same picture gets darker when printed

[alexphot]

Hello
I orderd a big printed photo from a company and was happy with the result.
But then i saw i had made some mistake in photoshop so i had to order a new print again, pretty much the same photo but i had made it sharper, a few % brighter, and reduced green color on a few trees.

Now the second time they printed the picture, it became extremley dark and i was not happy with the result, so they had to print it again.
Now they have done it 2 more times and still very dark.

What could be the problem?
Its basicly the same picture and they look the same on the screen when it comes to contrast and color.

They said the histogram was quite different on the pictures but i dont really know what that means or if that can be the problem.
And if it is the problem, how do i fix it?

Wierd that the picture i have made more bright came out extremley dark when printed.

Here you can see both pictures and them printed side by side on the floor:

https://files.fm/u/amkyk7x3c
 

[ed_farmer]

Off the top of my head . . . Many online services have a check box to indicate if you want them to correct color/density or print as you sent the image.  You may have checked this on one order and not the other.  But, I would suspect that the lab would have noticed this when you complained.

 

[AlanKlein]

Digital Dog will clue you in.  He'll be here soon.  😉

[paddler4]

The histogram shows the distribution of brightness in the image. Left is dark, right is bright. If the lab is correct that the histogram is darker (shifted to the left) in the second file, that means that you did something in your editing that made the image darker.

[glen_h]

Some years ago, I had 200 Christmas cards printed by Shutterfly.

The picture was fine when I looked at it, but the prints were very dark.

It must have been that no-one looked at them.

It turned out that in one corner, there was a tiny bright spot, sun where the

rest was in shade.  Somehow the printer exposed for that tiny spot.

(They nicely gave me store credit, which I used for other prints later.

I had them made somewhere else, with no problem.)

 

As with auto-exposure cameras, there is a system for figuring out the

exposure based on the image, and it might not be the one you expect.

 

In the olden days, it was average over the whole scene, as that is what

meters could do.  Then they got fancier, but once in a while get it wrong.

 

 

[glen_h]

On 1/1/2023 at 8:19 AM, alexphot said:

 

(snip)

Wierd that the picture i have made more bright came out extremley dark when printed.

Here you can see both pictures and them printed side by side on the floor:

https://files.fm/u/amkyk7x3c
 

 

Looking at them, at first I thought I knew what you meant, but then I find that it makes

whichever one I point the mouse at darker.

 

The difference, at least as viewed on my computer LCD screen, is darn small. 

But it could be exposing for the sky, when you are looking at other parts.

 

If I really worry about this, I get a smaller print made first, then the larger

one that I really want. 

[kmac]

Did you make a duplicate copy of the original image ?

The problem may have been that you modified the same image twice.

Selecting a new copy and working on that may have been more beneficial.

In other words, start afresh with a brand new duplicate copy of the original image and incorporate all the changes you intended, of the first time and the second time, all done under the one "modified" date and time. And name it differently to any image you've already sent for printing.

The lab will then be printing an entirely new set of data, (as long as they don't mess around with it, changing the histogram etc, but if the histogram gets changed automatically, then that will change your image. Specify that you don't want anything changed.)

It's also handy to remember that prints will be slightly darker than what you see on your computer screen. With all my prints, I found it necessary to brighten the image one click in the print panel - Print Options - Darken 1

 

 

 

[tom_mccabe]

You might try calibrating your screen and contacting the lab to download the IPC profiles for the paper they are using. Just at thought.

[Alfred_Pennyworth]

Your computer monitor and the printer operate in different color spaces, meaning they have different ranges of colors they can accurately reproduce. When you view an image on your monitor, you're seeing it in the RGB color space, while the printer uses CMYK color space. If the image isn't properly converted between these color spaces, it can result in color shifts and changes in brightness. 
To fix this, make sure that your image is properly converted to the CMYK color space before sending it for printing. Most photo editing software has built-in color conversion tools. You can also consult with the printing company to understand their specific color conversion requirements.