Exposure Vs Brightness???

fraggle101

fraggle101

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OK, so im getting used to the whole PP thing.. but, im not sure what the difference between Exposure and Brightness??

Can anyone let me in on it please??
 
Consider the histogram.
As you move exposure the histogram moves up or down and if taken too far you start to lose info either top or bottom of the histogram.
As you move brightness the histogram distorts to keep the top and bottom in the same place but the "brightness" changes.

Does this help?
 
So do you mean that the brightness increases the height of the histogram, but keeps everything in the same place ?
 
jgs001 said:
So do you mean that the brightness increases the height of the histogram, but keeps everything in the same place ?
Click to expand...

Not quite.

Exposure changes the shape of the histogram by shifting it left or right. If you take it too far then you lose info from clipping.

Brightness keeps the left(black) and right(white) where they are and distorts the histogram by changing the number of pixels at any brightness(height of the histogram). As you increase brightness the total area under the histogram remains the same but you will distort the histogram up at the bright end.

Any better?
 
gotcha thanks (y)
 
I have to add that different raw developers seem to act differently on this subject so I would be pleased to hear other views from our forum PP experts. What I have said in my previous posts is the Capture One interpretation that Mr. DonnaM uses. My Lightroom/Camera Raw acts differently and in a way I cannot fully explain, but that's Adobe for you!
Doing a Google on exposure vs brightness brings up a number of links. This one: http://www.thelightsright.com/ExposureVsBrightness is a good Camera Raw explanation.
 
So, would it be safe to assume that its best to keep away from the Brightness slider and stick to adjusting by using the exposure and/or levels??

Thanks very much for the explanation..(y)
 
fraggle101 said:
So, would it be safe to assume that its best to keep away from the Brightness slider and stick to adjusting by using the exposure and/or levels??

Thanks very much for the explanation..(y)
Click to expand...

Not strictly true. They do a subtley different job. Try adjusting the exposure to give the minimum clipping at either end of the exposure range then adjust the brightness to bring the shot back to make it "look right".
 
OK, thanks.. i'll have a play and so what happens..
 
DonnaM said:
Not strictly true. They do a subtley different job. Try adjusting the exposure to give the minimum clipping at either end of the exposure range then adjust the brightness to bring the shot back to make it "look right".
Click to expand...

I never understood the difference either but I appear to have (inadvertently) being doing the right thing all along :)
 
In Lightroom the Exposure adjustment operates mostly towards the right hand side of the histogram, leaving the lower mid tones and shadows relatively unchanged. The Brightness slider operates very much on the mid tones, brightening the overall impression of the image without pushing the highlights into clipping. If you hover the mouse of any of the first four adjustments (not Brightness or Contrast) you will see a section of the histogram become faintly highlighted, so you can see whereabouts the changes will have most effect. You can also select within the histogram itself and slide left and right there in order to invoke the Exposure/Recovery/Fill/Blacks sliders.

If you have a gap over on the right of the histogram and you want a lighter image then you might start your adjustment with the Exposure slider first. If you are already near or at clipping with your highlights but still feel you want to lighten the image then try the Brightness slider rather than Exposure.

If you have a flat, drab image, such as one taken on a foggy day, with a strongly centred histogram and gaps on both sides, then you might want to pull up the exposure slider to brighten the top end and also pull up the black slider to darken the black end. You can then use the brightness slider to position to mid tones wherever you need then and then tweak contrast to best effect.

In DPP you only have the one slider in the raw tab, called "Brightness", I believe it shifts the entire histogram left/right as though you had actually shot with a different exposure within the camera.

I don't know about other software.
 
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