PDA

View Full Version : Monitor calibration and using third party labs



Ben Calwell
23-Feb-2018, 06:16
I don't own an inkjet printer, so if I go to the trouble of calibrating my monitor for black-and-white photography, how will I know if the scanned negatives I send out to be printed will come back to me looking like what I saw on my screen? In other words, just because I have a calibrated monitor, does that mean that whatever lab I choose will be able to match what I saw on my screen?

malexand
23-Feb-2018, 07:06
Probably can't be sure right off the bat. If you calibrate your end, I'm sure it will be pretty close. You'd still want to send any lab you plan to use some sort of calibrated test before you go all-in with them.

bob carnie
23-Feb-2018, 08:18
I think that one needs to understand the Info Pallette and how the numbers work.. I use L and K values to measure pixel density , a L reading on your computer will match the L reading at my end. Also any colour can be easily tracked if you are laying down aim points and using same pixel size information draw as me...

It is always important to test on the final printer and adjust your files from these tests in PS , rather than hope your screen visual, is going to match my screen visual. An impossible probability.
We know with most papers where Highlight with detail falls off and where Shadow with detail blocks up. Knowing these points is important.

bob carnie
23-Feb-2018, 08:21
This thinking can also reverse... many people ask me to make inkjet negs for alt printing, It is a fools errand to attempt this without having the client print a test control target on the process of choice and then send it back to the vendor to make the appropriate curve adjustments.

I am very suspect of this vendor client relationship as if any thing goes wrong it is always the vendors problem... Photographers never make a mistake Right?

Ken Lee
23-Feb-2018, 09:35
Try sending them a step wedge or some other kind of calibration target. I don't mean one with only 10 steps.

See https://inkjetmall.com/blog/piezography/the-proof-of-piezography/. Note the emphasis on separation of low and high values.

See http://www.hutchcolor.com/Images_and_targets.html

Better still, create a page with several trial images and calibration information on the same page. That way you'll get both subjective and objective information.

If you have a typical consumer-grade monitor, even if you calibrate it, it may not be linear. See http://www.kennethleegallery.com/html/tech/index.php#calibrate

ventdesable
23-Feb-2018, 13:51
I don't own an inkjet printer, so if I go to the trouble of calibrating my monitor for black-and-white photography, how will I know if the scanned negatives I send out to be printed will come back to me looking like what I saw on my screen? In other words, just because I have a calibrated monitor, does that mean that whatever lab I choose will be able to match what I saw on my screen?


Short answer ? Nope !

Except when they give you a profile of their printer so you can make some "soft proofing". That soft proofing is a simulation of the paper rendition on your screen. Usually, you'll find your picture to be flatter and probably darker. So you'll need to had some contrast and open the shadows a bit.

But, to be able to do that, you need to be "certain" that your monitor isn't modifying your perception of the image. So, yes you need to calibrate your monitor.

There is one thing that you can do anyway. take one of your picture, select a shadowy zone. One where you want to see details. And, depending on the soft you use, try to get the LAB numbers (instead of RGB). L stands for luminosity. 0 is black 100 is white.

Hover your mouse on the selected shadows an look a that number. It's going to be somewhere between 5 and, say, 30. What you want to do is to know at what "L" level, the shadows show the details you want. So you modify them to render for L10, L15, L20, L25, L30 and send all those tests for printing.

When you get them, you find the one that dose seem to be right (with details but not too light). Like this you know, with your monitor where you'll find details on the shadows. You can also do it on highlights (aiming between L80 and L95).

Then, on regular picture, you check that shadows (where you want details) aren't under the chosen "L"number and highlights over the other border. Your monitor can fool you. Our eyes aren't good estimate absolute values (but better on comparisons). But the numbers aren't based on the monitor rendering. So you can trust them.

Jérôme

Pere Casals
23-Feb-2018, 16:47
I don't own an inkjet printer, so if I go to the trouble of calibrating my monitor for black-and-white photography, how will I know if the scanned negatives I send out to be printed will come back to me looking like what I saw on my screen? In other words, just because I have a calibrated monitor, does that mean that whatever lab I choose will be able to match what I saw on my screen?

Here you have another practical way:

http://www.harmanlab-us.com/page/92/Tutorial-2.htm

You can download and print that test image in the lab you are to work, then adjust monitor until you see the closest possible match.

In fact the presentation you see in the monitor depends a lot of lightning in the room, shadow detail is lost if room illumination is too strong.