Is there such thing as a universal brightness measurement?

[Ysarex]

Outside, the Sunny 16 rule, and variations, works well. Indoors, which is what the OP mentioned, it is much harder. Photographers took to meters for a reason.

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The OP mentioned both, "Where I'm at right now is that I'll walk into a room or outside..." For many decades before meters existed photographers managed to successfully take photos both outdoors and indoors. Erich Salomon's Ermanox wasn't equipped with a light meter in the 1920s. It is likewise possible to train oneself to reasonably judge the level of interior brightness, but yes it is more difficult than doing the same outside.

Not suggesting abandoning a meter if you have one -- just answering the OP's question.

I applaud the OP for the question and the effort to learn. There's advantage to having a good understanding of the photographic process. Another story: Again early in my career I worked selling Pro gear. I remember a fashion photographer who had to spend a lot of money paying for a re-shoot because he blew the original shoot. He brought me his light meter which we determined was at fault for his debacle. It had broken as was reading more than 5 stops off. How do you miss an equipment failure like that?

Joe

Joe,
Do you recall the circular calculator system that was sold for a time, mail-order mostly, in which lighting levels and exposures were tied to a simple X-value system, which began with the Sunny 16 rule as the Zero-X baseline, and then added exposure in one-stop or one-X increments? I read about it in Popular Photography magazine, but it never got off the ground really. Sort of similar to Fred Parker's Ultimate Exposure Computer, but a bit different, and I would say, better conceptualized. Parker's Ultimate Exposure computer is shown as an EV value chart that is directly associated with real-world lighting scenarios, like EV 16 which is light that is one exposure value brighter than Sunny 16, meaning EV 16 is "Subjects in bright daylight on sand or snow". The Sunny 16 rule means light that is E.V. 15 in brightness.

The EV System is fine as a framework, but it is almost always presented merely as a charted set of numbers and f/stop and shutter speed times, with no verbal or illustrated linkage to actual shooting scenarios or common types of scenes. We can say "EV 14! EV 15!", but without a kind of scene, a type of location, or some kind of general description, the saying of the two words, "EV fifteen" means...nothing to most people.

The X-System, as it was called (to the best of my recollection) began as I said, at Sunny 16 at let's just say, ISO 100 film speed, so f/16 at 1/100 second. Keep in mind, the Sunny 16 settings refer to an EV light value rating of 15. The X-system began there, as "O-X", or Baseline. As the light level grew dimmer, another "X" was added, meaning the lens was opened up one more stop, or the shutter slowed by one stop value, or any combination of both.

So...beginning at Zero-X,the X-system was like this:
The Full moon or weak, hazy sunlight was +1-X.
Cloudy-bright with no shadow light was +2-X.
Heavy Overcast or Open Shade lighting was +3-X.
Sunsets and Deep Shade was +4-X.
Landscapes and City Skylines just after sundown was +5-X.
Neon Lights,Landscapes, Skylines, 10 mins after sunset +6-X
Las Vegas, TImes Square,campfires,bonfires,ice shows, baseball, football, bright interiors with florescent light +7-x.
Indoor sports, circuses, bottom of rainforest canopy, +8-x.

This continued to Moonlight, at +20-X for moonlit landscapes, and ended at +21-X, starlighted landscapes.

The Minus-X stuff was all crazy-bright stuff, like "Welding Arc flame at work surface" and so on.
This system had basically 21 different scene brightness levels to work with in normal, everyday situations. The advantage it offered was that it began right at the Sunny 16 rule, and was based on the simple idea like, okay, some light clouds come out, I need to go Plus-1 "X". A little bit darker but still daylight, plus 2-X. Heavy Overcast or Open Shade, plus 3-X. So, basically, there are about 21 different exposure brightness values that a person could use for most of a lifetime, and only 12 of them which take you down in brightness (but "up" in X-value) to "Fireworks".

That sounds vaguely familiar -- I am aware of Parker's exposure calculator.

"The EV System is fine as a framework, but it is almost always presented merely as a charted set of numbers and f/stop and shutter speed times, with no verbal or illustrated linkage to actual shooting scenarios or common types of scenes. We can say "EV 14! EV 15!", but without a kind of scene, a type of location, or some kind of general description, the saying of the two words, "EV fifteen" means...nothing to most people."

Yes, so often when EV values are referred to a lot is assumed in the background. But this background assuming often muddies the meaning of the EV values. EV 15 is correct exposure for ISO 100 in direct sunshine -- there's no reason other than convention for that to be some kind of standard. If you spent your years in the 60s and 70s shooting Tri-X then EV 17 was the sunny day standard and for us Kodachrome shooters it was EV 14. By itself an EV number is not a brightness level or a film/sensor exposure.

All the EV number really does is take the two variables of shutter speed and f/stop and combine them into a single value which is then a constant. At a fixed EV the camera "light pipe" is set to a fixed value. That value doesn't identify a brightness level. Thinking "light pipe" again the shutter and f/stop are like the hot and cold handles to a sink faucet. How much water get's through is a function of both the size of the opening set on the faucet as well as the water pressure. In our case (photo) the EV value plus the intensity of the ambient light (water pressure) determine the exposure brightness. Exposure being a function of ambient light intensity plus shutter speed plus f/stop: exposure = light intensity + EV.

That still doesn't work in ISO. Back to the water faucet analogy ISO is the size of the glass you're holding under the faucet. Ideally you want to fill it.

Joe

 

[timor]

. exposure = light intensity + EV.
Joe

Really ? How you add this two things ? Let say light intensity is 640 fc, to which EV you will add this ?

 

[Ysarex]

. exposure = light intensity + EV.
Joe

Really ? How you add this two things ? Let say light intensity is 640 fc, to which EV you will add this ?

Any EV you want: how about 6 since that's now much light, but if you prefer, 7 or 8.

The EV is a shutter speed and f/stop combination. EV 6 would include the combination 1/15 sec. at f/2. So 640 fc of light intensity plus a shutter speed of 1/15 sec with the lens at f/2 will produce an exposure of either film or a sensor.

Joe

 

[timor]

. exposure = light intensity + EV.
Joe

Really ? How you add this two things ? Let say light intensity is 640 fc, to which EV you will add this ?

Any EV you want: how about 6 since that's now much light, but if you prefer, 7 or 8.

The EV is a shutter speed and f/stop combination. EV 6 would include the combination 1/15 sec. at f/2. So 640 fc of light intensity plus a shutter speed of 1/15 sec with the lens at f/2 will produce an exposure of either film or a sensor.

Joe

Don't get it. Any shutter speed and aperture stop will produce "exposure". Good or bad, but it will. EV "system" helps with nothing, when comes to determination of sufficient exposure for given light conditions. Readings of the light meter could be translated into EV. But what for ? Cameras with EV setting ring are gone long ago. (Still have couple of them.)
640 fc is actually good for EV 15 for ISO 100 film

 

[Ysarex]

. exposure = light intensity + EV.
Joe

Really ? How you add this two things ? Let say light intensity is 640 fc, to which EV you will add this ?

Any EV you want: how about 6 since that's now much light, but if you prefer, 7 or 8.

The EV is a shutter speed and f/stop combination. EV 6 would include the combination 1/15 sec. at f/2. So 640 fc of light intensity plus a shutter speed of 1/15 sec with the lens at f/2 will produce an exposure of either film or a sensor.

Joe

Don't get it. Any shutter speed and aperture stop will produce "exposure". Good or bad, but it will. EV "system" helps with nothing, when comes to determination of sufficient exposure for given light conditions. Readings of the light meter could be translated into EV. But what for ? Cameras with EV setting ring are gone long ago. (Still have couple of them.)
640 fc is actually good for EV 15 for ISO 100 film

I thought 640 fc was less light than that, but I'm not very familiar with fc measurement.

Any shutter speed and aperture will produce exposure in the presence of ambient light. X quantity of ambient light will always produce the same exposure at the same EV. So EV 17 plus X light intensity is always the same exposure. The advantage of the EV value is that it reduces the complexity of the equation and creates an exposure constant from the two variables shutter speed and f/stop.

The base ISO on my camera is 200. Today here was a gloomy heavy overcast day and outside today EV 12 would have been a good exposure for the sensor in my camera. It's easy for me to learn and remember that because of the single value constants. ISO 200 is a constant and EV values are constants. The light intensity we encounter outdoors even with variations for weather and shade etc. are reasonably quantifiable -- sunshine is a constant -- even lighting indoors is more uniform than not. That was the OP's original question: Is there some uniform consistency? Yes there is and yes you can learn it.

Stop using your light meter? Of course not, but if my light meter fails I'll know it and I'll go right on shooting. I think it's worthwhile to have a basic ability to assess exposure without total reliance on a light meter.

Joe

P.S. I wish my cameras still had EV locking shutter speed and f/stop controls --maybe that's why I like and use Program mode.

 

[andytakeone]

I don't mean Kelvin or Candles or this kind of thing. I mean:

Let's say you're in a room and it's fairly dim and so you say to yourself, "This is about 20% bright."
Then you go outside and it's almost night time so it's quite dark out, and you decided that there's about as much light as there was in your room, so you also attribute it this "20% brightness."
Is this a reasonable comparison?

Yes.

Now in this hypothetical situation, 0% brightness would be pitch blackness and 100% brightness would be light that would blow out any picture.
I came to this question by reading a textbook that used a technique where the photographer would give "brightness" measurements to differently lit areas of his photograph, and then expose for the average brightness of that aggregate.
For example, if it was dark in the foreground (30%), and light in the background (70%), he would expose for "50% brightness." (Let's say in this hypothetical, there was no main subject so it wasn't a matter of deciding what you wanted to expose more).

Is this a legitimate way of deciding exposure?
When you walk into a room, do you think in your head "I have to expose for 30%"?
If you're getting 30% light from a lamp and you walk out and you get 30% light from the ambience, do you expose them the same way?

If this is a legitimate way of deciding exposure, do you guys have different exposure combinations and their equivalent exposure settings (for different f-stop/shutter speed combos) ready to switch to?

As Derrel noted, I think in terms of EV, but yes what you're doing is identifying constant levels of ambient light intensity. Using EV values we do that by selecting the range of shutter-f/stop combinations that would expose correctly.

The main reason I'm asking this is because I still have trouble walking into a room and determining the brightness level and where to start with my settings. Where I'm at right now is that I'll walk into a room or outside and say, "Oh it's kind of dark in here," then I'll open up my aperture and lower my shutter speed in a sort of wild guess, then adjust it by resorting to the light meter.

I wanna stop wildly guessing and want to know how to get to the proper settings, or close to it a bit more methodically.

Kind of a long winded question, but thanks to any who answer.

Time for a story: When I became seriously interested in photography it was the 1970s and I was a student at Saint Louis University. The city's local camera store was just on the edge of campus and I used to hang out there. One day in the store I met old man Bob Arteaga -- old man meaning neither of his two sons Eldon and Wayne who were also in the business. Bob Arteaga had been a photographer for a long time by then. Here in St. Louis he is best remembered as the person who photographed the construction of the Gateway Arch -- wonderful photographs.

One day I was walking between classes and there was Bob Arteaga with his camera. It was a big old camera with a bellows. The camera was on a tripod and he was looking at the ground glass with a black rag over his head. He was photographing one of the campus buildings for the college. I introduced myself and asked if I could watch him work. When he had the camera ready he inserted a film holder, pulled the slide and made an exposure. Then he shot another one; I guess as a backup. I then asked him this question: "Excuse me Mr. Arteaga but I never saw you take a meter reading. How'd you know what the proper exposure was?" To which he answered as he pointed skyward: "For heaven's sake, the bleep bleep sun's shining. I was doing this before they invented light meters. I didn't need one then and I don't need one now."

What Bob had done was learn a range of reasonably constant lighting conditions -- he had trained himself to identify them with pretty good accuracy. Using EV values makes that process possible because you don't have to remember shutter speeds and f/stops -- only a single number.

This chart is on the back of one of my antique cameras:

Those are EV numbers. Exposure on this camera was set by setting the EV value. The shutter speed and f/stop dials on the camera were locked together so that changing one changed the other.

EV vlaues

Another story: I remembered my encounter with Bob Artega and decided to train myself to do the same. This came in very handy when I started to do a lot of canoeing. I didn't want to take the expensive cameras with me on canoe trips and what I had that I was willing to take were some older camera's made in the 60's that took great photos but didn't have light meters. Like this one:

Not a problem setting the correct exposure without a meter -- like Bob said, "the bleep bleep sun is shining."

Joe

Wow, thanks so much for taking the time for this reply. Exactly what I needed to hear, and interesting to boot.

 

[andytakeone]

Thanks to everyone who replied to this thread!
This clears up so much--the heart of the matter it seems is EV (as Derrel simply put in his first reply).

I appreciate all the long and comprehensive answers and will definitely bookmark this thread for reference.

Lastly, what I meant by "wildly guessing" exposure before looking at the light meter is this:
Say if my camera is set at 1/1000, f/16, ISO 100, from the last time I snapped a photo.
But now it's night out and it's fairly dark.
I know for a fact if I took a shot with these settings, the picture would come out pretty much black. So before I even look at my light meter on my camera (which wouldn't help anyways since I already know it's massively underexposed, and it would just show up as <<-3), I would ballpark (wildly guess) the settings. Say 1/50, f/4.5, ISO 400-800. And then use the light meter (so I can actually see it's suggestion between -3 - +3) to get the exact settings.

I hope this makes sense.

 

[Derrel]

Take a good look at the X-system I mentioned above as the easiest framework to learn actual scene types and the right general exposure settings.

There are basically 13 different exposure values needed, ranging from a bright sunlighted beach, to birthday candles on a cake.

Look at Fred Parker's Ultimate Exposure system, Ultimate Exposure Computer and transpose its EV value system and make it into the X-system. You can easily learn the 12, or 13 common exposure settings. I gave you the first nine exposure setting for the none most common daylight lighting scenarios from full sun down to indoor sports events.

Starlighted landscape shots at Plus-21 X and Moonlighted landscapes at Plus-20 X are about the darkest exposure setting most people will ever encounter.

I'm not really sure that a 12-step range of exposures is really "wildly guessing". You probably alreqdy have memorized frameworks with more that 12 items...the NBA teams, the NFL teams, the McDonald's menu,your favorite TV shows and nights and network channels, the Taco Bell menu, the shelving system at your local grocery, you favorite iPhone MP3 playlists, etc..

There's an old joke: "What is the right exposure for Tri-X?"

"Whaddaya 'mean "the" right exposure for Tri-X? There's TWO right exposures for Tri-X....f/5.6 at 1/250, and f/2.8 at 1/30!"

 

[unpopular]

Photons per second

Photon Counting Detectors | PicoQuant

Then it's just a matter of attenuation according to the T-ratio of the optical system and calculating the total signal with respect to the quantum yield of the sensor or film.

Or, you could just use EV. Whatever floats your boat.

 

[timor]

. exposure = light intensity + EV.
Joe

Really ? How you add this two things ? Let say light intensity is 640 fc, to which EV you will add this ?

Any EV you want: how about 6 since that's now much light, but if you prefer, 7 or 8.

The EV is a shutter speed and f/stop combination. EV 6 would include the combination 1/15 sec. at f/2. So 640 fc of light intensity plus a shutter speed of 1/15 sec with the lens at f/2 will produce an exposure of either film or a sensor.

Joe

Don't get it. Any shutter speed and aperture stop will produce "exposure". Good or bad, but it will. EV "system" helps with nothing, when comes to determination of sufficient exposure for given light conditions. Readings of the light meter could be translated into EV. But what for ? Cameras with EV setting ring are gone long ago. (Still have couple of them.)
640 fc is actually good for EV 15 for ISO 100 film

I thought 640 fc was less light than that, but I'm not very familiar with fc measurement.

Any shutter speed and aperture will produce exposure in the presence of ambient light. X quantity of ambient light will always produce the same exposure at the same EV. So EV 17 plus X light intensity is always the same exposure. The advantage of the EV value is that it reduces the complexity of the equation and creates an exposure constant from the two variables shutter speed and f/stop.

The base ISO on my camera is 200. Today here was a gloomy heavy overcast day and outside today EV 12 would have been a good exposure for the sensor in my camera. It's easy for me to learn and remember that because of the single value constants. ISO 200 is a constant and EV values are constants. The light intensity we encounter outdoors even with variations for weather and shade etc. are reasonably quantifiable -- sunshine is a constant -- even lighting indoors is more uniform than not. That was the OP's original question: Is there some uniform consistency? Yes there is and yes you can learn it.

Stop using your light meter? Of course not, but if my light meter fails I'll know it and I'll go right on shooting. I think it's worthwhile to have a basic ability to assess exposure without total reliance on a light meter.

Joe

P.S. I wish my cameras still had EV locking shutter speed and f/stop controls --maybe that's why I like and use Program mode.

Well, OK. In simple light situations using guess like sunny 16 is fine, especially with b&w film. Not so much with colour transparency. With digital there is always instant review. But sunshine is not that constant as we tend to believe or maybe rather it is luminosity of our subjects, what is more important. For fine photography light meter is indispensable.

 

[Ysarex]

. exposure = light intensity + EV.
Joe

Really ? How you add this two things ? Let say light intensity is 640 fc, to which EV you will add this ?

Any EV you want: how about 6 since that's now much light, but if you prefer, 7 or 8.

The EV is a shutter speed and f/stop combination. EV 6 would include the combination 1/15 sec. at f/2. So 640 fc of light intensity plus a shutter speed of 1/15 sec with the lens at f/2 will produce an exposure of either film or a sensor.

Joe

Don't get it. Any shutter speed and aperture stop will produce "exposure". Good or bad, but it will. EV "system" helps with nothing, when comes to determination of sufficient exposure for given light conditions. Readings of the light meter could be translated into EV. But what for ? Cameras with EV setting ring are gone long ago. (Still have couple of them.)
640 fc is actually good for EV 15 for ISO 100 film

I thought 640 fc was less light than that, but I'm not very familiar with fc measurement.

Any shutter speed and aperture will produce exposure in the presence of ambient light. X quantity of ambient light will always produce the same exposure at the same EV. So EV 17 plus X light intensity is always the same exposure. The advantage of the EV value is that it reduces the complexity of the equation and creates an exposure constant from the two variables shutter speed and f/stop.

The base ISO on my camera is 200. Today here was a gloomy heavy overcast day and outside today EV 12 would have been a good exposure for the sensor in my camera. It's easy for me to learn and remember that because of the single value constants. ISO 200 is a constant and EV values are constants. The light intensity we encounter outdoors even with variations for weather and shade etc. are reasonably quantifiable -- sunshine is a constant -- even lighting indoors is more uniform than not. That was the OP's original question: Is there some uniform consistency? Yes there is and yes you can learn it.

Stop using your light meter? Of course not, but if my light meter fails I'll know it and I'll go right on shooting. I think it's worthwhile to have a basic ability to assess exposure without total reliance on a light meter.

Joe

P.S. I wish my cameras still had EV locking shutter speed and f/stop controls --maybe that's why I like and use Program mode.

Well, OK. In simple light situations using guess like sunny 16 is fine, especially with b&w film.

It's not a guess. It's precisely accurate.

Not so much with colour transparency. With digital there is always instant review. But sunshine is not that constant as we tend to believe

Yes it is and any variations due to time of day, weather or atmosphere hinge on that constant and can be accounted for. Distance variations due to the earth's elliptical orbit amount to less than 3% -- photographically meaningless.

or maybe rather it is luminosity of our subjects, what is more important. For fine photography light meter is indispensable.

Tell that to these fine photographers:
Peter Henry Emerson
Matthew Brady
Julia Cameron
Samuel Bourne
Henry Robinson
Francis Frith
Alfred Steiglitz
....easy to make this list pages long.

The first selenium cell meters didn't start showing up until the 1950s. Before that all they had were actinometers and extinction meters and they were a joke. I'll take one of those on any day. We've got a history of 100 years of fine photography before pretty crude light meters were even invented.

AND no one in this thread has recommended working without a meter. I never recommended that. The OP didn't ask how to do that. But the answer to the OP's question is yes. We live in a world surrounded by constant brightness levels which you can learn to identify very successfully relative to photographic exposure. I'm going to keep using a light meter, but if I didn't have one it wouldn't stop me from taking fine photographs.

Joe

 

[desertrattm2r12]

When I was a callow youth I toiled as a photo-grapher for publications like newspapers, if you've ever heard of such a thing. Anyway, the newspapers I worked for would hold a seminar once in a while on legal problems/situations. A lawyer would ask, "if you photographed a crime scene and was asked to testify in court and the judge or an attorney asked if you were a photographic expert, what would you say?" The correct answer, even though a photog may have have 25 or more years of experience taking photos, is "no."
In many jurisdictions, the only persons that are considered by the law to be photography experts are college graduates who formally studies optics.
Just sayin'.

 

[Ysarex]

When I was a callow youth I toiled as a photo-grapher for publications like newspapers, if you've ever heard of such a thing. Anyway, the newspapers I worked for would hold a seminar once in a while on legal problems/situations. A lawyer would ask, "if you photographed a crime scene and was asked to testify in court and the judge or an attorney asked if you were a photographic expert, what would you say?" The correct answer, even though a photog may have have 25 or more years of experience taking photos, is "no."
In many jurisdictions, the only persons that are considered by the law to be photography experts are college graduates who formally studies optics.
Just sayin'.

ummmm.... What does this have to do with the current thread?

Joe

 

[petrochemist]

When I was a callow youth I toiled as a photo-grapher for publications like newspapers, if you've ever heard of such a thing. Anyway, the newspapers I worked for would hold a seminar once in a while on legal problems/situations. A lawyer would ask, "if you photographed a crime scene and was asked to testify in court and the judge or an attorney asked if you were a photographic expert, what would you say?" The correct answer, even though a photog may have have 25 or more years of experience taking photos, is "no."
In many jurisdictions, the only persons that are considered by the law to be photography experts are college graduates who formally studies optics.
Just sayin'.

All that means is ( as often said) 'The law is an ass!'
Studying optics doesn't make you a photographic expert. It might make you an optics expert - but it needn't have anything to do with many of the photographic processes.

 

[desertrattm2r12]

The real quote is "the law is a ass, a idiot." (Charles Dickens -- they didn't use "an" in his day.) Whut it means is legally those spouting off on this forum about this who ain't trained in optics is on fuzzy grounds.