Computers and Software > Separation Programs
OUR DOTS ARE FAT.
mk162:
This is something I was wondering about with one of our old DTS machines. The dots always seemed way bigger than 55lpi, more like a 35-40 dot. I would crank it up to 75-85 if I really needed some great detail and it worked without moire.
This is all now making perfect sense. I guess never assume one machines 55lpi is the same as anothers.
zanegun08:
This doesn't even make sense,
As illustrated below, 85 LPI on the left for a 30% black, vs 55 LPI on the right for 30% Black (from photoshop 600 DPI)
Just because you make your dots smaller doesn't magically compensate for gain as the dots end up just as they are described "Per Inch"
If your 55 LPI dots are gaining to be similar to the size of a 35-40 LPI dot, that means you are gaining in percentage and the 30% will be printing like a 40%-50%
Now on the smaller dots, with less margin of error as the dots are closer together, your gain is going to be more extreme and that will look solid once you have gain on films and gain on press
Yes you can do 80 LPI, you can do 120 LPI but you are going to have the same issues with gain except they will be more extreme in the low end and high end as you just made your margin of error smaller...
Dottonedan:
--- Quote from: tonypep on February 24, 2021, 07:21:53 PM ---I am not an old (white slapper ;) but this aging whipper slapping fool wants to know if "fat" is referring to D-Max/D-Min, or or shape of dot. Even the best I have seen (for textiles) is what I refer to as a "popcorn dot" under a loupe. And they deliver spectacular results. However, I as I am shifting towards fine art and paper serigraphs this may not be acceptable for continuous tone .
All that said, I am working on some translucent wet on dry images with a 10 dots per inch!
--- End quote ---
Tony, That’s white "snapper". Not slapper. You kidder you. ;)
Dottonedan:
--- Quote from: zanegun08 on February 25, 2021, 12:01:08 PM ---This doesn't even make sense,
As illustrated below, 85 LPI on the left for a 30% black, vs 55 LPI on the right for 30% Black (from photoshop 600 DPI)
Just because you make your dots smaller doesn't magically compensate for gain as the dots end up just as they are described "Per Inch"
If your 55 LPI dots are gaining to be similar to the size of a 35-40 LPI dot, that means you are gaining in percentage and the 30% will be printing like a 40%-50%
Now on the smaller dots, with less margin of error as the dots are closer together, your gain is going to be more extreme and that will look solid once you have gain on films and gain on press
Yes you can do 80 LPI, you can do 120 LPI but you are going to have the same issues with gain except they will be more extreme in the low end and high end as you just made your margin of error smaller...
--- End quote ---
Yes.
Printing from the same output device, I have one set of gain setting for film output for the 45-55lpi. Then I have another, that is more opened up for the 65-75 lpi. Don’t we all?
It makes perfect sense. I can open up the mid tones for the 55lpi (and change the positioning of the %) to be further part due to reducing the size. Like Reverse gain. But that 55lpi at 45% still looks fat even tho,,I ahve open dup the tone and cut back on the % making that dot smaller. It’s a larger dot than a 75lpi at 45%. But I order to print the higher lpi well, (without issue), we need to compensate and open that up...push dot %’s over so that the range works well (when it gains, it does not merge closer to the point of fill in). It would do this if I just left it alone at the 50% mark.
The higher the line count, the more you increase your chances of fill-in (dot gain) since there are many more dots in a square inch (looking more continuous). This is really why I use higher lpi. For example, when trying to simulate a large area of a consistence fill, (made up of 4 colors). Like a sand color I just did today. But I had to open up those mid tones more than I would for a 55lpi.
The original point was, that the dots we use today coming out of most machines...is not at a true size (due to the physical capabilities) of the common output devices.
Wet ink (epson digital printers) “build up multiple ink layers” to form the result.
Wet ink (Cts digital printers) “build up multiple ink layers” to form the result.
Wax. (Cts digital printers) “build up multiple wax layers” to form the result.
None of those above, are as exact as the photo chemical processors. That is what would be the bench mark of the most accurate sized dot in any given line screen that we have.
Squint your eyes at your example. Obviously those dots are “smaller”, and there are many more of them. You can start to see the left side (85 lpi forming a more consistent look) than the right. With the dots being smaller, it works better for this purpose. Like file resolution.
Your gain on press and at output is roughly (the same) % of gain wether it be 55lpi or 85lpi.
I feel like you already know all of that, but the difference that I was really pointing out, is that todays what seem to be (cheaper devices) or lower end devices is a better word) that we use for imaging put out a fatter dot than a true dot size. I call it “true” because I’m referencing those older (more perfect) dots. Maybe they should be called “ the original”good dots. The dots that were photo chemically imaged onto film at 3600dpi or higher. They were reproduced more accurately due to the process used in conjunction with the ability to do so at a much higher resolution than todays output devices. For this reason, the height of the black imaging on film, would be minute or fractions of the thickness as you see imaging devices from wet ink or wax.
Really, our fat dots are our “new” true dot size or our new benchmark. Your 3% is your 3%. These become our new standard. I have just seen the better ones.
Those who has used 65lpi photo imagesetter film know that the imaging of a 65lpi of today, does not compare to that film.
The one thing that CTS and Laser have over the quality of the old imagesetter films is the DIRECT CONTACT onto the stencil, eliminating the glass and the film thickness. For that reason you have better stencil duplication than any film. In this comparison, one would ahve to look at the benefits of a clean. more perfectly round dot and edge of dot...compared to the shapes we get from Epson printers, Wet ink CTs and Wax CTS.
While the Direct Contact of CTS is a game changer, some might feel the shapes of this photo film (dots) being more perfect has a measurable and positive impact on exposure and image duplication (over the benefits of the Direct Contact. That would be challenging to prove.
For this reason, I believe the LASER at it’s higher resolutions, would be THE closest thing to perfection we have easily available to us today in a price range that we tee shirt screen printers can afford.
Laser has both High Resolution, and Direct Contact. For this reason, it would seem to be THE best quality option. Now that they offer a machine that images two screens at the same time, this makes the production time needed per screen (half as much) when comparing to the time from WAX and WET ink imaging speeds.
zanegun08:
Please post photo evidence to backup the initial claim.
All it said in your follow up that you are doing more linearization in a roundabout way, I think that this should be controlled at the RIP level / Photoshop dot gain control level, not a turn your dots to 85 LPI and Pray it comes out like 60 LPI, and then actually be tweaking more in the separation to compensate further for the gain you know that's going to happen.
At the end of the day you are spending a lot of time chasing dots, post some prints to show that all these extra steps are worth it, and tell me how it is scalable.
:)
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