Light, Lines & Color

E is for Exposure Modes

When you first buy a digital SLR, there are several forces in play. You want to learn how to use this beautiful piece of equipment you just purchased but you also want pictures to look at and share immediately. The latter is known as immediate gratification and in my experience it almost always trumps the learning force. We all rationalize that learning about all the camera's buttons will come and it eventually does but a little further down the road. For now we set our cameras to Automatic, letting the camera make all of our decisions for us - happy to simply see results. My camera manual refers to the "Auto" setting as the "Point-and-Shoot setting which certainly has a place in our lives but every day? Why did you buy a DSLR if you wanted to "point-and-shoot"?

The next logical step up the bravery ladder is to use some of the automatic "Scene Modes" on the Mode Dial and these are designated by several easily understood symbols. They are still fully automatic but you can select the mode that more specifically fits your shooting circumstances. See you're already thinking about light, motion, and most importantly the results that you want. On my Nikon D90 there are five Scene modes and this is fairly typical on a DSLR you might buy at the start. They are: Portrait (for portraits what else), Landscape (for just that), Close up (for shots of flowers, bees, and other little things), Sports (for moving objects), and Night portrait (for portraits under low light). There are similar settings for Canons like those on this 30D.
For each of these modes, the camera makes assumptions about your subject matter and thus decides upon the shutter speed, aperture, and even the focus point. When I started, I was shooting a lot of surfers and running children at the beach, and I rarely moved off the sports setting - wanting to see good images as I was learning how to capture and frame these "moving objects".

Nikon D60 at 200mm on Sports Mode: 1/1000 sec at f/5.6, Auto ISO resulted in ISO 140
In Sports Mode the camera allows only AWB (Auto-White Balance) & Matrix Metering 

As a bi-product of using this automatic setting, I read the metadata on my pictures and learned what shutter speeds stopped the action, what aperture was selected by the camera in the process, and what I liked and disliked. 

Moving beyond the camera's automatic settings, semi-automatic is the next rung on the ladder and these include P, S, A, and M - Programmed automatic, Shutter speed, Aperture, and Manual (why the User's Manual rolls the latter into the semi-automatic modes is a puzzle to me).

• P - In Programmed automatic, the camera will adjust the shutter speed and aperture for the optimal exposure, but you can change one of these depending on your situation and the camera will adjust the other. 
• S - In Shutter-Priority Mode, you select the shutter speed and the camera will automatically select the aperture to produce what it assumes will be the best exposure. This is used for all manner of moving objects from planes to flowers moving in a breeze.
• A - Set to Aperture-Priority, you select the aperture to control the depth-of-field (See the post "D is for Depth of Field" here on LLC) and the camera automatically selects a shutter speed that will create an optimal exposure. This is used for landscapes but also when you want to create that Differential Focus effect we discussed in the last post.

I should also note here, that in these semi-automatic modes, you - the photographer - also determine the focus point, the white balance, the ISO, etc. It's a lot of responsibility but a heck of a lot of fun.

• M - In Manual exposure mode, you control everything - shutter speed and aperture are no longer inextricably tied to one another - they are now uncoupled and you decide the setting for each, along with all that other stuff.

The first time I used Manual mode, I felt like it was graduation day. Don't get me wrong, it was a challenge because I had to "think like the camera" and ask myself why the camera needed the setting I was providing and what effect I thought it would produce, but what a feeling of accomplishment, when I saw my images and they turned out pretty good.

Nikon D60 on Manual Exposure Mode: 30.0 seconds at f/10; ISO 200
Night photography often requires shooting in manual mode and lots of trial and error! 

Now all of the Exposure Mode settings on the dial are in my arsenal and I can choose when to use which one - but that only came from practicing and seeing the results using fully-automatic, semi-automatic, and finally the manual exposure modes. When you start, the camera is technically in charge, and by practicing and learning you take creative control. Enjoy the journey!

 

 

 

X is for Exposure

X has had me stumped for weeks now, and for that I apologize but I promised you a posting to Light, Lines & Color (LLC) for each week this year and I will. I'm only four weeks behind! Here begins my "catch-up". We learned early this year that exposure is determined by our favorite triumvirate - Aperture, Shutter Speed, and ISO - these are the basic tools we use to create the exposed image that we want. But there are lots of buttons and dials on our DSLRs and many will help us fine tune our exposures, such as the Exposure Compensation button discussed in the post on Brightness. Now here's another helpful button for getting you to the exposure you want, it's called the Metering Button. What's that you ask?

Well let's back up a little. When you've set the camera up to take a shot, it's reading the light in the scene you've composed. You can fine-tune that reading by having it read the light in a wide area of the frame (Matrix Metering), having it read the whole frame but assigning the greatest weight to the light in the center area (Center-weighted Metering), or having it meter the light on small a circle that is centered on the current focus point (Spot Metering). On most DSLRs there's a button, easily accessible while you're looking through the viewfinder, not far from the shutter-release button that will allow you to switch between these metering settings.

Here's an assignment: Find the Metering Button on your camera. Set your camera to Aperture setting f/11, with an ISO of 100, and go out to take a landscape shot on a high contrast day, meaning a sunny day when there's a lot of shadow in the frame. Now play with the different settings on the Metering Button: Matrix, Center-weighted, and Spot, and share your reults on our Google+ LLC sight . Get to know your camera and what it will do for you. 

Looking to make a silhouette shot?  I like this early morning shot of my husband on a dock on the Vineyard. He was back lit in early morning light and I didn't want the camera to try to "average" out the extremes in light, so I spot metered on him, which resulted in this semi-silhouette that I love. Play with this ... it's fun.

H is for Histogram

The word histogram strikes fear in the hearts of many a photographer - beginner and seasoned alike. It's that graph that you can see on the LCD screen on the back of your camera that looks painfully like those you saw in the statistics class that you nearly failed. I'm here to dispel the paralysis you feel just thinking about it. The histogram is your friend.

Let me over simplify an explanation so that you can begin to use it as the tool it really is. Here are 10 things to help you understand and use a histogram.

1. A histogram is a graph that shows the tones within a photograph, with dark/black being on the left and bright/white being on the right.
2. The height of any point on the graph indicates the amount of pixels at any particular level of darkness or brightness.
3. Just like in football "clipping" is bad, in this case clipped pixels.
4. When a histogram shows pixels climbing either end of the graph, they are clipped which means:
   • details in those tones are lost,
   • the appearance of the image will most likely be degraded, and
   • the photograph is incorrectly exposed
5. "Expose to the right." There is more data in bright pixels than dark ones, so a graph favoring the righthand side is a good thing.
6. Clipping or blowing out highlights (brights) is a sin in digital photography, so expose an image to the right but NOT the far right. 
7. If there's a line climbing the right hand side of the graph looking like it's heading for the stars, the highlights are blown - the data is gone. What can a photographer do?
8. Adjust the exposure in camera. Reduce the brightness in an image by stopping down - move the Exposure Compensation (+/-) in the negative direction until clipping is no longer a major issue. As you move the EV, the histogram will move left.
9. Avoid clipped shadows as well. There is less data in "dark" pixels; if you expose to the right you'll avoid ugly noise in the shadows.
10. Histograms can be really handy when you're shooting in bright light and can't see the image in the LCD screen; it enables you to reach every photographer's goal - a well exposed photograph in-camera.

 

 

E is for Exposure

Exposure - Photography is all about exposure to light and our tools to create an exposure that matches the image in our mind's eye are the triumvirate: Aperture, Shutter Speed and ISO. Let me focus first on Aperture and Shutter Speed.

I never shoot in the fully automatic setting available on my Nikon D90, rather I select Aperture or Shutter Speed depending on what I'm shooting. If I'm shooting a landscape or something static I will select aperture and then begin the thought process of how I want the image to look. If the background is messy I might want a shallow depth of field to throw the mess into a colorful blur so I'd select a low f stop number, or I may want as much of the image in focus as possible as it may all contribute to the story in the image so to maximize the depth of field I'd select a high f stop number.

Let me give a simple example of an image that is the same exposure but with differing results. For ease of demonstration, all of theses photos were taken on Aperture Priority with an ISO of 200. The only setting I changed was the Aperture; the camera adjusted the shutter speed accordingly to achieve a good exposure. Can you see the difference in the depth of field?

1/30 second at f/22 
Notice the blur of the moving palm fronds but the detail in the background. You can see the ocean especially in comparison to the last image below.

1/60 second at f/16

1/125 second at f/11

1/250 second at f/8.0

1/500 second at f/5.6
Notice the soft background resulting from the shallow depth of field created by the large aperture. You can hardly see the ocean.

"The same exposure can be achieved with different combinations of aperture and shutter speed. Fast shutter speeds and larger apertures freeze moving objects and soften background details [like the last image above], while slow shutter speeds and small apertures blur moving objects and bring out background details [like the first image above]." This is directly from my camera's manual and I can honestly say I "get it". Do you?

 

B Is For Brightness

Photography is all about light and capturing it in a manner that expresses what you, as the photographer, see and feel. To that end, we are always working with Brightness - trying to tame it, redirect it and/or extract it. Exposure to light/brightness is determined by the triumvirate described in the last post "A is for Aperture" - Aperture, Shutter Speed and ISO. Trust me there will be more on that later - "E" is not so far away.

Every year around the holidays, the village of Montauk, on the far east-end of Long Island, NY, decorates its historic lighthouse beautifully and it stands out incredibly against a dark late-day sky. On a recent shoot at Montauk Light, it was brutally cold as the sun was setting and as much as I wanted to stay to capture the lighthouse at its stand-out best, it was just too painful. When I took my first shots, I could see that they were just too bright and I knew I wouldn't last to shoot later, so I decided to adjust the brightness of my images by adjusting the Exposure Compensation - the EV (Exposure Value). 

Exp: ½ second @ f/11with 0 EV shot at 5:42:14 p.m.

Exp: ¼ second @ f/11 with -1 EV shot at 5:42:28 p.m.

Exp: ¹⁄₆ second @ f/11 with -2 EV shot at 5:44:21 p.m.

Exp: ¹⁄₆ second @ f/11 with -2⅔ EV shot at 5:48:29 p.m.

All of these images were shot with an ISO (sensor sensitivity) of 200 which I chose because it's fairly low and I wanted to avoid "noise" in the images at nearly any cost. As the shot was a landscape of sorts, I shot on Aperture Priority and I chose f/11 as it's a "middle-of-the road" aperture which would give me an "average" depth of field. f/22 wasn't needed for extra depth of field in these images and would have forced me to shoot with longer shutter speeds which most likely would have caused blur given the gale force winds; and, a larger aperture like f/5.6 would have exposed the image to less sharp focus throughout the image from the sign in the front to the lighthouse in the rear, so f/11 seemed the right choice to me at the time. As I took each picture and looked at it in the monitor, I began to reduce the brightness by "stopping down" the EV taking it from 0 EV to minus 2⅔ EV.

Now I have a question for anyone who might be listening and interested in participating in this new forum. If "a one-stop change in aperture will change the shutter speed also by one stop", should the same be true for Exposure Compensation? In Aperture Priority with a fixed aperture of f/11, between the third and fourth pictures I stopped the EV down ⅔ of a stop and yet the shutter speed didn't change from ¹⁄₆ second. Any idea why? The images were taken 4 minutes apart, could it be attributable to increased darkness, or could it possibly be attributable to the extreme cold? Weigh in here, we all want to learn.

At the end of the day, I was disappointed that the weather chased us away before we were able to get the shots we wanted, but these are a fair representation of what the Lighthouse looked like on that blustery winter's afternoon. Now the question is, which is your favorite?