[Marc Sabatella]

You can get the camera to record reality. Simply shoot the dark room at the same iso, aperture, and shutter speed that you use outdoors. That's reality - the dark room is dark, just as it is in real life. Of course, it will be so dark that it will look comoketely black. It doesn't look thst way to you because your eyes are not showing you reality, either. They are adjusting, both in aperture (your pupil size) and in iso (rods versus cones). But the eye doesn't adjust as perfectly as the camera. I'm sure someone could come up with some sort of heuristic to try to mimic the imperfections of the eye, but I doubt most would find it useful. Especially considering you can easily account for this manually if you happen to want the imperfections of your eye captured in print as well.

[rhodopsin]

If an incident light meter is used to determine correct exposure, and those settings used with camera in MANUAL, the image brightness will match what you saw.

[wildman]

A bit off topic for my own thread but...

Took a low light shot and just did it by hand. Ran it through all kinds of software to make it conform to my subjective minds eye of "reality".

Very early morning indirect light with light coming in through south exposure window. So windows were facing south and sun was rising low in East.

This comes pretty close to my subjective reality but it took a lot of work. No extra pop and hype just the facts as I remember the scene. It's a lot of work because the image must conform not to what you like but to what was - ideally at least.

The reason I brought up this topic in the first place is that so often, for me, what "was" is also what I like. That is the reason I press the shutter in the first place is - to try and capture what was.

Taken with a 200 buck Sigma 70-300mm zoom.
Converted to BW because we are just talking luminescence anyway.

[newarts]

A bit off topic for my own thread but...

Took a low light shot and just did it by hand. Ran it through all kinds of software to make it conform to my subjective minds eye of "reality".

Very early morning indirect light with light coming in through south exposure window. So windows were facing south and sun was rising low in East.

This comes pretty close to my subjective reality but it took a lot of work. No extra pop and hype just the facts as I remember the scene.

Taken with a 200 buck Sigma 70-300mm zoom.
Converted to BW because we are just talking luminescence anyway.

Pretty good job. Looking into human vision characteristics a bit shows that it'll be hard to make a photo display look like our mind's eye sees a dimly lit scene. That's because our visual sensitivity changes with time as we look at dark areas of a scene.

Sensation and perception - Google Books

As we look at a real scene our eyes adjust to light and dark areas of the scene - this information is used by the brain to paint a picture in the mind. If you look at a dark area in a real scene you will gradually see more detail in the scene but when you look at a dark area on a computer screen it doesn't matter how long you stare at the dark area - there's nothing there.

Our mind must use such clues to make judgements about the over-all context of a scene.

Here's a crop from a Vermeer painting. He was good at telling a story with light. somehow he let me "know" what time of day it was, that it was clear outside etc.



If it had been night time I think the contrast difference across her face would have been lower, shadow wouldn't have been so deep, we'd see detail in the wall behind her etc.

HDR might be a useful tool to turn daytime image into dusk images.

---

Last edited by newarts; 07-04-2011 at 09:36 AM.

[RioRico]

HDR might be a useful tool to turn daytime image into dusk images.

Another way to bring out shadow detail: Use lowest possible contrast, then diddle the dynamic range.

For example: I've been RAW developing thousand of K20D shots from my recent extended journey in the USA SouthWest and Colorado high coun try. I normally set Contrast pretty high. (JPG settings carry over into the RAW developer as defaults.) But I spent much time around 3000m / 10000ft. Light is harsher there, less softened by atmosphere. The ISO / exposure / Contrast / etc settings I use at 1/2 those elevations don't work right.

So in RAW development I fix WB (clear skies are too blue), take contrast WAY down, pump the EV a little -- and then stretch the curve's dynamic range on the histogram, dragging the pointers towards the extremes till I get the right balance of light and dark. And next time I'm at such elevations I'll use low contrast in-camera.

Anyway, with such a technique you have great control over how much shadow detail is shown. Turn up the dark, turn down the light, and it's night!

[wildman]

Our mind must use such clues to make judgements about the over-all context of a scene.

No argument from me. A camera can no more make a judgement than a fence post.

a Vermeer painting. He was good at telling a story with light.

Yes I see it that way too. It must have been a bright sun lit day. Notice the right shoulder is a pure white while the left is in a black shadow. Not the kind of DR a sensor could handle well. And then to give definition to the dark left side the background on this side is white. A very literal almost photographic picture as far as light is concerned.

Take a look at this however.
notice that the light falls on the right cheek and the shadow line pretty much follows natural light with the line across the left cheek then down the ridge of the left shoulder then down the left arm.

But notice the tail end of the head piece that hangs down the back vertically. The bottom third falls below the shadow line on the left shoulder. Shouldn't that bottom third part be cast in dark shadow given the light on the rest of the picture? But he shows it as fully exposed to the light from the left.

My guess is he knew exactly what he was doing and took liberties to literal reality to make a much stronger picture.

If Vermeer can get away with it maybe we shouldn't be so hard on the excesses of the HDR folks.

Take care...



Science is spectral analysis. Art is light synthesis.
Karl Kraus

[wildman]

Another way to bring out shadow detail: Use lowest possible contrast, then diddle the dynamic range.

Yes that's what i found also.

Even at my elev of 1000 feet I set the jpg settings at"natural" and sat=-2, hue=0, contrast= -3, sharp=0.

With these settings noise is also less noticeable. I use a K20.

[newarts]

Gazart's study https://www.pentaxforums.com/forums/winners-showcase/144932-may-2011-winner-e...ml#post1514861

Invokes an impression of "low light" but was it? A flash was used for fill...


I think it would not be seen by us a a low light photo if the edges were not in shadow and trickery had not been used to prevent the candle flame from overwhelming the scene.

[wildman]

I figured out my original question - operator error.

In ACR I apparently hit the "Auto" exposure rather than leaving the exposure at "default" ( I assume how the camera exposed it). It really ought to be labelled "as shot".

When I said in the OP "Its as if the camera is programmed to always give you a well lit scene regardless of the reality of the scene" that's true if you use auto exposure in ACR.

So all our discussion about the subjectivity of reality, while interesting, had nothing to do with it. It was just simple bone-headed operator error.

Case in point:
Taken 5:30 am this morning with available light only; one at default and one at auto with no other processing.
Given the time of day I don't have to tell which one is closer to "reality".

[Marc Sabatella]

Well now, wait. That first shot is surely not what the camera shot, at least not if you let the camea select the exposure. The firzt shot is very severaly underexposed. Your initial aassumption was indeed correct - the camera will strive to make all shots similar in overall brightness (the co ncept of 18% grey). As mentioned, there should still be clues based on the distribution of shadows that would still convey the idea of a dsrk scene versus a bright one, but the camera is ignorant of thwt - it's just going get the aveage brightness where it wants it. By "average" here, I don't necessarily mean literal average; this depends on the metering mode used. But still, the camera is most definitely not designed to produce exposures like that first one above. You must have dialed in negative exposure compensation, or shot in manual mode and not metered.

[wildman]

Well now, wait. That first shot is surely not what the camera shot, at least not if you let the camea select the exposure. The firzt shot is very severaly underexposed. Your initial aassumption was indeed correct - the camera will strive to make all shots similar in overall brightness (the co ncept of 18% grey). As mentioned, there should still be clues based on the distribution of shadows that would still convey the idea of a dsrk scene versus a bright one, but the camera is ignorant of thwt - it's just going get the aveage brightness where it wants it. By "average" here, I don't necessarily mean literal average; this depends on the metering mode used. But still, the camera is most definitely not designed to produce exposures like that first one above. You must have dialed in negative exposure compensation, or shot in manual mode and not metered.

Without comment:
"[PhotoME]
PhotoME version: 0.79R17 (Build 856)

[Overview]
File name: D:\Camera Download\0706\_IGP7054.DNG
File type: Adobe Digital Negative
File size: 23,671.9*KB
Creation date: 7/6/2011 05:30
Last modification: 7/6/2011 07:34
Make: PENTAX Corporation (PENTAX)
Camera: PENTAX K20D
Lens: smc PENTAX-DA 18-55mm F3.5-5.6 AL
Software: K20D Ver 1.00
Dimension: 4864 x 3136*px*(15.3 MP)
Focal length: 33*mm*(equiv. 49*mm)
Aperture: F8
Exposure time: 1" (-.3*EV)
ISO speed rating: 400/27°
Program: Aperture Priority
Metering Mode: Pattern
White Balance: Auto (White Fluorescent)
Focus Mode: Manual
Image Stabilizer: stabilized, not ready
Noise Reduction: Off
Flash: Flash did not fire, compulsory flash mode"

and same file run through Corel Paint, (not ACR) RAW converter with no PP.

[debbie]

eeh, try to take a shot with the cap on the lens with the same settings and see what shutter time the camera will use (at least with a k20 as you have)



(1 sec if you can´t wait for the answer)

[reeftool]

You can get the camera to record reality. Simply shoot the dark room at the same iso, aperture, and shutter speed that you use outdoors. That's reality - the dark room is dark, just as it is in real life. Of course, it will be so dark that it will look comoketely black. It doesn't look thst way to you because your eyes are not showing you reality, either. They are adjusting, both in aperture (your pupil size) and in iso (rods versus cones). But the eye doesn't adjust as perfectly as the camera. I'm sure someone could come up with some sort of heuristic to try to mimic the imperfections of the eye, but I doubt most would find it useful. Especially considering you can easily account for this manually if you happen to want the imperfections of your eye captured in print as well.

If you think about it, most of what we do with the camera is more of an art form than simply recording reality. We compose, crop, and make exposure and color adjustments all with the purpose of making the mundane world around us look pleasing enough to frame and hang on our walls. Even the news reporter uses light and composition to emphasize his scene. Our eyesight and what our brains register are not what the camera sees and light meter registers. We use the camera as an artistic tool in the same way a painter uses his tools.

[Marc Sabatella]

Not dure if the shutter speed is saying you had diaked in -.3 EV compensation, nut it looks like more than that. Was this by chance shot RAW but using a JPEG dynamic range option like D-Range? Could also be you were below the minimum metering limit, and the camera just couldn't come up wuth a good exposure. In any case, a fww more test should demonstrate than what you are seeing is not normal at all.

[wildman]

[PhotoME]
PhotoME version: 0.79R17 (Build 856)

[Overview]
File name: D:\Camera Download\100_0706\_IGP7062.DNG
File type: Adobe Digital Negative
File size: 23,661.7*KB
Creation date: 7/6/2011 23:48
Last modification: 7/7/2011 00:00
Make: PENTAX Corporation (PENTAX)
Camera: PENTAX K20D
Lens: smc PENTAX-DA 18-55mm F3.5-5.6 AL
Software: K20D Ver 1.00
Dimension: 4864 x 3136*px*(15.3 MP)
Focal length: 28*mm*(equiv. 42*mm)
Aperture: F8
Exposure time: 2.5"
ISO speed rating: 400/27°
Program: Aperture Priority
Metering Mode: Pattern
White Balance: Auto (Daylight)
Focus Mode: Manual
Image Stabilizer: not ready
Noise Reduction: Off
Flash: Flash did not fire, compulsory flash mode

----------------------------------

Same routine:
both run through ACR at default exposure and auto exposure
The only illumination was a single candle. EV=0

If this is what you mean by "the camera will strive to make all shots similar in overall brightness " then based on the default shot I can live with that - close enough.