what might be a glaring problem for me may not be an issue at all for you. Rejoice! Makes color printing all the more fun if you're not bothered by a pretty nasty problem that's usually hard or even impossible to solve.

I might dedicate a blog post to this one of these days with a couple of examples; perhaps by exaggerating it, things become clear(er).

 

[Murray Kelly]

If I cannot print a color chart correctly, what chance is there I can get a paper print to exactly match either the original chart or a color negative by any method?

 

[pentaxuser]

OK koraks and thanks for taking the time and trouble to identify for me the crossover areas. What I wonder about is whether I may be seeing what you see to a very large extent or almost the same as you see but in my case I imagine that what I see is what I'd also see had I been there. There are 2 shadows under the boat. One set is on the water from the two man crew and it looks as if these make the water look as it should where these shadows are. The second shadow is on the left side of the boat's hull but seems so small an area as to be difficult to ascertain if this shadow is cyan and if so may not be from the water reflecting onto the hull

As you have guessed the highlight on the boat's deck look normal to me. Is it slightly darker/greyer than the back of the hull? Yes possibly but can we be sure that the back of the boat is not a slightly different hue from the white outriggers. The inner crew member's red cap looks to be the red colour I'd expect it to be It is not a bright red but certainly strikes me as the sort of slightly weathered red that a cap worn on a regular basis when boating or possibly doing other things as well that is natural.


If on the other hand this was a bright red cap then I agree it does look somewhat de-saturated. The buoy is so far away that beyond looking a weathered red which I'd expect a buoy to look like, I cannot judge

Finally assuming that the colour of the water is not what it appears to be in Alan's corrected scan and I have certainly seen water that was this colour in similar light conditions I do wonder if under an enlarger a slight adjustment to the colour filters might not remove this cyan look without affecting what was clearly a red/magenta shore line in his previous picture

The problem is we may never know unless an attempt is made to optically print under an enlarger with RA4 paper.

I once took a picture of the centre of the town of Malahide on the coast but close to Dublin. In that picture was a square of pure grey block paving. At first glance my print looked perfect but isolating the grey block paving there was a slight red cast That was removed by 2M and 2Y so a very small change made all the difference

I have just had another look at it now and can see no other changes in the 2 comparison prints. That was probably the print that made me realise that small changes can make a difference and brought it home to me that the recommended grey/ grey card in one of the negatives can be really useful establishing colour balance

pentaxuser

 

[Alan Johnson]

@ koraks thank you for your clear explanations.
To me the worst outcome is that my inkjet printed pictures from film should be mistaken for pictures from a digital camera.
Maybe inclusion of some crossover would help to distinguish them.
@Murray, dinghy is a 49er ,fastest 2 man dinghy, spectacular. I like to leave the editing method to the choice of anyone trying the color developing process.
@pentaxuser, are you not careful that your prints are not mistaken with those from a digital camera?

 

[pentaxuser]

@pentaxuser, are you not careful that your prints are not mistaken with those from a digital camera?

Never gave it any thought, Alan. All I have or have ever had is a film camera and darkroom processes. If the RA4 print represents what I remember I saw at the time then that's all I ask for.

If I were given 100 prints and 50 were inkjet ones from a digital camera and 50 were RA4/ silver gelatin darkroom prints from film, could I separate each 50? I have no idea but I suspect not

My audience, such as it is, seems only ever to have commented on whether it liked the picture or not. No-one has ever said "Ah a traditional darkroom print and thank goodness it is.

My audience may be different from most of Joe Public but I can't think why it would be and in my limited experience my members of Joe Public could not give a damn. Actually most of my audience probably see the benefit of a darkroom b&w print to be its novelty, its "old days" look when that was all there was. All the rest of what they see is colour

pentaxuser

 

[koraks]

@ koraks thank you for your clear explanations.
To me the worst outcome is that my inkjet printed pictures from film should be mistaken for pictures from a digital camera.
Maybe inclusion of some crossover would help to distinguish them.

You're welcome. Of course crossover can be exploited for aesthetic merit; you're the artist, you make the rules! Personally, I would be concerned if the crossover is part of the deal and it's inescapable. Having it as an option is one thing, but having to deal with it as the default would be another. As to the inkjet prints...well, I sort of see your point, but it's also a personal thing, I guess. I don't enjoy inkjet much as a printing process. A well-made inkjet print can be a beautiful work of art. I don't really mind if the image has digital origins or otherwise. If someone mistakes an image for digital while it was shot on film or vice versa, well, that's OK by me. For you, it's evidently different. Perfectly fine!

I do wonder if under an enlarger a slight adjustment to the colour filters might not remove this cyan look without affecting what was clearly a red/magenta shore line in his previous picture

Try it out; you could rig an experiment in e.g. Photoshop to play with it. I don't think a simple color filter adjustment would fix it because like I said, fixing one part will create a new color balance problem elsewhere. You'd be chasing your own tail trying to fix it.

PS: in terms of illustration, I hope @Alan Johnson doesn't mind I abused his example image for a bit.

Here are 4 versions of that same image, but each time color corrected for a different region. The correction is each time a simple curve correction; the equivalent of what you might do when printing RA4. You could evidently get much better results by modifying the curves to become distinctly non-linear, and thus (more or less) fix the crossover issue. Things might become too 'digital' for some people's tastes
Top left is a version that I tried to correct for the highlight region on the deck, which is a more neutral white now. It creates a blue cast over the remainder of the image. Top right is an attempt (fairly poorly) to fix the suffering saturation in the red and orange hues; if you see the kind of fluorescent orange often used on equipment like this (e.g. the patch in the sail), you probably know what I mean. An accent like that really pops, but if I try to approach that in this image, the entire image shifts towards red. The problem is particularly pronounced because the orange accent (and to a lesser extent also the buoy and the man's cap) is a fairly off-center gamut hue and in a crossover situation, it's these rather pure hues that will suffer the most.
Bottom left is balanced to fix the color cast in the blacks on the people's suits. As you can see, this creates a yellow/lime cast elsewhere.
Bottom right is an attempt to fix the horizon to look natural with the a slight blue cast you'd expect from atmospheric filtering. This shifts the entire image again to cool tones, and note the sky takes on a magenta hue that I suspect isn't quite natural.

I hope this somehow helps illustrating the problem. It's not an ideal image because it largely consists of rather muted hues and very few objective references. But perhaps you'll recognize that in one way or another, each of the different renditions might be natural - depending on which image area you focus on. Now, which one is the 'truest' one? Or is it even yet another version I could make for any of the other hues? If you have an image that does not suffer (much) from crossover, you fairly easily (in my experience) hit upon a filtration where everything seemingly magically falls into place, color-wise. With this image, it just won't happen.

 

[pentaxuser]

Thanks Koraks I might try and rig an experiment in PS if I knew anything about PS but I don't. Nor have I ever used digital or a scanner as I tried to indicate to Alan

I think that I have to conclude that at least some of the "nuances" you see as crossover and requiring corrections are just not those I see

pentaxuser

 

[MattKing]

I can see all of the issues that koraks mentions.
Speaking very generally, crossover means that if you fix one area by adjusting the colour there, you realize the colour in another area gets worse.
If you don't have crossover, when you adjust the colour in one area to make it better, the other areas get better too. Sometimes it is like focusing a camera with a good viewing system - the colours suddenly "pop" into looking right.

 

[Alan Johnson]

Thanks for the clear expositions of color crossover in the Dignan 2 bath process.

 

[pentaxuser]

Your post might have been addressed to Alan, Matt but on the assumption it was for general consumption my problem is seeing most of what koraks and now you describe as crossover

As far as I can see( and maybe not far enough ) the corrected "print" from Alan appeared OK to me for the reasons I mentioned earlier. In summary some of what koraks saw as crossover just wasn't clear enough for me to see( the far-off buoy and the desaturated red cap for instance). What's key for me as a darkroom only producer of RA4 prints is: Is it possible to get to the kind of corrected print that Alan produced?

I fear the answer is " unknown" as it is not clear to me what changes have taken place to produce the corrected print that are not possible with a colourhead enlarger.

Hence my question in my previous reply as to whether a small change in colour filtration might be an improvement that even I would see

My form of ring-around that I mentioned in my previous post was set of 4 prints on a 8x10 print where I altered the red/magenta cast via small changes in the colourhead's filtration and it led to my discovery that as little as 2 units of Y and M on a 130 Durst dichroic head made a visible difference to a cast in a pavement of grey paving blocks( not sure if this is in use in Europe or N America but these are extremely hard wearing bricks used for pavements and driveways for houses) Before I did this I probably would not have believed that 2M and 2Y would have made that difference to a small cast that on my re-examination of the ring-around print in a grey area. In fact I examined the rest of the print's colour carefully and can honestly say that had there not been a large grey block-paved area a change of 2Y and 2M would not have made any real difference
Of course, others examining the print might disagree and say they could see small but important differences but of course they might be affected by knowing they were looking for "problems"

So in summary my concern is that the problem may be that short of someone having Alan's neg and experimenting with it under an enlarger we'll never know what is and isn't possible.

There may in fact be no way I will ever see at least some of the crossover. My pessimism in this respect is my recall of David Lyga's negative that he sent to, I think, koraks. That negative was a result of some process that he explained and the details of which now escape me. Koraks saw crossover in David's scans which David and I did not.

David sent koraks the neg and he printed it under an enlarger and the showed us the result He saw a crossover in the shadow area of a shop doorway in his version but I did not nor if I recall correctly did David

So it may simply be that I will never see the less obvious examples of crossover which is fine provided of course that in the case of Alan's "Dignan" negative it is possible to get to his corrected print under an enlarger. If this were not to be the case then I agree that where Alan is currently with his Dignan process would be of no value to traditional darkroom printers

Finally can I use this post to say to koraks that I confess to misunderstanding Alan's reference to "Dignan not liking the colour of mud" .

As you pointed out to me, koraks, the picture of the mud was fine as Alan had shown me mud flats to show what they looked like but it was not a picture from one of his Dignan negatives so my question about what was wrong with the mud was nonsensical. Sorry about that


Thanks

pentaxuser

 

[koraks]

You make valid points, @pentaxuser. Especially concerning the one about Alan holding the negative and none of us do. I don't know what's up with this negative and if any problem it has could easily be filtered away with normal color filtering.

There are two things I do know, though:
1: The kind of crossover the digital images exhibit in this thread match with the broader category of problems I run into when straying too far from the established C41 parameters. Hence, I suspect the negative really is problematic in this respect, without being sure of it.

2: crossover can't be fixed by turning the dials on a color head. It takes a correction mask to achieve this and frankly I wouldn't know where to begin when I'd be pressed to make one. I'm sure something could be done, but I'm not prepared to go there. It's just way too much work!

Finally, don't take my remarks ad dismissive of experiments, or the results thereof. To the contrary: they're valuable, they're fun, they tickle the mind and for the more artistically inclined among us (I'm too much of a bore I'm afraid), they're probably useful!

 

[pentaxuser]

koraks, what your very useful article on crossover showed me is that if you had been the taker of the example photos then the problem is clear in all cases, albeit some more obvious to me than others. Had the viewer not been the taker then in some cases I think the viewer would simply see nothing wrong but I now see that depending on the extent and nature of the crossover any small tinker with the colourhead may at best make no difference and at worst make it slightly worse.

So yes if your goal is colour perfection then anything involving other than C41 film, processed at very close to 38 degrees C for 3 mins 15 secs carries risk.

I have given up C41 and RA4 printing for the time being due to scarcity of film and its price so I do understand why cinestill has its attractions and for some the colours may even be an attraction

If it were me and I was desperate to continue with colour film as cheaply as possible, the key factor would be how many scenes would be OK i.e. not a perfect set of prints but close enough to represent a reasonable print under an enlarger and on RA4

For others who are hybrid workers their range of OK prints might be greater but I can certainly understand why in the current situation users are attracted to cine films

pentaxuser

 

[koraks]

I can certainly understand why in the current situation users are attracted to cine films

Yes, I'm with you on this. Indeed it's also why I spent many hours trying to get Vision3 films to work. I burned through most of 50ft of it, all of which was shot in test strips of 5 to 9 frames; just enough to test one or two parameters. I wouldn't have done this if it hadn't had a certain appeal to me. And surely, there's much to be said for the Vision3 films. Fine grain, large latitude, muted and realistic color palette (if used as intended....this was the tricky bit for me) - and yes, cost and availability also played a role. I'm certainly sympathetic to the effort if trying to get these films to work well, and I can only applaud those who manage it, regardless if they do so within my quality standards or any other standard.

 

[Alan Johnson]

Here are 4 on movie film. This is available in cassettes at low cost from China and resellers under the brand "My Heart". It has Remjet.

 

[koraks]

"My Heart"

I did a brief search for it; I see it's mostly offered in 12 exposure rolls, in a white box with pink/red hearts, is that it?
Does it have any edge markings that tell us something what film this might be? I understand it's probably something 250D, so I wonder if it isn't 'simply' Vision3 250D The edge markings should make this clear if it's the case.