certainly from the 50's to the 80's
Professionals could get Data sheets from both Kodak and Ilford on every product.
They were incredibly detailed and ran to many pages. Developers were tested with all of their own films and most leading brands. There were graphs, characteristic curves and data covering every aspect from gamma to density, dilution, agitation temperature, response to wave lengths of light, sharpness grain characteristics.
in fact every aspect you could imagine. nothing was left to chance.
The figures were accurate in the testing conditions specified and were repeatable.
Professional sheet colour film came with testing data for that particular batch. and gave correction factors for exposure and colour away from the normal. Particularly for long exposures.
don't forget people like jerry katz at photo lab index ...
he and others did exhaustive tests on films, papers and developers
it seems that it was not only the manufacturer but a lot of people
"in the industry" did a lot of tests ( including labs, professional photographers &C )
Dear Michael R
What is correct and what is incorrect ?
Firstly, at HARMAN we have a technical service department this covers QC Complaints, new product evaluation, competitor product evaluation and technical writing for for photo as well as inkjet. Also under the technical service head is the ILFORD processing and lab service.
We also have a QS Department or quality services department, they do all the online QC testing, processing, printing etc for the actual QC Before and during manufacturing.
For example :
Before : All raw materials are tested against the specifications before they can enter the manufacturing process.
Manufacturing : Film and Paper is coated : Multiple samples are taken and processed from every parent roll and evaluated against the specifications. This is for a huge range of performance factors both physical such as adhesion as well as for its sensitometric performance, The film and paper is then 'conditioned' or 'rested' to harden and further samples are taken, after it has passed those tests the film and paper is passed for converting or 'finishing' further samples are then taken and processed from the finished goods to test the finishing process etc, then samples from every finished batch are taken and stored ( for 5 years ) so they can be processed at anytime in the future against any QC enquiry. All our chemical products are also tested.
But I am sure your interest is in our product evaluation...
We have our own darkrooms, lots of them, R&D may do their own work and processing, only when it is a product would tech service 'evaluate' or be 'given' the product, it is their job to write the specifications and user guides ( clue in the word there! ) they evaluate from a host of different applications, they would then and only then pass the the film as fit for purpose and launch..
Take film ( last new film made was the two new KENTMERE emulsions ).
Photography, set procedures as well as random, indoor, outdoor, low light, bright light etc, etc, etc,
Manual processing,including different tank types, single film, multi film, mixed film, machine processing, push processing, latent image performance, physical performance heat and cold testing, different agitation methods, reticulation, different developers - not just ours, different temperatures on and on and on,
Tech service do all of this! and the sensitometry and produce the TI or Technical Information sheet.......it does take time.
They then produce a set of processing times ( in a wide range of developers, not just our own, but by no means exhaustive ) set to to a prescribed standard to produce an average density neg.
For sure, many people 'disagree' with our processing times, that is absolutely fine, they are a GUIDE, I have seen so many people on APUG say find a film, find a dev, find a process regime that works for you and stick to it and how right they are in my opinion, you do not have to have just one, just make sure you do the same thing every time, I use a lot of DELTA 3200 hand devved in DDX, I also use HP5+ devved in ID11 as well... I have the process written down and do it the same every time. No pre-soak high dilution, slowish dev, 10 seconds agitation per 60 secs of development, then chuck the dev.
But most important of all in testing : Customer evaluation :
During the testing or pre-launch stage of any product, in HARMAN known as the SP stage, we involve many fantastic photographers and printers from around the world, not only professionals, who kindly test the products that they are provided with and give us exhaustive feedback, both good and bad, in relation to the product used within the application that they specialise in. This way we have experience of the product in the real world and not just under controlled conditions.
Our maxim is :
NEVER ever presume what your customer wants, ask first, evaluate, make it, test it, and then finally CHECK back with your customer...if the circle has truly been completed LAUNCH, if not... start again...
Hope that helps...
Simon. ILFORD Photo / HARMAN technology Limited
Thanks so much for writing, Simon.
First - I totally agree there is not necessarily a "correct" or "incorrect" when it comes to guides, instructions etc. There are too many variables.
So at Ilford, the Tech Service department goes to work on all the darkroom, hands-on testing after the R&D phase. And based on your description, there is indeed a LOT of testing work. This is what I was getting at in my initial post. When you stop and think about it, it is really a huge amount of work given all the variables involved. And that's not to mention all the testing that goes on during the initial R&D phase. Hopefully one day I'll get to visit some of your facilities. It is fascinating to me.
Thanks again for all the support you give to us on APUG.
Sourdough, salami and blue cheese... and 2 dogs drooling with such sad, sad eyes. ... they're working me... they know I'll cave!
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Dear Michael R,
You are spot on... its all the variables.... and do we get it 100% correct each time, no we don't...
I suppose its about time we did another APUG factory tour? I will ask the board of directors.
Simon. ILFORD Photo / HARMAN technology Limited :
Dick Henn, when in the lab, may have had from 1 - 3 technicians working for him. When I knew him, he had about 20 graduate scientists (chemists, engineers etc..) working for him and each of them had up to 3 technicians.
Lab experiments were designed, coated, tested and evaluated - often in experimental processes so that early on C22 might have been used for color film and then they changed to C41 when the coatings were hard enough and the development and bleach cycles were ironed out. We worked on a test, deign, coat cycle of about two weeks total for all 3. Each coating set would contain a reference and up to 11 experiments. We got single layers of each experiment as well. Along with that were raw B&W coatouts of each emulsion. The emulsion makers ran loads of tests before we got them and I could give a long description of that as well!
Anyhow, once something looked good at 4.5" width, we went to 11" or 4.5" at high speed on the large KRL coater called J9. It sat on the top of B-59. Then we coated film on 21 machine (21" wide). If the coating looks good at 21" width, it is then scaled up to production.
At that point, all films (color and B&W) are run through a standard seasoned process. For B&W, the standard is (or was) D-76. All tests were run using a 1B Sensitometer set for Daylight or Tungsten illumination (depending on product). All films were tested for spectral sensitivity using a Spectro Sensitometer, and for sharpness and grain using special instruments. All products were tested for raw stock keeping, reciprocity and latent image keeping, and the images were tested for image stability using high intensity illumination, high teperature, high humidity, pollutant gases and combinations thereof.
(BTW, sharpness, grain and some other contrast dependent (and image polarity dependent) characteristics cannot be easily compared between film types. For example, it is difficult to compare a reversal and negative color image due to polarity and contrast.)
Again, for every batch of film, all chemicals and emulsions were pretested for suitability before the coating was even made and so each ingredient and each emulsion would go through dozens if not hundreds of pre-approval tests before being used in a product.
Does this help?
[QUOTE=Simon R Galley;1246873
I suppose its about time we did another APUG factory tour? I will ask the board of directors.
Simon. ILFORD Photo / HARMAN technology Limited :[/QUOTE]
That is an announcement that I would love to see.
Michael's specific question was who generates the data to populate the time/temp/developer charts that are provided in each film's data sheet, and how do they do it. How did that work at Kodak?
Originally Posted by Photo Engineer
My post covered all phases, but my 4th paragraph summarized what Simon posted. The product is tested in the "Film Testing Division" and also in the "Photographic Technology Division" both of which are much reduced in size and probably renamed by now. The PTD building went down about 5 years ago and it became part of KRL from which it sprang about 40 years ago or so. The FTD tested just films, but PTD tested the entire system including taking photos, processing and printing.
The standards were set using the guidelines sketched out in Mees and Mees and James for the best curve, and these conditions and test results are sent on to Marketing for publication as needed.