Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-08-2019, 01:38 AM   #1
Pentaxian




Join Date: Apr 2012
Posts: 1,306
What is 'correct' exposure ?

Hi there,

Remember in the old days we meter with grey card or incident light meter and set the camera accordingly to produce proper exposure, we also used spot meter to take multiple readings and average them to set the exposure. If we do D&P we will also adjust the develop and print time on different paper, so that both the highlight and shadow will best fit on the print. We either expand or compress the light level this is basically how Zone System works, and I believe shooting and processing RAW in digital has the same effect, but I don't know which one film, digital or our eyes having the greatest dynamic range. I always get washout of highlight or featureless shadow when shoot Jpeg straight in high contrast scene, shooting with cell phone always produce better result coz there is heavy POST done on it. So in my experience and to my understanding, a properly exposed image not necessary reproduce the scene faithfully, but reproduce the scene so that we can clearly see every detail of it, include parts that well beyond our eyes' dynamic range.

10-08-2019, 01:45 AM - 1 Like   #2
Pentaxian




Join Date: Oct 2009
Location: North
Photos: Gallery
Posts: 4,704
To me, its really whatever the photographer wants for the image.
This was more so in film with limited ability (for most folks) to process the film.
Less so nowadays with RAW.


With RAW (esp with the DR of cameras since K5), correct exposure often will be one that gets all the details in w/o clipping highlights and shadows.
This then allows the photographer to process many different version of the same shot to taste.

Indeed, the HP does a lot of this in the background which is why the layman usually claims that the o/p of the HP is better than their more advanced camera.
10-08-2019, 01:49 AM - 1 Like   #3
Site Supporter
Site Supporter
ffking's Avatar

Join Date: Nov 2015
Location: Old South Wales
Posts: 6,029
Well, there are some very knowledgable folks here when it comes to sensor tech, but just to kick this off - our eyes can take in far more dynamic range than sensors or film - that's which the other media often appear burned out or blocked up in scenes where we can see detail clearly - and yes, a lot of that detail is recoverable (the lower the ISO the better for that), but we still see better than a sensor does.- and yes - the RAW file out of a camera will seldom look the way the scene does, but if the histogram is bulked in the centre right of the image, and not too much lies ouside its range, most details will be available to you - after that it's just a matter of personal taste, like printing film

Last edited by ffking; 10-08-2019 at 05:20 AM. Reason: fat fingers
10-08-2019, 02:09 AM   #4
Pentaxian




Join Date: Apr 2012
Posts: 1,306
Original Poster
Right guys, we are not simply taking photo but 'making' it too, and to the extreme some photos I've seen are too unreal to be a real scene but heavy HDR one, it's all depends on our taste.

10-08-2019, 03:30 AM   #5
Site Supporter
Site Supporter
Belnan's Avatar

Join Date: Jul 2010
Location: Nova Scotia
Photos: Albums
Posts: 1,090
QuoteOriginally posted by lotech Quote
Hi there,

Remember in the old days we meter with grey card or incident light meter and set the camera accordingly to produce proper exposure, we also used spot meter to take multiple readings and average them to set the exposure. If we do D&P we will also adjust the develop and print time on different paper, so that both the highlight and shadow will best fit on the print. We either expand or compress the light level this is basically how Zone System works, and I believe shooting and processing RAW in digital has the same effect, but I don't know which one film, digital or our eyes having the greatest dynamic range. I always get washout of highlight or featureless shadow when shoot Jpeg straight in high contrast scene, shooting with cell phone always produce better result coz there is heavy POST done on it. So in my experience and to my understanding, a properly exposed image not necessary reproduce the scene faithfully, but reproduce the scene so that we can clearly see every detail of it, include parts that well beyond our eyes' dynamic range.
I suppose exposure is kind of dependant on what the photographer wants. I generally under expose my images and bring it up as required in post. I've seen great images very over exposed and some under. Whatever works for you.
10-08-2019, 03:48 AM   #6
Veteran Member
MJKoski's Avatar

Join Date: Aug 2016
Posts: 1,784
I would say that from technical POV correct exposure is made with ETTR principle. Expose as long as pixels are not overexposed.

For actual viewing of photos, adjust in post as needed.

This is why only 1 button is needed to adjust exposure. It is auto-ETTR button and no camera currently has it. Magic Lantern for Canon DSLR cameras has auto-ETTR function.
10-08-2019, 04:16 AM   #7
Site Supporter
Site Supporter




Join Date: May 2019
Photos: Albums
Posts: 5,976
QuoteOriginally posted by ffking Quote
Well, there are some very knowledgable folks here when it comes to sensor tech, but just to kick this iff - our eyes can take in far more dynamic range than sensors or film - that's which the other media often appear burned out or blocked up in scenes where we can see detail clearly - and yes, a lot of that detail is recoverable (the lower the ISO the better for that), but we still see better than a sensor does.- and yes - the RAW file out of a camera will seldom look the way the sceen does, but if the histogram is bulked in the centre right of the image, and not too much lies ouside its range, most details will be available to you - after that it's just a matter of personal taste, like printing film
From what I remember, it's more that our eyes work multi-exposure, very high-quality HDR all the time. But yes, we perceive a lot of DR compared to cameras.

10-08-2019, 04:18 AM - 2 Likes   #8
Veteran Member
CarlJF's Avatar

Join Date: Sep 2014
Location: Quebec City
Posts: 1,185
There isn’t one correct exposure. Technically speaking, any exposure covered by the dynamic range of the sensor is fine. From a photographic standpoint, it’s the exposure making the picture feels right. Which can be quite different than a technically good exposure. For example, it’s perfectly fine to have a nighttime picture underexposed by a few stops relative to what would be a technically good exposure...

And more often than not, there’s nothing wrong with having dark shadows and bright highlights in a picture.., It’s often what makes the picture lively instead of bland looking.
10-08-2019, 07:41 AM - 1 Like   #9
bxf
Veteran Member
bxf's Avatar

Join Date: Jul 2010
Location: Lisbon area
Posts: 1,660
The fact that often there is no single correct exposure becomes very obvious when doing post-processing. Sometimes I look at a low contrast image and I like it. Then I make some changes, producing a high contrast image, and I like that too, and it is hard to choose what is better.

Then again, more often than I'd like, I go back to an image I PP'ed in the past, and I ask myself what the hell I was thinking
10-08-2019, 08:36 AM   #10
Pentaxian




Join Date: Jul 2009
Location: Pugetopolis
Posts: 11,008
QuoteOriginally posted by lotech Quote
...we also used spot meter to take multiple readings and average them to set the exposure.
I still use a one degree spot meter. The old days are not over. What was that old saying that 98% of the people never did shooting film. That's right, expose for the shadows and develop for the highlights. What does that mean? Well, it's mostly done with BW film and more common using medium and large format film. You place the low values in the scene with your exposure using the one-degree and the developing time places the highlights. You can compress or expand the highlights that way for high and low contrast scenes.
10-08-2019, 09:52 AM   #11
Pentaxian
timb64's Avatar

Join Date: Apr 2012
Location: /Situation : Doing my best to avoid idiots!
Photos: Gallery
Posts: 9,503
It’s easier to say what the “wrong” exposure is, a “pleasing” result is much more subjective.
10-08-2019, 11:17 AM   #12
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 42,007
QuoteOriginally posted by lotech Quote
What is 'correct' exposure ?
It is what you decide it to be...assuming one has the knowledge and tools to make the decision.

To be quick and honest, nothing has really changed from working with film except that making a digital exposure exposes less flexible in regards to both dynamic range and tonal reproduction and/or detail capture of low values. One can still use a spot meter to place exposure and/or to measure the range of light in the frame. The difference is that the a range of light scan for digital capture is done with the intent to plumb the need to merge multiple exposures to retain shadow detail and tonality.

A gray card is still a very suitable substitute for an incident light measurement and on a Pentax dSLR should result in a nicely-centered histogram of a blank wall and/or reasonably exposed subjects when values within the frame are confusing to even our best matrix metering. FWIW, I carry both a gray card and an incident meter in my bag. I also have been known to use fill flash.

From the simple standpoint of correct metering, a centered histogram from a gray card is still "correct" exposure.

As noted above, it is probably easier to detect and critique "bad" or "wrong" exposure than to create a general rule or technique for "correct" exposure. To that end here are the bad hombres:
  1. Blown (clipped) highlights are unrecoverable since there are no available numbers to express the intensities that struck the sensor. The analogous case exists for all transparency films where there is truly nothing there. The common symptom is featureless snow or clouds.
  2. Blocked up (clipped) shadows are also unrecoverable since no data (true black) are no data. The most common symptom might be dark-gray textured fabric that renders as black. The analogous case for film photography is with negative films, though the "cliff" to black for a film negative is less severe in that an equivalent exposure that failed for digital may still be recoverable with many films at the same ISO.
  3. Muddied mid-to-low values that do not improve with combination pull/contrast boost. Inadequate data are inadequate data and while our software may do its best, there is little to work with in the lowest three stops of dynamic range.
  4. Poor color saturation and unintentionally "thin" rendering of high values.
  5. Blocked appearance of areas of saturated color despite detail being present in the subject. This is not true clipping, but happens none-the-less and is difficult to resolve in PP.
Working strategy? Work with the camera's meter while keeping ETTR in mind and remembering that either HDR or fill flash may be the only answers for some subjects.


Steve

Last edited by stevebrot; 10-08-2019 at 11:57 AM.
10-08-2019, 11:37 AM   #13
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 42,007
QuoteOriginally posted by lotech Quote
...to the extreme some photos I've seen are too unreal to be a real scene but heavy HDR one...
What you are describing is not HDR per se, but tone mapping for effect onto an HDR merge. It is possible to merge in several stops compression without going garish. Example below is not completely pertinent, but shows the difference between straight HDR and simple shadow pull with highlight reduction in PP.




Steve
10-08-2019, 12:57 PM   #14
Senior Member
Pentaxis's Avatar

Join Date: Jul 2012
Posts: 195
QuoteOriginally posted by lotech Quote
So in my experience and to my understanding, a properly exposed image not necessary reproduce the scene faithfully, but reproduce the scene so that we can clearly see every detail of it, include parts that well beyond our eyes' dynamic range.
I don't agree at all. My disagreement is fundamental.


That is why I hate High Dynamic Range effects. They appear to me unnatural, synthetic, garish and not at all aesthetic.
10-11-2019, 01:18 AM   #15
Pentaxian




Join Date: Apr 2012
Posts: 1,306
Original Poster
Correction and repost.

As far as I know, human eyes and brain are created and programmed so that we focus only in the center portion of the whole viewing area, the rest is graduately blurring out, we can not manually control the 'exposure' everything is done automatically, it is just like a center weighted metering system. When we view an image we can only 'meter' the center portion and adjust our eyes for it without taking much care the border area, so the end result may not comparable to a HDR image which adjusted for the whole frame, this may explain why we see a properly adjusted/HDR image unreal,

I don't know how an image produced with a good lens compare to a properly adjusted/HDR one, but once I saw a photo produced by a Leica film P&S that so real to life I can almost touch it, I rarely have this impression with modern digital cameras.

Last edited by lotech; 10-11-2019 at 03:35 PM.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
exposure, eyes, highlight, light, meter, photography, print, range, scene, shadow
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Light meter on my pentax MX not showing 'correct' exposure hit3k Film SLRs and Compact Film Cameras 33 03-08-2020 07:08 AM
New ACR Lens Correct vs K-5 in Camera Correct emblemex Pentax K-5 & K-5 II 12 12-08-2010 12:20 PM
peterson's "correct exposure" Deiberson Photographic Technique 3 09-21-2010 08:58 AM
K-x correct exposure indicator. boosted03gti Pentax DSLR Discussion 12 04-27-2010 04:16 PM
What constitutes correct exposure? photog Pentax DSLR Discussion 29 10-01-2009 06:53 PM



All times are GMT -7. The time now is 01:50 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top