Newbie trying to produce b&w halftones

Archived from groups: rec.photo.digital (More info?)

I think this is done through the Image > Mode > Convert to Bitmap where
it asks you how to dither. You'll need to choose a ridiculously large
resolution that makes enormous files which do not display on screen
unless zoomed 100%. Experiment on a small patch till you find the right
settings. I'm not even sure a 600dpi file would be big enough, maybe do
it at twice the size & xerox reduce.

DavidF wrote:

> I am trying to produce halftone images, (black and white, no colour)
> from digital photographs, suitable for including in our village
> magasine. I have Photoshop 7 and Cannon iP4000 inkjet printer. We
> occasionally use professionally produced halftones, but these are too
> expensive to use as often as we would like.
> I currently prepare 'camera ready' pages of text, and this is
> printed by off-set litho by a guy who clearly knows his stuff, but who
> operates out of his shed with limited equipment. He requires images to
> be 100 lpi, with 45 degree lines. I thought that I could do this
> direct from Photoshop, using the Pint-with-Preview/Show More
> Options/Screen command, but this clearly is not so, although I don't
> really understand why. I also tried Filter/Pixellate/Colour Halftone,
> but could not get a good image with the minimum dot size of 4 pixels. I
> have researched this on-line, and seen many articles which have left me
> confused. It seems that there are programmes available for achieving
> halftones, but the software seems to be expensive and over technical
> (ie lot of effort in giving good colour).
> Is there a cheap solution to my problem e.g a plug-in filter for
> Photoshop, or a simple, limited performance bit of software?
> Two other queries. What is RIP. Is my printer Postscript compatible?
>
> (Please do not be offended if I do not respond to replies immediately,
> as I am away until 15 June)
>
> Regards, DavidF
>

--
Paul Furman
http://www.edgehill.net/1
san francisco native plants

Archived from groups: rec.photo.digital (More info?)

Don Stauffer wrote:
> Paul Furman wrote:
>
>> I think this is done through the Image > Mode > Convert to Bitmap
>> where it asks you how to dither. You'll need to choose a ridiculously
>> large resolution that makes enormous files which do not display on
>> screen unless zoomed 100%. Experiment on a small patch till you find
>> the right settings. I'm not even sure a 600dpi file would be big
>> enough, maybe do it at twice the size & xerox reduce.

I don't understand the above.
>>
>> DavidF wrote:
>>
>>> I am trying to produce halftone images, (black and white, no colour)
>>> from digital photographs, suitable for including in our village
>>> magasine. I have Photoshop 7 and Cannon iP4000 inkjet printer. We
>>> occasionally use professionally produced halftones, but these are too
>>> expensive to use as often as we would like.
>>> I currently prepare 'camera ready' pages of text, and this is
>>> printed by off-set litho by a guy who clearly knows his stuff, but who
>>> operates out of his shed with limited equipment. He requires images to
>>> be 100 lpi, with 45 degree lines. I thought that I could do this
>>> direct from Photoshop, using the Pint-with-Preview/Show More
>>> Options/Screen command, but this clearly is not so, although I don't
>>> really understand why. I also tried Filter/Pixellate/Colour Halftone,
>>> but could not get a good image with the minimum dot size of 4 pixels. I
>>> have researched this on-line, and seen many articles which have left me
>>> confused. It seems that there are programmes available for achieving
>>> halftones, but the software seems to be expensive and over technical
>>> (ie lot of effort in giving good colour).
>>> Is there a cheap solution to my problem e.g a plug-in filter for
>>> Photoshop, or a simple, limited performance bit of software?
<< Snipped bits out >>

You can make an action in PS that'll do most of the work after you get
the first one down pat.

>>
> The printing firm you are using may well need a particular dpi and
> format, so you need to use what they require.

The more specifics you can get from them, the better.

--
John McWilliams

Archived from groups: rec.photo.digital (More info?)

Don Stauffer wrote:
>>
> The printing firm you are using may well need a particular dpi and
> format, so you need to use what they require.

My understanding is they want a physical print to use for optical offset
printing plate production.

--
Paul Furman
http://www.edgehill.net/1
san francisco native plants

Archived from groups: rec.photo.digital (More info?)

Ray Fischer wrote:
> DavidF <david_p_f2001@yahoo.co.uk> wrote:
>
>>I am trying to produce halftone images, (black and white, no colour)
>
>>from digital photographs, suitable for including in our village
>
>>magasine. I have Photoshop 7 and Cannon iP4000 inkjet printer. We
>>occasionally use professionally produced halftones, but these are too
>>expensive to use as often as we would like.
>>I currently prepare 'camera ready' pages of text, and this is
>>printed by off-set litho by a guy who clearly knows his stuff, but who
>>operates out of his shed with limited equipment. He requires images to
>>be 100 lpi, with 45 degree lines. I thought that I could do this
>>direct from Photoshop, using the Pint-with-Preview/Show More
>>Options/Screen command, but this clearly is not so, although I don't
>>really understand why.
>
>
> Well, I'm using Photoshop 9 and it took me just a few seconds to look
> up halftoning in the help. The short version is
>
> 1) Convert to grayscale
> 2) Image > Mode > Bitmap menu item
> 3) Choose "halftone screen" from the method popup and fill in the
> appropriate values.
>
There is a similar function in Paint Shop Pro. It does not produce a tue halftone, in
which darker areas have bigger spots, and lighht areas have smaller spots. The actual
print is black and white, but to the eye it resembles a half tone. A print made with
this effect may be close enough to meet the needs of your printer.