Tag Archives: howto

The Absolute Basics Of Exposure

I have the privilege of knowing a growing number of beginning photographers. It’s always casual but sometimes folks are a little shy about asking questions. I remember being new to photography, and in a lot of ways I still am. No, really. For example at San Jose State Univeristy I nearly flunked out of Photo 101 (yes I did much better later). I loved it, but I utterly didn’t have any sense for composition, basic lighting, and oh my goodness I had a crush on the pretty girl I shared the darkroom with. Stop it, I was a complete gentleman in college. That may mean that I missed out on some of the typical college guy things, but I digress. (Note to self, maybe edit that out) (Note to self, no leave it in, it’s kind of funny) (Note to other self, stop it) (Note to other other self, OK) (All the other voices in my head: GET ON WITH IT).

So here I am writing about the absolute basics essentially for a group of friends but also for anybody else who cares to read it. I mean, OK, folks are asking me. Maybe I can help.

Photography is all about light. It’s in the word. Photo (light) graphy (writing). Light writing.

Let’s start with the basics of exposure.

Most cameras since the 1980’s have built in light meters. That means that there is a sensor that measures light reflected off of a subject and back into the lens. The earliest camera that I have that did that is my old Canon A-1. This technology is not terribly new.

My trusty old Canon A-1

How brightly an image is exposed depends on how much light is allowed through the lens, striking the camera’s sensor or film. This is intended to be all about digital photography so I won’t talk a lot about film here, but there are analogies that help occasionally.

There are 3 things that will effect how your image is exposed, and they are all related in what’s usually referred to as the “exposure triangle”. When one of those three aspects changes then the other 2 change too. It breaks down like this:

  • Shutter Speed (the amount of time the shutter is open)
  • Aperture (how wide the opening in the lens is)
  • ISO (how sensitive the sensor is to light)

Update:

A couple of friends of mine read this and correctly noted that I’ve assumed your camera is in manual mode. JC Dill  thought that manual mode deserves a little explanation. She’s right.

Below are three cameras that I use fairly often. All three have a manual mode that allows for complete control over aperture, shutter speed, and ISO. Each one has a control with “M” for manual. The other modes worth noting are (on the Canons anyway) Av (aperture priority), Tv (shutter priority), and P (program mode — aka “automatic”). The Panasonic is similar: M, A (aperture priority), S (shutter priority), and P (program mode).  For this discussion we’re not letting the camera make any decisions for us. When the camera calls the shots, you get what the camera decides what you want. It’s almost never what you really wanted.

My trusty Canon 7d Mk II
My very, very well used Canon Rebel XT
The reliable Panasonic Lumix DMC-FZ47

The rear panels of these cameras show some helpful details. Each shows a basic light meter (-3…-2…-1… | …1…2…3 ). The middle is what the camera is calling well exposed. -3 is 3 stops under exposed, 3 is 3 stops over exposed. There is also a graph displayed with red, green, and blue. This is an optional display that I rely on. This histogram tells me about the dark values (on the left side of the graph), the bright tones (at the right side), and the mid tones (in the… ok you get it). The default is one single graph for overall luminance. I have it set to display red, green, and blue so I can see if any one part is over exposed. There’s a lot of bright reds here, so I would call it a little over exposed.

The live view on the 7d Mk II. Note the meter at the bottom of the camera’s LCD: 3…2…1…|…1…2…3 .

The back of the Canon Rebel shows similar information, just in a much more basic way. This is telling me that the image is a little under exposed the way I have it setup.

The rear display of my older Canon Rebel XL has something similar: -2..1..|..1..2
Another image of the back panel of the Canon Rebel XT. The meter is centered. The camera’s light meter is calling this well exposed. This is a little more subjective than you’d think, but it’s a good starting point for discussion. Don’t look too closely, this camera is really filthy. It’s seen a lot of adventures.

This Panasonic Lumix is a nice example because it’s essentially a low end consumer camera with full manual control. The light meter at the bottom should seem familiar now. Note the graph towards the right of the LCD. It’s another histogram similar to what’s on the 7d Mk II. This histogram is displaying overall luminance instead of breaking it down in to red, green, and blue (RGB). This graph is telling me that there’s a lot of dark values and midtones, and not much that’s excessively bright. While this isn’t a terribly exciting photograph (really it just shows you how very messy my desk is), it does say that this is a reasonably well exposed image.

The rear of the Panasonic is a little different. It has a meter in the LCD much like the Rebel and the 7d Mk II : -2..-1..|..1..2 .

That’s a lot of information and I encourage you to comment and ask questions. OK.. back to our regularly scheduled program picking up with… (drumroll please…) shutter speed.

Shutter Speed:

Put simply, the longer you leave the shutter open then more light passes through the lens to the sensor. A short amount of time results in a dark image (under exposed). A long amount of time results in a bright image. A very long amount of time results in white or nearly white (over exposed). What’s “correct?” That’s really up to you and what you were looking for. Unless you’re working under some very strict guidelines this is art. You either achieved what you wanted or you didn’t. I’ll go into shutter speed in greater detail later, but I touch on it in this earlier post that you might like. : MY VIEWS ON SHOOTING BETTER SURF PHOTOGRAPHY

We’ll use one of my favorite wide angle lenses. This is great for this demo because it’s entirely manual.

Aperture (aka “f-stop”):

The typical camera lens has a roughly circular opening that can be adjusted to be larger or smaller. A larger opening allows more light in while a smaller opening allows less light in during the same amount of time. A smaller number means a more open aperture. f/4.0 is a fairly wide aperture and lets in quite a lot of light. A higher number means a smaller aperture and lets in less light for the same exposure time. For example f/8.0 is a smaller aperture than f/4.0.

Aperture: f/2.8. Wide open for this lens.

If I were to point my camera at exactly the same subject in exactly the same lighting and let it expose for exactly the same amount of time for two shots, one at f/4.0 and the second at f/8.0, you would see that the photograph shot at f/8.0 is much darker than the one shot at f/4.0. For the same image shot at f/8.0 to be the same luminance as the one shot at f/4.0 you could let it expose for more time. Exactly how much time is a little beyond the scope of this introduction to the exposure triangle but you can probably start seeing how these two sides of the triangle are related now.

The aperture is smaller now. f/5.6

Right about now you’re wondering what the heck the “f/” part is in f/4.0 and f/8.0. The aperture is measured as fractions of the length of the lens. f = focal length.

Aperture is smaller still: f/8

This is very much like the pupil in your eye. When it’s dark you see a little better when the pupil opens wider. When it’s bright your pupil becomes much smaller and allows in less light. Something that’s super cool is that your pupil will change diameter as you scan across a scene. Your typical camera doesn’t do that. Not yet anyway.

The smallest aperture for this lens: f/22

A closer look at aperture and shutter speed together:

Let’s walk through an example demonstrating how changing your aperture will change the amount of time (shutter speed) needed to keep the same exposure while the same amount of light remains constant. Notice that each picture takes twice as long to expose as the one before it.

Aperture: f/1.8, ISO: 200, Shutter speed: 1/40 second
Aperture: f/2.5m ISO: 200, Shutter speed: 1/20 second — twice as much time to expose
Aperture: f/3.5, ISO: 200, Shutter speed: 1/10 second

I’d like you to notice something else that should be apparent by now. More of the items in the photo are coming into focus. In the first  example the item in the foreground was in focus. Then bits of the item behind it. From here the clock in the background will come more into focus. I didn’t change my focus point at all. I set the focus to be on the candle and never changed it.  What has changed is the aperture. By using a smaller aperture we get a greater “depth of field” (or in English “there’s more stuff in focus”).

Aperture: f/5, ISO: 200, Shutter speed: 1/5 second

Aperture: f/7.1, ISO: 200, Shutter speed: .4 seconds
Aperture: f/10, ISO: 200, Shutter speed: .8 seconds

Now here’s something interesting. There’s not much difference between these two last pictures is there? The candle, the clock, and everything in between is in pretty much the same focus. At some point you reach a practical infinity. Different camera models will behave a bit differently. At a point beyond that your photo will actually become less sharp. That’s an effect called “lens diffraction” which is outside the scope of this quick intro.

Aperture: f/14, ISO: 200, Shutter speed: 1.6 seconds

ISO (sensor sensitivity):

Finally there’s the topic of ISO, the third side of the exposure triangle. By increasing the ISO you shorten the amount of time needed to expose the image. It becomes possible to freeze action in lower light situations. A higher ISO number means greater sensitivity to light. There is a tradeoff which you may or may not mind. A low ISO number is less sensitive to light but will usually result in a higher quality image. A higher ISO value is more sensitive but will reduce image quality by introducing a grainy look, aka “noise.”

f/1.8, 1/15 sec, ISO 800. At 1/15 second I can’t hold the camera still without a tripod.

My good friend Dave Anderson suggested that I explain the captions in the snapshots above and below. I took these snapshots hand held. You are moving no matter how hard you try not to. When you have a slow shutter speed there’s very little chance of having a sharp photo because you moved a little while the shutter was open. A good rule of thumb for a reasonably sharp picture when hand held is to keep your shutter speed at the inverse of your focal length.

f/1.8, 1/25 sec, ISO 1600. That’s still a long time for hand held so it’s not very sharp.

I can here you from here: “Whaaat??”  Let’s say I have a typical kit lens that zooms from 18mm to 55mm. If I’m shooting at the wide angle, 18mm, then I would need to keep the exposure time 1/18th second or faster. If I’m shooting at the tighter end, 55mm, then I need to keep it at 1/55th second or faster. This is oversimplified because different cameras will behave differently. For example a crop sensor camera like the Canon Rebel series, the Nikon 3000 series, should still be a little faster. Explaining why is a little outside the scope of this one post. It’s also pretty unlikely that you’re going to keep completely still for 1/18th of a second.

f/1.8, 1/80 sec, ISO 3200. This is closer to what I can shoot hand held. It’s starting to get a little noisy. Your camera may vary.
f/1.8, 1/160 sec, ISO 6400. A much faster shutter speed and easily hand held. Kitteh’s action freezes mid-yawn (I bore her). It’s very noisy now.
f/1.8, 1/320 sec, ISO 128000. Easily handheld, very noisy, and Kitteh is tired of me. Click on the the picture to see the noise details.
Are you done yet?? Yes Kitteh. Thank you. Please don’t poop in my shoe.

My views on shooting better surf photography

Yesterday my friend John and I were talking about some general photography topics while at an art & wine festival in the Santa Cruz Mountains. He asked me what settings I use and I gave an honest, brief answer: “They’re all different.” I thought to myself “Self, that was a lame answer.” The response was true enough, a longer answer would have gone on all day. I thought I’d try to write a brief answer for the subjects I tend to shoot. The plan was to write something short and introductory. Naturally that turned into something long and introductory. I broke it up into 3 topics (Landscape, Surf/sports, and portraits). Let’s start with my favorite: Surf

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I shoot a lot of surf. You probably already knew that. I recently read a blog about how to shoot better surf photographs. I disliked that article loudly and had many, many points of disagreement. So, rather than rant about that I thought that I would write my own thoughts.

I use shutter priority as my main setting. Things happen so fast that there’s just not enough time for manual mode. I keep it to 1/1000 of a second or a little faster to freeze the action. There’s not a lot of added value in shutter speeds faster than 1/1600. Sometimes the extra blur in a wave tells a great story about motion so there are times when a slower shutter speed may be exactly what you want.

Shoot RAW. This should need no serious explanation. You have options when editing the RAW photo. Those options mostly go bye bye if you’re shooting in JPEG.

Longer lenses are generally better. A 70-200mm telephoto is great. I prefer my Canon 70-200mm f/4 because the autofocus is fast, smooth, and silent. The quality of the lens is very high while still being affordable. I also like to use my Sigma 150-500mm  (check out Gordon’s review of the lens). Both have their moments when they are the right tool for the job. Both have their moments when they are just wrong. I think this can only be learned with personal experience. Bringing your most expensive lens might be a mistake because of the wear and tear that happens in this environment; leave the Canon 70-200 f/2.8 at home.

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Faster autofocus is better. My Canon and Sigma lenses are perfect. My Tamron 70-300 is a pig. I’ve found that even the consumer level Canon telephotos are pretty good.

My ISO tends to be higher which catches more light and allows for faster shutter speeds. This will vary depending on the conditions, but consider a range of 400 to 1600 as a good target. Allow for noise in the image, but honestly with today’s cameras it will still be OK.
I try to keep the aperture from f/8 to maybe f/13. F/8 works well for a couple of reasons:

  • Most lenses are optimized for f/8. My Sigma 150-500 will get a sharp image at f/8 but will be rather soft at something more open than 7.1.
  • F/8 will also yield a decent depth of field. Let’s face it, your subject is usually a single surfer with a wave behind her. That’s usually a distance of a meter or so. That’s more than enough depth of field usually.

Shutter priority adjusts the aperture automatically to keep as close to your set shutter speed as possible. If you find that you’re getting apertures smaller than f/13 (f/13 to f/22) then consider reducing your ISO because your camera thinks that it has plenty of light.

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Focus: AI-Servo for Canon. I think it’s Continuous Servo for Nikon (feel free to correct me on that since I’m a Canon user). Your subject is moving so you need a focus mode that tracks the moving target. “One Shot” mode will get you a photo of where your subject was, not where she is. Setup your camera for back-button focus if it’s available.

Focus point: I keep focus on my subject’s head. If you find that her face is smaller than the focus point then you may be too far away. I set that focus point manually with a few things in mind but I can summarize like this:

  • If she is moving towards your left, then set the focus point on the right and give her some room to move left in the frame.
  • Pan with her as she crosses your field of vision. This creates a more visually interesting photo because it tells more of a story than if she was dead-center.
surfing, Santa Cruz
Give your subject room in the frame to move

Set up for burst mode. More shots per second is better (not quite “spray and pray”). Things happen fast so give yourself the opportunity to choose the best moment out of a selection. I like the Canon 7D, 7D mk II, and 1D because I’ll get 7-10 shots per second (the Canon 70D also looks like a good bet). I have heard that the latest Nikon D500 is killer. Faster cards are better so that writing to media from the memory cache happens quickly enough so you can shoot again in a second or two. Plan well if your camera gets 4 frames per second or fewer.

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Use a lens hood. This keeps some of the crud and sea spray off of your glass. I prefer this to a UV filter “for protection” any day. (Again, I loathe UV filters. I think they’re better at earning a salesman a few extra bucks than they are at doing anything useful for you). If you really need to clean off your glass, do so with great care. Chances are you’re making sand paper. Blow it off first with a Rocket Blaster or similar first. Honestly I’ve found that gunk on the lens itself doesn’t impact the image nearly as much as gunk on the sensor does, so I kind of let it go.

Turn off any image stabilization features. At these shutter speeds there’s really no need for it and it can result in blurry or missed shots. Image stabilization is there to help you keep still. With sports you are shooting a moving subject and you need to move. Image stabilization works against you here.

Use a monopod if you’ve got a super telephoto (> 200mm) or if you find holding a telephoto to be difficult and heavy. I will hand hold my 70-200, but I’ll use a monopod for my 500 after a while (that Sigma is over 4 pounds, so swinging that guy around for more than a couple of hours is a workout). Be very aware of people around you because it’s easy to follow the action and smack the person standing next to you. This is extra true with longer lenses. I don’t like using a tripod for this and here’s why:

  • It limits your ability to follow the action quickly.
  • It limits the angles that you can get (the idea of a tripod is to hold your camera still for a highly planned composition)
  • It takes more space. I’ve mentioned that I prefer the cliffs. If I’m turning on the tripod then chances are that I’ll trip over one of the tripod legs. If this happens then at best everything gets knocked over. At worst everything goes into the ocean. There’s also a likelihood that somebody else will trip over it and you never saw him coming.
  • It’s one more thing to carry. You need to move fast and this slows you down.

A buddy of mine played “devil’s advocate” to my assertion regarding tripods. His point was that for very expensive glass then a more sturdy platform is better. Generally I agree with that, but man, that shot had better be worth it. I’m not bringing a $10k lens unless I have a very, very good reason.

A rule of thumb for shooting hand-held: Hand held photography is prone to blurry images due to camera shake. This can be minimized with a faster shutter speed. The inverse of your focal length in terms of fractions of a second is a handy rule. So, if I am shooting at 200mm then I’ll get my best results starting at 1/200 of a second. There is some argument about if this works with crop-sensor cameras which have the visual effect of making the focal length look longer. I haven’t found that to be the case but I have no objection to the idea. When you’re shooting at 1/1000 sec then this is a non-issue.

Be extra aware of your surroundings. I can’t stress this enough. It’s easy to get too comfortable and then be in grave danger before you know what hit you.

  • Never turn your back to the ocean. Note the sets as they roll in. Even when you think you know what’s coming a sneaker wave will eventually come and clobber you.
  • I prefer to stick to the beach or cliffs. Cliffs are dangerous, and more so than you realize. You don’t know if you’re actually on an overhang or over a cave. Heck, I didn’t realize that one of my favorite spots was an overhang until I saw footage from a drone.
  • If you see gopher holes along the cliff then back off because that’s weakened ground.
  • Dorsal fins: this should need no explanation. Get out of the water. Again I prefer to stick to the beaches and cliffs.
  • Look around for other opportunities. Backstory often says more than the surf action does. Look for it.
surfer, sunset, Santa Cruz, California
A surfer hurries runs ahead of a dazzling sunset

Water housings: I don’t have a lot to say about this topic because it’s not my thing. Higher quality is clearly better. If you’re going this route then spend the money on higher quality gear. Dave “Nelly” Nelson, Clark Little, and more get some incredible results from being in the water.

Drones: I have mixed opinions. They get unique photos at a time when we really need something that looks different. I also believe that they are an unwelcome distraction to the athlete. Let’s just see where this goes. Bring popcorn.

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Avoid shooting right into the sun. This will result in lens flares that distract from your subject. Some people like this look. I generally don’t and consider them an error. Break this rule occasionally for fun.

Tell the story. This is essentially photojournalism. Get names if you can.

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Watch for a while before shooting. Get to know who’s going to do something interesting. Watch what he does and when. Look for the bottom turn — a key, decisive moment. He may shoot across, up, and get some air. This can be your best shot of the day, so pay attention.

surfer, Nat Young, Santa Cruz, Steamer Lane
Nat Young at Steamer Lane, Sept 2015

Lighting: Shoot when the light is good. A complete discussion on this is beyond the scope of this blog post. Just consider that light from the side and at an angle results in a better photo. Shooting at noon will have light straight down resulting in shadows that make a person look like a raccoon.

Our water is pretty cold around northern California, so our surfers are almost always wearing wetsuits. The practical upshot is that you have a dark subject (the surfer) against a midtone (the wave). The photo’s histogram can have a tendency to lack detail in the darkest darks and the lightest lights. Adding some black and pushing the whites up in post add a lot of pop the photo. Then go about recovering shadow areas on the surfer as needed via Lightroom.

surfer, photo editing, lightroom, surf photography
An unedited photo from Pleasure Point, Capitola. A dark subject against midtone waves.
histogram, lightroom
The histogram for the above image. Note the bump in the middle indicating the midtones, the edge at left for darks, and almost nothing for brights to the right. This has a rather narrow dynamic range and will need some editing to bring out details.

Planning: This is a doozie. Don’t just go to the beach and expect to shoot some surf. Plan for success.

  • Check the surf reports. I like Magic Seaweed, but will sometimes use SurfLine .
  • Check for good surf early and late in the day. The light is best at these times.
  • Check the weather reports.
  • If the weather lines up with the good surf on the report then you may be golden. One exception might be overcast skies — overcast works as a great natural diffuser so push that ISO and have fun.
  • Check for events. I like SurfingAmerica . Maybe there’s a contest going on and some rock stars will be there.
SMC_5205, Autumn Hays, Santa Cruz, Sean McLean Photography
Autumn Hays, local superstar competing at a Surfing America scholastic event. Feb, 2016

Don’t be a jerk: I usually avoid photos of surfers wiping out. My general thought is that if they don’t look good then I don’t look good. But once in a while it is really funny. Season to taste but don’t be a jerk. I also don’t reward surfers acting badly. If somebody’s mistreating somebody out there then he’s ignored. End of story.

I try to avoid taking photos of children. Kids surfing in an event is a different story, but I’m a parent and I totally get it. If I catch a creep taking weird pictures of my daughter I’d be that dude in his face making him reconsider some life choices.

What’s legal to use for print depends on local law. In most cases in California it falls under “public person”. Sometimes if I have something that will be used commercially then I ask permission and may even have a model release form handy (there are apps for this). Most people are stoked about it and happily grant permission.

Pick up some trash while you’re out. See some cigarette butts? Plastic bags & wrappers? Pick them up so they don’t end up in the ocean. Others notice, comment, and start doing the same. Treasure these places.

Break the rules: So many surf photos look so similar that it’s hard to tell the difference between them. Look for something unique. Look for something that you can call your own. It’s the most amazing feeling when somebody can flip through a set of surf photos and identify one as being yours because of how it looked.

surfing, surfer, long exposure
Break the rules by using a slow shutter speed