Garyminor Loc: Raleigh, NC

I've seen this advice given by Gene51 in several of his post and I wondered if he really meant what he said.

If the brightest area is only one stop brighter than middle grey, then middle grey will be properly exposed. All is good!

However, this doesn't seem to be a good idea. Most cameras (with 14 bit sensors) have middle grey fall in the range of 1000 to 2000. This allows the brightest areas to be 3 stops brighter in the range of 8000 to 16000.

If the brightest areas are three stops brighter than middle grey, and you expose it as one stop brighter, then middle grey will be underexposed by two stops, and the darkest areas will be underexposed two stops more than necessary.

To say the same thing in a different way:
If the brightest areas are exposed one stop brighter than middle grey, then the largest values from the sensor will be in the range of 2000 to 4000, and two stops of dynamic range will be wasted. This may not be significant in a low contrast scene, but if there are some very dark areas, then they will have more noise.

Kozan Loc: Trenton Tennessee

You give numbers 1000, 2000, 4000, 8000. What are these numbers referring to? As for zones, even Zone 8 or 9 should have detail.

Kozan

TriX Loc: Raleigh, NC

I believe he's referring to ~16K levels represented by 14 bits...

Angmo

I prefer incident light metering versus reflected. Hand held meters. Of course it depends on your use.

rmalarz Loc: Tempe, Arizona

Gary, actually Gene is correct, but a bit conservative. Each camera, even within the same model, will vary a bit on how much detail it can capture before blowing out highlights. The only way to find out for yourself is to test your particular camera and see just how far you can push the exposure to the right before it fails. BTW, this only applies to RAW captures.

Once you know that, spot metering the brightest part of a scene will place that, as metered, in the middle of the 0 to 255 limits. Each stop of exposure added will raise that metered value on Zone. 1 additional stop - Zone VI, 2 Zone VII, etc. Some cameras have less tolerance to the amount one can push them.

Now, the nice thing about this is that it also raises the exposure on the lower brightnesses of the scene, as well. This is where the additional benefit of noise reduction comes into play.

Once the exposure is made and opened in your favorite RAW processor, the overall exposure can be reduced and bright the entire image back to the appearance of the original scene. Adjusting shadows and highlights creates your vision of the scene.

This entire process takes a good bit of testing and I don't mean taking random photos of various subjects. Ideally, you could use a black, gray, white photo card setup, these can be purchased from B and H for less than $20. A scientific approach to the tests will provide you with the performance characteristics of your camera. Once you know those, you're on your way. Then it's just a case of careful study of the scene and spot metering the appropriate highlights.

Once proficiency of the use of this technique is attained, it's little more difficulty than point, meter, and shoot. Of course, this works best in manual mode.
--Bob

srt101fan

Bob, could you please provide some more details on how to test for the "performance characteristics" of a camera? Is this testing for the Dynamic Range of the camera?

BebuLamar

But how does the OP know what value the camera gives middle gray? For 8 bit I have it 117 and I want it 117. For 14 bit I don't know because I can't really read the value of the pixels in 14 bit format.

oisin59

In my experience you want to go a stop and 1/3 or a stop and 2/3. The important thing is to get your highlights properly exposed in camera. You can take care of underexposed areas later in post-production this is of course with bright highlights such a sky or clouds

pete-m Loc: Casper, WY

I get good results using 2 stops. Be sure not to use specular highlights. Do a few practice shots.

camerapapi Loc: Miami, Fl.

What those numbers you refer to when you talk about exposure actually mean? When photographing highlights, are we talking about highlights in sunlight or highlights in the shadows?
If the exposure is correct for the highlights all other tonalities will fall about right. In my case I am very careful exposing bright subjects in sunlight because the reflectance usually exceeds the dynamic range of the sensor.
I tend to UNDEREXPOSE slightly and make a slight correction during editing to my original exposure. Nothing worse with digital than to clip the highlights but I know you are well aware of that.
When my bright subject is in the shade and using my cameras I do not tend to overexpose by more than a third of a stop and again I make corrections during editing. I do not know if this will work for others but it does work for me.

Notorious T.O.D. Loc: Harrisburg, North Carolina

I have calibrated my camera to my Sekonic meter and ColorChecker Passport. I know I can meter for the highlights and go as much as 2 2/3 stops open from there.Joe Brady has several YouTube videos on this subject with these tools. Worth watching in my opinion.

selmslie Loc: Fernandina Beach, FL, USA

The numbers he is referring to are for a 14-bit raw file:
Two stops over middle gray should work for a JPEG but zone 8 is usually discarded by your camera when creating its JPEG. If you develop from raw on your computer you have access to zone 8 so it's safe to go 2-1/2 stops over. There is no zone 9 for digital.

When crating a raw file on your computer you will be mapping those raw numbers to the 0-255 range. You can do almost anything with the raw information from exposure zone 8 on down but around exposure zone 1 and lower everything starts to get noisy and blotchy depending on how much light was captured.

blackest Loc: Ireland

Maybe this link would help.
https://photography.tutsplus.com/tutorials/understanding-using-ansel-adams-zone-system--photo-5607


https://www.techradar.com/news/the-a-to-z-of-photography-exposure-compensation
A plus (+) setting will make your image brighter than the 'standard' exposure, while a minus (-) setting makes an image darker, with each movement up or down the scale recorded as a 'stop', or an increment thereof. A full stop adjustment will double or halve the exposure, but most cameras offer intermediate 'half-stop' or 'third-stop' increments for more subtle adjustment.

I, II, [III, IV, V, VI, VII,] VIII, IX , X normal metering exposure centred on zone 5 the mid tone detail +/- 2 stops.

I, II, III, IV, [V, VI, (VII), VIII, IX ], X metered on the highlight zone 7 your subject is under exposed 2 stops

make it brighter +1 exposure compensation

I, II, III, [IV, V, (VI), VII, VIII], IX , X +1 exposure compensation subject under exposed 1 stop

I, II, [III, IV,(V), VI, VII], VIII, IX , X +2 exposure compensation normal exposure.

ok how about if the highlight is in zone 8

I, II, III, IV, V, [VI, VII, (VIII), IX , X] ok subject is now black

I, II, III, IV, [V, VI, (VII), VIII, IX , X] +1 exposure compensation subject in shadows highlights not blown

I, II, III, [IV, V, (VI), VII, VIII], IX , X +2 exposure compensation highlights still not blown subject under exposed 1 stop.

if the brightest highlight was zone 6 then you would be over exposing the subject by 1 stop with 2 + stops compensation.

If you are metering off highlights then it seems adding +2 to the value would ensure they don't blow
if metering the subject then -1 would allow for 3 stop higher highlights instead of the normal 2 stops with detail.
if you are pushing to the right then +1 stop on the subject would give just one stop for highlights in the jpeg but 2 stops can be recovered from the raw.

Is that confusing ?

Rich1939 Loc: Pike County Penna.

You seem to have a different zone system than what Adams used. No zone 9 but -1,-2 and -3?

selmslie Loc: Fernandina Beach, FL, USA

There is a difference between exposure zones and print/image zones.

Adams defines print Zone 0 as maximum black, Zone I as dark tonality with no detail or texture ... Zone V as middle gray ... Zone IX as light tonality, no detail or texture and Zone X as paper white or maximum white.

If you develop film normally you can get exposure zones 3-7 to line up closely with print Zones III to VII. But that is not always desireable and it's the whole point behind the Zone System.

With film you cannot go below film base plus fog and that is usually printed as Zone 0. With digital you can't go above exposure zone 8.

However, B&W film can easily reach exposure zone 11 or 12 and still retain texture, especially if you pull the processing. Digital can also easily reach below exposure zone 0 and still provide texture and detail that can be recovered during the raw conversion. But keep in mind that digital also starts to get noisy around exposure zone 0 depending on the camera. It gets worse as you go lower.

For more on the subject, see Film vs. Digital Characteristic Curves.