Archive for the ‘Photography’ Category

The Exposure Triangle

Posted: September 21, 2010 in Photography

As I stated in my post “Understanding White Balance”, photography is all about light. Each of the three aspects of the triangle relate to light and how it enters and interacts with the camera. The 3 aspects of the triangle are;

ISO – the measure of a digital camera sensor’s sensitivity to light.

Aperture – the size of the opening in the lens when a picture is taken.

Shutter Speed – the amount of time the shutter is open.

It is at the intersection of these 3 elements that an image’s exposure is worked out. Most importantly, a change in one of the elements will impact the others. In other words, you can never really isolate one without affecting the others.

ISO

ISO is measured in numbers (100, 200, 400, 800, 1600, etc.).  My Nikon goes 200, 400, 800,1600, and HI1. HI1 is actually 3200, and no, I have no idea why they didn’t just call it 3200. The lower the number the less sensitive your camera is to light and the finer the grain. Higher ISO numbers are usually used in darker situations to get faster shutter speeds. One thing to keep in mind with higher ISO is it creates ‘digital noise’.  Instead of having a flat black, it is now more of a dark grey with specs, or pixels, of assorted other colors.

100 ISO is accepted as ‘normal’ and will give you tack sharp pictures in situations where the lighting is good.

When you do override your camera and choose a specific ISO you’ll notice that it impacts the aperture and shutter speed needed for a well exposed shot. For example – if you bumped your ISO up from 100 to 400 you’ll notice that you can shoot at higher shutter speeds and/or smaller apertures.
When selecting the proper ISO setting, ask yourself these 4 questions;
  1. Is the subject well lit?
  2. Do I want a grainy shot or one without noise?
  3. Am I using a tripod?
  4. Is the subject moving or stationary?

If there is plenty of light, I want little grain, I’m using a tripod and my subject is stationary I will generally use a pretty low ISO rating.

However if it’s dark, I purposely want grain, I don’t have a tripod and/or my subject is moving I might consider increasing the ISO as it will enable me to shoot with a faster shutter speed and still expose the shot well.

Of course the trade off of this increase in ISO will be noisier shots.

Situations where you might need to push ISO to higher settings include:

  • Indoor Sports Events – where your subject is moving fast yet you may have limited light available.
  • Concerts – also low in light and often ‘no-flash’ zones
  • Art Galleries, Churches etc- many galleries have rules against using a flash and of course being indoors are not well lit.
  • Birthday Parties – blowing out the candles in a dark room can give you a nice moody shot which would be ruined by a bright flash. Increasing the ISO can help capture the scene.
Here are some shots I took using different ISO settings. First set of 5 is from outdoors, full sunlight.
Indoor shots with no lights on.
Notice the noise in the last shot, especially on the red wall. Click images for full size.
Aperture
Aperture refers to the amount of light that falls onto the sensor.
Just like successive shutter speeds, successive apertures halve the amount of incoming light.  To do this, the diaphragm reduces the aperture diameter by a factor of 1.4 so that the aperture surface is halved each successive step.
Apertures are listed in terms of f-numbers (expresses the diameter of the entrance pupil in terms of the effective focal length of the lens; It is the quantitative measure of lens speed), which are marked on the lens.  On a camera, the f-number is usually adjusted in f-stops.
Each “stop” is marked with its corresponding f-number, and represents a halving of the light intensity from the previous stop. Modern electronically-controlled interchangeable lenses, such as those from Canon and Sigma for SLR cameras, have f-stops specified internally in 1/8-stop increments, so the cameras’ 1/3-stop settings are approximated by the nearest 1/8-stop setting in the lens. The F number can be displayed as 1:X instead of f/X
Lenses with larger apertures are faster because, for a given ISO speed, the shutter speed can be made faster for the same exposure. A smaller aperture means that objects can be in focus over a wider range of distance (depth of field).
Portrait and indoor (sports and theater also) photography often requires lenses with large maximum apertures in order to be capable of faster shutter speeds (and narrower depth of fields) in order to combat the low light problems with no camera shake.
The narrow depth of field in a portrait, as well as in macro photography, helps isolate the subject from the background.
Here are some examples of adjusting the aperture for different effects.
Large depth of field
Aperture – f22
Shutter Speed – 1/60 sec
ISO – 400
Focal length – 34mm
Focus – AUTO
Shallow depth of field (focus on subject in front)
Aperture –  f5.3
Shutter Speed – 1/60 sec
ISO – 800
Focal length – 42mm
Focus – Auto
Shallow depth of field (focus on subject in back)
Aperture – f4.0
Shutter Speed – 1/60 sec
ISO – 400
Focal length – 24mm
Focus – Manual
Shutter Speed
Shutter speed is simply the shutter time.   Normally your sensor  sits around in the dark waiting for a bit of action. It is the shutter – like the blinds or curtains which shut light out of your room – which keep the sensor in the dark. When the shutter opens, it lets in light and the sensor gets to work.Exposure time, then, is the time interval or duration during which your camera’s sensor  is collecting light to capture your image.

Shutter speed is measured in seconds – or in most cases fractions of seconds. The bigger the denominator the faster the speed (ie 1/1000 is much faster than 1/30).
In most cases you’ll probably be using shutter speeds of 1/60th of a second or faster. This is because anything slower than this is very difficult to use without getting camera shake. Camera shake is when your camera is moving while the shutter is open and results in blur in your photos.
If you’re using a slow shutter speed (anything slower than 1/60) you will need to either use a tripod or some some type of image stabilization (more and more cameras are coming with this built in).

Shutter speeds available to you on your camera will usually double (approximately) with each setting. As a result you’ll usually have the options for the following shutter speeds – 1/500, 1/250, 1/125, 1/60, 1/30, 1/15, 1/8 etc. This ‘doubling’ is handy to keep in mind as aperture settings also double the amount of light that is let in – as a result increasing shutter speed by one stop and decreasing aperture by one stop should give you similar exposure levels (but we’ll talk more about this in a future post).

Some cameras also give you the option for very slow shutter speeds that are not fractions of seconds but are measured in seconds (for example 1 second, 10 seconds, 30 seconds etc). These are used in very low light situations, when you’re going after special effects and/or when you’re trying to capture a lot of movement in a shot). Some cameras also give you the option to shoot in ‘B’ (or ‘Bulb’) mode. Bulb mode lets you keep the shutter open for as long as you hold it down.

When considering what shutter speed to use in an image you should always ask yourself whether anything in your scene is moving and how you’d like to capture that movement. If there is movement in your scene you have the choice of either freezing the movement (so it looks still) or letting the moving object intentionally blur (giving it a sense of movement).

To freeze movement in an image you’ll want to choose a faster shutter speed and to let the movement blur you’ll want to choose a slower shutter speed. The actual speeds you should choose will vary depending upon the speed of the subject in your shot and how much you want it to be blurred.
Focal Length and Shutter Speed – another thing to consider when choosing shutter speed is the focal length of the lens you’re using. Longer focal lengths will accentuate the amount of camera shake you have and so you’ll need to choose a faster shutter speed (unless you have image stabilization in your lens or camera). The ‘rule’ of thumb to use with focal length in non image stabilized situations) is to choose a shutter speed with a denominator that is larger than the focal length of the lens. For example if you have a lens that is 50mm 1/60th is probably ok but if you have a 200mm lens you’ll probably want to shoot at around 1/250.

Here are some shots I took of a ceiling fan using different shutter speeds.

Aperture – f4.5  (yes, the fan is on!)
Shutter Speed – 1/10 sec
ISO – 400
Focal length – 32mm
Focus – Auto
No tripod
Aperture – f2.5
Shutter Speed – 30 sec
ISO – 400
Focal length – 28mm
Focus – Auto
Tripod
Here is the same shot with the same settings, but without using a tripod.
So, there you have it. Pretty much the basics of how to take a great shot. Use this information and practice, practice, practice. Get out your camera manual and see how to change these settings, then start shooting.  If you understand these concepts, you should be shooting ‘gallery ready’ shots in no time.  It is not the camera that takes the great shots, it is the photographer.
Leave a comment, or send me an e-mail if you have questions. Good luck, and enjoy!


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Understanding White Balance

Posted: September 19, 2010 in Photography

Photography is all about light. One of the major characteristics of light we depend on in photography is how color is communicated. The human brain is able to detect and compensate for different lighting temperatures. As a result, a white object will look white to the eye, no matter if it is viewed under sunlight, cloudy diffused light, incandescent or fluorescent light.

Every time a digital camera takes a picture, it needs to establish the white point as the basis from which the percentage of each color is derived. Because this is affected by the quality of light in a scene, most cameras offer adjustable white balance settings.

In auto mode, complex algorithms in the camera decide where the white point is. This is usually fairly accurate, though under cloudy conditions it may cause the image to be slightly blue. Incandescent or tungsten setting should be used for pictures indoors without flash. This will adjust the white balance when the subject is lit by light bulbs, such as those in a home.

Use the fluorescent mode when the scene is lit by tube lighting.  As there are several types of fluorescent lighting (cool white or warm white), you may find more than one fluorescent adjustment.

Many digital cameras also offer a manual setting in which the user has to decide what the exact white point is. A rectangular piece of white card can serve as a good reference and you can adjust white balancing by using this. Just point the camera at the white card, filling the frame in the viewfinder, and take a picture.

Below are pictures I took outside on a sunny afternoon. The camera was in ‘Program’ mode, ISO was at 200, manual focus. I used the 7 different white balance modes to show the difference between all modes.

1st Row –  Auto White Balance, Cloudy

2nd Row – Direct Sunlight, Flash

3rd Row – Flourescent, Incandescent

4th Row – Shade

Here are some pictures from indoors. Once again, shot in ‘Program’ mode, ISO was 400, and manual focus.

1st Row – Auto White Balance, Cloudy, Direct Sunlight, Flash

2nd Row – Flourescent, Incandescent, Shade

Mystery Solved

Posted: September 13, 2010 in Photography

First day of class down, and I learned something today that I have always wondered. What does that ‘mm’ on a camera lens actually measure? For example, what does 18-55mm actually mean.

When parallel rays of light strike a lens focused at infinity, they converge to a point called the focal point. The focal length of the lens is then defined as the distance from the middle of the lens to its focal point, and that is measured in millimeters. The ‘f/’ number, or ‘f stop’ is a measure of aperture, or light. Aperture is expressed as F-stop, e.g. F2.8 or f/2.8. The smaller the F-stop number (or f/value), the larger the lens opening (aperture). We will get into that and shutter speed next week. Can’t wait!

All in all, a good start. Most of today’s class was basic camera knowledge, which I have a pretty good understanding of. Camera care, storage, memory cards, different types of software, white balance, compression (jpeg and RAW), etc. Good class and good teacher. Looking forward to next week!

Back to School

Posted: September 13, 2010 in Photography

Today is day 1 of school for me, Digital 101. Seems pretty basic stuff, but hoping I can learn some new stuff that I thought I knew. Looks like digital 102 and 103 is where I should be starting after reading the coursework, but I’ll be happy with these baby steps first.  I will share some of the stuff I have learned with others. We will be taking field trips and doing some shooting, so I will post images and hopefully as the class progresses, my shot taking capability improves. Folks are free to critique the images I post. That way I can learn what I am doing wrong, and others will also learn.

I can’t remember the last time I was so eager to start school!

WOW!!!!! That is what I have to say about that! When I bought my 2007 Nissan 350Z 3 years ago, I was told I have to take it on ‘The Dragon’. I finally did, and it was AWESOME! That car handles like a dream.

For those not familiar with ‘The Dragon‘, it is 318 curves in 11 miles located in the mountains of western North Carolina, Robbinsville to be exact. They say it is the #1 road for motorcyles in the US. I saw quite a few sports cars, but mostly motorcycles. If you have a bike or a car with great suspension, I HIGHLY recommend adding this to your bucket list.

I will post some pics after I have them all downloaded. I took 500 pictures this weekend, so it will be a while.

On the way home, we drove what the locals refer to as ‘The Wayah‘.  It was as good as riding the Dragon. Steep climbs, switchback turns, steep descents, flat straightaways. It was scenic for the passenger as you travel along the banks of the Nantahalla River. This route takes you into Franklin, NC, then followed signs to Highlands, NC. The ride to Highlands was also a twisting mountain ride as we made our way to ‘Bridal Falls’. From there, we followed signs to Clayton, GA. Coming down from Highlands was a steep 10% grade down the mountain with a few tight turns, but mostly downhill into Dillard, GA. Then it was back to normal driving conditions.

What a great trip it was.  After riding 3 days in the mountains on those roads, it is going to suck driving in the Atlanta traffic.

Time To Get Serious

Posted: August 31, 2010 in Photography, Uncategorized

Well, it has been a very humbling experience. My shots that are considered to be keepers is getting smaller and smaller. Maybe I am being to critical? Would the client maybe like some of these shots I am throwing away? I keep looking at Terrilyn’s site (http://orpheusandaphrodite.com), and I am trying to measure up to the quality of her shots, and I just don’t. It is time to get better.

I signed up for classes this morning at a local photography school (Showcase School of Photography). I start Digital 101 on Monday, Sept. 13th.  I have never had any training in photography, except for what I have read in books, magazines, and on line. I have a lot of questions, and I need to be in a classroom environment so I can get answers. I am excited to get this started so I can start producing the shots that my mind has already developed. I would also like to take part in discussions and answer questions instead of always asking questions.  I will post pictures here as I progress through the class. Hopefully my skills will improve. As always, comments will be welcome and appreciated.

Oh, by the way. I had a picture spinning around in my mind a few weeks ago, so I decided to do it. I took a picture of my car in a parking lot at night, and then removed it from the original background and created a wall in Photoshop, then added the skyline of Atlanta to it. Here it is;

Looking forward to ‘hump day’.

First Wedding – Post Thoughts

Posted: August 30, 2010 in Photography

Well, Saturday (08/28/10) was my first wedding shoot, and it was a real eye opener. I never knew there was that much work involved with shooting a wedding.  From the moment I got out of my car, it was go, go, go, go. Next time,  I get there a little earlier and find the wedding planner and see their schedule.  Luckily, Terrilyn is a pro, and she handled it flawlessly! I just followed her wherever she went. Which brings up another thing I never thought about – positioning.

She is the 1st shooter, so she set up the scene, I just followed along and got the pictures from a different angle. The problem with that is, the shots that I thought would be a great angle would put me in her line of fire.  Nothing worse then her getting a perfect shot with me in the background. I had to be aware AT ALL TIMES of where she was at. I had to keep in mind to look out for her, as she is probably not looking out for me.  I also had to be aware of my flash interfering with her shot.  Also, all my shots of the wedding party, they were looking at her, not me, so my shots have everyone looking away. At first I thought this would be kind of cool, but when I got home and started looking at the images, they all seemed to be the same, nothing stood out as a ‘great’ shot.

Weddings are ‘fluid’, or in constant motion. You do not get a 2nd chance for a shot. As a landscape photographer, I always try to picture in my mind what I want the ‘scene’ to look like, position myself for that shot, then take several shots and choose the one I like. In a wedding, you can’t stop the motion, position yourself, take several shots, and pick out the one you like. I spent a good part of my day on Friday imagining what that perfect shot would be without knowing what the ‘lay of the land’ looked like. I knew I would not be the one to get the picture at the alter, so I was relaxed knowing that I could just freelance and be creative. Terrilyn and I talked a little about composition, but you really don’t have time to discuss your game plan when the game is already in the 2nd quarter. For instance, about 10 minutes before the ceremony was to begin, Terrilyn said that she would like for me to get a shot of the bride and her father walking down the aisle from behind. To set it up, there was a little walking bridge about 30 yards back from the aisle. They would walk out of the house and stand at this bridge, kind of like a staging area if you would. They would wait for the wedding planner to signal them to start walking, and away they went. They were about 20 feet from the bridge, so I set up for that shot, and when I looked through my viewfinder, their was Terrilyn on the other side of the bridge ready to get a shot from the front. I couldn’t go to the right as there were bushes, and if I go left, I am looking into the sun. Time to think real fast. Run into the bushes or look into the sun. I took the ‘into the sun’ route, and kept the sun to the right of my viewfinder so as not to get an overexposed image, but this also meant I couldn’t square them up in the frame. I am absolutely obsessed with centering my subject in a shot. Once I got home to look at the pic, I figured I could do some cropping to make it appear that they are centered, but that is when I noticed that one of the folks from the wedding party was dead center in my shot taking a picture.  I don’t know what Terrilyn’s picture looked like, but I can guarantee you that I am not in her picture, and it came out a lot better then mine.

Once the wedding started, I finally got a chance to collect my thought on what had happened in the previous 2 hours, and started to pre-plan for the reception.  I kind of started thinking about the route the bride and groom would take as they are leaving and started mapping out a strategy of where to position myself.  I thought they would come back across that bridge, so I thought now would be a good time to set up with my back to the sun and get a shot of them coming at me. I took a few shots of the bridge and viewed it on my 2″ viewfinder to make sure of the lighting. As the wedding ended, they were coming right at me, but as I got ready to shoot, there was Terrilyn and they stray photographer in my viewfinder. I moved out of her line of fire, keeping the sun at my back, but I couldn’t get the other guy out of my site. I kept moving, and by the time I had a perfect line of sight, the moment was gone as the bride and groom had already moved past the point where I got them from the front. I did get 2 shots as they stopped on the bridge, but the flower on the grooms lapel was hiding her face. It is not like it was a huge flower, but from the angle I was at, it looked like it was swallowing her face. Lesson learned is as the 2nd shooter, you can’t pre-plan a shot. Chances are the primary shooter is already 2 steps ahead of you.

By the time I got into the reception hall, it was already crowded, and I couldn’t move around inside very well. Not to mention the lighting inside wreaked havoc on my pictures. I couldn’t get the correct white balance to save my life. My shots were either over-exposed, blurry, under-exposed, or a combination of all three. I also got pinned against a wall and couldn’t get out.  By the time the bride and groom came in, I was 3 deep against a wall with no way to get around them.

All in all, it was a great learning experience. My next shoot I will go in prepared.  Also, wera comfortable shoes! I was on my feet for 5 hours, and my feet were killing me!

Post-Production

I downloaded my pics as soon as I got home with the memories of that night fresh in my head. I had a few pictures in my mind that I wanted to look at in particular because I thought they had potential. Big difference between a 2″ viewfinder on my camera and my 30″  desktop monitor. Of the 400-500 pictures I took, about 60 were decent shots. But once I blew those 60 shots up on my monitor, maybe 20 were good and crisp. I don’t know what the percentage is for most photographers, but less then 10% isn’t what I would consider a good job. I will admit, it was a little de-moralizing.  When I am out shooting, I would say that I usually keep about 50-60% of my pics. The creative shots, or what I would call ‘Landscape’ shots that I took came out good, and I can turn around a good image with some work in Lightroom and Photoshop. The majority of the shots that I took of the wedding party came out crisp, but they are not looking at me and that kind of takes away the ‘wow’ factor some.

Lessons Learned

I need a better camera then the one I have (I have a Nikon d40), I need some better glass, and I need to take classes in lighting and portrait photography.

Before the first picture is taken, walk around the property of where the shoot is to happen. Maybe go a day before the event and get some ideas of where you want to get your shots from. It is difficult, if not impossible, to do this during the event.  One location maybe looks great at 4:00 PM, but it looks totally different at 7:00 PM.

If the reception is held in-doors, stake out your ground well before people start flooding in. They are hot, tired, and hungry, and they will fill up the room fast. Get to your spot, and try your best not to move. Make sure that spot is close to where the action will be. Get shots of the cake, tables,  guest book, etc. before. If you are the 2nd shooter, you can get these shots during the ceremony when everyone is outside.

I have a lot to learn, but I knew that going in. Time to sign up for some more classes, learn more, and keep practicing.