View Full Version : Visually determining the correct exposure
mandab99
13-08-2011, 3:11pm
Hiya
Being a newbie I have noticed how advanced photogs can just look at a photo and know that it is over/under exposed. I may look at a photo and think, yep thats awesome and then read CC'ing on it to discover that in fact it is not correctly exposed. Is this just something that in time will come with experiance? Any tips for us mere newbies?
Thanks!!!
Manda
JM Tran
13-08-2011, 3:22pm
Hiya
Being a newbie I have noticed how advanced photogs can just look at a photo and know that it is over/under exposed. I may look at a photo and think, yep thats awesome and then read CC'ing on it to discover that in fact it is not correctly exposed. Is this just something that in time will come with experiance? Any tips for us mere newbies?
Thanks!!!
Manda
It comes with experience, which comes from a lot of practice and trial and error
so my best advise to you is - get out there and practice in all condition, not just in ideal conditions:)
Exposure is a balancing act!
See:
http://www.ausphotography.net.au/forum/showlibrary.php?title=New_To_Photography:Sunny_16_and_exposure_guides
http://www.ausphotography.net.au/forum/showlibrary.php?title=New_To_Photography:What_is_Exposure_Value
There are many 'right' exposures, but some are more creative than others.
Say ISO 400, 1/250 and f/4 has the same in terms of light as ISO 100, 1/2second and f/22
But you could capture water movement with the 2nd exposure (and a tripod).
Over exposure is simply blown highlights - i.e. loss of detail.
Under exposure is not enough light leaving areas of darkness.
You can use under and over exposure creatively as well, comes with experience.
The short answer to your question is yes, it will come with experience. After you have seen thousands of images (particularly the same image differently exposed) you should be better able to tell more easily which are more accurately exposed. This is very subject to at least 2 points (for the moment):-
However, you cannot account for taste. Some people just like things better even when they are less correctly exposed. Example, when Mongo shot normal colour film (this was a very brief period in history), the processing place would always develop and print the photos at least 3 stops too bright in Mongo’s opinion. The processor’s view was that this was correct because you could see all the details. .....WRONG !! So, all Mongo’s images shot in semi darkness or at the bottom of a rain forest would all look washed out and useless. This frustrated Mongo to the point where he bit the processor severely and went straight to slide film for the rest of his days until digital came along when he could control the exposure without interference.
You must also have some regard for the intention of the photographer in any specific image. Some are meant to be “hot” or deliberately underexposed for a purpose just as if they had been deliberately shot with , say, shallow DOF, soft (as in some portrait work) or pin sharp all over.
So , there is no absolute right or wrong . Mongo learned a long time ago that “everything in life is relative”. So, it is Mongo’s opinion that the thing you can best improve with experience is the ability to better tell how any image (having regard to all of the above) can best be enjoyed, appreciate and constructively critiqued
arthurking83
13-08-2011, 6:52pm
Hiya
Being a newbie I have noticed how advanced photogs can just look at a photo and know that it is over/under exposed. I may look at a photo and think, yep thats awesome and then read CC'ing on it to discover that in fact it is not correctly exposed......
In a nutshell:(especially for JMT, as I know he likes 'em short and sweet! ie. the short version)
Learn to read Histograms and then use them wisely.
..................
(The longer version!)
Under and over exposure is a state of mind.
That is, in addition to having a wealth of experience there is the matter of taste, or preference towards a particular style .. etc, etc.
One person's critique of an image as underexposed may be translated by another person as ... "Oooh, I like the dark and moody feeling. Good use of black tones" ... etc, etc.. blah blah!
Another person waxing lyrically of an image as "Wow, it's so light and soft with angelic overtones. Nicely done high key effect", can also be more succinctly described as overexposed.
:D
It's up to the individual to decide which is the best translation.
I think there are limits to acceptable exposure, and that over and under exposure can, and should, be used for creative effect when the scene allows for it. But the pushing of those boundaries should be appropriate for the scene, otherwise it will simply look like exposure error.
Also note: In general, over exposure is less desirable than under exposure.
To help you understand exposure errors, learn to read histograms correctly.
Once you've crossed that boundary of truly understanding what a histogram is indicating to you, you'll then easily and instantly understand the difference between over exposure and artsy fartsy angelic lightness with a splash of high key! ;)
ps. there are many ways to view a histogram(of an online image). First up, it's imperative that you are web browsing with Firefox, and that you have a few addons installed and at your disposal.
Two that I regularly use are Histogram Viewer (https://addons.mozilla.org/en-US/firefox/addon/histogram-viewer/) and PhotoMe (http://www.photome.de/).
PhotoMe asks if you want to install the rightclick context menu option, and if you do, you rightclick an image and use the PhotoMe option to view exif and the included histogram.
Histogram viewer is a simple rightclick addon option only for use within Firefox itself.(PhotoMe allows you to do so within Windows).
Note tho: PhotoMe is now old.. very old, and no longer supported. At some stage I'm also going to stop using it and switch to GeoSetter instead. For as long as PhotoMe works tho, I'll use it.
In a nutshell, learn to read histograms, and then use them wisely!
graemelee
13-08-2011, 7:50pm
great info thanks
mandab99
16-08-2011, 11:06pm
Thank you guys! I really enjoyed reading your comments regarding my question on correct exposure. I love that you emphasized the fact that it really is all about ones taste or creative view, as that was my thoughts exactly....."beauty is in the eye of the beholder"
P.S - Mongo...you are a funny bugger!!! :p
ricktas
17-08-2011, 5:44am
Thank you guys! I really enjoyed reading your comments regarding my question on correct exposure. I love that you emphasized the fact that it really is all about ones taste or creative view, as that was my thoughts exactly....."beauty is in the eye of the beholder"
P.S - Mongo...you are a funny bugger!!! :p
Also remember there really isn't such a thing as correct exposure! Being experimental and doing some creative exposures is what leads to some exciting photos at times. Having said that it is something that usually comes after knowing about correct exposure and then starting to understand when correct exposure can be bypassed for creative exposure, to get a specific result.
Photography is an Art, and therefore correct and creative can both play a part.
Example, when Mongo shot normal colour film (this was a very brief period in history), the processing place would always develop and print the photos at least 3 stops too bright in Mongo’s opinion. The processor’s view was that this was correct because you could see all the details. .....WRONG !! So, all Mongo’s images shot in semi darkness or at the bottom of a rain forest would all look washed out and useless. This frustrated Mongo to the point where he bit the processor severely and went straight to slide film for the rest of his days until digital came along when he could control the exposure without interference.
Exactly my experience too.
nightbringer
17-08-2011, 6:37pm
Noone's mentioned the Sunny 16 rule?
Way back when cameras didn't have light meters, photographers used this nice little rule of thumb. At ISO 100, on a clear sunny day, you should set your camera at f/16, and 1/100 shutter speed to get a well-exposed image. On overcast days, it's f/8, etc (I may be wrong, I can't remember clearly the different settings)
Of course, how you want to expose is up to you, but a great read on this would be Bryan Peterson's Understanding Exposure - I feel like I know a bit about photography but even then, reading that book led me to learn a lot more and think more also about how to take a picture, and to look at more than just how much light you want to let into your camera.
arthurking83
17-08-2011, 7:08pm
Noone's mentioned the Sunny 16 rule?......
May not have been pertinent in the context of the question raised by the OP.
I think the OP was asking about what indicators in the image are people using to determine if the image is correctly exposed.... and not really about how to go about capturing an exposure from the camera itself.
Sunny 16 and other such generalisations are used for trying to capture an exposure at the time of shooting(for times when a meter is not available), whereas the replies given to the OP are more in line with using a histogram as a guide, blown highlights and lost shadows not necessarily the evil many believe them to be and using creative license to determine artistic merit, and so on.
Noone's mentioned the Sunny 16 rule?
:Doh:Check the first link in my post above
JM Tran
17-08-2011, 7:40pm
Way back when cameras didn't have light meters, photographers used this nice little rule of thumb. At ISO 100, on a clear sunny day, you should set your camera at f/16, and 1/100 shutter speed to get a well-exposed image. On overcast days, it's f/8, etc (I may be wrong, I can't remember clearly the different settings)
that rule doesnt apply well to the Digital age Im afraid.
F16 at ISO100 and 1/100th shutter speed on a full frame camera will yield a very different exposure than the same settings on an APSC sensor camera when using the same lens at the same focal length. Bigger sensor will naturally draw in more light etc
arthurking83
17-08-2011, 9:17pm
It's not that the bigger sensor draws in more light, it's a simple, well known, but all too readily forgotten fact that ISO ratings on sensors don't have to match the ISO standards set out by the ISO organisation for films.
That is, certain APS-C sensors are better at exposing for a given shutter speed and aperture combination, than other similarly sized sensors are.
I know that the difference between my D70s and D300 is that the D300 is 2/3rds of a stop brighter in exposure for the same aperture and shutter values.
Add into the mix different characteristics from different lenses, and you have the possibility for up to 1 1/3rd or more variability of exposure between two seemingly similarly set up cameras!
So this sunny 16 rule, even as a guide can be so far out of whack, mainly for digital, but not limited too. I mean it's great to have a guide, but I think it's better to determine for yourself, the actual Tv losses that the lens is known for, and how this rule relates to your specific gear. It's better to use it for initial guide purposes, and then after a few test images, determine if it's working for that gear setup.
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