The Price of 8x10 Color Film Out of Control

[DREW WILEY]

Adrian, yes, deep shadows under a blue sky are blue, just like the Impressions discovered. But with Ektar, that blue gets inflected with an annoying cyan cast, whereas in chrome films it is not, even when exaggerated, and in traditional portrait CN films it is artificially warmed. The problem was way worse with the prior Ektar 25. Of course, since you're working with other people's shots you have the challenge of salvage printing quite a bit of the time, no doubt. But I'm speaking of optimization by having every step under personal control. Digital workflow can't recover anything that darkroom options can't. Curve reconfiguration was done for decades prior to scanners; it was just a big expensive headache potentially involving quite a bit of film and print dye tweaking. But sometimes it can be done fairly simply. PS just mimics these functions, often right down to the names for the operations. Then there are all kinds of squirrelly gamut limitation of inkjet inks, which one simply has to make the most of, just like with any other color photographic medium. I tried to become a watercolorist as a kid, which offers tremendous hue control, but just never had the right disposition to be a painter. More of a hiker for whom a camera is a much better fit.

 

[138S]

As usual, 138s, you have so little experience with certain actual products that you're speculating about how much of a curve is actually usable

Drew... I've shot quite a lot of Ektar, in rolls. It had been my main color film for around four years for my F5.

Bellow you may learn what Ektar exactly does, of course the +6 overexposure test image has color shifts (that can be corrected), but in an average metered +6 overexposure you may have areas at +9.

Anyway, this youtube video is exactly consistent with what I found.




For the record:



For urban legends saying that "it cannot be overexposed" that +4 overexposure result is quite disturbing

My view is that graphs in kodak datasheets are totally exact, densities mostly linear in 10 stops and some creative color shifts for +5 and +6 overexposure. Not that weird that you have some shift at +6.

 

[DREW WILEY]

Typical half-baked web nonsense. First, he picks a lens with serious falloff, which tells me he doesn't have a clue how to do an objective test. No standardized chart or lighting, no color temp meter, no actual printing, and worst of all, an untrained eye. Just a lot garbage-in/garbage-out rushed want-it-by-yesterday BS. The fact that you reposted it doesn't lend much credibility to your own opinion. Any worthy test involves a thousand times more work than that pitiful video.

 

[faberryman]

Bellow you may learn what Ektar exactly does, of course the +6 overexposure test image has color shifts (that can be corrected), but in an average metered +6 overexposure you may have areas at +9...

For urban legends saying that "it cannot be overexposed" that +4 overexposure result is quite disturbing

My view is that graphs in kodak datasheets are totally exact, densities mostly linear in 10 stops and some creative color shifts for +5 and +6 overexposure. Not that weird that you have some shift at +6.

Why would you test for such gross overexposures?

 

[138S]

First, he picks a lens with serious falloff,

No problem, compare the image centers... no fall-off there.

just a lot of hurried garbage-in/garbage-out BS.

A 10 stops bracketing, not a lab test but a practical test, showing real results in practice.

No need to throw rude words aganist that test, point no you have no other argument to discredit it.

Anyway I can show you a dozen of exposure tests pointing the same, so perhaps you may evaluate again what Ektar does.

 

[DREW WILEY]

I'm not being rude. It is what it is - a worthless shoot-from-the-hip pseudo-test. My argument is that I know what real tests actually consist of, and that isn't even remotely one of them. As for falloff, it means there would automatically be center to edge color shifts, and not just density falloff, as he progressed further and further away from optimal exposure. That he didn't even seem to notice these tells me he wasn't looking at any of the results seriously.

 

[138S]

Why would you test for such gross overexposures?

One has to know how mediun works if wanting to take advantage from medium capabilities when situation is challenging.

There are scenes with high dynamic range, and sometimes we want to preserve highlight detail in glares to help volume depiction.

It is important to know at what overexposure/underexposure an spot is to be degradated. If we want to record well some shadows we may have to overexpose other areas in the image, understanding what happens allows to balance an optimal exposure: recording well shadows while not damaging the rest.

Frank, do I have to explain you that? Really? Suposedly you had to be aware...

I'm not being rude. It is what it is - a worthless shoot-from-the-hip pseudo-test. My argument is that I know what real tests actually consist of, and that isn't even remotely one of them.

I don't know in your country, in mine arguing about defecations from bulls (BS) is considered rude and other that I won't mention...

If you personally make a similar 10 stops bracketing you'll find the same.

 

[Adrian Bacon]

Adrian, yes, deep shadows under a blue sky are blue, just like the Impressions discovered. But with Ektar, that blue gets inflected with an annoying cyan cast, whereas in chrome films it is not, even when exaggerated, and in traditional portrait CN films it is artificially warmed. The problem was way worse with the prior Ektar 25. Of course, since you're working with other people's shots you have the challenge of salvage printing quite a bit of the time, no doubt. But I'm speaking of optimization by having every step under personal control. Digital workflow can't recover anything that darkroom options can't. Curve reconfiguration was done for decades prior to scanners; it was just a big expensive headache potentially involving quite a bit of film and print dye tweaking. But sometimes it can be done fairly simply. PS just mimics these functions, often right down to the names for the operations. Then there are all kinds of squirrelly gamut limitation of inkjet inks, which one simply has to make the most of, just like with any other color photographic medium. I tried to become a watercolorist as a kid, which offers tremendous hue control, but just never had the right disposition to be a painter. More of a hiker for whom a camera is a much better fit.

yeah, it’d be awesome if everybody exposed correctly all the time, but that just isn’t the case for most of the film sent in to me, so, you look at it and use the tools you have available to salvage what you can. It’s certainly not as good as what you’d probably be able to produce with a totally optimized workflow, but like I said before, it’s better than doing nothing about it and having a customer never send you film again as a result, and often times, actually looks better than than you’d think it would, given how it was exposed.

 

[138S]

often times, actually looks better than than you’d think it would, given how it was exposed.

Probably CN film looks better when exposed +2 than when exposed -2

 

[faberryman]

Frank, do I have to explain you that? Really? Suposedly you had to be aware...

I guess I am just not as sophisticated as you are.

 

[David A. Goldfarb]

Me, I don't understand why the same emulsion has to be sold at 200% or 300% price if coated on sheet instead rolls, when manufacturing sheets it's cheaper than rolls.

Sure ilford doesn't loss money when selling BW sheets at similar price than rolls, so when kodak sells BW of color sheets at that insane 200-300 overprice (specially in the EU) I feel that they practice destruction of LF.

It’s not obvious that they are actually the same emulsion. PE (Ron Mowrey) used to make the point that some emulsions had to be reformulated to coat successfully on different bases. I had this discussion a few times with Simon Galley, when he was at Ilford, about why they didn’t produce Delta 400 in sheet sizes, and he said it was because they would have had to reformulate it to coat evenly and retain its grain properties, and it wasn’t worth the expense. I suppose that if they did do that research, we’d be paying $20 an exposure or more for 8x10” Delta 400 as well, but instead, we have no Delta 400 in sheet sizes.

 

[138S]

PE (Ron Mowrey) used to make the point that some emulsions had to be reformulated to coat successfully on different bases.

IMO the single thing that may have to be changed from rolls to sheets is the undercoating layer that may have to be specific to adhere well to the kind of base plastic. But this is of low technical or economic impact and Estar can be pre-treated to take the same kind of liquids (lipo or hydrophilic) than acetate.

For the rest, manufacturers give the same sensitometric/spectral curves for rolls than for sheets, making no distinction so it has to be much the same.

Some people have been saying that emulsions are different because Kodak gives different development times, but this is related to the typical agitation in specific tanks, Kodak gives the same times for rolls and sheets when agitation is the same like in the "Rotary-Tube Processing—Rolls and Sheets" section.

It would be totally crazy to develop a complex emulsion like Ektar or Portra specifically for sheets as sales are that low, IMO sheets are a subproduct from rolls business, they simply coat some master rolls with a different base and perhaps using a different undercoating... if not it would not be viable.

Today the single known emulsion (I recall) it's specifically made for sheets it's TXP, which probably it is a bare derivative from TX, perhaps simply having different amounts of component emulsions mixed, anyway TXP was not invented for sheets alone but for 220 rolls (half of Salgado's Genesis was shot with it).

 

[jtk]

Theology vs buggy whips.

 

[Lachlan Young]

IMO the single thing that may have to be changed from rolls to sheets is the undercoating layer that may have to be specific to adhere well to the kind of base plastic. But this is of low technical or economic impact and Estar can be pre-treated to take the same kind of liquids (lipo or hydrophilic) than acetate.

For the rest, manufacturers give the same sensitometric/spectral curves for rolls than for sheets, making no distinction so it has to be much the same.

Some people have been saying that emulsions are different because Kodak gives different development times, but this is related to the typical agitation in specific tanks, Kodak gives the same times for rolls and sheets when agitation is the same like in the "Rotary-Tube Processing—Rolls and Sheets" section.

It would be totally crazy to develop a complex emulsion like Ektar or Portra specifically for sheets as sales are that low, IMO sheets are a subproduct from rolls business, they simply coat some master rolls with a different base and perhaps using a different undercoating... if not it would not be viable.

Today the single known emulsion (I recall) it's specifically made for sheets it's TXP, which probably it is a bare derivative from TX, perhaps simply having different amounts of component emulsions mixed, anyway TXP was not invented for sheets alone but for 220 rolls (half of Salgado's Genesis was shot with it).

Nope.

They have to match the sensitometric behaviour between formats because consumers will complain if they didn't - this might involve quite a degree of emulsion alterations as David outlined above, with the aim of being able to deliver the same characteristic curve and effective behaviour across all formats.

For example, I think you are underestimating the coatability differences between tri-acetate and polyester bases, not to mention how the machines must be run to prevent jamming & damage from the extremely strong polyester base. Merely altering surfactant type or quantity may induce undesirable problems elsewhere in the layer build-up. You might use the same building-blocks in layer terms, but they may require a sequence of alterations that have to be tested, scaled, tested again to ensure in-spec behaviour for the final product. There might be several full-scale coating tests before the first production run.

TXP was and is part of a larger Tri-X 'family', it used to include TXT, and Tri-X Ortho etc. TXP and TXT had very close sensitometric performance, but different development times - but by the time they transitioned to B-38, it seems likely that a single development time for all of the TXP/ TXT products was desirable (always think about this from the perspective of large batch professional usage - the fewer different developing times you need, the better) & several other factors likely pushed towards unifying the products' end user experience through manufacturing knowledge. See also Ilford Ortho+ - long available as a sheet only material, it will have had to undergo a fair bit of engineering to make it coat on tri-acetate with equivalent performance - and it's a relatively much simpler material to do this with than any colour stock.

this can be addressed in post, specially easy in hybrid. NC and VC did not make sense in the digital minilabs era and they did the same easily with soft. What is critical is spectral response, converting spetral information to 3 colors is a loss of infomation, what you loss in that step is lost.

OK then. Show us how you'll do this. I'd like to see you convert 160VC into NC. You might get a bad impersonation, but it won't look like the real thing. You seem very determined that just because you personally have arrived at the belief (with no practical experience) that a potato can be turned into a carrot, the rest of us should believe you - despite the large amount of evidence to the contrary. To take your line of argument to its conclusion: why, if your claims about post correction are true, did Kodak produce a more neutral film (Portra 160) and a warmer film (Portra 400)? Fixing things in 'post' rarely looks as good as getting them right in the first place through appropriate exposure and material choice.

Ektar : No way you get 7 stops linearity if you expect clean dye curve independence; crossover will set in one extreme, shouldering the other. I'd say realistically, no more than one stop either side of what you'd normally expect from a mid-contrast chrome film like Provia or E100.

Yeah - I was being kind & assuming he wasn't dealing with the effect of the paper curve too!

 

[DREW WILEY]

138S - Well, I apologize for using a steer manure acronym. It's an ordinary expression here; but I was unaware of its cultural unacceptability in your case. But back to the pricing issue. I just sent off some 8x10's for C41 processing, and figure that if I was buying that film at current pricing, and adding the current processing rate and minor fees like sales tax and mailing, it is running around $35 USD per shot, and will probably trend upward to around $40 later this year. You can convert that to Euros and see how the overall pricing compares with here.

 

[138S]

Nope. They have to match the sensitometric behaviour between formats because consumers will complain if they didn't

I've never seen a sensitometric difference rolls vs sheets with fresh film, at least with films I calibrated.

Across all internet you won't find a single technical document (even no graph) showing sensitometric or RMSG differences of same modern emulsion in different formats, I challenge you to find it.

Also you won't find any technical reference (Shanebrook, etc) reporting any modification in the emulsion for LF vs rolls, or reporting any difficulty in curtain coating the LF base.

You will find nothing because commonality (when possible) is common sense, and making small batches specific for LF is not about common sense at all.

OK then. Show us

Royal we? Are you two people or more? Dissociative identity ? How many are you ? (take with humor)

OK then. Show us how you'll do this. I'd like to see you convert 160VC into NC.

My point was that two Porta flavors were less a need as vast majority of C-41 film is scanned and by common digital processing the image can be controlled beyond the different nuances the two flavors had.

Anyway, if you want a NC vs VC matching then you can get it perfect.

The most technically perfect way would be a 3D LUT matching colors in the negatives before color conversion. Scans should be made in reference conditions. ie taking 16bit/c all DR in the scanner with all adaptive enhacements disabled.


See the NC VC graphs:




As Spectral Sensitivity and Sensitometry are exactly matching then difference has to be in the final dyes. So advanced colorimetric Math says that a Perfect match can be obtained with a 3D LUT and that it's a kid's game, if mastering 3D LUT colorimetry.

From that evidence, just applying a bare 3D LUT to the raw scan you would have a totally matching emulation, not mattering the scene kind or illumination source in the particular frames.

To me it was interesting to learn that Spectrums/Sensi. were the same in NC vs VC, and that simple difference was only in final dyes.

"Characteristic curves" in the datasheets show an slightly different contrast that it has to come from the final dyes (rather from halides and filtration) because spectral sensitivity is matching. This allows a perfect matching with a simplistic technical approach.

If spectral sensitivity was different (it isn't) a general perfect match could not be obtained, because depending on illumination and on subject spectral reflectance a different 3D LUT would be required for each particular situation.

 

[Lachlan Young]

I've never seen a sensitometric difference rolls vs sheets with fresh film, at least with films I calibrated.

Across all internet you won't find a single technical document (even no graph) showing sensitometric or RMSG differences of same modern emulsion in different formats, I challenge you to find it.

Also you won't find any technical reference (Shanebrook, etc) reporting any modification in the emulsion for LF vs rolls, or reporting any difficulty in curtain coating the LF base.

You will find nothing because commonality (when possible) is common sense, and making small batches specific for LF is not about common sense at all.

Read what I wrote: the emulsions are tweaked to ensure identical performance across all formats and base materials. LF base isn't that difficult to coat today because the discharge equipment is inline - but all the evidence points to every m2 costing more to coat than tri-acetate and requiring alterations to the coating formulae to ensure identical performance to tri-acetate. A minimum coating quantity will produce in the order of 140,000 sheets of 4x5" or 35,000 sheets of 8x10" plus (on the basis of available evidence) more start up and shut down waste than an equivalent tri-acetate coating event.

My point was that two Porta flavors were less a need as vast majority of C-41 film is scanned and by common digital processing the image can be controlled beyond the different nuances the two flavors had.

Anyway, if you want a NC vs VC matching then you can get it perfect.

The most technically perfect way would be a 3D LUT matching colors in the negatives before color conversion. Scans should be made in reference conditions. ie taking 16bit/c all DR in the scanner with all adaptive enhacements disabled.


As Spectral Sensitivity and Sensitometry are exactly matching then difference has to be in the final dyes. So advanced colorimetric Math says that a Perfect match can be obtained with a 3D LUT and that it's a kid's game, if mastering 3D LUT colorimetry.

From that evidence, just applying a bare 3D LUT to the raw scan you would have a totally matching emulation, not mattering the scene kind or illumination source in the particular frames.

To me it was interesting to learn that Spectrums/Sensi. were the same in NC vs VC, and that simple difference was only in final dyes.

"Characteristic curves" in the datasheets show an slightly different contrast that it has to come from the final dyes (rather from halides and filtration) because spectral sensitivity is matching. This allows a perfect matching with a simplistic technical approach.

If spectral sensitivity was different (it isn't) a general perfect match could not be obtained, because depending on illumination and on subject spectral reflectance a different 3D LUT would be required for each particular situation.

That's why I was telling you to show everyone watching this thread your actual approach (with examples) to matching the two films. Not hypothesise vaguely - demonstrate. You quite evidently haven't done the work before making a loudly confident proclamation on the basis of nil experience. If you had, you'd realise it's not as simple as you think - these films use altered colour contrast via dye purity etc, not image contrast. Heavily correcting it digitally won't look very good. And you still haven't answered the logical question of why they wouldn't design both current Portras to the same colour balance if your claims about digital correction have any truth to them. Especially because altering colour warmer or colder is a much easier proposition in terms of a 3d LUT.

 

[138S]

but all the evidence points to every m2 costing more to coat than tri-acetate and requiring alterations to the coating formulae to ensure identical performance to tri-acetate.

You won't be able to point any specific formulae alteration in a modern emulsion to coat on LF base having an overcost. You won't find anything in no book or reliable source because this does not exist.

Curtain in the coating is mantained by adjusting (Shanebrook):

>flow rate,
>lip design,
>angle of slide,
>distance to the web
>air flow in both sides of the curtain
>curtain speed
>temperature
>electrostatic charge
>web speed
>liquid character

Liquid character is the single easy/forFree modification you may do, all layers have a viscosity ranging 20-200 centipoises, ideally all layers have same viscosity. Changing viscosity of layers it would be very cheap, but emulsion is designed to coat well in any machine.

Look, Estar and 3Acetate are coated with exactly the same emulsion and parameters in the same machine. I can happen that you coat in several different machines and one may have a lower web speed, in that situation you may have to adjust some of those parameter to have the curtain stable, the last you would modify is viscosity character of layers (which is cheap, more or less water), if wanting more viscosity you first decrease temperature, for example, as all layers are similar gelatin and temperature makes same effect in all layers.

Please understand that those changes are not related to the plastic base, but to the particular machine specific design, mostly about web speed, it can happen that you have to make adjustments for 35mm film, if you have to coat in another machine because the other is serviced, case you have more than one machine.

http://www.makingkodakfilm.com/

It's just a "waterfall" falling on the web, with some vacuum in the back !!!

Latchlan, please see: Shanebrook p181-262

You quite evidently haven't done the work before making a loudly confident proclamation on the basis of nil experience. If you had, you'd realise it's not as simple as you think

You don't know that.

 

[Luckless]

Well, you're coming in here and making bold statements of fact that directly contradict comments from the late Ron Mowrey, [Former Kodak chemical engineer with his name on a wide range of industry patents.] But, we should totally take your word that all these things are super easy and barely an inconvenience?

You should clearly go digging around expired film patents, build your own coating line, and prove to the world how cheap and easy film is to make and keep profitable. You can be set for life making all the film large format photographers could need, and vastly undercutting the know-nothing giants of the industry...

 

[138S]

fact that directly contradict comments from the late Ron Mowrey, [Former Kodak chemical engineer with his name on a wide range of industry patents.] But, we should totally take your word that all these things are super easy and barely an inconvenience?

Please just explain what specific modifications are needed in a modern emulsion to coat for sheets instead for rolls. Have you a single one?

Don't tell me that's adjusting water content in the gelatins to adjust viscosity for a certain coating machine...

Look, you won't find a single specific one, form ilford, fuji, kodak, adox, foma... there are thousands of books and thousands of patents out there, where such a modification is?

I bet you will be luckless in finding a single one for modern emulsions, I challenge you to find it: You have tons of literature out there.


The single thing you may have to change it's the subbing layer, because it has to adhere well to the particular plastic of the base, beyond that... what do you have to change to coat for sheets ? Any remotely feassible guess ?

https://www.kodak.com/uploadedfiles...wsletters_filmEss_04_How-film-makes-image.pdf

Ron Mowrey

Every week I learn something from him, I have his "PHOTOGRAPHIC EMULSION MAKING, COATING AND TESTING", I'm totally grateful. This is not religion, everthing can be discussed.

 

[warden]

Don't tell me that's adjusting water content in the gelatins to adjust viscosity for a certain coating machine...

We get it already, man. You think it's too expensive. Do you know you've replied to this thread an incredible 73 times? Have you made your point yet or do you need another hundred posts to make absolutely certain your opinion is hammered home? This is an interesting thread to me but your over-posting and arguing with people sucks the oxygen out of the room. I don't have anyone on an "ignore" list but damn man, can you please consider giving it a rest?

 

[138S]

We get it already, man. You think it's too expensive. Do you know you've replied to this thread an incredible 73 times? Have you made your point yet or do you need another hundred posts to make absolutely certain your opinion is hammered home? This is an interesting thread to me but your over-posting and arguing with people sucks the oxygen out of the room. I don't have anyone on an "ignore" list but damn man, can you please consider giving it a rest?

This is true, but 90% I'm only answering to direct interpelations, check it.

My over-posting is due I'm defending alone a minoritary position facing several posters, one of them very agressive going easy to personal disacreditation, rather answering in the same way I try to bring technical facts, which contributes to that over-posting in this case.

Film price has always been a heated debate because some have commercial interests.

If you explore my positions you may find that debate is also technically enriched.

...anyway rather complaining, tell what are those LF emulsion modifications that some say it explains kodak sheet overprice, because nobody showed one...

Also you are free to ignore what you want, of course, I don't feel offended.

 

[Sirius Glass]

This is true, but 90% I'm only answering to direct interpelations, check it.

My over-posting is due I'm defending alone a minoritary position facing several posters, one of them very agressive going easy to personal disacreditation, rather answering in the same way I try to bring technical facts, which contributes to that over-posting in this case.

Film price has always been a heated debate because some have commercial interests.

If you explore my positions you may find that debate is also technically enriched.

...anyway rather complaining, tell what are those LF emulsion modifications that some say it explains kodak sheet overprice, because nobody showed one...

Also you are free to ignore what you want, of course, I don't feel offended.

The reason that you are defending the minority opinion is that you are just wrong. Patents do not tell the whole story. Details are purposely left out so that others cannot duplicate the emulsions easily. Those details are company proprietary information. You do not understand that fact and the rest is based on what you had for breakfast.

 

[Luckless]

The single thing you may have to change it's the subbing layer, because it has to adhere well to the particular plastic of the base, beyond that... what do you have to change to coat for sheets ? Any remotely feassible guess ?

Have you ever worked in a factory setting, that produced anything? Do you have experience in establishing quality control for something even as basic as a box-folder? Not even a box printer, but a box folder: Take ready made and cut sheets that run through a machine to fold them into a box kind of equipment...

You don't walk in the door, load a different film base, flip a switch and watch it go assuming everything is fine. Changing out a subbing layer for mass production coating is not a trivial industrial engineering task, and I don't know why you believe it is.

Production scale chemistry is not 'mix a gallon and we'll correct the next gallon if there is an issue' kind of thing, and what works for a gallon jug of something on a lab bench is not guaranteed to work in hoppers with a hundred gallons of the same chemistry. If something fails during production-scaling, then you're out the cost of an entire batch, and the cost of that batch has to eventually be eaten by all the batches that eventually DO work and can be sold as a viable product.

 

[138S]

Have you ever worked in a factory setting, that produced anything?

Yes, me I manufacture industrial equipment, as small company owner.

Do you have experience in establishing quality control for something even as basic as a box-folder?

Yes, the equipment I produce in my company it incorporates complex Machine Vision systems, with some 1 million C++ personally hand written lines, also incorporating several kinds of machine intelligence for QC: expert systems, neural neworks, genetic algortithms and several kinds of less popular machine learning algortihms it won't be worth I mention you, but if you want I can explain you.

Another discipline I master in practice is chemometry, having implememted inline PCA/PLS to predict chemometric content from spectral footprint.

Production scale chemistry is not 'mix a gallon and we'll correct the next gallon if there is an issue' kind of thing, and what works for a gallon jug....

I'm well aware, I deal professionaly with such kind of things.

_______

I only ask you if you are able to mention a single specific emulsion modification that's needed to coat LF. Do you know a single one? What emulsion modification are you talking about ? Let me know it !!!

Because if you can't point a single one... what are you talking about ?

The reason that you are defending the minority opinion is that you are just wrong.

Ok... What emulsion modification are you talking about ? point it !!

You won't be able...