Archive for the ‘aperture’ Tag

Friday Foto Talk: Depth of Field III   13 comments

This Friday I’d like to continue with depth of field. But before I do I want to thank all those who contributed to my campaign to replace my camera gear (which tumbled over a waterfall several months back) and get back to showing you all some fresh material on this blog. I will be sending out a reminder email to those folks, to pick the images they want.

I didn’t make it all the way to my goal, but I got partway there. And that means something. I’m busy right now working 7 days/week doing the only thing I know how to do that makes me money quickly. And it’s actually legal, go figure! So it won’t be long before I make up the difference myself.

Make sure and check out the first two parts of this series: Part I and Part II.  They go over the basics behind depth of field.  The example here will show how to apply those basic principles in the field, so it’s important to know them.

Cape Ground Squirrel

I was traveling through Namibia when I took a break from the road.  Namibia is one country in Africa where you can very easily rent a car and take off on an impromptu road trip, like you would in the western U.S.  If the roads in the west were still largely unpaved that is.  

I strolled up a small ridge with my camera and one lens (a 400 mm.).  Suddenly directly ahead this cute little fellow popped his head up and looked at me with big dark eyes.  I had never encountered this rather tall slender rodent before.  Later I found out it was a cape ground squirrel, native to southern Africa.

Of course I wanted a shot of him, and quickly before he decided I wasn’t all that interesting.  But as usual my position wasn’t ideal.  A portion of the scrubby hillside formed the background not far behind him.  My lens only opened up to a maximum aperture of f/5.6.

Since I wanted a portrait that showed him plus a bit of the bare ground at his feet but little else, the hillside was a problem.  It was too close and would have been too much in focus, too distracting.  I wanted as shallow a depth of field as I could get.  But I was limited in what I could do.  I couldn’t open the aperture larger than f/5.6, couldn’t go longer than 400 mm., and couldn’t change lenses.

I was down to one option, changing relative distance between camera to subject and subject to background.  And since I couldn’t move closer without scaring him off, increasing the subject to background distance was all I had.

I grabbed a quick shot or two, in case he ran away. Then I slid down low, lying on my belly so that the hillside behind him was out of view. Now a much more distant ridge formed the background.  Problem was, the lower point of view put my little friend out of view.

So I waited, hoping that his curiosity would get the best of him.  Sure enough he popped his head up again.  Luckily his long tail (which is what fascinated me about him in the first place) trailed to the side.  I had been framing a vertical photo, but I quickly switched to get his tail in and fired off a few frames before he zipped off to continue his daily desert rounds.

The Cape ground squirrel lives in rocky areas of Namibia and South Africa.

The Cape ground squirrel lives in rocky areas of Namibia and South Africa.

I ended up with a pretty good shot of him, a key part of it being the smooth gray out of focus background. The shallow depth of field was afforded by a relatively long focal length of 400 mm. combined with the squirrel’s proximity to me relative to the distance between him and the ridge behind.  The low point of view resulted in the picture’s main weakness, an out of focus rock low in the foreground.

I tend to combine all the factors controlling depth of field (aperture, focal length and positioning).  But since focal length is pretty much dictated by the composition I’m after, aperture and positioning are the main variables.  I’ll move closer or farther from my subject, change point of view to move background forward or back, or ask my subject to move if that’s possible (I haven’t figured out how to speak to animals yet).  All the while I will adjust aperture to the degree that I can.

Of course I run into shutter speed limitations when adjusting aperture.  But it’s easy to mitigate that by adjusting ISO.  Better to have a little noise from a higher ISO than to have a blurry subject because of a shutter speed that is too slow.  I have ruined many a shot because I thought animals or people were perfectly still when they weren’t.  I’ve been a very slow learner in this regard.  Always shoot live subjects at somewhat faster shutter speeds than you think are necessary. 

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Friday Foto Talk: Depth of Field II   19 comments

Sometimes quick off the cuff shots are the best. At a small rodeo in Oregon, not only the perfect depth of field, but the expression on this rider’s face was perfect as he looked respectfully at the bull that’d just “had fun” with him.  180 mm., 1/2000 sec. @ f/4.5, ISO 200.

This is the second of a three-part series on depth of field.  Take a look at my 1st one, where some basics are covered.

Depth of field plays a big part in how most images look. Thus it’s important that you are deliberate. I’m not saying be rigid; experiment with different apertures, focal lengths, etc. in order to get different looks. But when it comes time to select your best, when it’s time to decide which pictures you will put out there as representative of your subjects and your photography, then I think you need to take a more conscious approach.

It’s a fact that your choice of depth of field will influence the impact each of your images have. But your choices will also help to set the tone for each of them.  And what’s more, your choices will to some extent collectively influence your photographic style.  It’s like a sort of flow where you select and filter on the way to your unique identity as a photographer.  How you use depth of field is simply one aspect of that.

Along the Kafue River in Zambia, this black-backed barbet had some personality, so I went for shallow depth of field.

Along the Kafue River in Zambia, this black-backed barbet had some things to say, so I went for shallow depth of field.  400 mm., 1/640 sec. @ f/5.6, ISO 200.

Who needs shallow depth of field when you place your subject at the entrance to a relatively dim barn.  This is Gold Dancer, apple of my eye for 8 happy years, who I just had to sell last week.

Who needs shallow depth of field when you place your subject at the entrance to a relatively dim barn. This is Gold Dancer, apple of my eye for 8 happy years, who I just had to sell last week.  121 mm., 1/60 sec. @ f/5.6, ISO 200.

Honey-sellers in Ensenada, Mexico pass the time playing cards.  I wanted to put them only slightly out of focus.

Honey-sellers in Ensenada, Mexico pass the time playing cards. I wanted to put them only slightly out of focus.  28 mm., 1/80 sec. @ f/5.6, ISO 160.

Whatever you do, you should not think of a particular aperture or depth of field as being right or wrong as judged by some imagined body of photography “experts”. It’s not even strictly right or wrong for your subject and conditions.  Rather, it can only be right or wrong based on your particular interpretation of the subject, light, mood, etc.  Trust your instincts and tune out the noise on Facebook etc.

That said, there are some general considerations:

      • Shallow depth of field is used most often to isolate a subject. The photographer wants the viewer to put maximum attention where the focus is and nowhere else. Along with relative brightness, focus is a great way to force a viewer’s eyes to go where you want them to go.
      • Large (deep) depth of field is used to show the whole story. In fact it’s known by many as a “storytelling” aperture. I’m not so sure that you can’t tell a story with an image that has shallow depth of field, but in general giving everything equal weight, focus-wise, facilitates movement of a viewer’s eyes through the scene. How you guide that eye movement is a big part of the art of composition.
      • Moderate depth of field is used when you don’t really have a good reason to go either shallow or deep. When everything in your frame is roughly the same distance away or when your subject is set against a featureless background, you might as well shoot at a medium aperture like f/8. The aperture at which most lenses are at their sharpest is in the f/5.6 to f/8 range.
Two Nicaraguan vaqueros, one of whom I wanted to focus on and the other not totally blur out.

Two Nicaraguan vaqueros, one of whom I wanted to be the focus while the other a supporting character (thus not totally blurred out).  127 mm., 1/250 sec. @ f/4.0, ISO 200.

 

When a large male great curassow stepped out of the jungle at Tikal, Guatemala, I didn’t worry about the fact that I had a messy background that was too close to blur no matter how shallow I went with depth of field.  I just thanked my luck and snapped the picture.  200 mm., 1/60 sec. @ f/5.0, ISO 200.

With this brown pelican in Sian Ka'an, Yucatan, I didn't need to go shallow with depth of field because the sky is featureless and would not distract.

With this brown pelican in Sian Ka’an, Yucatan, I didn’t need to go shallow with depth of field because the sky is featureless and would not distract.  200 mm., 1/2500 sec. @ f/6.3, ISO 200.

There are many ways to play around with depth of field, many ways to create a variety of looks in your images. Add to that all the additional control afforded by post- processing software, where you can simulate any lens effect and more, and you have a plethora of options.  Take it slow is my advice.

It all starts with the capture, and this is where the decisions you make regarding depth of field will make the most difference.  As I laid out in the 1st post in this series, aperture, focal length, positioning and lens choice are all worth adjusting and playing with in a wide variety of photographic situations. Soon enough you’ll know what works for you, and getting the look you want will become quicker and more unconscious.

But don’t let it become too automatic. Depth of field is too important a part of your photography to put on autopilot. Instead it should remain an integral part of your photography’s growth. Learn by shooting and making mistakes, by thinking and reevaluating, by questioning assumptions and yet going with it if it feels right.

Thanks for reading!  Next time we’ll look at an example or two.  All these guidelines are well and good, but how are decisions about depth of field actually applied while shooting in the real world?  Stay tuned.

Mount Hood Oregon and a blooming blue dick, and no way to possibly put them both in focus (without blending 2 shots), so I played around with different depths of field and selected this one.

Mount Hood and a blooming blue dick, with no way to put them both in focus without blending 2 shots.  So I played around with different depths of field and selected this one.  100 mm. (macro lens), 1/20 sec. @ f/32, ISO 160.

Monument Valley's Totem Poles at sundown.  This shot was all about maximizing depth of field.

Monument Valley’s Totem Poles at sundown. This shot, with elements I wanted in focus from the bushes a few feet away all the way out to the moon at a quarter million miles, was all about maximizing depth of field.  28 mm., 1/40 sec. @ f/11, ISO 100.

Weekly Foto Talk: Depth of Field I   8 comments

 

California poppies bloom in an impromptu roadside wildflower garden.

California poppies bloom in an impromptu roadside wildflower garden.  65 mm., 1/60 sec. @ f/13, ISO 200.

Depth of field is one of the most important elements of photography. For most of your captures, you’ll need to more or less consciously control depth of field. You probably already know that aperture is the way to do that. You may also know that it is not the only tool at your disposal. This post will briefly summarize the art of controlling depth of field, then I’ll discuss some of the factors you should consider when choosing depth of field for your images.

What is depth of field? A good working definition goes like this: The extent to which parts of an image are in focus from front (near the camera) to back (far away) is that image’s depth of field.  As you can see it is rather subjective.

Depth of field is often confused with depth, which I posted on awhile back. Giving your images a sense of depth, though related to depth of field, is quite different. Depth is the degree to which you foster the illusion of three dimensions in your two-dimensional pictures. A photograph with good sense of depth, for example, can have a depth of field that is shallow, deep or somewhere in between.

In the northern Guatemala forest, near the ruins of Tikal, a young brown basilisk posed for me while I worked out a good angle for the background depth of field.  200 mm., 1/60 sec. @ f/8, ISO 320.

In the northern Guatemala forest, near the ruins of Tikal, a young brown basilisk posed for me while I worked out a good angle for the background depth of field. 200 mm., 1/60 sec. @ f/8, ISO 320.

A hoary marmot high up on Mount Rainier, Washington.

A hoary marmot high up on Mount Rainier, Washington. 280 mm., 1/1600 sec. @ f/5.6, ISO 200

I wanted this young Himba in a Namibian village to be the star of the picture, but I also wanted the village to be noticed too, so a moderately shallow depth of field was necessary.  68 mm., 1/320 sec. @ f/8, ISO 200.

I wanted this young Himba in a Namibian village to be the star of the picture, but I also wanted the village to be noticed too, so a moderately shallow depth of field was necessary. 68 mm., 1/320 sec. @ f/8, ISO 200.

 

Control depth of field in your images using one or a combination of the following methods:

      • Aperture: Small apertures (big f/numbers) yield greater depth of field, where more of the scene is in clear focus. Large apertures (small f/numbers) give shallow depth of field, where just your subject is in clear focus.
      • Focal Length: The longer the focal length you use, the shallower your depth of field will be. A short focal length (wide angle)will give yield greater depth of field.
      • Relative distance:  To get greater depth of field, increase the distance from you to the closest thing you want in focus. To get shallower depth of field, simply move closer to your subject. That’s the simple way to explain it. Really what you want to do is change the relative distance between you and the subject as compared with the distance between the subject and background. For greater depth of field increase this relative distance. For shallower depth of field decrease the relative distance. See the example images below.
      • The right lens: It may not seem so, but a particular lens’s characteristics can lean the images it produces toward greater or lesser depth of field. This is a minor factor compared with the others, but it’s real. I’m not talking about lenses with large maximum apertures (“fast” with low f/number designations), in order to achieve shallow depth of field. That’s all about factor #1 above.

I’m talking about how some wide-angle lenses allow you to photograph scenes where all is in focus, even if elements are both very close and far away. And how other lenses tend to yield an especially smooth out of focus background, or nicer-looking bokeh (out of focus highlights). Tilt-shift lenses are a somewhat extreme example of lens build influencing focus characteristics. And of course macro lenses have much shallower depths of field than other lenses do (see images below).

A macro shot of the inside of a flower.  Shallow depth of field is virtually guaranteed.    100 mm., 30 sec. @ f/16, ISO 200.

A macro shot of the inside of a flower. Shallow depth of field is virtually guaranteed. 100 mm., 30 sec. @ f/16, ISO 200.

Fairy Bells bloom in the forest with more shade than most flowers prefer.  100 mm., 1/25 sec. @ f/7.1, ISO 400.

Fairy Bells bloom in the forest with more shade than most flowers prefer. 100 mm., 1/25 sec. @ f/7.1, ISO 400.

This will get us going on the discussion.  Please let me know if you have anything to add or any questions.  And if you’re interested in any of my images, whether on here or on my main gallery page, please let me know by contacting me.  I would be happy to honor any request no matter how unusual.  Stay tuned for more on depth of field.  Thanks for reading and have a great week!

My girl, Gold Dancer.  70 mm., 1/1250 sec. @ f/4, ISO 200.

My girl, Gold Dancer. 70 mm., 1/1250 sec. @ f/4, ISO 200.

 

Friday Foto Talk: Sharpness vs. Depth of Field, Part II   3 comments

A train runs up the Columbia River Gorge in Oregon.  This is not an image with many tradeoffs.

A train runs up the Columbia River Gorge in Oregon. This is not an image with many tradeoffs.

This is the second of two parts.  Last time we discussed lens sharpness in general, & learned how to find a lens’s sweet spot.  Check out Part I.  Did you do your homework?  Hint: it was finding the sweet spot for your lenses!  Remember all these images are copyrighted and not available for free download without my permission.  Just click on them to check out purchase options on the main part of my webpage.  If you can’t find something or have any other questions just contact me.  Thanks for your interest.

Now we come to the meat of the matter.  How much does all this matter?  For one thing, you should realize that photography has changed with the advent of digital cameras, specifically the emergence of high-quality digital cameras.  Sharpness and clarity are now expected by people.  This is not generally a bad thing.  But it is narrowing the range of images that people will look at for longer than a nanosecond.  And that is a bad thing.

Dawn on the upper Columbia in Washington.  Shot at f/22 to maximize depth of field.  Sharpness is not at maximum for this lens though.

Dawn on the upper Columbia in Washington. Shot at f/22 to maximize depth of field. Sharpness is not at maximum for this lens though.

Notice I said sharpness and clarity, not focus.  As an example take my post for Single-image Sunday, the Fog Returns.  It’s an image that, while perfectly focused, is not particularly sharp.  I’m using the word sharp in its broader sense here.  It is encouraging that I a little push-back against this quest for sharpness in all images.  But there are currents that are taking us in the other direction as well.  For example focus stacking (where several images are captured and combined in Photoshop to have several focus points in the same image) is subtly changing the expectations of image viewers.  To think I’m essentially being forced to do composites in Photoshop: ugh!

I posted this in a previous post, but here it is again because it's one of just three images I have photo-stacked thus far.

This image from Olympic N.P. appears in a previous post, but here it is again because it’s one of just three images I have thus far captured & processed by photo stacking.

But let’s leave that aside and focus on sharpness vs. depth of field.  You might be aware of all the tradeoffs in photography, and this is certainly one of them.  But before we discuss that, here are a few givens:

      • Some lenses are sharper than others, but that’s not your concern.  Your concern is to get the best pictures possible with the equipment you have.
      • Most images that are not as sharp as they could be are down to user error.  If you don’t stabilize your camera on a tripod (or shoot at a fast-enough shutter speed if hand-holding), do not expect a sharp image.  Use a cable release or timer delay as well.  Mirror lockup, if your camera has it, has a lesser effect but is still worth doing.
      • Atmospheric conditions, particularly at longer focal lengths, will also affect apparent sharpness.
      • Some lenses are capable of being sharper stopped all the way down than other lenses, and can thus give you a greater apparent depth of field.
      • The wider your focal length, the greater your depth of field will be.  Though it’s a continuous change, think about 21 mm. as the cutoff between very short/wide focal lengths and just wide/longer focal lengths.  Telephoto lengths (greater than 70 mm.) will yield much shallower depths of field.
      • Despite the above factor, aperture is still the biggest influence on depth of field.
Sandstone formations in Utah.  I was very close to the foreground and my focal length was not super wide.  While managing to get good sharpness in the foreground, I sacrificed some sharpness in the background.

Sandstone formations in Utah. I was very close to the foreground and my focal length was not super wide. While managing to get good sharpness in the foreground, I sacrificed some sharpness in the background.  Since I did not want this to be too noticeable, I used a small aperture – f/22.

Shooting “Deep” Scenes: The Trade-off

Now let’s get to that tradeoff between sharpness and depth of field.  If you want to maximize depth of field in your image (that is, sharpness from very close to very far away), you will be shooting at small apertures.  So unless you are going the focus stacking route as mentioned above, you will be shooting a good ways past your sweet spot.  Once you are two stops above the sweet spot (f/16 if your sweet spot is f/8, for example) you’ll notice a small drop in sharpness.

Let’s take an example.  Say you are shooting a sunrise over a lake, with interesting rocks close by and beautiful forested mountains in the background.  If you get low and close to those rocks, you might choose a very wide angle in order to get everything in.  This will also help to maximize depth of field, but to really get there you will also use a small aperture like f/22.  In order to show the fascinating detail in those foreground rocks, you will be  focusing fairly close, perhaps only a foot or two past the closest rock.

Sunrise at Lost Lake with Mount Hood emerging from the fog.  This is the same scene as last Wednesday's post, the Fog Returns.

Sunrise at Lost Lake with Mount Hood emerging from the fog. This is the same scene as last Wednesday’s post, the Fog Returns.

This all sounds wonderful doesn’t it?  But as with many things in life, there’s a hitch.  One of photography’s tradeoffs has raised its ugly head!  Depending on your lens the overall sharpness of your image will be just a bit less than what it is at the sweet spot (say that is f/8).  This is because of diffraction, as mentioned in Part I.

But that’s not all.  With most lenses, that image will also have its background slightly out of focus.  If you’re lucky (rich?) enough to have a Nikon 14-24 mm. or other similar lens with a big curved front element, this effect is certainly minimized.  But it is still there.  You can focus deeper into the image, but then your foreground will be slightly out of focus.  Shooting at a very wide angle and with a high-quality lens helps out with this tradeoff, but it will always be a balancing act.

This is hot off the presses, from last night.  If you are interested in the high-resolution version, just click on it.

This is hot off the presses, from last night. If you are interested in the high-resolution version, just click on it.

I normally just accept some diffraction-related softness and go with f/22.  But this is when I’m using my Tokina 16-28 mm. lens.  With my Canon 24-105 f/4, I know it’s softer at f/22 than the Tokina and does not attain quite as large a depth of field.  This is only partly because of the longer focal lengths; some has to do with the lens optics. The Canon does more things than the Tokina, so it can’t do the one thing as well.  More tradeoffs.

Focal Point & Depth of Field

Let’s dive a bit deeper into the focal point: where to focus?  It’s a question many photographers struggle with.  For me, it not only depends on my desired focal length, but on the balance between background and foreground in the image.  You should ask yourself, which is the dominant feature in my image: is it in the foreground or background?  That main subject is what you should try to keep as sharp as possible.

Sometimes I will sacrifice and move back from my foreground, especially if my background subject is a strong one.  This will increase apparent depth of field, but it might also force a longer focal length, which in turn decreases depth of field.  Again, a balancing act.

Death Valley, California.  Good detail in the foreground sand was most important here, and the background dunes were not as big a part of the image.  So I shot at f/16 and focused on the sand in front of me.

Death Valley, California. Good detail in the foreground sand was most important here, and the background dunes were not as big a part of the image. So I shot at f/16 and focused on the sand in front of me.

Blooming beargrass on Silver Star Mountain in Washington, with Mt Adams in the background.  At this focal length (165 mm.), no chance for sharpness in both fore- and back-ground.    But I still shot at f/22 so the mountain wasn't too out of focus.

Blooming beargrass on Silver Star Mountain, WA. At this focal length (165 mm.), no chance for sharpness in both the flowers & Mt. Adams. But I still shot at f/22 so the mountain wasn’t too out of focus.

Focal Point & Subject

Say you have a strong foreground and a less important background.  It’s a seascape with a fascinating foreground and no interesting boat or other element in the background.  You may just focus on the foreground and not care much about the background, even shooting at f/11 in some cases.  This is how I handle those scenes.  But I will often bracket my apertures, shooting at f/11 to f/22 (or whatever the minimum aperture is).

Now say you’re shooting a scene where your background subject is most important, yet you still want maximum depth of field.  First off, definitely consider putting your foreground a bit further away as mentioned above.  But this time, since the background is dominant, focus closer to it; about one third into the scene is the rule of thumb.  Since your background is most important, you might increase focal length to make it bigger (longer focal lengths increase magnification).  But careful!  You could lose too much depth of field, putting your foreground out of focus.  This is more likely if you’re tempted to shoot at wider apertures (smaller f/number) to get closer to that sweet spot.

Mount Rainier in the morning.  This is a shot where sharpness on the background is important but so is good depth of field.

Mount Rainier in the morning. This is a shot where sharpness on the background is important but so is good depth of field.

Recent foggy shot at Lost Lake. While sharpness is somewhat important for the baby tree, great depth of field is not that important.

Recent foggy shot at Lost Lake. While sharpness is somewhat important for the baby tree, great depth of field is not that important.

You can always keep a very wide angle and crop later, thus helping to get better (apparent) depth of field and sharpness both.  The tradeoff in that case is a smaller digital file, which is not really good if you’re thinking of printing the image large.  If you’re using focal lengths of 50 mm. or greater, focusing one third into the scene should be your default point of focus.  Just don’t get too locked into this, and always try to check focus right after the shot by zooming in on your LCD.

Okay, that’s enough for now.  I’m willing to answer any questions on this somewhat convoluted topic, so fire away.  If you’re not getting a quick answer it means I’m probably out shooting!  Have a great weekend everyone.

It's getting dark earlier!  Although some depth of field is important here, I opened aperture up a bit (f/8) to avoid using a high ISO and keep exposure time reasonable (to avoid smearing the clouds and moon out too much).

It’s getting dark earlier! Although some depth of field is important here, I opened aperture up a bit (f/8) to avoid using a high ISO and keep exposure time reasonable (to avoid smearing the clouds and moon out too much).

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