CTP plate dots

[SZmetana]

I think this must be your first experience of looking at printed digital halftone dots through a microscope.

These are completely normal printed offset dots. In fact, they are pretty good quality. If you saw the same dots printed flexo, they would look much more irregular.

A digital halftone dot is made up of discrete pixels. At 175 line, 2400 dpi, a 60% dot (what I estimate these printed dots to be) is only going to have around 9 x 9 pixels available to make the curve of the dot, and it's easy to see the steps of these pixels.

When you add the fact that the dots gain slightly due to ink spread, and that this spread will be varied, depending on the grain and roughness of the paper at the microscopic level -- what you see is a completely normal appearance for printed halftone dots.

[gordo]

To Nishanth:

You've posted this question before with the same two images. The answer remains the same.
The smaller the dot the greater any difference in dot shape you'll see. The larger the dots the less difference you'll see. You should compare halftone dots that represent the same tone value instead of these different dot areas.

Also you should compare screens of the same frequency and angle which these also don't appear to be.

BTW, why are the dots and plate colors so different?

You seem to be comparing "apples and oranges"

best, gordon p

[mannyx]

To Nishanth:

can you specify sir if the fogra image is produce using film and the 150lpi is expose in ctp process
base on my observation the 2 images you send is produce in a different process... gordon is right
you cant compare apple to orange... as far as the dot shape is concern...

thanks,
Manny