selmslie Loc: Fernandina Beach, FL, USA

The value of analysis is in what you can learn about your equipment and the process from carefully constructed experiments under controlled conditions. Knowledge is power. The most important thing will learn from these experiments is how little benefit there is in precise exposure.

Modern digital sensors have plenty of latitude on the dark end and film on the bright end of the scene's dynamic range range. An exposure error of +/- one stop is easily corrected during post processing if you don't blow the digital highlights or lose shadow detail in film.

There is no point in over analyzing during the picture taking process. With a good foundation of knowledge your work with real subjects should be easy. You can concentrate on the non-technical aspects like subject selection, composition, framing, focus and timing.

BebuLamar

Even if I don't take one single picture it's still interesting for me to know how the camera works. I enjoy learning about how the camera works by itself. People can criticize all they want and I wouldn't care less.

larryepage Loc: North Texas area

A glassblower who doesn't know what materials produce which colors is going to have a difficult time getting his desired result. If he doesn't know how hot the furnace needs to be, the whole process is going to be difficult or impossible. If he doesn't know how much glass to gather, his plate may end up as a saucer or as a platter. If he doesn't know which shaping tools to use, his plate is likely to end up looking more like a bowl. If he doesn't know how to operate his annealing oven, everything is going to shatter into pieces. If he doesn't know how to manage his process and work safely, he is not going to be around very long.

A sculptor who doesn't understand how each type of stone works is going to have a hard time selecting the proper tools to do her work. If she doesn't understand how her chisels and other tools work, she is going to have a really hard time removing all of the material that isn't part of her finished statue...

A metal artist who doesn't understand how to weld properly...

A painter who doesn't understand...

A potter who doesn't understand...

A woodcarver who doesn't understand...

Tools, technique, and craft are part of every artistic endeavor. A photographer who claims to be anything beyond a snapshooter needs to understand the tools, techniques, and craft of the art in order to readily and reliably produce good images. There is certainly a point at which some of this becomes well understood...maybe even second nature. But Ansel Adams and others never stopped inquiring, learning, and yes, testing. Adams continually focused on understanding his materials, his equipment, and his technique. He kept detailed records of exposure and of his printing process for each image. Part of that was so that he could reproduce his images easily. Part of it was so that he did not have to learn things again.

We seek to be artists, but we have to know how to do that. We need to understand our materials. We need to understand our equipment. We need to understand our craft. The level may vary among us, but the more we understand, the better and more perfectly, and more easily the art can come. But I am not aware of any artist that gets to just stick a battery in a machine and push a button. Or even gets to just stick a battery in a machine, turn some knobs, and push a button.

I'd like to encourage us to all work to improve our craft.

a6k Loc: Detroit & Sanibel

Once again, the reader is ignoring my explanation of why my experiments were done, are being done. By ignoring the full content of the thread he is able to be dismissive. If it were only about 1/6 of a stop I'd have done something else.

The tests are designed to better understand and predict where on the gray scale this particular camera places the metered subject. Is it 12.5%? Is it 18%? Something in-between? What does that mean for ETTR with this particular camera? Is this testing method useful for other cameras? Does auto vs manual affect the results? How about the plus or minus EV on exposure compensation?

And here's a thought for the naysayers: Since the difference, on my camera, between automated exposure of some kind and manually controlled exposure, even ISO, can be in either direction, the full magnitude of the possible error is 1/3 of a stop (less a hair).

OK, 1/3 is still not huge but it's unpredictable and non-trivial. If you are a point & shoot JPG shooter then none of this is at all important. If you try to work hard at your craft then perhaps it is.

dsmeltz Loc: Philadelphia

I do not misunderstand it at all. I am saying if it makes you happy do it. However, I am also saying in real world shooting other things impact the process that vastly diminish the value of predicting with that level of precision. If variations in changing conditions in uncontrolled situations can affect a result by 3x, knowing the adjustments to achieve 0.5x will be of little little real world operational value. I can think of no situation in which I have taken a picture where, on the fly, I thougth "Wow, I better adjust 1/3 of a stop, and do it NOW!" That may (as I have said) have some value in studio or laboratory settings. If that is where you do your photography, go for it!

selmslie Loc: Fernandina Beach, FL, USA

You can see the difference under controlled conditions.

But in the field with random subjects and variable framing and lighting, +/- 1/3 stop is not significant.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

I don't believe in doing everything to extremes- crash diets, binge eating kinda approaches to life and my work. I am not going to carry on tests and experiments every day, in the midst of shooting assignments or before each shoot. Testing, experimenting and verifying accuracy of equipment and methodologies is part of the job but I am not preoccupied with it.

Time is important to me so I invest it carefully. Testing is part of quality control. Time spent in learning all the aspects of the equipment, making certain that everything is operating properly and that I am in control of the gear (and it ain't in control of me) is time well spent because it precludes anomalies that occur during important shoots, spending excessive editing time to remedy sloppy or inaccurate shooting or spending hours of troubleshooting on issues that shoud have been dealt with ahead of time. In professional work we tend to take a dim view of costly re-shoots due to equipment failure or technical glitches.

I can't understand how or why technical investigation and savvy could possibly interrupt or stymie the creative, emotional or reflexives process in shooting. When you know that all systems are "go', you can better concentrate on all the aesthetics, composition, expression and lighting.

Even is a controlled "studio" environment, some folks would be surprised how fast and unencumbered shooting is required. Some might think that portraiture, fashion shoots and commercial work is stagnant and stodgy work- certainly not the case! When photographing people, expression and body language is fleeting. A steaming food shot is "perishable" everything has to fall into place within seconds. Model and stylist fess are ticking away like a taxi-meter and deadlines need to be met. There is no time to fumble with equipment or begin troubleshooting in the midst of a session.

For me, admittedly, old habits die hard! After so many years of shooting large format transparency film, with comparatively little latitude, especially in low key or high contrast (lighting ratio) situations, 1/3 or 1/6 of a stop does make a difference. Processing temperatures needed to be within 1/2 of 1 degree...so you get accustomed to precise controls. Of course there is more latitude in current digital photography, however, I consider the latitude as a backup- a margin for error but not an excuse for sloppy shooting.

This is my thing- it ain't carved in stone and each photographer has their own approach.

rook2c4 Loc: Philadelphia, PA USA

Most modern cameras do have a manually adjustable exposure compensation feature, which should generate the same exposure results in semi-auto mode as manual mode - if used correctly. Although I do feel it is beneficial to understand how to use manual exposure mode, it is equally important to be able use the auto/semi-auto modes effectively. Failing to capture a rapidly fleeting moment because you were fiddling around in manual mode instead of using auto mode is not what I would consider particularly "perfectionist".

selmslie Loc: Fernandina Beach, FL, USA

The same can be said of relying on the cameras reflective light reading when shooting in broad daylight. A lot of shots are missed by trying to spot meter a flying bird and trying to figure out the exposure compensation.

You should not need to meter a scene at all in broad daylight. The brightness of the sun does not change.

It's just a matter of knowing how much of the scene is directly illuminated by the sun and whether you have the sun behind you. In most cases, Sunny 16* is accurate enough and you can get a lot of information at Exposure value (EV) like, "As a rough general rule, decrease EV by 1** for side lighting, and decrease EV by 2 for back lighting."

* Sunny 16 suggests 1/ISO @ f/16 or equivalent.
** Decreasing the EV by one means opening the aperture one stop (f/11 > f/8) or cutting the shutter speed (1/500 > 1/250).

rook2c4 Loc: Philadelphia, PA USA

I agree. As I regularly use old film cameras without built-in light meters, I've learned that metering for every shot is not necessary, as long as the overall conditions don't change. And that a 1/3 stop exposure difference rarely ever has a noticeable impact on the image... at least not with negative film.

dsmeltz Loc: Philadelphia

Yes. And the time and energy cost of trying to adjust 1/3 of a stop goes against the law of diminishing returns. The benefit is you have "perfect exposure" the cost is you miss the shot.

Lab and other controlled tests are nice, but they are based on the concept of "all other things being equal" when the one thing you can be sure of outside of a lab is tha all other things are NEVER equal.

a6k Loc: Detroit & Sanibel

But the whole point of my post about the "error" is that semi-automatic gives you as much control as possible yet yields the probably higher accuracy. So it's LESS trouble, not more and gives equal or better exposure accuracy. That's even more true when the light is changing a lot or rapidly such as on a breezy day with some clouds. So, respectfully, I think you have the diminishing returns analysis backwards. I do agree that the sum of the factors is never equal. However, any technical or scientific analysis strives to limit the variables and "control for" others.

I have not yet verified that auto ISO is equally accurate compared to auto shutter but that's on my to-do list. When shooting birds I need high shutter speeds and typically am limited to F 4.0 or even F 8.0 when using long lenses. So with an aperture that is forced to wide open and a fixed shutter speed because it's birds, then auto ISO is my choice. That leaves me free to think about the subject, composition, timing, frame rate and so on. For other kinds of subjects, especially architecture and landscapes, other techniques may be better.

So, now the important issue is to determine how much, if any, exposure correction to pre-set into the camera in order to get the best result when exposing with spot metering on the critter. That's what analysis of the middle gray vs blown-out results gives me. So to re-emphasise the point about auto vs manual, user-set exposure compensation in advance of a session is not possible in manual. You can certainly apply a 1/3 stop correction in manual but my data suggest strongly that A. you don't know in which direction to move and B. in variable lighting such as outdoors on many or most days you will be doing a lot of fussing with dials and readings. There are two corrections at issue here: 1. the error between auto and manual and 2. the adjustment you may want to apply based on your meter's calibration.

It's easy to demonstrate that cameras vary considerably on this. It's also possible, with little effort, to demonstrate that the post processing applications that are both raw developers and picture manipulators vary a great deal in how they interpret the actual raw values in the file. RawDigger is the only way that I have found to do this. For that, FastRawViewer and (for Mac) RPP64 are the least biased. CaptureOne, Darktable, RawTherapee can be tweaked and used skillfully to get near that goal but the problem with them is that unless you have first used FRV or RD then you don't have a valid starting point. Btw and as an aside, Luminar is not showing you the raw file at all. I accidentally discovered that it shows the raw file as modified per EXIF values. That surprised me. I will do a separate post on it, later. I don't have every popular application so perhaps there is another available that can help with this issue.

BTW, I agree with Scottie that if the conditions are conducive to it, then the Sunny 16 technique is excellent and I've been known to use it myself. I did use it a lot more in the days of film. To me, it's a special case of incident light metering. I always thought that incident light metering was the most correct when it could be used. That and a little bracketing and you are almost guaranteed good results. As many of you have said, with modern gear and computer post processing, getting it exactly right is less important than with, for example, color slides.

Speaking of bracketing, many cameras, mine included, can bracket for you very fast and very accurately. Of course, if you are shooting birds either in flight or merely active, then you have to choose between bracketing and catching that perfect pose with bursts.

selmslie Loc: Fernandina Beach, FL, USA

I can speak only about the three digital cameras I have in hand at the moment (A7 III, D610 and Df) but this discussion forced me to review my previous tests using a blank white screen as a target and RawDigger to look at the results as I had in the past.

My expectation has been that the raw values for the middle of Zone V should produce a raw value of about 1414 - half way between 1000 and 2000. Adding three stops of exposure would place the middle of Zone VIII between 8000 and 16000 (11,314). This confirmed the results with the D610 and A7 II (with a variety of lenses) on which I based my conclusion that Zone VIII is the limit for digital sensors. As before, neither camera needed any exposure compensation to get these results.

But the Df produced slightly different results. I thought this was odd until I realized that I had not accounted for the fact that the Df had a different lens on it (Voigtlander Ultron 40mm f/2) than the D610 (Tamron 35mm f/2.8). Once I switched the Tamron to the Df, all three camera's agreed.

The A7 II (with a Voigtlander Nokton 40mm f/1.4) worked the same as the D610 - maybe dumb luck.

a6k Loc: Detroit & Sanibel

UPDATE

Scotty's post and many of his previous ones (Thanks!) got me to buy Raw Digger. Then I tried to follow the instructions on one of the articles "How to Use the Full Photographical Dynamic Range of Your Camera". At first, the numbers did not look right. I wrote to tech support and got the help I needed (settings) immediately. This was certainly one of the better uses for $20 that I've found lately.
https://www.fastrawviewer.com/blog/how-to-use-the-full-dynamic-range-of-your-camera

It turns out that my camera's meter is assuming the world is 7.6% reflective. As most already know, that's quite a bit lower than it "should be". The nominal standard is either 12.5% or the more traditional 18%. One consequence of this is that I have 3.7 stops between middle gray and maximum-not-blown. The other consequence is that since the camera is underexposing an abnormal amount, there is more probability of noise, especially at higher ISO's.

There is so much difference between post-processors and so little real clarity about what part of their display is or isn't interpretation that I could not have pinned this down any other way. I could have kinda-sorta decided to adjust the camera but I'd have been flying blind so to speak. I set out to discover where middle gray was on the scale (and to understand it). I found that out, finally. I also found out that using exposure automation has an unanticipated benefit as well as the obvious convenience.

In hindsight and with the confidence that using RawDigger gives me I can recommend to any that are interested only in the evaluation and not the quite challenging detail a way to back into a good estimate of where the middle gray is or should be. PM only on this, please.

"Life is like a box of chocolates."