Exposing to the right

I don't fully understand this. I'm told the best way to see if you've exposed a shot correctly is to check the histogram.

Exposing to the right is very popular. But just how far to the right of center should the histogram peaks be? Can anyone link a typical exposed to the right histogram shot?

What am I missing? When I expose a shot using the camera's light meter the histogram peaks are nowhere near the right but the images look fine. Infact I would say the peaks are more to the left of centre.

This is one of those things I've never fully understood

Linky: Exposing to the right

The histogram can go as near to the right as possible without being clipped.

However, if by exposing to the right the photograph looks overexposed or not how you wanted, change it and expose nearer the centre, or to the left. Ultimately, it is the result that you are looking to achieve that is important and exposing to the right is not always going to suit.

Remember though, if you do under expose and want to correct the exposure, you run the risk of adding noise to the image. Noise will be less prevalent in "properly exposed" images.

What the simple practice of 'expose to the right' does not cover adequately:

You are inside, shooting a scene with a bride in white bridal gown and a black tuxedo'd groom using available light (nice bright well windowed room).The room does not have direct sunlight coming in, and you have some of the windows in the frame looking out to a bright exterior, which let indirect light into the room to illuminate the bride, but which also leaves some of the room interior in shadow (where the groom is sitting). You want the highlights of the gown, you care nothing about the highlights of the outdoors visible thru the window, you look at the histogram and see 'clipping whites'...which are they, the outdoors or the hightlights of the gown?!?!

This might be of interest

http://www.luminous-landscape.com/tutorial​s/expose-right.shtml

Cheers

!. ETTR is a viable method only for RAW shooting because it presupposes that, if neccessary, you will be able to reduce the exposure (move it back to the left) during the conversion from RAW to RGB.
2. What needs to be to the right is not neccessarily a "peak". Peaks are formed when a large number of pixels have the same or nearly the same tonality. What does need to be to the right is the portion of the histogram that represents the brightest part of the subject and this may not be big enough to form an actual peak. An example: You shoot a sort of medium grey bird against a background of dark foliage and the bird has a tan colored spot on his throat. In a so-called "correct" exposure the histogram (which goes from 0 - 255) would have a peak at, say, 50 for the background and a peak at around 128 for the bird and a little bumb in the histogram at 220 for the tan spot. ETTR advises exposing so the tan spot is 250, almost the maximum, and then in the RAW converter reducing the spot back to 220, the bird to 128, etc.

Thanks guys for all the information, it's a lot clearer now. The histogram is clearer now I'm not expecting peaks to be on the right, just part of the histogram itself.

primalcarl wrote in post #6139205
Exposing to the right is very popular. But just how far to the right of center should the histogram peaks be? Can anyone link a typical exposed to the right histogram shot?

What am I missing? When I expose a shot using the camera's light meter the histogram peaks are nowhere near the right but the images look fine. Infact I would say the peaks are more to the left of centre.

It helps to understand why this technique is used. The reason is that the 12 bit A/D converter on most cameras uses most of the bits in the highlights. Since you have 4096 gradients of a color to work with the first range of luminance (the highlights/white) takes up 2048 of them, then the next section is 1024, then 512, 256, 128, 64, 32, 16, 8 (shadows/black). This may not be 100% accurate, but it's close. Therefore the more of your picture you get to the right, the more gradients of color you have to work with.

This only works for RAW. When you bring in the picture within the raw converter it typically looks overexposed and what you do is draw down the exposure (normalize it). Theoretically you get a finer picture this way.

There are caveats. The histagram cannot be 100% trusted on the camera because it's sampling just a small JPG image, not the RAW data, to display that histagram so you may not get any highlight burnout warnings on the camera but later find you have overexposed your whites. So don't get right up to the right, just get somewhat close to it.

Furthermore if you have a 14 bit a/d camera (1Ds III, XSi, 40D, 1D III) this becomes less necessary because those cameras have 16,384 gradients which leaves a lot more left over for the shadows. So on a 14 bit camera I wouldn't be so worried about it. Although it's still better to not leave too huge of a gap on the right so that you're not wasting the best part of the sensor capture.