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PRNU problem


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Please anybody help me because I am going nut! I am doing the PRNU and scan it and  when it is done with the PRNU calculation 100% and I make the test print it come out bad.I have tried 15 time now and all the time the same. I do not know what to do else. I have removed all the ping files from the parameters folder too and tried that way and still the same.

Does anybody had this problem before and help me to solve it please?

Please note that the first Pic is the last one .

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if I understand well you want to start PRNU from zero.

Do you really know full procedure ?

FIRST OF ALL - change the bulb. It looks like yours is really at the end of useful life. Seems not to be Osram Xenophot lamp at all  ;)

1. do LLCD stability

2. Check LCD response (LUT)

3. Check everything is clear from the benginning (optics) to the end (racks) Cleaning the rack rolls will be very helpful.

4. Install PRNU Filter (red 40 + neutral 40), do the paper calibration.

then you can start PRNU activities.

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Thank you very much for your reply.

I never did LCD gain and LCD response and LLCD stability. I am afraid to do them but I have no choice I think.

When I do the prnu I always change the lamp.

At the end I managed to do a prnu but I had to change 4 new lamps.I did not do the LCD gain and LCD response and LLCD stability but soon I need to do the prnu because for some reason it come with pacths very quickly.The Lamps that I am using called Sylvania. For some reason the coating wear out very quickly.

Thank you again.

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jjfury, it's a madness. that's why you need a one good lamp which will work longer -  you can't save on the basics. I know that Philips lamps and Osram Xenophot were recommended for the machine on the beginning. Philips lamp were failing down due to the heat - the lamp foot was turning into sand :)  and finally Osram Xenophot stayed alone. With this lamp you can work very very long time. changing lamps during PRNU is a waste of time. each lamp could have his own pattern you will not be able to compensate all.

buy at least one of them and use for PRNU if you really want to have it correctly done.

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