Color halftone questions [SOLVED]

[TiagoRocha]

Question 1: [SOLVED - click here to read the answer]: If I have a small image (800 by 500) how can I apply the color halftone without the dots being too big?

When I try 1px as the radius, I get the warning that a value between 4 and 127 is required.

Question 2 [SOLVED - see the second image below]: I'm applying the filter and I still get a visible pattern, even though I'm using the "recommended" angles of 15, 45, 0, 75

I'm no expert in halftone and I was just reading on a website about it. I understand that angles can create these patterns if not set properly, so I'm confused as to why this is still creating the patterns?

UPDATE - Solved the issue with these values instead: 15, 75, 0, 45:

 

Any tips on these?

[c.pfaffenbichler]

What are you trying to do? 

If you don’t want the visible Pattern why are you applying the Filter at all? 

[TiagoRocha]

Look closer to the 1st image. There's a pattern of oblique squares, whereas the second image, doesn't. I'm not talking about the halftone pattern, of course 😉

[mglush]

Hi!

Are the halftone patters being used for effect? Or are you sending your file to print?

Michelle

[TiagoRocha]

Just effect

[Stephen_A_Marsh]

Q1: Increase the resolution of the image, apply the filter, and resample back to the previous size.

Q2: In addition to having the correct screen angles, you also need to view at 100% (1:1) magnification for evaluation.

Best to work in CMYK mode, then convert back to RGB mode after filtering if you wish to have the correct halftones:

Left is the filter run in RGB mode, right in CMYK mode converted back to RGB.

[TiagoRocha]

"Increase the resolution of the image, apply the filter, and resample back to the previous size."
I tried that as well, but the issue is that when you increase the size to something super big, you introduce blur and all that so when you create the effect you will be applying it based on the bad quality of the image, right? I was thinking if it could just reduce the size of the dots. Apparentely, it can't.

"In addition to having the correct screen angles, you also need to view at 100% (1:1) magnification for evaluation."

The images I shared were actually at 100% and they were CMYK. I started with RGB and didn't looked good, but then I decided to change to CMYK and what a difference! I mean, it also depends on what look you want. Maybe sometimes RGB will create a different effect that isn't supposed to look good or realistic. But yeah, CMYK is great for this, especially because I'm working on a macro that let's me pick custom colors for each channel, for creative effects, so CMYK is best!

Thanks 🙂

[davescm]

The smallest unit Photoshop can use is 1 pixel. There are no half pixels and each pixel is a square. Round shapes are created by using multiple pixels, so the only way to get 'round' dots is to increase the pixel resolution.

Dave

[TiagoRocha]

Thank you for the clear explanation, Dave. It makes sense now 🙂