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z-man
08-06-2007, 09:53 PM
Boy, you scientist types sure can get Nasty! Do they teach that in your PhD program? I think I would rather go to art school.

- Jim

haveing been at both i found the art school phd's the most nasty and sneaky

but seriously now. . .

so why is it that pe is constantly attacked by obvious ringers and shills?????

cause they are payed to------?!?!?!?!?!?!?!?!?!?!?!?!?!?--------you think????????

could it be that pe has revealed to much of what is considered to be proprietary but actually isn't; by those who are in a position to either lose money or gain money?????

FOLLOW THE MONEY

vaya con dios

Photo Engineer
08-06-2007, 10:05 PM
Z;

Too many people want to be heros. To me, this is not being a hero, it is a painful situation. Someone claims to have proof that I have faked my background and was nothing more than a technician or lab assistant.

I ask only for proof of that assertion and a response with their credentials to make their own claims on APUG. I don't criticize them. I leave them open to 'out' my 'lies', but so far, they prefer to go away and act insulted.

If you look on APUG, a challenge to one of these people about a year ago resulted in them saying something like "I will not respond to such childish things" and they left APUG for several months. They never responded to their compaints about me and never published any of their work.

You note that MG has avoided answering my challenge. It is like this.

1. Prove I faked my background.
2. If true, then I have a lot of explaining to do, but if false, they should apologize and back off. They have no proof and lied!

3. If they lied, I have grounds for stating that this is a case of outright slander.

4. Either way, one of us is a liar.

I have proved my work in 4 workshops with many students and with the posts on APUG. You want more? Read my patents, RDs and DPs or my book when it comes out.

I know that Kodak does not care about these petty arguments. People there laugh and say to me "I told you so", and "this always happens". This type of event is why 99% of my associates will not post (or will not post anything of substance) anywhere, or prefer to lurk.

PE

mgarelick
08-07-2007, 09:39 AM
All I will say about my education is that I have more than an AS degree. My professional experience is not with emulsion technology. From my private communications with Ron there are certain areas he was lacking on critical information relating to matrix film technology and many other areas. I know who a few people are that actually worked in this area for many years and contradict what Ron tells me is proven fact when in fact it is not. I can back up nearly everything I say in regards to matrix film technology with peer-reviewed publications, patents (sometimes useful but are not peer reviewed scientific papers), books, experts and my own experiments with Kodak matrix films. If he wants to argue and attack me on this forum I have the information that will contradict his claims and will post it here. I should also make everyone aware that Ron Mowery (“Photo Engineer”) attacks my work with people he speaks to privately. And it seems that Ron has been very successful using his BS to convince others to ignore me.

I do make dye transfer prints and I can certainly show anyone the proof if they need it. I work with old stock Kodak matrix film 4150 and Kodak pan matrix film 4149. If seeing some test prints from me would convince Ron, I’m not just trying to post conjecture or speculation on how I think a matrix film should perform I can send some scans.

This subjective approach that Ron takes will not work with matrix film technology. It doesn’t work well when describing techniques in DT as well. Ron also claims in Internet forums and privately that seeing the resulting prints indicate a degree of technical competence among the amateur experimenters. Sometimes Ron wants people to prove themselves to him to even listen to them, and not accept reasonable information. Matrix film technology has many special areas that few people know anything about. Any of Ron’s statements would need to be verified experimentally, as he is not qualified in this area to say whether something will work or not in a matrix emulsion without testing it. For example, Ron has never tested the red sensitizing dyes he recommends. Ron claims that he doesn’t have IR goggles for working in total darkness. They really are not that difficult to obtain and I have been asking him privately about panchromatic matrix emulsions for a couple of years now. I think Ron should prove that he could coat a functioning panchromatic emulsion in his home laboratory using his coating blades. This doesn’t need to be a matrix film but it will prove that those sensitizing dyes he recommends do work well.

Ron, why don’t you explain why you don’t agree to the peer review process in scientific research? Why are the amateurish sloppy experiments you so often cite a preferable means for you to determine whether there is a success or failure for a particular emulsion, procedure or in determining a level of competence?

How do you know Ron that the Melinex 583 stock doesn’t absorb dye aside from seeing Jim Browning’s prints? Do you know this from an empirical basis for this statement of yours? Have you ever attempted to measure it compared with the Kodak matrix film (ortho or pan)? Do you have a densitometer to measure the dye fog level? Subbing adhesives are designed to adhere hydrophilic gelatin emulsions to a hydrophobic polymer support material, so they have a mixture of both hydrophobic and hydrophilic components. Anionic dyes used with the process generally have some degree of affinity to these substances as Jim Browning noted for the Dupont Cronar film. Here are a few reasons why I believe there is a slight dye fogging: the Melinex 583 polyester base has some kind of aqueous coating that has been found to adhere the gelatin to the film base but I would imagine there are still some cations that form or a weak interaction with certain functional groups that the dye will be attracted to. In fact the scans I have from a few prints made from Ekfe matrix film WITHOUT a highlight reduction treatment do show the whites to have magenta and slightly yellow fog to them. I never tested the Efke film myself, but I have reason to suspect there is a very small dye stain forming that isn't there on Kodak pan matrix film. Also there are people I'm in contact with that actually coated matrix film emulsions and they tell me exactly the same thing, being that virtually any emulsion adhesive (designed specifically for subbing silver halide gelatin emulsions) will cause a small amount of undesirable dye staining.

If Ron ever looked at his old pan matrices he made and not photographs of them he will find they have a blue-black cast to them. This blue color results from a pigment dispersion within the gelatin itself. Earlier matrix films did in fact contain carbon. Experts in matrix technology have told me exactly the same thing. Any dye either cationic or anionic will wash out of the matrix film at either below or above the isoelectric points for either type of dye, respectively. Before hardening by the oxidized pyrogallol (oxidized tanning developer) takes place the gelatins isoelectric point of Kodak Pan Matrix film 4149 is around pH 8.5 (+/-0.5 measured by myself), so an anionic dye will wash out of the gelatin at above the pH of its isoelectric point. I have some old stock of pan matrix film and performed this experiment. The “dye” does not wash out at all. I have also placed the unprocessed film in a solution below its isoelectric point and nothing happens. This tells us that either the dye is poisoning the matrix gelatin or it’s a pigment dispersed in the gelatin. The acutance dye must not poison the matrix gelatin in any way, so this possibility is false. I have evidence to believe Kodak Pan Matrix film has a small amount of carbon in it part of the pigment suspension.

The very first matrix film was invented in 1881 for the Hydrotype process and did contain carbon black as a relief forming pigment, I have read. The book Colour Cinematography by Adrian Cornwell-Clyne, second edition 1950 has some information on the history of the dye transfer processes and lists every process until 1950 starting with a description of the monochrome Hydrotype process. It even has the actual Technicolor dyes used in the London plant during the 1930’s and lists every Technicolor patent (US, UK, etc.) relating to its dye transfer process until 1950.

Who is this other former Kodak engineer that remembers what they added as an acutance material in pan matrix film 4149? People that coated films usually don’t know very much about the films they make. Does this colorant have a CI number? This is actually interesting because Ron told me privately by email last fall that he believed there was “no-one alive” anymore who coated matrix film. I know there are people alive that coated this film (aside from the technical experts I spoken to) but you will probably never see them appearing publicly on Internet forums! This may be another example of Ron’s grandiose thinking in that he is claiming to have more information and more sources than he actually does. From what he implied there was one person he knew that had information relating to matrix film manufacture.

I am more than 95% sure Ron’s pan matrix film formula will not be successful with the single emulsion method. One would probably need to make three different films: a film sensitized for red, green and blue. Andy Cross a dye transfer printer from Australia says Jay Patterson of the former Dye Transfer Co. tried to make a panchromatic matrix film and was only able to make it work with three separate films. I don’t believe he ever sold any of this film or orthochromatic matrix film commercially because from what I have heard from others who spoke to him, he believed the films and papers were not of the level of quality that he wanted. Also a matrix film made by Defender for the dye imbibition transfer Pan Chroma Relief Print Process was panchromatic, I think. This was commercially available until the 1940’s or early 1950’s. From what I remember reading about this, this process used three different types of sensitized matrix film to form tricolor images. From what I can gather reading about it this process was inferior to the Kodak Dye Transfer process and much more difficult to use. Useful dyes I would recommend can be found in US patent# 5620833. An expert who designed matrix emulsions told me about this patent. This patent has a partial formula for three different types of matrix emulsions each sensitized for red, green and blue. This patent lists four spectral sensitizing dyes for use with a matrix film titled in the patent BSD-1, RSD-1, GSD-1 and GSD-2. The sensitizing dyes and the basic components in the matrix film are not what was actually used five years ago, but serve as examples of useable components for matrix emulsions. Gelatins are very critical with these types of emulsions having certain characteristics e.g. isoelectric point [extremely critical with matrix film dyeing properties], purity, melting point, glass transition temperature, dielectric permittity, elastic modulus, etc. Also this uses carbon as the depth penetration relief forming material. For matrix film emulsions used for tricolor printing, the curve shapes should all align well with this method.


M.

Photo Engineer
08-07-2007, 10:09 AM
Interesting Michael;

I have seen a thick stack of used matrices made by Jim Browning and they were not colored in any way. His prints are vibrant and have clean whites with matched toes and no color cast in the dmin. This is with both hand coated film that he made and with film from EFKE all on Melenex support.

The former Kodak engineers you speak of are concerned with your messages and are blocking you now from their e-mail. I'm sure you know that so why bring up private e-mail? You argued with them and namecalled in private e-mail to friends of mine, as you well know. I won't go any further with that.

The following is a quote from one of your posts here:
-------------------------------------------------------------------------
In addition to not having extensive knowledge in materials sciences Ron is simply misrepresenting his past at EK. The people that actually design emulsions normally have Ph.D degrees in chemistry, materials sciences, chemical engineering and physics. Nearly all of the papers published in peer reviewed scientific publications by Eastman Kodak scientists normally have at least an MS degree. It is absolute total nonsense that EK was hiring people with Associate degrees to design emulsions. Those people like Ron are technicians, engineering aids, etc.
----------------------------------------------------------------

This is either a lie or the truth. Justify it please and don't blather on, or apologize.

In the final analysis, the proof of dye transfer being far less sensitive to all of the parameters in your claims is the fact that the Matrix film formula of Jim's works. My philosophy is that if it works, use it.

As for Pan Matrix film using carbon. My word is that it was a dye. It came from an engineer who worked with it. I never worked on any dye transfer product in research. I've done them, but done no research as all research had stopped in 1965. They just did minor changes to the dye formulas in another division.

Louie Condax and Spot Inkley complained about the lack of research, but there it is. So, I never coated it, nor have I claimed to have.

Since you are sure that my suggetsion to make a Pan Matrix film are wrong, you must have done the experiments, or at least you are an expert in spectral sensitization. Right?

I probably did my first spectral sensitization experiment when you were in diapers. I cannot be perfectly sure that what I posted will work, but I have pointed a direction as I said in my post. Before I posted that, I did do experiments with the dyes mentioned on one of my emulsions to verify the levels and the effects. They worked as specified. And, I have used that method before.

I get my dye suggestions from Paul Gilman himself. In fact, I get information from a lot of sources. Therefore, reading peer reviewed papers is not needed. I get information from the author in many cases.

If you wish to see my credentials, look in the front of Haist. My name is there among others who contributed to the book. I was a peer of Grant's. That is my proof, what is yours to the contrary?

PE

Photo Engineer
08-07-2007, 04:13 PM
After thinking this over, I decided to mention that there is unpublished (AFAIK) work by Liang, Tong and Willis that prove that dye forms both a 'salt' with gelatin, but is also entrapped by the gelatin coils in the matrix of undenatured gelatin. The amount depends on swell or uncoiling of the gelatin matrix.

Thus, isoelectric point becomes less important in Dye Transfer and allows transfer of dyes in instant products at a pH of 12 or higher with bone gelatin. The gelatin holds two reservoirs of dye. In fact, in instant products the transfer of dye is continued from a pH of over 12 to one of about 4 simply by depleting this reservoir. A similar methodology may be inferred in DT products based on the ease with which Browning achieved a workable solution to this apparent problem.

Also, it might be well to comment on the fact that the DT dyes do not complex with Thorium Nitrate per-se but rather change hue (by a small amount) as a function of the salt they form. A real hue change caused by complexation is found when a dye which is magenta, complexes with a metal salt and forms a cyan dye. This was the basis of the patents by Kodak on metalized dyes. It also confers extremely high dye stability, beyond that observed in DT products. A dye group forms a cage around the metal as well as forming a salt.

It may also be of interest to note that "J" aggregates are found in at least 3 forms and that "H" aggregates rate a one sentence comment in Mees and James who infer (but do not state) that this is just a special case of "J" aggregates. Of course there is Hypersensitization, Unsensitization, Desensitization and a host of other interactions that one could discuss.

I hope this helps clarify some things posted here.

PE

KenM
08-07-2007, 06:51 PM
I've found this discussion really quite interesting. While I have no intention of ever making my own emulsions, I do find the technology behind the art a good read.

However.

Personal attacks have no place on this forum. Guys, relax. This is an exchange of information, a watering hole for photographers after a day of photography, a place of knowledge. The last thing we need is for people get get into a pissing match over credentials, over what someone says, or whatever. Disagree, sure, but think before you post that note - would you say what you've typed to someones face? Would you, really?

Relax. Have a home brew. Make some photographs.

BTW, I'll invoke Godwin's law here: http://en.wikipedia.org/wiki/Godwin's_Law

At this rate, we're approaching 1 pretty fast.

Photo Engineer
08-07-2007, 07:13 PM
Ken;

I couldn't agree more. OTOH, I am continually bombarded with these accusations that I'm falsifying my background or my data. What would you have me do? This topic, emulsion making and coating, seems to bring out the worst in people out there for some reason.

I have made no personal attacks BTW, but have asked for proof of the claims of another person, or a retraction.

After over 3 years of this, I am becoming quite sensitized to this and annoyed. As I said elsewhere, I have only 2 choices; withdraw from APUG or take the abuse. I can face it and stop it of course but this is not looked on kindly by most as you indicate in your post. To just sit back and take the abuse is rather unpalatable and I think you would agree if you considered the matter by putting yourself in my place. Nevertheless, I agree with you in principle.

In addition to the above though, I hate to see incorrect information being spread which sometimes takes place under these circumstances.

PE

Michel Hardy-Vallée
08-07-2007, 07:49 PM
After over 3 years of this, I am becoming quite sensitized to this and annoyed. As I said elsewhere, I have only 2 choices; withdraw from APUG or take the abuse. I can face it and stop it of course but this is not looked on kindly by most as you indicate in your post. To just sit back and take the abuse is rather unpalatable and I think you would agree if you considered the matter by putting yourself in my place. Nevertheless, I agree with you in principle.

Dyes should be hypersensitized, not you, Ron.

So far the other fellow has not provided any evidence for its accusations, so I'd suggest his posts/accusations be removed.

David A. Goldfarb
08-07-2007, 08:20 PM
I think at this point the posts speak for themselves, and it's not really necessary to push it any further. Ron, you've presented your background and your work, and if the other party doesn't have an answer, well, that's an answer.

bdial
08-07-2007, 08:24 PM
Ron,
You have my profound respect. I am one of probably several members who find your information on emulsion technology and emulsion making fascinating, even though we may never attempt to try it. (I'm hoping that it doesn't become a necessary skill in my remaining lifetime).
FWIW, I plan on buying your book whenever it becomes available too.
Speaking for myself, you would be sorely missed here where you to leave, I'm confident that many others would feel the same.

There is nothing wrong with a spirited debate, but personal attacks aren't warranted, I agree with Michel's opinion on removing the offensive posts.

Barry

Photo Engineer
08-07-2007, 08:28 PM
David;

Amen.

PE

mgarelick
08-08-2007, 04:35 AM
After thinking this over, I decided to mention that there is unpublished (AFAIK) work by Liang, Tong and Willis that prove that dye forms both a 'salt' with gelatin, but is also entrapped by the gelatin coils in the matrix of undenatured gelatin. The amount depends on swell or uncoiling of the gelatin matrix.

Thus, isoelectric point becomes less important in Dye Transfer and allows transfer of dyes in instant products at a pH of 12 or higher with bone gelatin. The gelatin holds two reservoirs of dye. In fact, in instant products the transfer of dye is continued from a pH of over 12 to one of about 4 simply by depleting this reservoir. A similar methodology may be inferred in DT products based on the ease with which Browning achieved a workable solution to this apparent problem.
PE

I can name numerous peer-reviewed papers that examine swell of gelatins and dyeing properties for both anionic and cationic dyes with three mainf types of gelatin. ... This property of gelatin obtaining an affinity for anionic dye below the pH of its isoelectric point has been studied and is well understood. Empirical scientific evidence for this property of dye affinity for gelatins of given isoelectric points has been published by S. E. Sheppard, R. C. Houck, C. Dittmar titled "The Sorption of Soluble Dyes by Gelatin” in the Journal of Physical Chemistry v. 46 (1); 158-176 (1942). I can supply anyone a copy if you would like. If you read this you will find that swelling of gelatin does not have a very large effect in determining dye density. Swelling of gelatins was studied thoughly in this paper. This is also unprofessional of Ron to quote an unpublished paper when there is no way of verifying it. A 0.5 CHANGE IN THE GELATINS ISOELECTRIC POINT WILL CAUSE HIGHLY SIGNIFICANT CHANGES IN PRINT DENSITY!!!!!! This is based on the isoelectric point of the gelatins used in the tests. These differences cannot be corrected by altering pH of the dyes past a cartain point.

Please get a copy of this at an academic library.

Having dyes form salts in the gelatin will slowly poison it! It can block the charged regions of the gelatin proteins. I can find peer reviewed papers to back this up.

If others don't do their own research no one will make any useable films. ...

mgarelick
08-08-2007, 05:02 AM
Ken;
I have made no personal attacks BTW, but have asked for proof of the claims of another person, or a retraction.

PE

I have copies of email messages from two trusted colleagues of mine that Ron does attack me in private communications with others. He is attacking me here also; just in a more settle way. Regarding your misrepresentations I don't think it would be a good idea to prove it on this thread. I have many examples of Ron's lies. This doesn't help people make a functioning panchromatic matrix film. My intent is to expose Ron's attempts to interfere with emulsion projects and cause inferior results.

Regarding Ron's background I have no doubt that he worked at EK and has the credentials he says. He often distorts it in private communications to a point I would consider lying. The areas of gelatin chemistry, solid state physics, material sciences and other areas convince me that he has large gaps in his knowledge of emulsion science.

Ron does not know who all the experts I am in contact with are. The people I cannot discuss are not in contact with Ron or his group or Jim Browning or anyone that regularly communicates with Jim Browning. I again consider this an attack against me on this forum.


M.

Photo Engineer
08-08-2007, 09:36 AM
The work of those I cite regarding the dye - gelatin interactions dates from the 1980s, and for all I know is unpublished. This is far more modern work than that from 1942. There was a lot of understanding of gelatin - dye interactions in the intervening years during development of instant imaging in order to understand dye migration. I have read much more modern work internally at Kodak and fully understand it. It indicates that path length (swell) is as important as any effect of isoelectric point, and indicates that the coiling of gelatin is important in determining path length.

In any event, the fact that print density might change with isoelectric point is immaterial in this case with Jim's coatings, as they work perfectly well. And, that seems to be what the argument of isoelectric point is all about. Jim has something that works and another person is arguing that it isn't a good solution. IDK how that can be argued in the face of success.

I rarely make unsolicited comments about people in private mail, but when I do it is for a good reason. I have no cause to discuss my credentials with colleagues, friends or students, nor do I discuss them unless solicited or questioned as here. I would rather earn my way here by the nature of my posts.

PE

ben-s
08-08-2007, 08:02 PM
While I certainly don't want to further inflame a potentially nasty thread, I would like to say this;
I deeply respect Ron for his work and the fact he is prepared to share his knowledge. I am evidently not alone in this view.
He is obviously very knowledgeable on the subject of emulsion making and coating.

Mgarelick; As Bob M has already stated, we would be interested to see your work. If you are able, please post some examples.
Likewise, if you can prove Ron is not who he says he is, I'd like to know about it. I expect more stony silence on this point... Ron has never struck me as being a liar, either in public or private conversation.



Before you start posting anything you should have some repeatability. Anything done in scientific research requires that the experiment be repeatable.

May I point you in the direction of Denise Ross, who is using one of Ron's formulas? She is getting good repeatable results: DWR Photos - Emulsion Research (http://www.dwrphotos.com/blog/EmulsionResearch.htm)

As an aside, I'm not overly impressed by your unprofessional approach to the forum. It is comprised heavily of amateurs, who resent having mud slung at them -

Ron finds truth from highly amateurish experiments done by unqualified individuals and claims to understand how they work from them. He infers facts about physical and chemical properties from these sloppy amateurish experiments that are poorly documented, poorly tested and poorly researched.
Ron doesn't strike me as a sloppy researcher. I doubt he would have lasted long in Kodak if he was.
In addition, nearly all of the early researchers in photography were amateurs. They got results. Why shouldn't modern day amateurs do likewise?

Why pull someone's work apart when they are getting good results? Jim Browning has a very workable film with which he can feed his (and others') interest and practise his craft. Put in context, does it really matter if it doesn't precisely emulate Kodak's material? - "If it ain't broke, don't fix it" comes to mind.

Gustavo_Castilla
08-08-2007, 08:05 PM
So how may people have try to do this successfully?

mgarelick
08-08-2007, 11:01 PM
The work of those I cite regarding the dye - gelatin interactions dates from the 1980s, and for all I know is unpublished. This is far more modern work than that from 1942. There was a lot of understanding of gelatin - dye interactions in the intervening years during development of instant imaging in order to understand dye migration. I have read much more modern work internally at Kodak and fully understand it. It indicates that path length (swell) is as important as any effect of isoelectric point, and indicates that the coiling of gelatin is important in determining path length.

In any event, the fact that print density might change with isoelectric point is immaterial in this case with Jim's coatings, as they work perfectly well. And, that seems to be what the argument of isoelectric point is all about. Jim has something that works and another person is arguing that it isn't a good solution. IDK how that can be argued in the face of success.
PE

I never said swell isn't involved with the complex charge interaction it just doesn’t effect dye density to any measurable degree. In fact during the dyeing of a gelatin the swell DECREASES and this is measured in this paper also, I believe. This also doesn’t need more recent papers to prove this concept. For example, a gelatin whose isoelectric point is at pH 4.8 will not absorb any anionic dye at pH 6.0! The dye will simply wash out although the gelatin does still swell a lot, this is independent of the swell profile for the gelatin.

To further clarify this situation let me use the following example of two dyes. If we assume a matrix has a gamma of 1 for the silver image with a constant pH acid solution these dyes will produce a higher gamma compared to other dye at identical pH with multiple anionic groups. The more anionic groups it has to its molar mass the lower its imbibition contrast. This is due to the fact that the hardened matrix gelatin exists at a certain isoelectric point and contains charged regions that attract negatively charged dye molecules. The higher the number of sulfonate groups it has the more charged regions in the gelatin are occupied by the one dye molecule. Thus a dye consisting of one sulfonate group will have a much higher dye contrast from Acid Red 80 than Kodak yellow does at the same pH as is supported in the published literature. If we dye a sheet of gelatin isoelectric in the acid range using a dye bath consisting of equal amounts of both an anionic magenta dye with one sulfonate group and an anionic yellow with eight sulfonate groups (Kodak yellow has three), the resulting color on the gelatin will be mostly magenta or pinkish. This is due to the charge effect on the dyes with the gelatin. Anyone can try this experiment and verify the results.

Technicolor is the only company to study the interaction of imbibition dyes with gelatin more than anyone else in the world. They find that suppressing swell is necessary for sharp prints. In fact the matrix film they have developed can easily produce a Dmax of 5.0 and swell less that Kodak's pictorial matrix films. I have spoken with a few experts from Technicolor and they tell me that there is no need to make their matrix film swell more to accept dye. They also spent several million dollars in research developing special dyes with special characteristics. The latest motion picture dye IB transfer process developed during the 1990's is at the same level of sharpness as Eastmancolor with much better quality!

Photo Engineer
08-08-2007, 11:38 PM
Unfortunately, your explanation is offset in part by the increase in size of the molecule. The size increase will slow down dye diffusion but as you also see effects from charge. Models attempt to separate out these effects. In the end, Isoelectric point is less important in some cases than the path length and size of the molecule. A cyan dye with 3 azo groups and one sulfonate can diffuse more slowly than one with 2 azo groups and two or three sulfonates. Of course 3 or 2 azo groups can both yield cyans, and two or one azo groups can give magentas with the right side groups. This further confounds the picture as does the localized charges in the molecules due to side groups.

This is a very complex intersection of materials science and organic chemistry that can often only be solved by empirical experiments in some cases.

A big fat Guaiazulene dye will be very difficult to diffuse but may give an excellent cyan or magenta depending on pH. It is path length and coil size of the gelatin that can overwhelm the effects of isoelectric point, but then selection of other dyes tilt it the other way. This fused ring type of dye structure completely offsets some predictions.

The bottom line is the resultant print though and not these discussions.

There were many solutions to the problems presented by Dye Transfer and Kodak selected the most economical. There were others that might have been better and others that were 'don't care' situations. This is important here as well and cannot be ignored!

Jim Browning's method works nearly perfectly but is somewhat different than Kodak's method. This is an example of an empirical solution optimized for result rather than economy or production I would suspect.

That is what I'm trying to get across. The major factor in this equation is what the producer is trying to do, as the actual useful envelope is broader than you might imagine.

Also, the requirements for 'sharp' prints at 35mm or 70mm size for projection is different than that for a reflection print. Trying to compare these is like comparing apples and oranges. In fact, the Technicolor I remember was two color and one version had dyes applied to opposite sides of the support. The transmission products and reflection products differed so greatly that this is a futile argument.

We may also argue, just for the sake of mentioning it, that Technicolor has virtually vanished in the presence of modern color negative motion picture films. The sharpness of ANY transmission image transfer is poor in the presence of a comparable chromogenic film. The same is true for reflection products but is hard to see without side by side comparisons.

PE

Sean
08-09-2007, 01:43 AM
While I certainly don't want to further inflame a potentially nasty thread, I would like to say this;
I deeply respect Ron for his work and the fact he is prepared to share his knowledge. I am evidently not alone in this view.
He is obviously very knowledgeable on the subject of emulsion making and coating.

Mgarelick; As Bob M has already stated, we would be interested to see your work. If you are able, please post some examples.
Likewise, if you can prove Ron is not who he says he is, I'd like to know about it. I expect more stony silence on this point... Ron has never struck me as being a liar, either in public or private conversation.




May I point you in the direction of Denise Ross, who is using one of Ron's formulas? She is getting good repeatable results: DWR Photos - Emulsion Research (http://www.dwrphotos.com/blog/EmulsionResearch.htm)

As an aside, I'm not overly impressed by your unprofessional approach to the forum. It is comprised heavily of amateurs, who resent having mud slung at them -

Ron doesn't strike me as a sloppy researcher. I doubt he would have lasted long in Kodak if he was.
In addition, nearly all of the early researchers in photography were amateurs. They got results. Why shouldn't modern day amateurs do likewise?

Why pull someone's work apart when they are getting good results? Jim Browning has a very workable film with which he can feed his (and others') interest and practise his craft. Put in context, does it really matter if it doesn't precisely emulate Kodak's material? - "If it ain't broke, don't fix it" comes to mind.

Well said.

mgarelick
08-09-2007, 04:44 AM
Unfortunately, your explanation is offset in part by the increase in size of the molecule. The size increase will slow down dye diffusion but as you also see effects from charge. Models attempt to separate out these effects. In the end, Isoelectric point is less important in some cases than the path length and size of the molecule. A cyan dye with 3 azo groups and one sulfonate can diffuse more slowly than one with 2 azo groups and two or three sulfonates. Of course 3 or 2 azo groups can both yield cyans, and two or one azo groups can give magentas with the right side groups. This further confounds the picture as does the localized charges in the molecules due to side groups.

This is a very complex intersection of materials science and organic chemistry that can often only be solved by empirical experiments in some cases.

A big fat Guaiazulene dye will be very difficult to diffuse but may give an excellent cyan or magenta depending on pH. It is path length and coil size of the gelatin that can overwhelm the effects of isoelectric point, but then selection of other dyes tilt it the other way. This fused ring type of dye structure completely offsets some predictions.

The bottom line is the resultant print though and not these discussions.

There were many solutions to the problems presented by Dye Transfer and Kodak selected the most economical. There were others that might have been better and others that were 'don't care' situations. This is important here as well and cannot be ignored!

Jim Browning's method works nearly perfectly but is somewhat different than Kodak's method. This is an example of an empirical solution optimized for result rather than economy or production I would suspect.

PE

For my example we are assuming that the molar masses of both dyes are about the same. We are also assuming that the diffusion rates of both are equal and there are no other attractive forces between the molecules except for the forces induced by the charges of the sulfonate groups. In actual case there are many differnt factors but don't effect the empirical result very much.

Actually the accepted dyeing theory of proteins including gelatin involves charges and isoelectric points not the path length nonsense Ron insists is so important. The charges on the dye and gelatin are an empirical property. I need to point out that what Ron is stating in respect to path length is not science, comes from him and has NO empirical basis!!! The empirical basis is due to charges from dye molecules and gelatin and is orders of magnitude more significant that variations in path length. In other words Ron really needs to look at a chemistry textbook and that paper I recommend.

Ron, did you ever place a dyed matrix in a bath of pure water for five minutes or so? What happened? I have done this and the dye washes out. If we consider the swell profile for Kodak matrix film there is really no large difference between neutral pH (7.0) and the pH range where dyeing occurs. The dye and gelatin are conforming to the accepted theory.

That paper I recommend Ron read uses "photo grade" gelatin and examines swelling curves and dying curves along different pH ranges. You will see some experimental proof for which he is absolutely afraid to believe! Another part that will probably scare Ron is that the authors are all Kodak scientists that understand gelatin chemistry much better than he does.

There probably are cases where coil size and path length may be important. The paper I recommend tests a few types of common imbibition dyes. Guaiazulene dyes are not used for dyeing matrices, so Ron may be speaking of a rare case where there is an exception to the theory of dyeing proteins (assuming he knows what he is talking about). This theory works for any anionic dye. If there are other types of dyes that exhibit some other force of attraction to the gelatin proteins it may be true that isoelectric point would not be important in those cases. THOSE ARE NOT WHAT WE ARE DEALING WITH IN DT!!! However there are other rare cases where this would be true as described in the scientific literature (that one could find in a library).

The important point is EVERY common anionic imbibition dye is subject to the laws of the dyeing theory of proteins. There are ways to improve on it but they all relate to the empirical properties. This gelatin sponge analogy is actually a myth among DT printers. For example, Bob Pace believed matrices absorbed dye because they acted like sponges and capillary forces trapped the dye in the matrix and the acid fixed the dye in place so it didn't bleed. Ron needs to know this is a myth and doesn't involve path length and the coil size BS that he cannot reference a single published paper anywhere to verify it.

Let us assume for a moment that Ron really is correct and the accepted scientific theory published everywhere has it wrong. If we look at the volume occupied by the gelatin relief itself and compare that to an equal volume of dye solution the density will be very low probably <0.1 D on print (approx. 2X the density of matrix), and we would see this on print very light and not even close to 2.7 D Dmax! Basically we find density using the Beer-Lambert law constant for the dye solution. We know the dye solutions used in DT are on the order of 10-3M or about 1.5 g/l. So we know the gelatin is absorbing dye from the dye solution not just dye solution like a sponge does. The dye density measured in the gelatin relief is significantly greater that the same length of dye solution in the gelatin substrate. Ron must be incorrect. This proves dye molecules are attracted into the gelatin matrix and NOT simply absorb dye solution.

Jim Browning's film is a 19 century film and in no way does it work "nearly perfectly". Ron you never tested the residual dye stain level experimentally!!! Anyone can say Jim's prints look fine or not; that is not being scientific. Please Ron if you have a densitometer measure the Dmin from one of Jim's grayscales made with his film without any highlight reduction treatment.