Digital BW, The Print

> From: Tom Husband <tom.husband@...>
> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Date: Sat, 13 Jan 2007 16:31:49 -0800
> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Subject: Re: [Digital BW] Emedding Photoshop Curves in ICCs
> 
> Thanks Steve.  I'm understanding some of this but most is over my head.
> I'll have to dig into this more.
> 
> On 1/13/07, Steve Kale <stevekale@...> wrote:
>> 
>> Saving a curve as an ICC is easy.  Go to Edit-> Color Settings-> Spot ->
>> Custom Dot Gain and then create the curve you want then OK.  Click on
>> Custom
>> Dot Gain again and Save Spot.  This of course creates an ICC profile but
>> doesn±t help you with identifying the coordinates of the appropriate
>> transfer curve.  I prefer to use QTR Create ICC. I print a step wedge with
>> my preferred Epson Adv B&W settings and then create an ICC profile from
>> that
>> with QTR Create ICC.
> 
> 
> Now I create ICC profiles using QTR Create ICC-RGB and an ABW created step
> wedge and then print through Qimage.

Yes because Qimage needs a colour file (as I understand it) you need to use
the RGB version of QTR Create ICC so that it has 3 channels in the output
tag.
> 
>   A transfer curve that accounts for the vagaries of the
>> output, white point compensation (media relativity) and black point
>> compensation is calculated and embedded in an ICC profile.
> 
> 
> I don't understand this bit.   A transfer curve that accounts for the
> vagaries of what?  The ICC profile you just created?  Then do you create
> another ICC profile using the numbers from the first one and the transfer
> curve?

3 things:

(a) the luminance ramp produced by your particular ABW settings (stimulus
response behaviour)
(b) adjustments to (a) for paper white
(c) adjustments to (a) for ink black

> 
>   In addition,
>> full colour information from my spectro readings is recorded in the ICC
>> tag
>> used for soft proofing.  Not only do I get good and easy luminance
>> management at printing but I get full colour soft proofing.  Quite cool.
> 
> 
> I don't have a spectro but do have a densitometer.  Am I still OK?

If you only have a densitometer you can not record colour information and so
can't use this facility.  However, the luminance management side of things
is fine.

Sounds like you're in good shape using QTR's ICC tool.

Regards

Steve