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Pshop 6.0.1 Mac: Halftone Pattern Problem, Please Help!


J

jonc

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i recently upgraded my iMac from 9.1 to 9.2, and all seemed to work well. however, there is a problem with Photoshop. i routinely use halftones in my work, and am having a big problem selecting a halftone pattern. no matter which pattern i select (elipse, round, line, etc.) all i get are squares.

i've tried deleting my preferences and also upgraded from 6.0 to 6.0.1, but the problem remains.

does anyone have any idea what's up, and how to rectify the problem?

thanks very much.

jon
 
Wlecome to the community jonc, enjoy your stay. ?[excited]

This is indeed an odd problem. I've never seen this before, so i'm going to guess that it's an OS update issue.

I don't use a Mac myself, but there are several here that do. One or more of them should be by shortly to lend a hand.
 
Can you be more specific regarding the problem?
When you say "squares," what happens when you adjust the sliders for size and contrast? Does the halftone change at all?

Also, when you then choose "line" or "circles," what happens? Anything? How about after you move the sliders.

Also, what version of Photoshop are you running, and have you installed any upgrades available?

Can you post a screen shot? That might help.
 
thanks for the replies. they're greatly appreciated. i'll try grabbing some screen shots tonight and upload them for you folks to view, and at the same time will answer the questions posed.

thanks again.

jon
 
hi.
well , first i turn the color photo to a greyscale, then that to a bitmap. before i upgraded to os 9.2 i had sort of nice dots (they could be better but i can't find another example) as in image"bitmap 1". after the upgrade all options resulted in "square" dots (image "bitmap 2").

the only sliding i saw was in the halftone filter under sketch. but the filter only gives the apperance of a halftone with some grey, and i am looking for black and white, without grey :(

this is important as i am using them for silkscreening.
the "squares" happen with any of the "halftone" options i choose (round, diamond, ellipse, line, square, or cross).

any suggestions?
 
I'm almost comfortable guessing that your problem looks like a bad combination of settings. From dpi to lpi to angle, etc. Have you tried varying them at all?

Make sure your dpi is at least 300. That will leave you a little more room to tweak the lpi and angle. And not get such a 'crunchy' looking effect.

Asides from that though... here jonc, checkout this guy's free plugin for PS. He says it's a PC plugin, but since PS's file format is OS independant, it would stand the reason that the plugins it uses would also be. (although i'm fairly sure i'm wrong on that... i'm just being optimistic) [honesty]

http://www.geocities.com/murakuma/mmplugins.html

It's a halftone filter with some great setting options. One of which is that it allows you to stay in RGB mode, THEN convert to BMP (optional), without having to use PS's default halftone filter. Plus, it allows you to preview the effect before you apply it. AND... it also has an anti-aliasing option that smooths out the look, it you want. You wouldn't want that though for silk screening; because it producing grey levels. And ontop of all that, it will allow you to use any 2 colours you want to create the effect. It really is a great lil' free plugin. :righton:
 
Although I appreciate plug-ins for often doing the calculations and hard work for me (as well as sometimes offering some different settings I wouldn't think of), I always like to push PS to the limit and see what it truly can't do, as it can do so many things...

For the halftone, Keeper's right about having a high res picture, for the fastest, easiest, best results...
But what if all you have is a web shot?

If you have a lot of jpg artifacts, the result will not be as clean, but nevertheless...

Desaturate your color image, go to Filter>Pixelate>Color Halftone, and set the angle for all 4 channels to 45 degrees, and set the maximum radius to 4 pixels, click ok.
 
It appears the size of your image can affect the "flaw" line that appears...
Here is just a section of the image, and no "flaw." I had to draw the marquee 4-5 times though to eliminate it...Something to do with the complex math algorithms, I am sure, but something you may have to tweak to get the effect smooth.

Good luck!
 
Nice effect indeed, but for print you do need different angles. Offset print that is...
 
I'm not up on printing, I'll admit. Once you get the effect of dots, though, why would you need to change the angle for offset printing?

If it's for silkscreening, if you get the original dot pattern in PS, can't you just print that out as a silkscreen pattern?
 
WOW!
thanks you guys for all the suggestions!

the Keeper was absolutely right! it had been so long since i did halftone that i COMPLEATLY forgot that it needed to be high resolution! not to mention that i needed to avoid certain angles (45, 90, 180,0).

thank all of you for helping to relieve my brain ache!
and for all the cool new knowledge!

HAPPY! HAPPY! HAPPY!
 
The main reason why the four channels are at angles is that they are transferred to offset plates. When the paper goes through the press four times (or through four heads of the press in sequence), there is a risk of moir? patterns.

Apart from that, it's visually more pleasing.

Apart from all that, I never tried what you came to show here, and it is a very good idea indeed. I'll try it out, and it will be useful some day!
 
I might be wrong, but surely if you try silkscreening a halftoned image you will end up with Moire patterns all over the shop???

What is required is a greyscale separation per spot colour.
This would then be used to create the exposure area, usually onto film.
When this is processed onto the screen it allows the screen material to
pass the graduations needed for the ink. As in offset printing where the plates are created from a laser print.

Certainly you will get a halftoned effect by applying the PS Halftone filter and then printing out on an inkjet printer.

Wish I'd learned more about what was actually involved in screen processing at a previous job I had.
Artwork was made into separations but without the use of PS Halftone Filter. The black art of the printer worked that little bit of magic.

If I am totally wrong, you may cover me in honey and stake me out on the nearest ant hill. :(|

Cheers, Al.
 
:D Yup, a plethora of smartie pants are we. :B

A couple of points about your original post Jon. (After reading the fine print.)

The reason you were getting 'square pixels' is the conversion to Bitmap.
You only have black or white pixels so you dont get the apparent soft edges of which you have with Greyscale.
Try painting a big splodge with a large soft edged brush and then convert it to bitmap to see what I'm jabbering about.

The other speckled effect you have is an early Photoshop dithering pattern.

Finally, you will need to watch this un-natural affinity to Moire Patterns you seem to be developing.
Yes they can be hypnotic but should be avoided at all costs.
The only sure cure is to post on this forum more often.

We will save you. :B
Won't we kiddies? \:]

Al.
 
Rantin Al said:
:D Finally, you will need to watch this un-natural affinity to Moire Patterns you seem to be developing.
Yes they can be hypnotic but should be avoided at all costs.
Click to expand...

Don't you listen to Al! The moir? patterns are good, good I say! [stuned] Just read the definition over at
Artlex.

Listen to the moir?...the moir? is your friend...

The only sure cure is to post on this forum more often.
 
[saywhat] [confused] }P 8))

Ye--ssss master, I must post more often.......
I must post more often.......
I must post more often.......
I must post more often.......

:bustagut: Al. :P
 
one last thing...

a bit unrelated, but it may be worth while to someone out there...

if any of you are using the waterbased Speedball method of silkscreening (i have recently started up again, duh...)

i was cleaning a week old screen with photo emulsion on it, and it came clean! the directions tell you to wash it out in a timely manner to avoid permanence, so i was sort of suprised... and then i tried a screen that was exposed about two YEARS ago, and it came clean!!!! skip the Mr. Clean that is the recommended product and jump right to the Clorox cleanser!

my wrists will be so happy with fewer screens to re-stretch (pain in the butt!) horah!

that's all. thanks again!
 
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