Do some of the camera settings intimidate you? Do you want to learn how to develop your photography skills and learn how to use your camera effectively without always going back to the “auto” function? These challenges are for you!
These are designed for those experienced photographers to share their knowledge with others who are anxious to learn and improve their skills. This fortnight's challenge is ...
Exposure Compensation
What is Exposure Compensation?
Firstly, it’s useful to know/remember a little background info:
1. Your DSLR camera will have a scale visible through the viewfinder and also often on the screen at the back that looks something like this:
-2 . . -1 . . 0 . . 1 . . 2
Some cameras may go from -3 to 3.
Generally speaking, “correct exposure” is considered 0 and should read as such with a flashing indicator. If you are using ANY automated setting (including Shutter Priority, Aperture Priority or M with Auto ISO etc), your camera will always expose your image to “0”.
2. Negative numbers indicate underexposure, and positive numbers overexposure. Each number indicates “one stop”, and the dots indicate 1/3 stop increments. You will remember that increasing exposure by one stop means DOUBLING the light hitting the sensor (eg. from 1/250 sec to 1/125 sec, or f/8 to f/5.6) or the ISO sensitivity (eg. from 200 to 400). Likewise you can decrease the exposure by one stop by HALVING the light or the ISO.
3. “Correct exposure” is measured on most cameras as around 12-14% grey. This means that if your scene is evenly lit, at “0” everything should look in your image pretty much as it does to your eye in real life. If the lighting in your scene is uneven, or you have a wide range of tones, you should also have a wide range of tones in your image, possibly ranging from true black to true white.
4. Metering modes play a part here, and will be the focus of next fortnight’s challenge. For now, I’ll just mention that depending on which metering mode is used, your camera may take this light measurement (of 12-14% grey) across the whole frame or only part of it.
The term Exposure Compensation means deliberately and manually over-or under-exposing your image. The question is, why would you want to do this???
Reasons/situations for using Exposure Compensation:
Essentially, this is a technique for when that 12-14% grey reading doesn’t work out. Some examples are:
1. White or very light-coloured subjects eg. snow (you don’t want them to look grey)
2. Black or very dark subjects (you don’t want these looking grey either)
3. Very high-contrast scenes, when part of the image is blown-out and detail is lost (recorded as pure white) AND this is a problem for this particular image (your camera is trying to brighten the dark patches and the light patches are lost in the process)
4. Scenes which include a very bright light source eg. shooting into the sun (your camera is trying to darken the bright light and the rest of your image may end up being very dark)
5. Some back-lit subjects (as above, when you want your SUBJECT correctly exposed)
6. Achieving silhouettes (when you want your subject black and the background correctly exposed)
For snow, back-lit subjects and scenes with a bright light source, you will likely want to OVER-EXPOSE your image by one or two stops (I’ve heard people say “dial in some extra exposure” etc). The rule for snow (in the film days) was +2 stops, but these days we have the luxury of simply checking our LCD to see if it “looks right”.
For black/dark subjects, achieving silhouettes, or for high-contrast images where you are losing important detail, you will probably want to UNDER-EXPOSE your image by a stop or two. This will help you achieve rich blacks where you want them, or recover lost detail in the highlights. (NB: recovering detail in a high-contrast scene will result in also darkening other parts of the scene, and relies on the use of software to brighten those shadows, which may compromise image quality. Further, IMHO, blow-outs are not always a bad thing – it depends on personal taste and whether the image suffers or not because of it.)
How to use Exposure Compensation:
Strictly speaking, this is for use in Aperture Priority, Shutter Priority or P Modes. Many cameras have a +/- button. Holding this down while turning your dial should allow you to move the cursor up or down from “0”. If your camera has two dials it will probably be the secondary one, and you may need to touch the shutter button first. What mode you are in will determine which variable gets changed. For example, if you are using Shutter Priority with a set ISO, using your +/- button will change the aperture. NB: your camera will retain this setting until such time as you dial it back to “0”.
Alternatively, if you are using full manual (M) mode, you will know that you are always needing to adjust one of your three variables in order to stay at “0”. So you can achieve the same thing by manually increasing or decreasing the shutter speed, aperture or ISO in order to get your cursor where you want it.
If you are having difficulties with your camera just shout out and we will do our best to help.
Task/Challenge:
Choose one of the 6 scenarios outlined above. Hopefully one will resonate with you as something you’ve tried before and had difficulty with, or a situation that is relevant to you at the moment. Use whichever mode you feel most comfortable with/most suits your shooting situation. (Keep in mind previous lessons such as comfortable hand-held shutter speed; appropriate apertures for different subjects etc; how much light you have to work with and what compromises you may need to make.)
1. Try taking the image with the camera’s automatic reading of the light (cursor on “0”).
2. Assess the image: does it look too dark/too light, in line with the guidelines I provided above?
3. You can try making a guess at how far you want to under- or over-expose your image, or start with one stop. Take another shot.
4. Assess your second image. Does it look closer to/further away from what you were trying to achieve?
5. Trial and error. Learn and have fun :) Post your results and talk us through your process :)
This challenge will run until Sunday 10 May. Please post your photos in this thread for comment and discussion.
Here are two examples from my (first! big challenge!) maternity shoot yesterday. One challenge with using exposure compensation is that it likely won't show up in your metadata how far under- or over-exposed your image was shot. From memory, this first image was shot somewhere between -1 and -2. I wanted to capture really just the shapes of the couple as they were walking.
For this second image, standing together their silhouettes were less definable, so I went for a brighter image, again from memory somewhere between +1 and +2. This means there's less colour in the sky, but all of their features and details are visible in this version.
I think this is a great one for people to try. Often people think about the 3 ISO, Shutter Speed and Aperture but the slight tweeking with the exposure compensation works really nice.
As a relatively inexpert photographer, I would like to thank you for the interesting article. I took this photo last week, leaning through a window into a dark building, and wanting to get a decent exposure of both the internal graffitti and the external landscape. I knew I could change the metering mode, but could not remember how. So in the end I under-exposed by 3 stops, the maximum the camera could do, and used fill-in flash to help with the inside of the building. I was using Aperture Priority with this, and there has been no processing of the image other than cropping. I had set the aperture to f8 as I wanted everything in focus.
I have only recently moved on from a small automatic compact, so am still rather in awe of what is possible with more advanced cameras. I will be reading your next article carefully!
@laroque Great work Tim. Fill flash in itself is an entirely other technique/setting (and I suspect we might be covering it later down the track), but you are spot on with your thinking re exposure, and compensating for the much brighter lighting of the outdoor scene. As you will know the sky is still blown-out (and I don't consider this to be a problem, just an observation) which just goes to show how amazing our eyes are!!
@laroque Hi Tim. An interesting shot. We'll talk about "fill flash" in a few weeks, but one thing to remember is that with a (basic) flash active you can never set a shutter speed that is faster than what is called the X-Synch Speed of your camera. I see that your shutter here was a rather slow 1/40 second despite your attempts to drive it faster. I *think* (reading a little about your camera) that the X-Synch Speed for your camera is 1/64. I see something in the specs about "fp" which in DSLR terms means that you can beat this synch speed with a smart external flash, but I don't know for sure. I'll check it out next time I am at the camera store, perhaps Friday.
Fill flash is a useful technique, but if there are strong highlights, strong natural light, it might not behave all that well, blowing out these highlights. Two other ways you might go about this shot other than flash, but they do involve post editing.
First HDR, shoot two (or more) images, one for the highlights and the second for the shadows and then combine them in an editor. Your camera does have some " auto bracketing" where you can do this automatically and quickly so you might not need a tripod.
Second, just shoot this normally, metering for the highlights, or perhaps even slightly overexposing so the shadows aren't too black, then in an editor like Lightroom, perhaps even the raw processor that came with your camera, "recover the shadows" selectively.
Good shooting with your new camera. It looks most interesting.
@frankhymus Thank you. Lots to get my teeth into here. At the moment I am concentrating on using the camera, and will address editing later in the year - do you think that is a good approach, or should I do both in parallel?
@laroque That is a big question and everyone will have a different opinion I'm sure! Personally I think there is merit in trying to figure out what you can do in-camera before getting too carried away with editing. To me, editing is a really important tool ... to enhance an already "good" image. It sounds to me as though you are dedicated enough about learning that you probably wouldn't go down the path of taking sloppy images or never leaving Auto and expecting to "fix" everything with software though ...
@laroque For me they go together, one without the other is like clapping with one hand. It's not about "fixing" in the editor, one should always strive to be as correct and accurate in the camera as possible, although you can achieve amazing results to recover missteps. But it really is to achieve things the camera can't by itself, as well as enhancing what it can. However, editors worth their salt can be intimidating (Photoshop, Lightroom) so of course, whatever feels right for you.
I took this one two days ago, I had been out trying to get the "golden hour" light, but by the time I got to the woods, it was really bright. I dropped down to I think -2 or -3 so that the blue bells weren't all blown out.
I find blue's and purples sometimes really challenging to get right.
@sioux Hi Sue, lovely image and yes you have captured the golden light nicely :) To be honest the lighting looks reasonably even to me so -2 or -3 seems a lot to get this image which looks quite well-exposed, given there aren't any extremely bright or dark patches (compare Tim's image above). My only thought is that maybe your metering mode is on spot-metering - I really do want to leave that for next challenge but basically that would mean that your camera is only reading the light from a tiny portion of your image and maybe that happened to be a dark shadow. Maybe @frankhymus will have better technical insight?
Re blues and purples, perhaps this could be more of a white balance thing (again, another future challenge) than an exposure thing? Like with exposure, our eyes do a lot of compensating and we don't notice the differences in light colour (or brightness/darkness) anywhere near as much as our cameras pick up. So in bringing out the gold tones maybe this is where you lose the lovely blues and purples?
@aliha Thanks Alison, spot metering? I am off to my manual to read up if my camera does this, being a bridge camera I am not sure. But I am really enjoying these challenges.
@sioux Yes, like I said metering is the focus of next fortnight's challenge, but the idea is that your camera could be taking an average reading from the entire frame (which is reasonably evenly lit, but has some shadows as well), or just the middle area, or just a "spot" in the centre. I really wouldn't think you would have to adjust exposure much (hey, maybe 1/3 or 2/3 of a stop) to get this image if your camera was reading across the whole or even a decent part of the frame. Does any of this make sense?? :) It really could be something else altogether but I have no other suggestions, hence calling in Frank's expertise :)
@sioux Out of interest, do you still have any images shot before doing the exposure compensation? And was that main trunk in the left of the image really blown out?
@aliha@frankhymus Thank you for your advice, which seems to be 'Start as you mean to go on'. I've looked through past Discussions and Lightroom seems to be the recommended means of editing photos, so I will be adressing that soon. It's just a matter of having the time to study these things!
@aliha@sioux I can only suggest that a "matrix" or "evaluative" metering (averaging across the whole frame, those are Nikon and Canon terms respectively) would have significantly overexposed the tree trunks.
Also, as to White Balance, just a passing comment that blue and yellow/gold are at opposite ends of the "temperature" scale, so it is practically impossible to make a global WB adjustment and keep deep blue and bright gold. If you have Lightroom or equivalent, you can make local adjustments ("painting" the white balanace) to have a go at enhancing both. As Alison mentions our eyes (and brains as the image processor) adjust so rapidly to WB changes (the color of the reflected light) as we scan a scene that without these "local" adjustments to a photo it is next to impossible to "correctly" (i.e. as the eye sees and the brain computes) render a complex light image. What the camera "sees" and what the eye and the brain "see" are often at odds with each other and image editors are essential to compensate, as much as SOOC fundamentalists would not like to grant us.
Another way to think about the problem, a photograph is a static presentation of a scene; what the eye and the brain register is most definitely dynamic as our eyes scan and re-scan across the "static" (no motion) scene that we are totally unaware of what is happening.
OK more than enough ranting on my part for now, so have a good night, and perhaps we can talk more later about WB and "the color of light."
The top photo, I used -1 exposure and the bottom photo I used 0 exposure. I used AV setting, f5.6, ISO auto. Only rotation was used in one photo. I should have used -1/3 and -2/3 as well so that I could see the differences. Well, next time :-)
@yeshanghai Cool! Did you notice how the top one has the sky rendered nicely (no blown highlights) and the bottom the nice detail in the shadows? I think you are on a tripod, the images seem well aligned, so HDR merge or manually loading them both in one stack and layer masking in the best pieces would get you all the benefits of both. Or simply taking the top one and recovering the shadows, or the bottom one and lowering the highlights in Lightroom or equivalent would get you almost all the benefits with one simple slider adjustment.
I put a white Ornament against a Black Background. With the Exposure Compensation Bar at 0 the Ornament had no definition in the face or on the Right Shoulder. Overall the White was too bright & you couldn't see the highlights from the light source. The 'pearls' were also too bright.
I guessed I would need to underexpose but as an experiment went through each increment from +2 to -2.
The Overexposed Images were completely blown out.
As I worked through the Underexposing the image gradually improved. -2/3 had definition in the ornament but was still a bit too bright.
-1 2/3 & -2 were too Underexposed and started to look a bit dull.
I tossed up between -1 and - 1 1/3 as being the best two. They were very close in the amount of definition in the Ornament & also in the Pearls. In the -1 1/3 image the catch lights from the light source stood out a bit better, they blended into the White of Ornament a bit in the -1 image.
This final shot is F8 @ 1/4, ISO 400. Underexposed by -1 1/3
@yeshanghai Think Frank has it covered but thought I should reply too ... these are great, and highlight well the options for exposure and what you lose/gain with each setting. Do you have a personal preference for one or the other?
@jennymallett Great exercise Jenny! And I think the image you have chosen to share here is beautifully exposed. Like you say, you have all the definition in your subject (without it looking grey) plus a really rich black for your background. And nice to know your guess was correct :)
I don't have a picture to share (yet) but I was shooting flowers in the sunlit garden at midday today, and fiddling about with EV while in Aperture mode, and I have a question. I wanted as shallow a dof as possible (F1.8) but then my (top) shutter speed of 4000 was flashing at me, which means it's not happy. So I thought I'd dial in some minus numbers to compensate, but I noticed that the camera ignored this, and the shots were all the same - over-exposed. When I increased the aperture to F3.5 so that the 4000 calmed down and stopped flashing, it would then accept the minus EV and under-expose. Which was a bit frustrating as then obviously I didn't have the wider aperture that I wanted. So am I right in thinking that EV will be ignored (at least by my camera?) if the light conditions are already so challenging that it's giving me a warning? I don't know if I've explained this at all well. Hopefully one of you excellent people will understand - and many thanks in advance for your help if you can :)
@pistache No, I can only think that you are also overexposed with -2EV f/1.8 and the fastest shutter that you can achieve. This is a situation where ND (Neutral Density) filters rescue you, wide aperture and bright light needing a shutter faster than you can achieve. Basically allowing you long shutter time in good light. Your ISO is dropped back as low as you can set it too, right?
This one is showing underexposed because of the dark background. I wanted to get the bright yellow of the flower pot and flower in the sunlight with the background dark. If the exposure had been a 0, the yellow would have been washed out.
@pistache Yes, sometimes this happens - that strong sunlight is simply too bright to use your widest aperture. The reason your 1/4000 was flashing at you is because it can't get any faster (and your ISO can't get any lower), and it was still over-exposing and the ONLY thing you have left to change is aperture. This is also why it wasn't letting you go into negative EV - because the ONLY way you can let less light in (and therefore "underexpose" is to close down the aperture. It's not that it's ignoring you (don't take it personally :) ) - it's just that there are only three variables, and if 1 and 2 are already at their minimum, you have no choice but to adjust the 3rd as well, even if that means a less shallow DOF than you were after. I guess this is what I was meaning in the challenge description re: "how much light you have to work with and what compromises you may need to make" :)
I guess the next best idea may be to try again in the late afternoon maybe? Or a day with patchy sunlight?
@aponi Yes and it works well. Very similar idea to what @jennymallett was working with above. I suspect that if you check for clipping, the white flowers on the pot may actually be slightly blown-out, BUT I think the image as a whole is beautifully exposed, because the bloom is your primary subject. If I may make a compositional suggestion, it might be nice to move slightly to the left or right so that the flower is on a "cleaner" background of dark green, rather than sitting over a combination of dark green foliage and bright blue sky - what do you think?
Av 5.6 ISO 100 1/320 OExp. 31mm FL. Found blown out highlights in sky and lilac
Trying to get a shot of the lilac blossoms that weren't a blb of white. Adjusted this to -0.1 exposure in next shot. Everything else the same except 1/60 sec. Enlarged it and found there was some difference in the clarity of the blossom.
Final photo, taken in the week before the others. Tried lots of different things to get rid of blown highlights. Eventually settled on F7.1 and the exposure to -0.7, which read -2/3 on the camera properties. However it was dark under the tree. Did try fill in flash bty that just lit everything up.
However I think the lilac is more defined in this than the previous shot. I do have trouble with blown highlights and narrow F stop doesn't always work. So maybe exposure adjustment the answer.
F7.1 1/250 sec ISO 100 48mmFL -0.7 exp adjustment.
@jennywren Nice series Jenny. I can immediately see the difference in the sky between images 1 and 2. Because the lilac blooms are very small in the context of the whole frame, it is harder to see a particularly noticeable difference at this size, although it's definitely evident on a closer look.
In theory, the aperture alone (f/5.6 v f/7.1) shouldn't make a difference to whether your highlights are blown out or not - what I mean is that f/5.6 @ 1/640s is the exact equivalent (in terms of light hitting the sensor) of f/8 @1/320s, or f/11 @1/160s, or even f/4 @1/1250s ... does that make sense? The exposure will be exactly the same in each image ... it's the depth of field that will change (with the aperture), and the effect on any movement (with the shutter speed - which is irrelevant in this image as there is no movement).
So yes, it's really the exposure value as a whole - somewhere around the -1 (not -0.1 btw) as you have demonstrated in image 2 or or -2/3 in image 3. Also if image 3 was taken on a different day than images 1 and 2 (or even a different time of day), then the absolute amount of light will have been slightly different and therefore your reading at 0 will have been slightly different also. So your conclusion ("maybe exposure adjustment is the answer") is probably correct :)
And yes, it's dark under the tree, but I don't have a problem with that ... I think it adds interest. Would be entirely up to your own taste if you wanted to brighten the shadows slightly in post-production. If I could make one compositional comment - this is a lovely garden scene (I wish mine looked like that!) but if you really want to take a photo that does the lilac justice ... I'd get in much closer :)
@aliha Thanks so much for your detailed comments especially re the exposure. I did take some more shots and realised that the exposure was the relevant thing and not the aperture. Hoping to get some lovely close lilac shots too. This thread has been a real boon re information, thanks for your time and input.
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For this second image, standing together their silhouettes were less definable, so I went for a brighter image, again from memory somewhere between +1 and +2. This means there's less colour in the sky, but all of their features and details are visible in this version.
As a relatively inexpert photographer, I would like to thank you for the interesting article. I took this photo last week, leaning through a window into a dark building, and wanting to get a decent exposure of both the internal graffitti and the external landscape. I knew I could change the metering mode, but could not remember how. So in the end I under-exposed by 3 stops, the maximum the camera could do, and used fill-in flash to help with the inside of the building. I was using Aperture Priority with this, and there has been no processing of the image other than cropping. I had set the aperture to f8 as I wanted everything in focus.
I have only recently moved on from a small automatic compact, so am still rather in awe of what is possible with more advanced cameras. I will be reading your next article carefully!
Fill flash is a useful technique, but if there are strong highlights, strong natural light, it might not behave all that well, blowing out these highlights. Two other ways you might go about this shot other than flash, but they do involve post editing.
First HDR, shoot two (or more) images, one for the highlights and the second for the shadows and then combine them in an editor. Your camera does have some " auto bracketing" where you can do this automatically and quickly so you might not need a tripod.
Second, just shoot this normally, metering for the highlights, or perhaps even slightly overexposing so the shadows aren't too black, then in an editor like Lightroom, perhaps even the raw processor that came with your camera, "recover the shadows" selectively.
Good shooting with your new camera. It looks most interesting.
All the best!
I find blue's and purples sometimes really challenging to get right.
Re blues and purples, perhaps this could be more of a white balance thing (again, another future challenge) than an exposure thing? Like with exposure, our eyes do a lot of compensating and we don't notice the differences in light colour (or brightness/darkness) anywhere near as much as our cameras pick up. So in bringing out the gold tones maybe this is where you lose the lovely blues and purples?
Also, as to White Balance, just a passing comment that blue and yellow/gold are at opposite ends of the "temperature" scale, so it is practically impossible to make a global WB adjustment and keep deep blue and bright gold. If you have Lightroom or equivalent, you can make local adjustments ("painting" the white balanace) to have a go at enhancing both. As Alison mentions our eyes (and brains as the image processor) adjust so rapidly to WB changes (the color of the reflected light) as we scan a scene that without these "local" adjustments to a photo it is next to impossible to "correctly" (i.e. as the eye sees and the brain computes) render a complex light image. What the camera "sees" and what the eye and the brain "see" are often at odds with each other and image editors are essential to compensate, as much as SOOC fundamentalists would not like to grant us.
Another way to think about the problem, a photograph is a static presentation of a scene; what the eye and the brain register is most definitely dynamic as our eyes scan and re-scan across the "static" (no motion) scene that we are totally unaware of what is happening.
OK more than enough ranting on my part for now, so have a good night, and perhaps we can talk more later about WB and "the color of light."
The top photo, I used -1 exposure and the bottom photo I used 0 exposure. I used AV setting, f5.6, ISO auto. Only rotation was used in one photo. I should have used -1/3 and -2/3 as well so that I could see the differences. Well, next time :-)
Well done!
I put a white Ornament against a Black Background. With the Exposure Compensation Bar at 0 the Ornament had no definition in the face or on the Right Shoulder. Overall the White was too bright & you couldn't see the highlights from the light source. The 'pearls' were also too bright.
I guessed I would need to underexpose but as an experiment went through each increment from +2 to -2.
The Overexposed Images were completely blown out.
As I worked through the Underexposing the image gradually improved. -2/3 had definition in the ornament but was still a bit too bright.
-1 2/3 & -2 were too Underexposed and started to look a bit dull.
I tossed up between -1 and - 1 1/3 as being the best two. They were very close in the amount of definition in the Ornament & also in the Pearls. In the -1 1/3 image the catch lights from the light source stood out a bit better, they blended into the White of Ornament a bit in the -1 image.
This final shot is F8 @ 1/4, ISO 400. Underexposed by -1 1/3
I guess the next best idea may be to try again in the late afternoon maybe? Or a day with patchy sunlight?
Av 5.6 ISO 100 1/320 OExp. 31mm FL. Found blown out highlights in sky and lilac
Trying to get a shot of the lilac blossoms that weren't a blb of white. Adjusted this to -0.1 exposure in next shot. Everything else the same except 1/60 sec. Enlarged it and found there was some difference in the clarity of the blossom.
This shot identical settings apart from 1/640 secs and exposure changed to -0.1. Got rid of the blown highlights.
Final photo, taken in the week before the others. Tried lots of different things to get rid of blown highlights. Eventually settled on F7.1 and the exposure to -0.7, which read -2/3 on the camera properties. However it was dark under the tree. Did try fill in flash bty that just lit everything up.
However I think the lilac is more defined in this than the previous shot. I do have trouble with blown highlights and narrow F stop doesn't always work. So maybe exposure adjustment the answer.
F7.1 1/250 sec ISO 100 48mmFL -0.7 exp adjustment.
In theory, the aperture alone (f/5.6 v f/7.1) shouldn't make a difference to whether your highlights are blown out or not - what I mean is that f/5.6 @ 1/640s is the exact equivalent (in terms of light hitting the sensor) of f/8 @1/320s, or f/11 @1/160s, or even f/4 @1/1250s ... does that make sense? The exposure will be exactly the same in each image ... it's the depth of field that will change (with the aperture), and the effect on any movement (with the shutter speed - which is irrelevant in this image as there is no movement).
So yes, it's really the exposure value as a whole - somewhere around the -1 (not -0.1 btw) as you have demonstrated in image 2 or or -2/3 in image 3. Also if image 3 was taken on a different day than images 1 and 2 (or even a different time of day), then the absolute amount of light will have been slightly different and therefore your reading at 0 will have been slightly different also. So your conclusion ("maybe exposure adjustment is the answer") is probably correct :)
And yes, it's dark under the tree, but I don't have a problem with that ... I think it adds interest. Would be entirely up to your own taste if you wanted to brighten the shadows slightly in post-production. If I could make one compositional comment - this is a lovely garden scene (I wish mine looked like that!) but if you really want to take a photo that does the lilac justice ... I'd get in much closer :)