Hi Marcial,
If you don’t have a proper colour managed workflow what you are attempting is,
with dt or any other software, essentially impossible. Before even thinking
about what to do in dt you will need to as a minimum:
1) Beg/borrow/steal a monitor calibration device and generate a profile
from this. Then make sure your operating system and/or photo processing
software is using that profile. Note that for your specific requirement of
reproducing the drawings you will want to use specific and controlled lighting
when you do this and use the same lighting when photographing the drawings.
2) Get an accurate printer profile made for the specific printer/paper/ink
combination you are going to use for printing the drawings. Or send them off
to a good printer who supports colour profiled work.
3) Optionally produce an input profile for your camera, and in the
specific lighting conditions you are going to use. This is an added complexity
you might not want though and I recommend not bothering with this, unless you
know enough to know you need it.
After you have done this you can photograph the drawings and do whatever you
want in dt (or something else) to adjust the image with the reasonable
expectation that what you see on the screen is going to be as close as
possible to what you get on the final print. Unless you are prepared to set
this up properly, which is neither quick, nor easy, nor cheap, attempting any
form of accurate colour work is frankly a waste of time as your print never
looks like what is on the screen so you have no way of deciding what
adjustments you actually need.
There is a reason why reproducing drawings accurately is a specialist service –
it takes time, money and commitment to learn the techniques and set up things
up. Which isn’t to say that it can’t be done if you want it enough.
Rgds,
Rob.
From: Marcial Gomez Martin [mailto:[email protected]]
Sent: 21 November 2014 07:47
To: [email protected]
Subject: [Darktable-users] art reproduction, right colors?
Helo everyone.
I need some help!
I'm trying to reproduce a set of drawins to make copies as faithfully as
possible. I have used a grey card in order to fix colors (wb) and exposition.
I figured I could do that by measuring 127, 127,127 in the card, but the result
has been absolutely unsatisfactory.
I know I can't control the printer output as I don't have any specific icc
profile, but even the jpg images are very redish/yellowish, and very clear
compared to the originals. The printed copies were even worse (clearer more
saturated and redish/yellowish).
I've been looking into the messages and I'm overwhelmed by all the concepts
involved. To begin with, I don't know if I should disable the base curve, as it
tends to add saturation. I don't know if the input color profie should be
linear or not. Then comes the output color profile "to the rescue":
output, perceptual?;
screen output, ¿?;
output profile: AdobeRGB?;
printer profile, a CMYK icc that I dont have?
screen profile, OS.
Then, in lightroom mode, export, I have another intent (I asume image config
will take into account the adjustments I've already done) and another profile...
My simple question is: Which would be the best workflow to produce a faithful
copy of a picture/drawing?
I hope someone can help me if I have made myself clear enough (which I'm not
sure of)
Thanks in advance.
This email is confidential and is intended for the addressee only. If you are
not the addressee, please delete the email and do not use it in any way. Please
note that any views or opinions presented in this email are solely those of the
author and do not necessarily represent those of the company. NHBC reserves the
right to monitor all email communications. The recipient should check this
email and any attachments for the presence of viruses. The company accepts no
liability for any damage caused by any virus transmitted by this email. NHBC,
the National House-Building Council, is limited by guarantee in England, No
320784. Registered address: NHBC House, Davy Avenue, Knowlhill, Milton Keynes
MK5 8FP. NHBC is authorised by the Prudential Regulation Authority and
regulated by the Financial Conduct Authority and Prudential Regulation
Authority. NHBC Building Control Services Ltd, registered by guarantee in
England with Company No. 01952969. Registered address: NHBC House, Davy Avenue,
Knowlhill, Milton Keynes MK5 8FP. NHBC Services Ltd registered by guarantee in
England, No 03067703. Registered address: NHBC House, Davy Avenue, Knowlhill,
Milton Keynes MK5 8FP. If you make a claim under a Buildmark policy your
personal details will be stored and processed in accordance with the Data
Protection Act. Your personal details may be passed to others involved with
your claim such as the original builder, or a consultant or remedial works
contractor that we may employ in connection with your claim(s) and matter
ancillary to your claim(s). Other than disclosure provided for in this
statement, we will not pass any data about you to any other party without your
permission unless we are required to do so by law.
------------------------------------------------------------------------------
Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server
from Actuate! Instantly Supercharge Your Business Reports and Dashboards
with Interactivity, Sharing, Native Excel Exports, App Integration & more
Get technology previously reserved for billion-dollar corporations, FREE
http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk
_______________________________________________
Darktable-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/darktable-users
