LUMINOSITY

[Kazoebber]

I have 6 portrait fotos of 1 person taken at different time and place. They all have complete black background, I try to give all six the same luminosity in the faces. I try with the histogram but do not succeed (scope is mystery).

Is there a solution outside de histogram ? Where is detailed information on the displayed histogram values ? 

 

[Aad Slingerland]

 

[smadell]

OK, this may seem a little convoluted but bear with me.

I've used 2 pictures of George Clooney (since they are readily available). I've placed them side by side in the same frame; you could do them individually or you could open both in Separated Mode (if you're on a Mac).

First, I used the Info panel to put 2 points down – one on each photo. These were points where I wanted to match Luminosity (and Color). I picked similar points on each photo – in this case, they were points on roughly equivalent spots on George's cheeks. I set the Info panel to read out L*A*B values for each of the points. You can see that they are close, but definitely not the same.

In my case, I put a Curves layer between the two images in the Layers panel. If you do them separately, you can put a Curves layer above each of the photos. For each Curves layer you use, set the drop-down menu near the bottom left to LAB (instead of the default value of RGB).

Now set the main drop down menu to Lightness, AOpponent, and BOpponent. Each time, click the "Picker" button, put the crosshairs over the appropriate Info sampler, and drag the cursor up or down. The goal is to get the values for L, A, and B to be the same in each of the photos.

Once you've done this, you've matched not only the Luminosity but also the Color. Note, of course, that you've only done this for a single point (so your choice of Sampler positions is critical). Also, this will not change the lighting on the photos, so they may not seem completely equivalent.

Nevertheless, this is the (admittedly obscure) way I would do it.

[Kazoebber]

Thanks for the info. But as I am 77  I want to keep it easy:   I created a large dark background on which I placed the six foto's. I then adjusted visually each image until all were in harmony.