Back in days of yore, when you were applying grease pencil to stone,
or even today with "traditional" digital plates, yes you'd need to monitor
your exposure settings. (some more often than others)
With Azura, the nature of the technology itself - literally melting the plastic
into the grain of the plate - has a tremendously wide "exposure" latitude.
If I recall correctly with the older Azura - this was a +/- 30 mJ/cm2 - or
60 mJ window of "correct" exposure. As today's Azura TS is faster, with
finer spheres which properly fuse at a faster exposure, this window is
no doubt proportionately narrower... perhaps not as wide enough to
drive a truck through, but perhaps now wide enough to drive a bus
through (in comparison with traditional digital - thermal & visible light
digital plates' exposure latitude).
The irony is that here we have a chem-free or processless plate
that one can easily read with a plate reader.... but due to the nature
of this specific technology itself - one rarely has to adjust the exposure.
If one does - that would tend to point to other problems - failing lasers, etc.
Regardless - Alois - we still love your invention of Lithography!
Regards,
Last edited by SteveAgfa; 05-12-2009 at 04:54 PM.
Steve Musselman, Agfa Graphics - USA,
Senior Corporate Account Executive
Way to stand up Santa, I am very tired of people giving rude comments (some personal) instead of helpful comments, suggestions or intelligent discussions.
yeah i'm on azura - very good plate and have found santa to be very knowledgeable on the azura subject, so keep your "IMMATURE" name calling to yourself - personally I left that at school. You don't like his post? don't bloody reply.
just because something isnt "your" way and you react like that proves who the fool is - there are ALWAYS more than one way to skin the cat
i've never had to adjust anything on my ctp, and am going to TS shortly - so we'll adjust drum speed and let it do what it's bloody good at - imaging sound, solid consistent plates with no problems. go ahead - pull that to pieces pal
Alois could you snip the part you are refering to, the link does not work. From what we have found there is alot of problems that printers/pressmen would blame on prepress that are nothing to do with prepress. That press instantly go as a reflex to blame prepress is sad. We find mechanical, and chemical stuff occurs at the press and even with paper, much more so that the plate. We did not have a measuring device that was able to read the contrast on the Azura plate, and did calibration on paper, skipping the plate linearisation.
We have found on odd jobs that one colour is out, but a one colour cast cannot be from a non linear plate.
Tha Azura plate does not have chemicals that are dependant on chemistry freshness/dosage or temperature to develop them. This makes the plate stable.
According to practice of certification there should be a verification of plate, this to eliminate that the plate instability is causing the problem.
Now letts go to science as a whole, if an assumed consant proves to be consistent. And in assuming the constants constant helps you localise and correct errors in other parts of the work flow is that constant not proof enough?
In relying on ANY measuring device you have to assume something is consistent, so the logic is not new.
Anyone who uses a ruler is assuming it is a constant, without proving it.
We have found larger variation in measuring equipment that in the plate itself, and it would therefore be to introduce error to fine tune to measurements in such circumstances. We do however at regular intervals, or as we see the need reevaluate our linearisation curves. We deliver printed material, and the dot on the plate is of no consequence. What is important is that prepress and press can keep a consistent Density, trapping, grey balance and TVI as specified by the ISO standard. Call me a fool if you will, but the greater folly is securing each step and loosing the whole due to extrapolated imperfections.
O.E.D. definitions of "Fool" -- FOOL - noun #1 a person who acts unwisely
# 2 a jester or clown, gentlemen the choice is yours !
Raison d' etre --- of Pre-press is the "Production Compliant Imaged Plates"
The ulitimate objective of the Pressroom is to apply the ink to the substrate to produce the best product possible using the the materials specified. It is assumed that all the preparatory operations were in control and that the Press Crew received good Plates.
Regards, Alois
Last edited by Alois Senefelder; 05-17-2009 at 04:35 PM.
Reason: **********
Hello Lukas, so you are saying that "Quality Test Targets" are no use ??
Then all the "Targets" produced by RIT, GATF, Fogra and Urgra are pointless ??
Alois, I believe that the assertion being made is that the :Azura imaged plates are so consistent that the users see no need to spend time checking them. "We have not found any need to check our plates on a regular basis." "I've never had to adjust anything on my ctp, and am going to TS shortly - so we'll adjust drum speed and let it do what it's bloody good at - imaging sound, solid consistent plates with no problems."
Because it is very difficult to counter a personal testimony, like the ones made, I hereby offer my services to do an objective, statistical in-plant analysis of :Azura imaging consistency. Please contact me at pritchardgordon (@) gmail (dot) com to discuss details.
BTW, I would like to know what CtP devices Santa and Beermonster are using - since the imaging device does play a role in plate imaging consistency.
best, gordon p
my print blog here: Quality In Print current video post: Platemaking at the Chicago Tribune - 1937
Alois, no I do not consider the targets pointless as there are many circumstances where plates are inconsistent. If I was using a plate making process that produced inconsistent results then I would by all means need to know that there was no inconsistencies. In a chemical process there are so many variables that play into making a good plate.
The test wedges are generic, and I am not saying that tests are bad. In some CTP + Plate + Chemistry combinations highly recommended. (though the targets you link are not all applicable on a daily testing).
(slightly off topic:
Now that the FOGRAL39 data is out it gives us a very clear target. And I would again emphasise that it is the result on paper that counts. I do not have a single client that asks what the plate values are. 8 years ago some colegues decided to go by the TVI on paper rather than get bogged down on the intermediate steps, the argument was then that all presses print differently. At that time we kept it simple we decided to all target a 17% TVI on paper, (that was our interpetation of ISO, since we found dotgain depending on process would giva a moving target for our common customers). We must understand WHY we nail down the plate dot, it is because we are tracking all variables. The goal is not to measure, but to continue to produce consistent results! If we are reaching the goal, then is there a need to question the process? To reevaluate it at times is good, but measuring for the sake of measuring is like watching paint dry.)
When we used film based flow we needed to check the film, because it was inconsistent. Exposure time, and plate. There were many variables. The plates were inconsistent and we needed to know in each instance where the error occured. IF we did find that there was instability in our workflow, we would reevaluate the need to implement regular checks on plates, but as is we do not see that need. No more than we send our rulers for recalibration at some international measuring institute to verify with som attomic calibration device that our rulers are correct (though we infact know that a ruler does expand and contract with heat)
I am not offended, merely stating that if what you trust is trustworthy it is not foolish to trust it.
I would also note that on installation of our CTP we do have it in a dustfree, temperature and humidity controlled environment, it may be in an environment with more variables then it is justified to have daily plate checks (provided your measuring euipment is as consisten or more consistent than your plates).
Reading through the forum, i see many people using the :Azura plate.
May i ask to those who use it, if they ever considered the :Amigo plate, and why have you chosen the :Azura over the :Amigo?
At first glance, i would tought the :Amigo would be better than :Azura, but the number of users i find using one our the other seems to tell me otherwise.
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Originally Posted by Alois Senefelder
