post-processing – Tactics to judge if a printed image will be bright enough?

I'm not sure how to judge if a photo will be bright enough when it will be printed while I work on it on my monitor. "Bright enough", of course, changes depending on the ambient or targeted lighting where it will be displayed, this, that and that, yes, but I would like to put that aside as much as possible here.

I do not print at home; I send my photos to labs (Whitewall, for example).

My monitor is calibrated and characterized. The candela is currently at 120 cd / m2. It's too bright … at least, let me explain.

Of course, one of the things I've tried is to lower the brightness of my screen quite low, 80 cd / m2, maybe even less. It helps, but it has the effect of reducing the colors and the contrast – at least I perceive them. In addition, the mark of 120 cd / m2 has the advantage of being bright enough for normal use of a computer with the shading of the window.

Another thing I'm trying to do is to consider the histogram. If the image presents a nice bell-shaped histogram, I try to make sure that the majority is located right. This tactic is useful, but only if the image is ready for it. When the histogram of the photo is everywhere, I have more difficulty using it to make decisions.

I've also recently noticed that adjusting the image window (the window in which the photo appears in Photoshop, etc.) on a white background totally changes the way you see the image: it instantly makes me want to increase the brightness and often the saturation. However, I have not yet tried this tactic for printing and I am afraid of over – correcting it in the other way.

My goal is of course to stop ordering gazillion test images; I would like to know that the photo will give a good impression from the start.

So, my first question would be, did anyone find that using a white background in his photo editing software was a good way to judge the brightness of the camera? print coming soon?

And more widelyThose of you who manage to "get the correct brightness the first time", how do you go about it? What is your thing?

Thank you in advance for your ideas and advice and I hope others will find this information useful.