Posts tagged “depth of field

Two of My Boys: Bokeh Panorama

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Two of My Boys: Bokeh Panorama 50mm, f/1.4, 1/640s, ISO 100,14 frames...sort of

[Update: Here’s another try at it]

This evening I photographed my youngest boys in the backyard with the goal of trying out something called the Brenizer Method, or bokeh panorama.  I first heard of it in a post by Brandon Brasseaux. The goal of the Brenizer Method is to create an image with extremely shallow depth of field.  If I were to take the shot above using a single frame I would either (1) use a very wide-angle lens or (2) use a “normal” lens and stand far back from the scene.  In either case it would be difficult to get much bokeh in the image.  I’ll let you consult a depth-of-field calculator for the exact details but suffice it to say that the wide-angle lens — even at an aperture of f/1.8 — doesn’t result in much bokeh when focused at any reasonable distance.  A lens like I was using in this shot — a 50mm f/1.4 — would require such a long focus distance (i.e. I’d have to stand so far back) that the depth of field would large enough to eliminate a lot of bokeh.  The Brenizer Method uses multiple frames to form the image — using a much shorter focus distance resulting in much shallower depth of field than if you shot one frame standing further from the subject.

The process goes as follows: Instead of standing far away, stand close (I roughly filled the frame with the two boys).  I used an aperture of f/1.4 to get the shallowest depth of field and set a shutter speed in manual mode to keep the exposure consistent in all the frames (I also set the camera to daylight white balance).  I prefocused on the boys and switched the lens to manual focus.  The first frame I took was the one with the boys in it (took many tries to get something decent).  I then let them run off and proceeded to shoot overlapping frames (with the camera in the same location) of the rest of the scene you see above.  I used 14 straight-out-of-the-camera frames to stitch the panorama in Photoshop but in the end I cropped the image quite a bit. It took all of two minutes to shoot the frames, even with the boys’ goofing off.  Since my goal was to try out the method itself, I didn’t stress about background, lens flare, etc.

After stitching I warmed the image a bit, added vignette, tweaked the exposure/clarity on the boys, and removed some of the color fringing on the branches so it wasn’t *so* prominent.  Pretty simple stuff.  I want to try more of these but next time I’ll find a prettier background.  I believe I’ve given enough info for one to start playing with it but if not, an internet search will turn up a lot more information in a hurry.

Here’s a link to posts by the man behind it all: http://www.ryanbrenizer.com/category/brenizer-method/


Fire Dancer…Capturing Motion

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Fire Dancer 50mm, f/7.1, 1/15s, ISO 1600

My wife and I (and several in her family) attended a luau while in Hawaii last week.  I have no idea what an old traditional luau was like or how authentic the festivities were but in any case it was immensely enjoyable.  Knowing that the main show would be after dark, I fitted my camera with my 50mm f/1.4 lens.  Night photography has never been something I’ve been good at (maybe that can be said about all my photography 🙂 ).  I’m always going back and forth with myself on the best combination for getting good exposures — shutter/aperture/ISO.  Noise is always a consideration (not so much now that one of my bodies is a 5D Mkii).

For much of this show I wanted to mostly freeze the motion (like in the second shot above) so I shot in manual mode with an aperture between 1.4 and 2.8, shutter speed in the 1/500s – 1/640s range, and ISO 1600-3200 (the stage lighting varied from act to act and I tweaked settings accordingly).  Depth of field wasn’t much of an issue because my focus point was quite far.  However, I also spent time trying to capture some of the motion in the dances.  I was shooting handheld so I did have to consider that when deciding how long to open the shutter.  I played around with various shutter speeds and came out with some fun shots.  For the fire shots I had hoped to be able to reduce the exposure enough to avoid blowing out the highlights of the flames completely but in doing so I ended up underexposing everything else much more than I liked.  In the shot above I like the balance between capturing motion in the flame yet keeping some clarity in the dancer.  Some shots blurred things more (see image below) and that’s interesting in its own right but I prefer the balance in the shot at the top of the post.

Processing was quite simple for all these shots.  I shot with daylight white balance so that I effectively captured the colors consistently.  The color turned out rather well.  I used a bit of clarity and sometimes bumped the exposure up a hair in Lightroom.  Finally, I exported from Lightroom with a preset that ran the images through a noise reduction action (using Noiseware) in Photoshop.


Strolling on the Beach

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Strolling On The Beach 50mm, f/2, 1/4000s, ISO 100

I was very surprised to find that one of my (not-so-freshly-pressed) posts was featured on WordPress Freshly Pressed. I started thinking about what post I should follow up with to hopefully meet the expectations of any new followers, etc.  I’m humble enough to realize that I’ve got nothing but photographs that *I* like — and hopefully others will like many of them.  What’s the Ansel Adams quote?  Something like “There no rules for good photographs, only good photographs”.  And of course “good” is defined by personal taste.  So…I’m just posting the next picture I had already planned to post in hopes that others like it too 🙂

On a recent trip to the Texas coast I was setting up for some bokeh shots with the 50mm f/1.4 and noticed this couple approaching.  I quickly focused on the sand and recomposed to catch them as they passed in front of the camera.  I said a quick ‘hello’ but otherwise pretended to ignore them and clicked off a couple of shots as they were in the frame.

My camera was already at what I considered a good aperture for this situation — f/2.  From experience I knew that anything larger and the background would be too blurred to provide enough detail to give a sense of where the shot was taken.  I had already experimented with some f/1.4 shots taken at a very close distance from the subject and the background was completely lost.  For all you could tell, I was in a bright room inside my house as opposed to the beach.  Sometimes that’s a nice effect but when I’m at the beach I typically want to show, or at the very least hint strongly, that I’m at the beach.

I knew my focus wouldn’t be perfect.  With such a shallow depth of field it usually doesn’t work to recompose your image since you end up swinging the whole plane of focus away from the subject [see below for a short, lame-ish explanation of that].  I had no time to worry about that nor did I care for this shot since I didn’t really want to capture any detail of the couple — I was going for the overall scene of “some couple” walking on the beach.  With the blown-out highlights and backlighting a precise point of focus wasn’t going to matter much anyway.  I’m not wild about the composition but again, this was a hurried, serendipitous shot.  The almost-opaque frame around the image was something I added while experimenting with OnOne Software’s Photoframe.  I’m not sure if I like it but I’m considering this one “done”.

About those depth of field issues when recomposing a shot…When you focus your camera on a particular point, imagine a plane that is perpendicular to line between your lens and subject.  Everything on that plane (including everything near the plane within the range of your chosen depth of field) will be in focus.  Taking that further, if you focus on a subject 10 feet away it will obviously be in focus, but so will anything on the flat plane (NOT arc) which goes left and right from that point.  [Here’s an illustration — not sure how helpful]  When you focus and then rotate the camera (recompose) that whole plane moves.  If you have a large depth of field (ie small aperture and/or fairly large distance to the focus point) that may not matter because the subject remains within the in-focus region even when you rotate the plane.  If the depth of field is very narrow there’s a good chance that you end up moving the subject out of the in-focus region (actually you move the plane of focus away from the subject as you rotate it).  I’ve seen a great illustration of this somewhere…I’m not able to find it with a couple quick internet searches though.


Out of Focus. Sort of…

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Former Flower 60mm, f/2.8, 1/2000, ISO 200

I shot this on a hike in Montana this summer.  Initially I just thought it would make a nice shot with a blurred background — usual stuff.  However, when I started shooting it I realized that no matter what I focused on within this “flower” it still appeared out of focus somewhat.  There’s so much going on in there that the shallow depth of field blurs out the rest.  I kind of like how it sort of has a focal point, yet sort of doesn’t.

Just for grins, another shot from the hike:

http://www.flickr.com/photos/michaeltuuk/6304473358/in/photostream/

Flower 70mm, f/2.8, 1/350, ISO 200


Capitol Star

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Star in the Capitol Gate

I always liked the stars that adorn the gates and fences on the Texas Capitol grounds.  I played with variations of this shot for a while but couldn’t seem to capture what I really had in mind — both the star and the Capitol in focus, with this perspective.  The formula may exist but I didn’t figure it out.  The wide-angle lens (used for this shot) gave a perfect perspective but I had to use a focus distance which precluded a deep depth-of-field.   Stepping back with the wide lens pulled in some out-of-balance elements (IMO) of the gate unless I centered the star (blocking the Capitol building). Tried the 24-70mm but the bit of added compression in perspective wasn’t quite to my liking.  That compression does help square up the star and Capitol relative to each other but again, it wasn’t what I was after.

I decided to post the shot anyway — still an interesting shot IMO and I hope you enjoy it.  It’s interesting how the tonemapping process turns the background blur into a somewhat dreamy scene while keeping the star a nice, realistic focus point.  I might experiment with this shot again someday.


Depth Of Field…Not Simply Determined By Aperture

Understanding depth of field (DOF) is one of the keys to great photographs.  Having too shallow a DOF can result in important subjects being out of focus.  A very deep DOF may result in background distractions — areas that you intended to be out of focus may be sharp and detract from your subject.

For a long time I thought that the only thing to know was “large aperture = shallow DOF”.  However, in addition to aperture, DOF depends on many other factors like the focal length of the lens, the size of your camera’s sensor, and the distance to the subject you are focusing on.

I have no intention to discuss the equations and physics which govern DOF here.  If you find that interesting then search for articles on a site such as photo.net.  What I will do is give a few examples of what to expect with certain settings.  All the calculations come from dofmaster.com.  I use their iPhone app — quite handy.  Google “DOF calculator” or search the iPhone app store to find other programs if you’d like.

Let’s assume you are using a Canon 50D (my current camera) with the trusty 50mm f/1.8 lens.  If your subject is 5 feet away (that’s your “focus distance”) and you’re shooting at f/2.8, whatever is between 4.85 feet and 5.16 feet will be in focus (roughly 4 inches).  In a portrait situation this implies that if the eye is in focus, the tip of nose will barely be in focus (depends on the size of the nose 🙂 ).  The back of the ear may be out of focus a bit.  If you stepped back to a distance of 20 feet (granted this will be an entirely different composition) you now will be in focus from 17.7 feet to 23 feet — total DOF of over 5 feet.  Note that this depth is obtained using the same lens and aperture as the portrait above but the DOF is different due to the focus distance.

Here’s a shot taken with a 50mm lens, f/2.0, approximate distance was 6 feet which gives a total DOF of only a few inches.  The near eye was my focus point.  Note how the rear eye and cheek are already a bit out of focus (I like it).

Elaina

Impromptu Portrait of Elaina

Here’s a shot taken with the same 50mm lens at f/4.5 (reasonably large aperture) but with a large focus distance.  Everything is in focus from the front of the car to the sign behind it.

VW Bug

VW Bug at Magnolia Cafe South

Let’s look at an example using a smaller aperture.  Most of us would consider f/7.1 to be a reasonably small aperture and expect this to give “good” DOF.  If you are focusing on a single person at a distance of 10 feet, they will be nice and sharp.  However, your total DOF is only about 3 feet.  If you were shooting into a crowd at this distance you would only be focused at a depth equivalent to a few people.

Five

Elijah Is Five Today!

In the above image of Elijah, a 28mm focal length at f/7.1 gives exactly the effect I intended.  The hand is in focus and prominent due to the wide angle, his face is blurred but still very much recognizable and part of the picture, and the distant background is quite blurred.  Someday I’ll photoshop the kiddie pool out of the background…

So — pay attention to DOF and know how it will affect your images.

There’s a LOT more to know.  I’ve ignored the fact that DOF is constant in a *plane* rather than simply a radius from the lens.  I’ve not explained hyperfocal distance.  Research and learn the basics at least.  You may avoid the disappointment of finding out your small aperture didn’t give you much DOF or that your large aperture didn’t blur the background like you thought it would do.

© 2009 Michael Tuuk

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