I've been stumped on this techinque for several years in the absence of examples I'll try to describe

If a greyscael gradient was to be converted to a dot pattern
with, the size of the dots ( combining dots into "blobs") the size of the individual dot and their their frequency
corresponding to that greyscale.

how would one go about it?
I've been racking my brain over this one for years and haven't figured out how to acomplish the effect.
It was fairly common for many "hip" adverts in the years past although its not seen too much anymore I wold like to use it for several things

I'll try a manual version to show what I'm talking about
any pointers would be great as itis not in any of the tutorals.

thanks

I'm not sure this is exactly what you mean but try this [alter sizes and step numbers to your needs]: Choose the paintbrush tool. In its options bar, pick the hard 19 pixel brush. Click on the brush thumbnail in the options bar and in the edit brush dialog, change the brush spacing to 100% [note; spacing will not "stick" once you switch tools unless you save this as a new brush]. Now go to the end of the paintbrush's options bar and click on the Brush Dynamics button. In Brush Dynamics, set both Size and Opacity to Fade and for Steps, enter 20 for both. Paint a long stroke and see if this is what you're after. If it is, tinker with the brush size, spacing and number of Fade steps to get the result you're after. You can make a custom brush of a bunch of dots lined up vertically if you want to make a bunch of dot rows simultaneously. -Jay Arraich

thanks jay however, this isn't a tool settings effect its something that has a graduation (greysale) as part of multi step process my example is a half assed, manual, time consuming arrrangement of dots that lacks the clean mathematical precision that this technique gives with complex forms (not to mention 100 X quicker). I've caught some of it when its been performed by one guy that viewed myself as one of his competators so they refused to show it to me when I politely asked ( imagine that!) like I've said, its an "old trick" that I've not found any tutorals on... if someone knows how to acomplish this effect and would not like to post it I'll be more than happy to reply privately -thanks

Attached Link: http://www.andromedasoftware.com

Perhaps not preceisely what you have in mind, but I made these "dots" with just a few clicks, using the Andromeda Screens series 3 filters. There are *many* optional settings, so it's possible you can find the effect you're searching for in there. I think they have a demo version, so you could try it out first to be sure. :)

thanks,
we're getting closer, that filter set wasn't installed upon those computers. I've been playing around inbetween the forum posts and I think it may be a pattern fill of some sort.. If I find it myself, I'll post it up here.

I do know its not a filter effect ( although it could be made into one) and its not a tool preset. its a multi step effect involving a greyscale

I know one of the plug-in packages has a halftone effect (like an old newspaper photo) which is what I think you're after. You might try playing with converting the image to indexed colour too (has to be converted to greyscale first) this will make all pixels solid black or white - no greys so it would only work on B&W images. Though you could try colourizing them after you've achieved the effect you're after. Hope this helps! Baz

OOPS! Sorry about that flip I meant convert the image to bitmap mode not indexed colour (it's early OK?) Embarrased grin! Baz

Hmm, the best I could come up with was this.

I used mask mode and ran Pixelate | color-halftone on a gradient. Then I inverted the selection and filled it with black. You can change the angle and such. I didn't do anything, other than run the default filter.

Here's the same thing (Pixelate | Color Halftone) on a star, all angles set to 90, gaussian blur at 8.

Kieraw has it almost right. I cheated and went over to ActionXChange where I found an action that does this. By running the action and backtracking through History, it appears to be done as follows: Make a new alpha channel. With that channel selected, create the shape you want to be "dotted". Run gaussian blur on the alpha - more blur will make the dots go further into the shape. Less blur will limit the dots to the edges. Next, use Pixelate > Color Halftone. Use the Max Radius setting to increae the size of your largest dots and thus dot size change over the effect. When you have what you want, Ctrl-click the alpha, click the RGB channel and go to Layers where you can then create what you want in the colors you want. Note: for some reason, the action I was looking at used Select > Similar after selecting the alpha. I'm not sure this is necessary - seemed to fudge my selection. Kieraw really had it already. -Jay Arraich

I don't use alpha channels all that much, except when I am doing masks for lighting effects. (Thanks, Dr. Ozone.) But it's a preference thing.. I imagine that it works out almost the same either way.

We've got it!!!! thanks aeveryone. I've Dl teh action and I also upgraded to PS 6 to exploit the technique quickly thanks everyone for their time on this sincerely flip