Camera adjustments

Most semi-serious photographers love their gear, love playing with their gear, love talking about their gear.  Usually the trick is to get us to stop talking about it all and show some pictures.

I use a lot of digital equipment but when I’m interested in really controlling the look of the image I get under the hood behind my view camera.  Being able to “disconnect” the plane of the lens from the plane of the film provides opportunities for images that are practically impossible with a regular camera.  Our brain does such a great job of interpreting what we see into the “correct” viewpoint that we’re generally surprised at pictures coming out of a regular camera.  Oddly, it takes a view camera with all its adjustment capability to deliver a photograph that looks “normal.”  The following three images are examples of what I’m talking about.

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Snap this shot with a regular camera and you’ll get something that might look similar.  Depending on where you stand the corners of the building might be vertical or slightly slanted, the near part of the curved wall at the bottom might be in focus or not, along with the trees in the distance.  It depends on the lens being used, the tripod setup and aperture selected.  For a view camera, making sure all these elements are exactly as desired is simple.  A little front tilt of the lens to “see” the foreground and an aperture stopped down to increase depth of field.

20161227011

This one would be harder for a regular camera.  The sign is about 5 feet from my camera where as the tower is about 50 feet away.  My camera is set up slightly down-hill from the tower and sign.  And the sign and tower are at different perspectives.  To make sure everything is in focus, and that the vertical parts are really vertical while the horizontal parts stay that way required using most of the view camera’s movements.  The lens and film plane are swiveled enough to get the focus for the tower and sign in the same plane, the lens has been lifted higher than the film to keep the perspectives the same while being tilted forward slightly to “see” the path in front of the sign, and the aperture is stopped down to f/64 so that everything is in focus.

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This was the simplest shot to make.  Level the camera, tilt the body down slightly to “see” the ice triangle in the river, tilt the film plane to vertical to keep the trees straight, and tilt the lens forward enough to put the foreground and distance in the same focus.

Setup and adjustments like this usually take 15-20 minutes per shot – definitely not a candid image.  Staring at the image developing on the glass screen under the hood is worth it, though, as you see how the adjustments render the shot just as you want it and just as your eye sees it.

One of the definitive books on this subject is Ansel Adams’ The Camera, which provides instruction on using the adjustments to get the image you want.  There are other sources out there but Adams writes well and serves up sound advice from years of experience crafting images exactly the way he wanted them.  It’s fun to read, and who knows, might encourage more people to try out a view camera for a different perspective on photography.

Depth of field? What depth of field?

Giving your images a distinctive and interesting look is always a challenge but there are several tools available.  Depth of field is a popular “art” tool that enables you to quickly bring the viewer’s eye to the exact subject you want them to pay attention to right from the start.  To use effectively, though, you need to understand what is the depth of field you’re going to get for your composition?  It’s a tricky question – each lens behaves differently based on aperture, distance from subject, focal length, etc.  You almost have to experiment with your bag of lenses and learn.  Or  you can look up the depth of field chart for your lens and memorize it.  My problem with the latter option is I have a hard time visualizing what a 3 inch depth of field or a 500 foot depth of field looks like.  I usually just play around with my lenses and see what they deliver.

It’s especially daunting with telephoto lenses.  The depth of field for these starts out short and seems to only get smaller.  Here’s an example:

I liked the little snowball sitting in the sunlight so I wanted to make an image of it.  I was sitting at a picnic table with my camera on my tripod, using my 300mm manual focus Olympus lens (from the OM film camera days).  On my digital Olympus body this is equivalent to a 600mm lens on a full format camera.  I’m about 10 yards from the snowball so this long lens really gets up close.  I think the aperture was around f/11 or f/16 since I was looking for maximum sharpness.  Notice the area that’s in focus – it’s a narrow band where the snowball is in the sunlight.  The grass in the foreground and snowbank in the background are completely out of focus.  Which is what I wanted – you eye should go right to the snowball.  But how much depth of field is really there?

100% crop from previous image

100% crop from previous image

If I zoom in on the image you can see the depth of field is REALLY narrow; according to one online DOF calculator it comes in at 4 inches.  Which means if I was making an image of a deer’s face using this distance and settings, their eyes would be in focus but their ears and nose might not be – and this is at a small aperture (not that I expect to be 10 yards from our local deer, at least not unless I’m holding a handful of corn for them).  It does give a cool look, though, as it centers your eye right on the subject I want you to pay attention to.  Like most specialized tools – and a long telephoto lens is definitely that – you get the best results when know the lens’ limitations and operating within them.

In my youth as a photographer I was always trying to get maximum depth of field, especially with landscapes.  I’ve learned now that shortening it up can truly bring some interesting features to your pictures.  Just have to know when and how to use the technique effectively and what tools work best to deliver on it.

Look down to see up

In September during my workshop we had the opportunity to photograph the full moon about a day or so before complete fullness.  What this means is just as the moon comes over the horizon there remains enough sunlight to illuminate the landscape and you don’t get the blown out highlights in the moon.  Most of us were working on a typical moon-over-mountains composition, something like this:

ISO 100, 200mm, 1/15 sec., f/8

Standing next to a small pond I noticed the scene’s reflection in the water but with the addition of grasses on the shore and some vegetation floating on the surface.  I thought it had a nice abstract look to it so I recomposed and make this image:

ISO 100, 200mm, 1/30 sec., f/5

Having everything razor sharp was of less interest to me for this image; I wanted to capture groups of shapes and tones that would define the composition more than simply a picture of the moon.  Reminded me of advice I got from a black-and-white photographer once.  He said as you are composing, look at the scene and squint to the point where all detail is gone and all you see are the blobs of light and dark.  Then compose to where those blobs form an interesting image.  Everything else will usually fall in place to compliment the composition.  It’s a good way to improve seeing for someone who easily gets distracted by the fine details and misses the complete picture!

By the way, reflections usually lose about one stop of light so you’ll have to adjust to keep your exposure when moving from the original scene.  And sometimes you’ll have to manually focus in order to get what you want to be in focus – autofocus sometimes can’t distinguish between the reflected image and something on the surface of the water.  For the second image I opened my aperture to shorten the depth of field and manually focused on the reflected mountain.

Sumac study

Growing up in the southeastern US my only encounter with the word sumac was when the adjective poison was used.  I never really learned what to look for in the woods in spite of years seeing drawings and photos, mostly because I’m apparently not affected by any of the “poison” weeds.  So I’d just ignore paying attention.

Here on the Plains, though, the term sumac takes on an entirely different meaning, especially this time of year.  It’s a harbinger of autumn, changing its identity from leggy, green leafed shrub to brilliant red beacon seemingly within days of the temperature going down to post-summer levels.  Drive by a place day in and day out with out noticing it and then suddenly one day there’s this near-neon hillside sea of red.

This is the smooth sumac, one of many different species of this world-wide genus.  I think it’s considered a pest in this part of the world – it’s the only reason I can think of that would explain all the farmers cutting it out of their fields.  Probably because it’s tenacious and hard to plow up, or because cows don’t eat it so it takes up valuable pasture space.

Turns out, though, it has economic value in various parts of the world.  The fruit (small seed-like objects that grow in a cluster at the plant’s top) is ground up and used as a spice in various Middle Eastern dishes to add a lemony flavor.  In Japan and other parts of East Asia fat is extracted from the plant and used to make wax candles or lacquer.  In North America the fruit is soaked in water to make a type of tea and the stems were used to make pipes.                           Source:  http://en.wikipedia.org/wiki/Sumac

With the dry weather this year I doubt the colors are going to stay long.  I’m already seeing sumac leaves turning brown and the fruit pods drying out.  I’m glad to see the colors, though, since it means autumn is right here and other plants will follow suit with their own tribute to fall.

Color quirks

I find it odd how my personal color palette has developed.  I don’t mean in a fashion sense (whatever’s comfortable and functional, that’s what I wear) but rather through the viewfinder.  It came to my attention when a friend was asking for advice on images to decorate their home’s interior, which is nicely done in greens and yellows (think fresh spring colors).  Looking through my portfolio I realized these are not colors that show up a lot as the primary theme in my images.  Surprising.

Even more surprising to me is how I’m drawn to the cool and warm colors – blues and reds – but hate their siblings of purple and magenta, casts I’m continually fighting in my slide scans.  For someone who enjoys cold weather it’s amazing how often warm colors of sunset and autumn show up in my images.

Some of it is simply lighting.  Using the late afternoon sun as a way to sculpt contrast on objects pretty much means you’re using warm light.  The atmosphere strips out so much of the blue wavelengths as the sun passes through it at sundown that getting a cool perspective is just about impossible (without some digital adjustments, of course).

ISO 100, 35mm, 1/60 sec., f/2.5

It’s similar in the early morning however the air at sunrise hasn’t accumulated all the dust from a day’s thermal activity so there’s less particulates in the air to scatter the light.  You can get some nice cool tones just before sunrise on a clear day as the blue sky radiates those shorter wavelengths everywhere on the ground.

Photographing flowers as much as I have now I’ve learned that truly yellow objects don’t appear to have much contrast and so the details are very hard to bring out in an image.  I don’t know if this is unique to yellow colored objects or if yellow flowers just don’t have that much detail.  It may be one reason there’s so little yellow in my portfolio – frustration at reviewing shot after shot of yellow things that just sit there without any characteristic depth to them.

ISO 100, 35mm, 1/40 sec., f/2.5

I do see one issue with these late afternoon, close-up photography quests.  With such a small depth of field it’s hard to hold focus on an object by just leaning down to photograph it.  The small swaying back and forth our bodies do in order to maintain balance, when magnified by a lens at close range, is enough to move the subject in and out of the actual focal point.  Tripod time, obviously.  Although sometimes you just can’t take the time needed to set up all that gear, get it oriented and then make the image.

ISO 100, 35mm, 1/60 sec., f/2

Because I was leaning over in the grass above this bush there’s very little of this mantis that is actually in focus but he contrasts nicely against the flower so I did get some detail in the image.  One of the more creepy aspects of mantis behavior is how they twist their head around to watch you – it’s not something we expect from insects.  This one did let me change positions a few times to get different compositions, but he kept a close eye on me the whole time.  With his antenna laid back from his head I got the sense I was disturbing something important but wasn’t so much of a threat it merited moving to a new flower.

Curse the light!

When you are setting up the exposure for your image (on any setting other than Auto/Program) it’s a game of trade-offs as to what you can do in order to get what you want.  Modern cameras have so many built-in tools to do this work for you it’s sometimes difficult to know what’s really going on in the camera.  So you get images back and think “this is not what I wanted the picture to look like” and wonder how your camera screwed it up.

Fortunately, there’s a setting on most DSLR’s that enables you to quit blaming the camera and start blaming yourself – Manual.  Yes, you get to set everything with respect to exposure settings.  And what you set is exactly what you will get.  Sometimes that’s exactly what you want….

Not that it’s any less frustrating; it’s just that you can’t beat up on your equipment any more.

Here’s an example.

ISO 100, 50mm, 0.4 sec., f/9

All I wanted was an image with the log and rock in focus, and an obvious small wave breaking on the shore.  Well, with these settings I do have both the rock and log in focus, but the wave is just a jumbled blur.  Obviously I need a faster shutter speed.

ISO 100, 50mm, 1/50 sec., f/2

There – I opened the aperture to let in more light, giving me the ability to have a faster shutter speed to keep the same exposure.  And I’ve got my wave.

Wait, though.  The log is in focus and the rock isn’t.  Obviously my bad – focusing on the wrong place.

ISO 100, 50mm, 1/60 sec., f/2

Ahh – now the rock is in focus and I’ve still got my wave.  It’s looking good.

Hey, now the log is out of focus!  What gives?

Oh, I see.  I’m fighting a depth-of-field problem.  At this aperture (f/2) the DOF is very narrow, narrow enough that focusing on one subject means the other will be out of focus.  Obviously I need to get a bigger DOF by closing down the size of the aperture.

ISO 100, 50mm, 2.5 sec., f/22

Yes – now everything is in focus.  But I’ve lost the wave!  It looks like the lake is completely still!  What’s wrong?

Nothing is actually wrong.  All four of these images are correctly exposed; i.e., capturing the same amount of light.  The camera is simply, and accurately, doing what I tell it to do.  So why can’t I get the composition I want?

I have two camera controls essentially fighting against each other.  For the amount of light I’m letting into the camera (exposure), a fast shutter speed that will render the wave I want requires I use a wide open aperture to give me enough light.  But a wide aperture results in a very narrow depth of field, meaning the rock and log won’t be in focus together.  Close the aperture down to get a wider depth of field and I let less light into the camera; to compensate I have to use a longer shutter speed to let more light in, which will not “stop” the wave as it travels to the beach.  I need enough light to use a smaller aperture AND a faster shutter speed.  What am I going to do?

There’s one more camera control I can use.  I can change my ISO setting to a higher number (notice these are all ISO 100).  Using higher ISO numbers basically makes the digital sensor more “sensitive” to light, thereby changing the exposure conditions of the scene (as seen by the camera) and allowing me to use a faster shutter speed and smaller aperture.  I imagine changing to ISO1600 will give me what I want.

There’s no picture to prove this works because I didn’t make one at that setting.  ISO1600 on this camera results in unacceptable noise in the image, especially in the shadow areas.  It will work, though.  Going from ISO100 to ISO1600 is an increase of 4 stops of light in the image.  I can go back to 1/60 sec. shutter speed (I know that will stop the wave) and close down the aperture from f/2 to f/8 (4 stops), giving me a depth of field sufficient to bring both rock and log into focus.  I could probably take care of most of the noise using software.

I could also have made this image earlier in the day when the sun was higher and giving me more light.  Possibly I could have used a reflector to concentrate more of the existing light on the scene (hard to do without an assistant).  Or I could use a small flash to increase the amount of light (but probably create undesirable shadows).

So, as I said, there are always trade-offs.  The master photographers use these to their advantage, crafting exposures that make the settings work for them instead of having to work around the settings.  Practice and experience – and paying attention to what you create and how.

Watch what you can’t see

Just because you think you know what you’re doing doesn’t mean you’ll actually get the result you expect.  The basis for some great science and technology finds or stuff to fill the waste bin of history.

Also, garbage in – garbage out.

Fighting the restrictions of a narrow depth of field you’ll find all sorts of techniques, gear, software, etc. offering to help you overcome the physics of lens design and light paths.  Focus stacking is popular – has been way back to film days – and interesting in how it assumes to provide a substitute for our eyesight.  To enable us, finally, to make an image that looks the way our eye really sees things.

Except it’s a lie.

Focus on reading the words on this screen.  Now, using your peripheral vision (you know, the corner of your eye), “look” at something about a foot to the right or left of the screen but don’t take your focus off the words on the screen.  What can you really tell about the details of that object off to the side?  A little blurry, isn’t it.  Here’s a better test.  While focusing on the words in the top part of a newspaper, “look” over the top at something in the distance, again using your peripheral vision.  What kind of details are you making out in that distant subject?  Not many, you say.

It seems our eyes have a depth of field as well, not only near to far but also around the circumference of our vision.  So, all those images of three dimensional objects that are sharply focused in all dimensions don’t actually mimic our eyesight.  They mimic the eyesight we wish to have.

Since they are artificial constructs, though, it means they lend themselves to interpretation and alternative versions.  From whence comes art, human and otherwise.

Taking a lot of images of a subject, each slightly focused on a different plane of the subject, and then “stacking” them together in software can result in one of those 3D objects with all aspects in focus.  Or it can result in what you see above.  Does this ball of bands exist in some alternative dimension, some slightly askew reality that periodically bleeds over into ours when we’re not looking?  Possibly, if you want to believe software programs have a mind of their own.

Your digital work seems to be becoming only as smart as your software.  The image above is not digitally enhanced, at least not in the manner you’d expect.  It’s the result of not turning on the right switch in my software, of selecting the wrong option (well, wrong unless I actually wanted this look to the image).  Instead of asking the software to deal with geometric distortions caused by moving the focal plane for each image in the stack, I simply told it to reposition each image to make sure it lined up with the others in the stack.  Except that’s not possible.

Each image in the stack is slightly different because when I refocused on a new part of the ball, all the other out-of-focus parts got slightly more out-of-focus.  Each variation adds up.  When the software was told to simply reposition all the images and line them up, it did the best it could, but in the face of an impossible task, decided to get creative.  The algorithm essentially said, “I’ll line up these few areas I can work with but with the rest I’m taking a wild guess.”  Apparently the wild guess included ignoring exposure information and color balance as well, resulting in the strange glow that appears to emanate from the ball itself.

The correct switch literally tells the software to correct for perspective shift, the phenomena that is occurring when I shift focal planes.  See, the software is actually smart – it’s the operator that gives poor direction.  You know, garbage.

It does raise the question of what other type of images you can make this way and what would they look like.

Like this, I guess.

How would you like to see that coming your way while on a Yellowstone hike?