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  • #16
    Originally posted by gordo View Post

    The problem is that the density reading is irrelevant. It's a thermal process. It's not like film at all. Using fountain solution on the Azura plate will work to remove the non-image area. But that's not how the Sonora works.
    Are you saying that it is binary? The image is either there or isn't?

    How is the Sonora XP different? We have been using both and don't notice a difference.

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    • #17
      Originally posted by kdw75 View Post

      Are you saying that it is binary? The image is either there or isn't?

      How is the Sonora XP different? We have been using both and don't notice a difference.
      Yes, thermal imaging is effectively binary. The coating is "cooked" by the laser during exposure. This is not the same process as exposing litho film and plate. When a plate is setup (calibrated) by the vendor engineer their job is primarily to have the ctp deliver a robust image on plate with no artifacts (like banding/stitching issues). The tone response on plate is not so important (as long as it's consistent). The tone response on the press sheet will be evaluated and if needed a tone compensation curve will be created to be applied in the RIP.

      Basically, with the Sonora plate the fountain solution makes the unexposed coating sticky which allows the blanket to pull the unexposed coating off the plate and transfer it to the paper for removal. The first few (around 10) sheets going through the press clean the plate. With the Azura TE the exposure fuses the image area to the plate and the processor solution essentially washes the unexposed coating off.

      Two different approaches to the problem. In marketing terms the Sonora plate is a true processless plate while the Azura would not be considered so since it has a processing step after plate exposure.

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      • #18
        Methinks you are asking the wrong question because you still have the film process in your mind. On the carton you will find a recommended energy in millijoule from the manufacturer, set this in your CTP and you should get the optimum exposure. Your dealer should also be able to supply you with this information.

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        • #19
          Originally posted by gordo View Post

          Yes, thermal imaging is effectively binary. The coating is "cooked" by the laser during exposure. This is not the same process as exposing litho film and plate. When a plate is setup (calibrated) by the vendor engineer their job is primarily to have the ctp deliver a robust image on plate with no artifacts (like banding/stitching issues). The tone response on plate is not so important (as long as it's consistent). The tone response on the press sheet will be evaluated and if needed a tone compensation curve will be created to be applied in the RIP.

          Basically, with the Sonora plate the fountain solution makes the unexposed coating sticky which allows the blanket to pull the unexposed coating off the plate and transfer it to the paper for removal. The first few (around 10) sheets going through the press clean the plate. With the Azura TE the exposure fuses the image area to the plate and the processor solution essentially washes the unexposed coating off.

          Two different approaches to the problem. In marketing terms the Sonora plate is a true processless plate while the Azura would not be considered so since it has a processing step after plate exposure.
          Maybe that is part of the problem. Agfa advertises that you can go straight to press with the Azura TE without any processing, yet we seem to have trouble unless we use the washout gum. The Sonora works like a charm going straight on the press.

          We are seeing the image working fine, but seeming to be fragile on the Azura. It currently looks purple, but if we up the exposure it turns more green.

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          • #20
            Originally posted by Slammer View Post
            Methinks you are asking the wrong question because you still have the film process in your mind. On the carton you will find a recommended energy in millijoule from the manufacturer, set this in your CTP and you should get the optimum exposure. Your dealer should also be able to supply you with this information.
            I will take a look for that.

            Comment


            • #21
              Originally posted by kdw75 View Post

              Agfa advertises that you can go straight to press with the Azura TE without any processing, yet we seem to have trouble unless we use the washout gum.
              Agfa doesn't consider the washout and gumming as "processing". But one can reasonably argue that in fact it is post exposure processing.

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