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Monthly Archives: March 2012
What is with this weather lately?? Seriously – did we skip spring here in St. Louis and just go straight to summer?? If we did, I love it… not only does it mean I get to break out my shorts early, but I also get the jump on some shoots… Nice weather = people are more inclined to go outside for pictures! HA!
He may look like a very serious little guy, but trust me, he was a barrel of laughs from start to finish… don’t believe me?? Fine, take a look…
See – look at that smile!! How could you not love that!?!
In fact, this guy is so awesome, I’m gonna shut up and let you bask in the joy of his smiley face…
His kissy face..
And his “Are you done taking pictures of me yet?” face…
You’re welcome world… sit back and bask in the joy of the many faces of Carter!!
NB: This post assumes you’ve read the previous instalments of ‘Photography 101’. If you haven’t, I highly recommend doing so now.
Right – I’m going to do something very weird to open this post… but bear with me, as always, there is method in my madness.
Before we start discussing histograms, exposure, how they tie together, and how the histogram is possibly the most under-used and under-valued tool on your camera, I want you to go away and read this post on my buddy Dylan’s website (you may remember him, I listed him among my ‘Go-To Guys’ – Once you’ve read that, come back here, and we’ll continue. Don’t worry, I’ll wait… And in the meantime here’s some music:
Okay; finished?? Awesome, right?? Good, glad you liked it.
Now to bring things back around…
The reason I wanted you to go read that post is because of this central conceit:
“The only good exposure is the one you intend to make.”
Pardon my French; but that’s bloody genius. And I can’t believe I didn’t come up with it myself (see why I say he’s inspirational??) I know my last few posts have been all about getting the ‘right’ exposure, or a ‘good’ exposure, but I neglected to actually discuss what a ‘good’ exposure was in any depth, and now I don’t have to. So: On to the Histogram, and ultimate kudos to Dylan…
For all those who have yet to discover the joys of the histogram, let me explain what it is:
A histogram is a graph. Plain and simple. There are various forms but the two most common in photography are known as the ‘basic’ histogram, which is monotone (a la the Photoshop ‘Levels’ module), and the ‘RGB’ histogram (a la Lightroom 3):
In order to see the histogram on your camera simply press the Info or Display button (for Canon owners) or press the up or down button when previewing an image to cycle through the different views (for Nikon owners).
In photography, the histogram maps the tones in your image from dark shadows/black (on the left) to bright light/white (on the right). The higher the graph at any given point the more pixels of that tone appear in your image. Most technically ‘well’ exposed shots tend to peak somewhere in the middle and taper off towards the edges, creating a bell curve. However, please remember everything you just read on Dylan’s website – The histogram is just another tool in your arsenal to give you more information about an image. As a photographer, the IMAGE is everything… Just as there is no ‘perfect’ exposure, there is no such thing as the ‘perfect’ histogram. Depending on how you are shooting, and what effect you want to create in your shot, you will see drastically different histograms.
Take a look at the above image. Cute, right?? Aaaaaaawwwwwwww!
Anyway – Take another look. Would you say that the shot was well exposed?? I would, but that’s because that’s the exposure I was aiming for… But let’s take a look at the histogram:
See how everything’s bunched up over there on the right?? Pretty far cry from that bell curve. But does it make my shot any worse? No – in fact, if I had gone for that balanced, ‘correct’ exposure then that shot would be a lot worse – mainly because you would then see the horrid sheet I was using as a backdrop! As another of my friends has taken to telling me – “When it comes to portraits, brighter is better” – meaning that a lot of the time when shooting people (particularly cute kiddoes and women) overexposure is the way forward – Lighter, brighter, happier…
Of course… it all depends on what you want…
Again – this is the exposure I wanted, NOT the exposure my camera sensor told me was ‘correct’. I shot this for my ‘About’ page, and wanted to create a feel of searching for light, looking for something in the dark – which is, essentially, the core of photography…
But just look at that histogram!! Euch! All stacked up over in the dark… complete and utter black covering half the shot…
At this point, you’re probably thinking: Ok Mr. Smarty, if the histogram is telling you it’s wrong, but you know it’s right, why even bother with the histogram??
Good question – and here’s the answer: Because when you know how to read the histogram, you can very quickly and very easily see if you’ve achieved the exposure you wanted.
Both of the above examples were extremes of light – high-key for the baby shot, and low-key for the self-portrait – but by using the histogram I knew very quickly that I’d nailed that ‘lighter, brighter, happier’ motif for the high-key, and the ‘moody, dark and shadowed’ feel for the selfie – I didn’t need to check anything else.
And that’s the power of the histogram. When you’re stood chimping at the 2.5” LCD screen after you’ve taken your shot, it’s a very quick, easy reference to see how close you got to the exposure you wanted!
For example, this long exposure of the Yi Sun Sin statue in Gwangwhamun, Seoul:
This was a 10 second exposure, at night, so I knew that my primary tones were going to lean towards the dark side… but I also wanted that column and statue looking nice and bright and clear… So here, before I even took the shot, I was expecting to see the histogram bunched up over in the left of the screen, with (hopefully) some peaks on the far right. This is what I got:
No peaks on the right, everything bunched up on the left… but that’s fine. It was close to what I was expecting, so I knew I could work with that shot, and of the several versions I shot, this was my final choice.
Finally, take a look at this shot:
Now – this is possibly the closest example to that ‘bell curve’ we’ve got. Trying to expose so that as much of the image as possible is ‘lit’ correctly – trying to get as close to what the eye sees as possible – I didn’t want anything blown-out, and definitely didn’t want any harsh dark shadows… So, I aimed for the middle, trying to get that ‘correct’ exposure. Here’s what I saw in my histogram:
First instinct here (for me at least) was that this was too bright – that peak in the mid-tone highlights threw me – but that was before I saw the image and realized just how goddam BLUE the sky was. Thank you, Polarizing Filter. As for the rest of the histogram, it may not be a bell curve, but look at the edges – nothing there. All of my data – all of my pixels – were in that midtone range, nothing was blown-out, nothing was darker than dark. Close enough to my desired exposure to be a keeper.
And let’s just take a minute to highlight another bonus to using histograms – I was on a beach, in Thailand, in the middle of the day, with the sun blazing down – dya really think that I could have judged the quality of this shot by looking at it on the LCD screen of my camera?? Hell, I could barely SEE it! But the histogram?? Clear as day – on my Nikon D40, it shows up as a bright yellow graph against a dark background – how easy is THAT to look at on bright sunny days?? (Answer: Very)
Hopefully you’ve gained two things from this instalment of Photography 101…
- To quote a friend “The only good exposure is the one you intend to make”
- The histogram is an amazingly useful tool for judging whether or not you made the exposure you intended.
World, meet Rocco… Rocco, meet world…
This little guy is, quite possibly, the coolest kid I’ve ever encountered…
This little guy has so much personality it’s unbelievable… He is a wisecracking little fun-machine… Not bad for two years old…
Rocco’s folks are pretty awesome too… and the little guy insisted on getting some cool family shots (or at least, that’s what he told me!) so we grabbed Mom and Dad to get a couple of shots in the amazingly awesome sunshine (not bad for January!!)Pin It
Revenge of the Exposure Triangle!
Yes folks, we’re back!! I know I left you hanging last time, but hopefully playing around with those Aperture and Shutter priority settings has illuminated a few lightbulbs for you… and so today we’re rounding things off (in a tringular way) by looking at the final branch of the exposure triumvirate…
ISO is, in a very simple sense, the camera sensor’s sensitivity to light. ISO ratings range from 100 to 800 or 1600 typically, doubling in magnitude for each ‘stop’ of light (so ISO 100 is one stop down from ISO 200, and ISO 800 is one stop brighter than ISO 400… Got that?)
That, at a very basic level, is the difference ISO makes in exposure: It is a way for you to tell your camera to be more or less sensitive to light. So, if you’re trying to squeeze the last few moments out of the daylight, and you realise your shutter speed is starting to drag dangerously close to ‘motion-blur-town’ even though your aperture is wide open… you can crank that ISO up and keep shooting. There is a catch though… the higher you pump up the ISO, the “grainier” your photos get. This happens because the camera pushes its own boundaries to improve light, and sacrifices quality in the process.
Take a look at the above shot – a REALLY good look… This was taken at the Albert Dock in Liverpool, at night (duh!)… I had my aperture set to where I wanted it and, for once, didn’t want to slow my shutter speed way down. So, instead, I pumped up the ISO. Not a problem… until you start pixel peeping, especially up in the dark sky areas… See that grainy, dotty, noisy nonsense?? THAT’S your payoff for cranking the ISO.
The lesson you need to learn form all this is that you should keep your ISO settings as low as possible when you have enough light, and push it up as needed when you are in darker situations. On a day to day basis, I generally keep it around ISO400. If it’s particularly bright and sunny, I may drop to ISO200… You get the idea, right?
Bear in mind though that all cameras are NOT created equal. In general, the more expensive cameras have ‘better’ sensors, which allow you to push that ISO boundary a little further. The big question is whether you care enough about noise/grain in your night-time shots to need that extra ISO leeway.
Bringing it all together!
So now you understand the three arms of the exposure triangle, how does that effect your photography?? Let’s take a look at a couple of examples, and the choices made to get those shots, shall we??
Okay, first up is this shot of a Korean street… Now the pixel peepers amog you will instantly spot the noise/grain in the sky that signals a high ISO… and you’d be right. But there was logic. I made that decision, NOT my camera. Why? Simple… I didn’t have a tripod, so needed my shutter speed to stay fast in order to keep things sharp, and wanted a reasonably high aperture to keep as much of the scene in focus as possible… Fast shutter, plus high aperture, at night = Necessary high ISO.
Ok – second example – and a slightly different focus (literally). See the way my subject is in sharp focus, but the background is all blurry and out of focus? That’s called ‘bokeh’ and is (by all accounts) a pleasant aspect of photography. There are several factors that contribute to this (we’ll get into those later) but one of the main players is your aperture. The wide apertures (around f/2.8 and wider) tend to create a shallow depth of field in images, like this one. Of course, having a wide open aperture on a bright sunny day requires a fast shutter speed, and a low ISO… otherwise things might get VERY bright…
Knowing what you want to achieve, and choosing the settings to make that happen are two MASSIVE steps towards improving your photography, and understanding the exposure triangle is the basis for making those choices!
Here Endeth the Lesson.Pin It