True color: how to achieve it?

So I am working on some product photography for book quality images. I am photographing various types of antiques on a white background and I like to expose them so the white comes out looking like pure white. I find however that it is difficult to judge what is "pure" white and what might have a hint of shade to it. I have heard something about a gray card or something along those lines. Does this have something to do with achieving true color? It is funny how different images look on different computers as well, and forget about how they come out when printed. Anyone have any tips or pointers? What is the best way to match the white background from the photo with the white of the paper that the image is being printed out on? Or the white of the background wallpaper on the web page that the image is being posted on?

Use exposure compensation to overexpose the background (blow the highlights) and it will be pure white, as white as you will ever get it, and should give about the right exposure for the subject too.

for hi end printing for publishing purpose...
the workflow is

•best white balance adjustment (manual) using grey card, McBeth card and if it is necessary calibration of camera
•RAW shooting only
•superb calibrator monitor (4 eizos, 1 nec available)

•calibration of monitor by profile maker resembling the Lab values of the paper on which the job will be printed
•cmyk according to ugra/fogra 39 standards
•accordingly calibrated proofing
•photoshop experienced on this workflow user
•pdf 1bit tif export
•fine print house compliant with the above standards workflow

Don't try this alone without expert's help (buying the necessary equipment is out of the question), it's time and money consuming more than the usually affordable amount u may have in mind....

keqwow said:

So I am working on some product photography for book quality images.
I am photographing various types of antiques on a white background
and I like to expose them so the white comes out looking like pure
white. I find however that it is difficult to judge what is "pure"
white and what might have a hint of shade to it.

Click to expand...

"A hint of shade" can mean two different things.

One - the background is slightly tinted with a shade of orange or blue or green and so on.
Two - the background is darkened slightly with a shade of neutral grey.

These two issues are somewhat separate. The first one can have various causes. For example, I've seen a shot where one side of the subject was lit by light from a window, and the other by an electric lamp. The different colours of the light source caused colours to appear in the background which were very difficult to deal with.

So the starting point is control of the light source. Having ensured that the lighting in even in colour, set the camera white balance using the custom setting. This will involve aiming the camera at a white or neutral grey target at the subject position. Follow the instructions from the manual for your particular camera to set the custom white balance.

The second issue, where the background is neutral, but grey rather than white, can be dealt with in post-processing, where the brightness levels are adjusted to lift the grey towards whiteness. There may be some issues here depending on the brightness and evenness of the lighting for the original scene.
Regards,
Peter

Can someone translate the following response below into 'english' for me? Also, as an example of what I am talking about, check out my photo of the trap on this page:
http://people.hws.edu/cicciarelli/bonanza.html

Notice how the background in the photo is more gray than the background of the webpage. Same sort of thing happens when printing out on 'white' paper. Just curious how one goes about correcting this?

Response:
for hi end printing for publishing purpose...
the workflow is

•best white balance adjustment (manual) using grey card, McBeth card and if it is necessary calibration of camera

•RAW shooting only
•superb calibrator monitor (4 eizos, 1 nec available)

•calibration of monitor by profile maker resembling the Lab values of the paper on which the job will be printed

•cmyk according to ugra/fogra 39 standards
•accordingly calibrated proofing
•photoshop experienced on this workflow user
•pdf 1bit tif export
•fine print house compliant with the above standards workflow

Don't try this alone without expert's help (buying the necessary equipment is out of the question), it's time and money consuming more than the usually affordable amount u may have in mind....

keqwow said:

Can someone translate the following response below into 'english' for
me?

Click to expand...

It sounds like aris14 isn't a native English speaker. But I don't think that rewording will solve your problems. His message is that you need to have a complete color managed workflow, if you are preparing images that will be published.

keqwow said:

Response:
for hi end printing for publishing purpose...
the workflow is

•best white balance adjustment (manual) using grey card, McBeth card
and if it is necessary calibration of camera

Click to expand...

At the very least, white balance with a gray card. Preferably, use a Gretag MacBeth color card (because it has multiple shades of gray, so you can validate that your white balance is neutral across the brightness spectrum.) You can also use the color card to calibrate your camera. (A GM color card is a known reference. You need to base your color management on a known reference.)

keqwow said:

•RAW shooting only

Click to expand...

Only shoot RAW.

keqwow said:

•superb calibrator monitor (4 eizos, 1 nec available)

Click to expand...

You need to use a high end monitor. i.e., the four highest end Eizo monitors, or the highest end monitor that Nec makes. (Any of these will cost more than $1,500, US.)

keqwow said:

•calibration of monitor by profile maker resembling the Lab values of
the paper on which the job will be printed

Click to expand...

Calibrate the monitor so that white on the monitor is the same shade that the paper you will be printing on. You need to understand color management to know what "lab values" means.

keqwow said:

•cmyk according to ugra/fogra 39 standards

Click to expand...

Google for "ugra/fogra 39 standards" And CMYK. You are in deep color management here.

keqwow said:

•accordingly calibrated proofing

Click to expand...

Whatever printer you use to make proof prints must be calibrated and profiled. i.e., you need to be able to calibrate and profile whatever printer you use to make proof prints. (In addition to calibrating and profiling your monitor and (maybe) your camera.)

keqwow said:

•photoshop experienced on this workflow user

Click to expand...

You need to understand how to do a color managed workflow in PhotoShop.

keqwow said:

•pdf 1bit tif export

Click to expand...

This I don't understand.

keqwow said:

•fine print house compliant with the above standards workflow

Click to expand...

The company that will print your book must also use a color managed workflow and will cooperate with you, so that their color managed workflow meshes with your color managed workflow. Otherwise, all bets are off.

keqwow said:

Don't try this alone without expert's help (buying the necessary
equipment is out of the question), it's time and money consuming more
than the usually affordable amount u may have in mind....

Click to expand...

You need to hire an expert--don't expect to be able to do this yourself.

The above was my attempt to "translate." I don't have enough experience with this to agree or disagree with what aris14 said. (But I do know that high end profiling equipment can cost $10,000, and up.)

I can suggest that you read a book or two about color management. Like:

Real World Color Management (2nd Edition)

http://www.amazon.com/Real-World-Color-Management-2nd/dp/0321267222/ref=sr_1_1?ie=UTF8&s=books&qid=1231796685&sr=1-1

or

Color Management for Photographers: Hands on Techniques for Photoshop Users

http://www.amazon.com/Color-Management-Photographers-Techniques-Photoshop/dp/0240806492/ref=sr_1_5?ie=UTF8&s=books&qid=1231796685&sr=1-5

You can start by reading the color management tutorials at
http://www.drycreekphoto.com/

Wayne

...thank you for being self-appointed translator for me, really appreciate it!
Of course English is not my native language since I am Greek.
Anyway jargon is jargon... lol!

The real problem with what our friend keqwow asked in the forum is that he cannot even imagine in what deeply complicated subjects he is into, no matter how much he really wants to learn and no matter the personal resources he can afford.

Anyway you have done an excellent job trying to translate my jargon and rather frustrating english. FYI one bit tif pdf is a form of pdf that we usually use to ensure that no further colour management can be applied in a final document ready to print.

BTW my dear keqwow I am in your disposal if u need any further help and "never fear my dear, dr.Zachary Smith is here..." (favorite moto of the ancient "Lost in space" show) since these kind of problems combined with lack of know how, are exactly the same in all countries of the world no matter if it is USA, UK, Italy, France at least to my real experience. I just tried to write in synopsis the whole story.
Keep in touch.

please read my answer as I sent it to Wayne

"...thank you for being self-appointed translator for me, really appreciate it!
Of course English is not my native language since I am Greek.
Anyway jargon is jargon... lol!

The real problem with what our friend keqwow asked in the forum is that he cannot even imagine in what deeply complicated subjects he is into, no matter how much he really wants to learn and no matter the personal resources he can afford.

Anyway you have done an excellent job trying to translate my jargon and rather frustrating english. FYI one bit tif pdf is a form of pdf that we usually use to ensure that no further colour management can be applied in a final document ready to print.

BTW my dear keqwow I am in your disposal if u need any further help and "never fear my dear, dr.Zachary Smith is here..." (favorite moto of the ancient "Lost in space" show) since these kind of problems combined with lack of know how, are exactly the same in all countries of the world no matter if it is USA, UK, Italy, France at least to my real experience. I just tried to write in synopsis the whole story."
And please keqwow keep in touch

If your background is a true white, why not set the lightest part of it as your white point by using the white point eyedropper in levels. It's exactly how you use a white, grey, black card in photoshop. It will remove any colour cast.

At least for me, true color is how I remember the original scene looked.

So, I load the raw file into photoshop or DPP raw viewer and adjust the image until it looks like what I remember.

then, I upload it to Walmart, which does a GREAT job of matching what my calibrated monitor looks like when sRGB is the source space.

done. true color....what I imagine it is......printed in reproduction mode by Walmart.

keqwow said:

Also, as an example of what I am talking about, check out my
photo of the trap on this page:
http://people.hws.edu/cicciarelli/bonanza.html
Notice how the background in the photo is more gray than the
background of the webpage. Same sort of thing happens when printing
out on 'white' paper. Just curious how one goes about correcting
this?

Click to expand...

One very simple way to fix it is to adjust the "highlight" slider in the "levels" adjustment. It is useful to refer to the image histogram while doing this. Your original image shows a peak nearly, but not quite at the right hand edge of the graph. Simply adjust the slider by a few points to the left, the histogram will then reach all the way to the right hand edge. Job done.

The result looks like this:



Note, I made the adjustment in Paint Shop Pro, but similar controls exist in Photoshop Elements. Nothing complicated or long-winded is necessary in this case.

Also, you can check the results using the "eyedropper" control to sample the colour values. Pure white should show as R: 255 G: 255 B:255. (Note, the background on the dpreview forum page is almost white, but not quite, it has a value of 239 rather than 255).
Regards,
Peter

sRGB is far from "true color"
a decent color workspace is Adobe RGB,
especially if the job is to be printed in a variety of HiFi/Hexachrome.

1bit TIFF PDF is a separation in layout,
a halftone/line, not continuous tone, at as high resolution as 3600dpi
(Walmart would really mess that up : )
even Kodak Approval does, but that's a proofer.

Anyway, you don't need to know all that.

If the job is to be offset printed, a skilled pre press specialist will take care of whites, blacks and most colors in between, if they are achievable and wanted.
Fluorescents, metallics won't be there unless added on purpose.

You just make sure that you use a good dynamic range camera, shoot a color target every time you change the lights and give a good pre press bureau RAW captures.
White balance would be nice but don't overexpose for the whites.
I prefer tone in whites, except for specular reflections on glass, metal...

It is obvious I still have a lot to learn....color chart? White balance vs gray card? So much to learn just to get the quality result one wants....

Levels control for the original image, showing histogram:



Notice the left end representing shadows does not quite reach the edge. More importantly, the right-hand (highlight) part of the graph does not reach the edge.

So I pulled the two sliders inwards, taking a very bold approach at the right hand side, to force a pure white. This has caused the overall brightness of the image to appear a little lighter, so I moved the middle slider a touch to the right to darken the midtones a bit. Like this:



The resulting image has a histogram which looks like this (vertical lines or gaps can be ignored):



Hope this helps.
Regards,
Peter

start with the tutorials on the left side of this page:
http://www.colormunki.com/colorknowledge/training?type=photo

You could also consider creating clipping paths around the objects in your photos so that the background becomes transparent and will therefore eliminate the concern about exactly matching the white background in your photo to the colour of the paper stock. You can create the clipping paths in Photoshop yourself, but I believe there is other software that may do a better job. There are even services available that can do it for you--google clipping paths services.

Proper colour balancing and colour management is still important though in order for the objects you are photographing to come out true to life, but clipping paths can eliminate the concern about matching the background white to the paper.

HTH,
Marion