Depth of field is affected by image size.

As an image gets larger, out of focus areas become more apparent.

Depth of field is a cardinal concept in photography.  The main aspects of controlling depth of field include focal length, aperture, and point of focus.  An often overlooked aspect relates to the size that the image is to be viewed at. 

Consider this scenario.  You are photographing something and check the image on your rear LCD display to make sure it looks good.  Yes, everything seems great, including the focus.  All the stuff you wanted to be in focus seems to be.  You take the image home and view your creation on the computer.  The now much larger image wasn't what you expected.  There are blurry areas before and after the subject.  Zoom in a bit and it gets even worse!  How could you have missed that?

It happened because depth of field is based on a number of criteria, including size of the final image.  As the photograph gets larger areas that originally appeared in focus become progressively more blurry.  This seems like an enormous problem, but only counts based on another factor; proximity of viewer.

Have a look at the images above.  The top one seems fine with everything nicely in focus.  It would have looked fine on the camera's LCD screen.  As you view following enlargements it becomes apparent that the focus wasn't quite what it could have been.  However, an important consideration has been overlooked. 

Move further away from your viewing surface, whether it is laptop, desktop monitor, cellphone, or tablet.  As you get farther away the enlarged components of the photo see less blurry than they were.  This is why you can enlarge a photo to fit a highway billboard sign and it seem all in focus.  Chances are that, as you get closer to it, parts of it may start to look a little fuzzy.

Enlargement size and viewing distance go hand in hand.  It turns out the real factor affecting whether something is in focus or not is based upon the image falling upon your retina.  By managing the amount of enlargement, including cropping, and the viewing distance, you can alter depth of field to some extent.  It is not the main method of course, but it is something to consider.

Thanks for reading.   www.ericspix.com

Reflection on a pond, compensating in manual exposure mode.

Reflection of the shoreline on a pond; exposure was way off.

Although I am a big fan of aperture priority exposure mode (the "A" selection in the PSAM group) for many of the situations I find myself in, my second most common choice is manual.  In this mode the camera reads light coming into the camera and compares it to the current exposure and ISO settings.  If everything is bang-on, the meter will show that a "correct exposure" is possible in the viewfinder and/or on other camera mounted LCD displays. 

The reason "correct exposure" is in quotation marks is because the camera may just be mistaken.  In the situation above, my first image proved to be an overexposure.  It turns out there are a lot of dark areas in the scene.  The camera's meter read the situation as there wasn't too much light available and so suggested a longer shutter speed.  The resulting image was clearly off by quite a bit.  My solution was to change the shutter speed by letting less light in than what the camera suggested.

In an automatic mode this is done by using either exposure compensation or exposure lock.  In manual mode the command dial controlling shutter speed is rotated.  Alternatively, you can also change the aperture value, the ISO, or a combination of all three.  For the most part though I opt to change shutter speed as I want depth of field to remained unchanged.  With vibration control technology being so common and good, this often is not an issue.  In this case it was even less so, because I actually had to increase the shutter speed to let less light in.

I decreased the light by 4/3 of a stop (1.3 stops for those with a fraction phobia) and shot again.  The result was much better, rendering the dark areas dark and the bright areas properly exposed.  The nice thing about shooting in manual exposure mode is that, once you have figured out the correct settings, you can continue to use them if the light remains the same.  Areas of shadow and backlighting may occur, but I find previously used manual exposure settings will often be correct.

I used a polarizer in this situation as well which helped remove unwanted glare from the water and deepened the already very blue sky.  The shutter speed was 1/50th of a second at an ISO of 200 and an aperture of f/7.1.  I used a 28 mm focal length on a full-frame camera.

Thanks for reading.   www.ericspix.com

The Railway Trail, Hayward Lake, near Mission, BC.

The piles making up an old trestle along Hayward Lake.

We owe much to our forefathers, the pioneers of old, that built our country one mile at a time.  Many of the routes they constructed were the life-blood of civilization.  These byways still exist, although  they would not be recognized today by those original travelers that meandered along them.  Simple farm trails have become major thoroughfares, used by thousands of commuters each day.  Other paths have been abandoned and fallen into disuse and disrepair.

A common history has befallen many a rail line.  The reasons for them being forsaken varies.  Shorter routes, exhausted resources, better grades, or simple economics all have spelled their doom.  Fortunately, many of these have been revitalized.  No longer facilitating the passage of giant iron beasts, these woodland lines now allow the easy flow of people searching for a quiet path to free their thoughts. 

The Railway Trail (click here), as the south path around Hayward Lake is called, boasts stunning views of the lake with the remains of trestles periodically dotting the trek.  I was out on this path Sunday afternoon with a friend.  The walk was peaceful and easy; one of the benefits of using a railbed as a pathway.  Modest elevation changes exist along its length, especially if you start out at the south end.  We hiked the northern part from the park to a point midway to the other end.  We saw other hikers, many walking their dogs, who seemed to appreciate the trail as much as we did.

Thanks to my friend, Bert, who phoned me up and asked if I wanted to go for a walk.  I did, and I thoroughly enjoyed it.

Thanks for reading.   www.ericspix.com

Moraine Lake, Banff.

Moraine Lake in the morning.

One of the most remarkable sites I have had the pleasure to see is Moraine Lake in Banff National Park.  Its pristine turquoise waters contrast against the grey limestone peaks in the background with talus slopes testifying to the age of the vista.  On a clear day, the azure sky adds to the scenescape producing a true national treasure.

The moment I was there, photographing in awe all that was before me, did not prognosticate what my daughter would later do with the image.  The shot above, and another like it, is being used by her in a quest to find subjects to paint. 

After taking art classes for many a year, she found herself in a conflict of sorts.  The problem lay with where she was getting the material from.  Books, works of art, and other people's images were the inspiration for what she put upon canvas.  It was all copyrighted; protected from being duplicated without permission or recompense.  After some discussion with her family, she decided to use the images I had created over time.  She would peruse through many hundreds of images cached in my hard drives and find one which suited her creative desire.

Her current project is to paint the above photograph, on an especially large canvas.  She wants to use it to cover the television which will eventually be mounted on the wall in her newly fabricated suite.  I don't always get to see my photos used, and it nice to see that something wonderful will come of a joint project between my daughter and I.  It makes the majesty of the scene all the more poignant.

Thanks for reading.   www.ericspix.com

St. Kitts: There's no place like home.

A shanty located in St. Kitts.

It is easy to look at this and feel bad for the inhabitants; they don't have any of the basics which we take for granted.  No power, no running water, and a home that is more hovel than hotel.  How is it that they could live in such poverty?  It must be terrible for them.  Or is it?

The truth is dependent upon what you are used to.  Most of us North Americans would be uncomfortable here.  Our "quality of living" standards would take an enormous hit, and it wouldn't be long before we were in a desperate state.  There are many in the world, however, that would look upon this as an upgrade.  Its got a roof, a beautiful view, and it is dry.

There are some things going on here though which need a closer look.  Notice that there is no garbage, debris, or other wastes hanging about.  The area is relatively free of weeds.  It is built on a bit of a knoll so that the substrate is dry.  Even though the structure is built out of salvaged bits and pieces, they are assembled in a way that makes them relatively solid and keeps the elements out.  There is a safe place for kids to play.  In short, the occupants take pride in their dwelling.

The reality is that we don't need much to survive.  Shelter, food and water, and a way to deal with wastes fit the bill.  The question becomes less about what you have and more about how well you care for it and the people who live there.  If there is one standard we were to look at, it should not be where you live, the size of your house or the kinds of cars you own.  It should be how well you look after the things in your care.  That is the measure of success, and the only real way to make a place your home.

Othello Tunnels - different exposure methods.

A nested series of the Othello Tunnels.

If you happen to be spending time around Hope, BC, you may want to consider checking out the Othello Tunnels.  Once a railway line, the defunct route has been converted to a pedestrian and bike trail.  The tunnels themselves are impressive but not too long; walking through any one of them takes only a short period of time.

I photographed the above shot using manual exposure mode on my camera, although an automatic mode with exposure lock would have worked equally well.  In order to get the correct settings, I established my aperture and shutter speed outside under full outdoor light.  It was important not to trust the camera's meter inside the tunnel as the dark edges may have caused the central image to be overexposed.  By metering outside and using those settings inside I ensured a correct exposure.  The inside of the tunnel would be black, but that in itself is great for framing purposes.

If I had been using an automatic setting I would have selected a scene without any backlighting or other lighting issue and then pressed the AE-L button on my camera (Canon cameras use the button marked with an asterisk (*)).  Then, going into the cavern, I would frame the shot and take the photo.  The disadvantage of using exposure lock is that, once you take your photo, the camera resets to its default settings and you have to repeat the process if you want to take another. 

There is a way to do this without moving, but it requires a little more effort.  You have to zoom your camera in to frame the outside area without the dark perimeter.  Move the camera about until you get the exposure you want and press the exposure lock button.  Zoom out to your desired focal length, reframe and shoot.  I have used this procedure when I cannot effectively use manual mode and can't get out into the zone where the exposure will be based.  It is not my first choice, but it works in a pinch.

For those of you who want to use an automatic mode but not lock the settings, you can always try bracketing.  This would involve either exposure compensation (+/- button) or turn on the automatic bracketing feature.  Three photos at 0, -1, and -2 would probably suffice.  You want to underexpose from the suggested setting as the dark values would cause the camera to let in more light than what is actually required.

Thanks for reading.   www.ericspix.com

A fumarole in Rotorua.

A large singular fumarole located near Rotorua, New Zealand.

Fumarole; that's a new one.  What is it, and what does the photo of a large mud puddle have to do with anything?  A fumarole is a vent that allows hot gases to escape from underground volcanic activity.  The mud pit above is an example of one, although there is less gas and more liquid. 

Beneath the surface of the earth we walk on, many miles below us, temperatures and pressures increase to incredible values.  Water, which finds its way down through percolation and cracks in the rock, becomes superheated.  Water turns into steam and expands; the hot gases then rise.  In some situations, the water itself may well up to produce hot springs or bubbling mud pits. 

The barren land around the fumarole is a testament to the heat and noxious gases associated with this geothermal activity.  Although there is plenty of water, light, and nutrients, plants cannot tolerate the conditions nearby.  Certain species have adapted to the conditions though and thrive; tea trees are one of them.

Often when photographing such scenes I have the sky represent only a small portion of the scene, often representing part of the upper third in the photo.  I used a polarizer filter when creating this shot, and the clouds responded nicely with the sky deepened to a deep azure blue.  The contrast between cloud and sky complimented the stark landscape.  The polarizer also removed the strong blue hues associated with such a day and rendered the colours of the land in their natural tones.

This is all part of the reason I enjoy traveling; seeing new sights and being able to photograph them while enjoying the awe of the moment.  There is so much more to do and see! 

Thanks for reading.   www.ericspix.com