Monday, December 31, 2018

Dogs with adamantium skeletons

Notice the "adamantium" nails on Rookie's feet (lower right) - a born digger.
Think "Wolverine meets Pluto" and merges into one beast; a dog with an adamantium skeleton and claws which are harder than rock, resist wear, and are sharper than any razor blade.  Well, I can tell you it won't be sitting on my lap for starters.  Of course, when it wanted a cookie treat, you can bet it wouldn't have to do a string of tricks like "sit" and "roll over" first.  And to make its own bed, it wouldn't have to run in circles twenty or thirty times to make it comfy; it would simple paw a couple of times on a couch and voila; instant shredded mattress.  Meals would be taken when desired; in fact meals would be whatever it desired.  Who needs a can opener?  Tins would melt on demand and boxes would be a mere formality.  Then there are trees; do you think a dog as such would be thwarted by wood, made out of soft fibrous cells?  Regular claws might fail it but the adamantium ones would work like crampons on an ice climber's boots.  Cats all over the world would pay homage to their canine foes and take up duties such as facilitating exercise, making even more cat videos, or playing a dog's favourite music on piano.
What we should be really impressed at though is the capacity for work.  We call dogs "man's best friend" for a reason; they are loyal to a fault and have served us in phenomenal ways.  Traditional roles played by our furry friends would be enhanced.  Blind users wouldn't have to worry about traffic any more; the dog could cut through traffic easily.  In fact, it could cut through cars, bikes, trucks, trains, - whatever got in the way.  And the whole time it would wag it's tail and the "master" would just follow along as it left carnage in its wake.
Another example of enhanced doggy duties include drug and explosive detection.  These adamantium assisted hounds would still have their acute sniffing abilities, only now when it found something it would just tear through whatever was about.  I can just imagine the conversations between border guards and those crossing.  "Sorry about your motor home, sir, but you really shouldn't have had illegal substances stored in it.  Please pick up the pieces first before we arrest you."
Then there are all the new things these beasts could do; jobs we never thought up for them before.  Mining could be a whole new industry.  Sniff, sniff, sniff.  OK, that's what gold smells like.  Next thing you know a dog sized hole is burrowed into a cliff face straight to a seam.  Imagine jobs with lumber or pulp; tree climbing was just for starters.  A dog could shred any tree into powder which could then be turned into paper of whatever variety.  Want big pieces; get a doberman to do it.  Little ones; bring the shiatsu in.  The same is true for recycling, making gravel, and so on.  
Thankfully our adamantium assisted assets would become even more helpful to its owner.  Man and beast working together to make a better world.  OK, cats would take back stage, but what if they developed the ability to make people do what they wanted?  Oh wait, they already do.

Sunday, December 30, 2018

Depth of field in the field

Point of focus and depth of field choices will change how you look at an image.
Take a minute to examine the three above photos.  They were all shot from the same position with the same amount of available light.  In each one though there is something different.  In the first one (far left) you can see that the pillars are in focus but the church windows are not.  The middle one is reversed with the pillars being out of focus and the church being in focus.  The last one (far right) has both in focus at the same time.  There was no photoshop magic going on here; it all has to do with how the camera is set up.
There are three different parameters which were altered to create the different images.  The first involves aperture setting; that's the "iris and pupil" of the camera lens.  Once it is set the second parameter, shutter speed, falls into place.  In the case of the first two images that is f/5 at 1/200th of a second (ISO was constant in all three being set at 100).  The third image used an aperture of f/14 at 1/20th of a second.
Both the aperture and shutter speed (including ISO, but don't worry about that now) are responsible for the exposure component of the shot.  The f/5 aperture setting lets in a lot of light but also gives very little depth of field.  Since the aperture is open so wide, the shutter speed has to be faster to give the correct exposure.  The f/14 aperture is much smaller, letting in much less light; at the same time though it gives more depth of focus to the photo.  Since there is so much less light a longer shutter speed is needed to provide the same exposure, which is why the last shot has a shutter speed of 1/20th of a second.
The third parameter is point of focus.  Since the first two shots use low apertures causing little depth of field, the lens is focused on the pillars (first) or the church (second) causing the other components of the shot to be blurry.  It is interesting how focus will help draw your eye; the way you look at an image is partly based on what is in focus.  In the third photo the point of focus is about a third of the way to the church from the pillars.  Greater depth of field means there is more in focus in the shot; in this case it is just barely enough to allow both parts of the scene to be in focus.
Playing with aperture, shutter speed, and point of focus will allow you to develop an understanding of how these things work.  As you play with them more and more you will get better at it.  The basis of this is one of the cornerstones of photography.

Thursday, December 27, 2018

Perspective on a church

Perspective change from varying focal length and position
One of the great things I love about traveling is the opportunity to go to new places and see things I have not previously had the opportunity to enjoy.  The word "travel" is a very broad term and means many things to many different people.  It could be taken in the simplest of concepts through just leaving your house or it could encompass global relocations by car, plane, train, bike, or even foot (and any combination thereof).  There is one thing I have learned though, and that is your photographs tend to improve as you broaden your whereabouts. 
In photography, the term perspective has a specific connotation.  It refers to how the camera sees the world in front of it.  Although our eyes are built to see things in one specific way, the camera lens has the ability to change its focal length, thus altering perspective.  Focal lengths (the millimeter value that you alter on the lens to go from wide angle to telephoto) affect perspective.  A wide angle lens allows you to perceive a scene differently than a telephoto.  Most of us are really aware of how a wide angle lets you see more of something while a telephoto "zooms in" to reveal less of it but in greater detail.  What most of us don't recognize is how it affects perspective.
While mulling about in Alberta we came across this great church.  Not only was the building itself interesting, there was a small duplicate of it positioned just in front of it and off to the side.  I saw it as an opportunity to not only shoot an interesting subject, but to play with perspective.  The photo on the left was taken quite a distance from the buildings using a mild zoom lens (65 mm on a full frame camera); the one on the right with a wide angle lens (28 mm) fairly close to them.  The results speak for themselves.
Telephoto lenses cause an effect called "compression".  Backgrounds are brought up relative to foregrounds.  Notice the how the trees on the left image appear larger and closer to the buildings than the trees on the right.  The small church is clearly much smaller than the large one.  Telephotos also narrow how much background you see; the right shot indicates that another building is present whereas there is no such suggestion on the left.  Look at the large church itself.  Notice how the dome is about the same size as the front entrance on the left but is clearly smaller than on the right.
Wide angle lenses cause "distortion".  Foregrounds are made to look larger than backgrounds and distances between the two are exaggerated.  This is why portrait photographers use mild telephotos lenses to do close ups of people instead of wide angles - faces end up looking strange with large eyes and noses if low focal length values are chosen.  Notice how the larger church looks stretched out on the right; the foreground (entrance) looks larger than the tower.  The small church in front also looks larger than the one in the left photo.
I use these properties of wide and telephoto lenses when shooting to capture relationships between foregrounds and backgrounds.  Want to exaggerate a foreground feature?  Move close to it and use a wide angle lens.  Need to bring the background up relative to the foreground?  Back up and zoom in.  Playing with focal length and your subject's relationship to what is around it brings an entirely new way of thinking about what will make a shot work.  Play with your zoom lens; move around as you shoot, and discover a new perspective on the world.

Tuesday, December 11, 2018

Lori and Howard on Caribbean Cruise - Before and after fill flash

Lori and Howard - with and without fill flash
Cell phones are all the rage now, their powerful chips driving screens with everything from global communications to intense gaming.  The cell phone housing also contains a camera.  Snapping selfies or shots of friends has also taken off, with those images being posted on social media sites by the thousands each second.  No wonder compact digital camera sales are down.  Why buy a camera that is larger and heavier than your cell phone which does the same thing.  Or does it?
It is true that cell phone cameras are convenient, and that they can take a good picture.  More people are carrying cameras than ever before; enough evidence of that is on You-tube anywhere you look.  But those images, both video and still, are not what they could be.
There are a myriad of features which compact and larger cameras have over cell phones ones.  One of those is the flash.  Now, many of you will tell me that your cellular device has a "flash" built into it, but in truth it is little more than a bright flashlight.  It helps reduce red eye and can augment an exposure in perfect dark, but really that's where the similarities end.  When dutifully put to the task of illuminating a subject at any modest distance, especially is the sun is up in any manner, those built in so called flashes fail miserably.
Case in point is the above photographs of our friends, Lori and Howard Allan.  We had the pleasure of joining them on an adventurous cruise to the southern Caribbean earlier this year (March, 2018).  There were lost of walking and talking and exploring, not to mention card playing and eating,  There were evening shows and musical events to enjoy too.  And then there was the scenery.  It was spectacular.
I captured a good many images, some of which I may eventually post, but I wanted to talk today about the benefit of flash.  My cameras are DSLRs and as such have the capacity to use a powerful external flash unit.  The allow me to do something special called a fill flash photograph.  It is really simple to do, and compact cameras are capable of doing them too, but you won't get a shot like this out of a cell phone.
The first thing to notice is that the background is properly exposed.  The first rule about doing fill flash shots is to make sure the background comes out looking good; I usually set my controls to manual, although aperture or shutter priority can work.  Once I know the background is taken care of I turn on the flash.  The tricky part here is convincing the camera to use the flash, because if it can take a photo of the background it should also do the foreground.  The trouble is that the lighting on the foreground may be different or it may have only part of the same lighting.  This is where things like hats block part of the face.  Fill flash takes care of those problems.
The first shot is without flash; the background is properly exposed.  Yes, you could ignore the background and just expose for the people, but then you loose all details of where you are.  The shot could come from your front lawn or balcony and you wouldn't know the difference.  It turns out this is pretty much what a cell phone shot would look like, even with flash turned on.  That is because there is just not enough light to compete with the light shining behind the subjects.
Camera flashes, especially external units, have much more power and can illuminate their subjects much more completely.  The second shot uses the same settings as the first, but then has the light from a flash filling in the dark front shadows.  The difference is amazing.
Certainly, by all means, continue shooting with your cell phones, because they capture those moments of life which would otherwise go unregistered.  However, if you want something more demanding which your device can't do well, turn to a proper camera.

Wednesday, November 28, 2018

Depth of field in a flower garden

Changing aperture and focus settings.
My wife and I recently visited the Auckland botanic gardens.  We quite enjoyed the walk and marveled at the wide assortment of plants and flowers present.  There was one area which grew a variety of spring blooming annuals which made a perfect setting for this depth of field blog.
Depth of field is controlled by a number of factors, but the three which the photographer has direct control over are focal length, aperture, and point of focus.  I shot three images of Kathryn, seen above, using my 150 - 600 mm birding lens.  Set at the 150 mm mark, it had a relative focal length of 225 mm on my Nikon digital crop sensor camera.
The first image would be the one I would normally go after, with foreground and background both blurred so draw your attention to the subject.  The key here is a longer focal length lens with a small f/number (wide aperture).  Larger sensors produce images with less depth of field given the same relative focal length, so using a full frame camera will produce narrower depth of fields than a compact camera will.  Focusing on the subject renders most other objects out to focus.
The middle image used all the same settings except that the point of focus was changed to the red poppy indicated.  The wide aperture and closer point of focus led to a very narrow depth of field, causing my subject to be very blurry.  If you notice though, your eye goes to the poppy without much prompting - this is a terrific way to draw your eye.  I will go into this in anther blog.
The last one used a small aperture (large f/number).  I increased the ISO so that my shutter speed would not be too slow.  The lens had vibration reduction, and I was three stops under the recommended hand held shutter speed without vibration mitigation technology.  Since I had this turned on, I was within its effective range, as long as the subject wasn't moving.  Point of focus placement is important, and I chose a spot about 1/3 of the way from the front poppy to the person.  You can see that depth of field was increased significantly.
This is one of the reasons I suggest shooting in aperture priority instead of program or an auto mode; you have much more control over aperture.  As you become more familiar with your camera its many controls you will be able to make better choices regarding the composition of your images.

Friday, November 23, 2018

Using a polarizer filter

A house in Russel, New Zealand.  The left was taken without a polarizer; the right used one.
Two shots, same building, same exposure.  The difference is the polarizer filter.  If you have never used a polarizer filter, you will be surprised by their usefulness.  It is an essential part of any well equipped photographer's arsenal.  And the good news is, they are not very expensive.
To really appreciate the difference in the two shots, I will take time to point them out.  The first is obvious; the sky.  Notice how the clouds stand out better in the second image.  Also the blues are darker and much more saturated.  This is not because it is blue, it is because of what the polarizer is doing.  We will get to that.
Take a look at the red roof.  The house had a vibrant red roof which starkly contrasted with its walls and windows.  The image without the polarizer does not capture that, but the one with the polarizer does.  Again, it is not a function of colour or hue; it is a function of what a polarizer does.
Another difference, more subtle, is the polarizer's effect on white balance.  Notice the right image appears a cleaner white.  The image on the left is flatter in contrast and has a certain hue of colour associated with it.  Polarizers remove some of the colour cast associated with blue skies.
OK - so it works.  The question is, "Why?"  The answer has to do with light coming in from the open blue sky.  Light from the sun vibrates in all planes, and they are not polarized.  That means that each ray of light vibrates at a random angle.  Polarizers do not let light pass though it that vibrate at a particular plane.  It will remove some light, which is why polarizer filters appear grey.  You have to give up about a stop of light.  But their benefits greatly outweigh this disadvantage.
Light reflected from open sky has a decidedly blue colour associated with it.  When it comes to earth it throws a colour cast on everything.  Whites and greys appear bluish, greens are much darker and the skies are brighter.  Put on a polarizer and look what happens.  That blue light gets pulled out so skies darken up, blue shades get removed, and colours appear the way they are meant to be.
Polarizers don't work all the time; they only work in situations where there is polarized light.  I take mine off indoors or during events which do not benefit from it.  There are times though, that it is great to have.

Wednesday, November 7, 2018

A lake near Hobart, Australia - with and without a polarizer

Lake near Hobart, Australia - Polarizer used.
Lake near Hobart, Australia - No polarizer used.
Anyone interested in doing the best job they can when capturing landscape images should think seriously about acquiring a polarizing filter.  They can be expensive, especially for lenses with large filter sizes; but a polarizing filter for your basic kit lens shouldn't set you back very much.  I have a 77 mm polarizer that I use for my ultra wide angle lens and my 28 - 300 mm lens.  I always travel with it because it just makes such a difference.
Notice the difference between the skies in the two images.  Even the boat and the sand are affected.  The grass is also changed.  This is because of what a polarizer does.  It filters out light traveling along a particular plane.  If there is no polarized light, it makes no difference other than acting as a bit of a neutral density filter.  However, on sunny days it can make an enormous difference.
The trick with a polarizer is to put it on only when it can make that difference.  Inside it has very little value, and cloudy days typically are without merit.  The place where it shines though is on sunny days, partly cloudy days, or in situations where you have annoying reflections coming off things like water or other shiny surfaces.
The best way to experience a polarizer is to get one.   Start off with a small one so you don't have to make too much of a sacrifice expenditure wise.  Borrow one if you can.  Play with it for a while and come to your own conclusion.  You will find that it is well worth the purchase and the time needed to attach it and play with its properties.

Monday, September 24, 2018

The focal length you choose will affect the outcome of the image.

Photograph of a beautiful Catholic Church at different distances and focal lengths.

One of the things which I frequently encourage people to do is to take a picture, then change something and take the same picture again.  Examine the two images and determine in what ways they are similar, but more importantly, different.  Then try to understand the reason why they are different, and you will have learned something.

You can do this with anything in photography really; ISO, exposure, white balance, shutter speed and aperture settings, and so on.  In the shots above, I changes my position relative to the subject (the church) and focal length I used to capture the image.

The left image used a 31 mm focal length on an APS-C sensor camera so it had a relative focal length of about 46 mm - in other words it looked "normal" (as it appears to your eye).  The right image used a 16 mm focal length, which has a relative focal length of 24 mm.  This is a wide angle setting, and it alters perspective.  You will notice that the entrance way appears much larger in the second shot and the spire seems much higher in the first.  This has to do with perspective; the way that different focal lengths alter the image, rendering near and distant features differently.

Creston granary - with and without power lines

Creston granary - with and without power lines

What has changed in the above pictures?  They are the same image, only the one on the right has had all of the power lines removed.  I did this in Photoshop, and it took a modest amount of time but nothing that was unreasonable.  The sky was relatively easy to fix as it was just a matter of replacing the cable with the same colour that was present immediately above or below it.  What really took time was the granary itself as the boards had to be lined up and the fading matched to the local areas I was cloning.

The original image was 12x18 inches at 300 dpi, so the detail was incredible.  I used photoshop CS6 to do the job, but any of the Elements programs or the newer CC series would have done the same thing.  I prefer to use the clone tool instead of the heal tool because I find it does a better job, especially when it comes to precision.  Once you figure out the idiosyncrasies of the tool options, the process becomes straight forward.

I photographed this during our summer holiday this year.  Creston was quite beautiful and I especially enjoyed the bird sanctuary.  The blog I posted earlier about my book was written partly there, and the picture of the kingbirds was taken at the preserve.

Using fill flash

Umbrella man - with and without fill flash

If you look at the two pictures above, you may initially think they are exactly the same.  Yet, upon closer inspection, differences begin to emerge.  Differences in shadow, colour, white balance, and details are clearly visible.  So, why the difference?

One of the best tools you can have in your photographic arsenal is a good flash.  The image on the left (before) did not use a flash, the one on the right did.  There was certainly enough light present to take the photo without the use of a tripod, extreme ISO values, or flash, so why was one used?  The answer is in the details.

Fill flash is defined as the use of a flash to fill in shadowed areas, usually on the subject, which otherwise would appear dark and lack significant detail.  The shadows exist because light cannot adequately get to those parts of the image.  Flash then fills those shadows, providing enough light to ensure that image detail and colour all are expressed.

When do you use fill flash?  The need arises when your subject is underlit because of background lighting (backlit situations) or if light is being blocked from part of the subject.  In this case the sun is coming from behind the subject (notice direction of shadow) and the umbrella is also blocking any ambient light that otherwise might be available.  Flash provides that extra light.

Notice as well how the colour is different - look at the colour of the brick work and the wall in behind the statue.  The camera's white balance has been altered and the second image is far better than the first.

There are a lot of little tips and tricks to using fill flash; you can do it with the flash built into a camera but are typically severely limited by distance.  Generally though, it is a simple matter of turning your flash on even though there is enough light to take a photo without it.

Here is an idea - which is the main reason why I do these blogs - take two photos, one without flash and one with.  You will see that it is a simple matter of just popping it up.  An external flash unit will do a better job, but you may be able to see the difference with a built in one.  Push play and have a look; zoom in - did it make a difference.  Sometimes it will, other times not so much.  But the more you do it, the more you will see what works and what doesn't, and your photographs will improve in the process.