Monday, August 30, 2010

Depth of Field

So, here's a tool that I have found quite useful lately. It's called Simple DOF and it help you determine how much of your subject/s will be in focus. This is critical to understand while shooting portraits of more than one subject.

To illustrate... let grab an image...

So my girl is in focus. My boy... well, there goes the picture... he's not in focus.  The boy is about 2 feet further from the camera than the girl.
Clearly I intended for both to be in focus.  But it appears that we are giving some precedence to the girl here. I need to explain what I could have done to avoid this error.

First of all, because it was in the evening and I wasn't willing to push my ISO up (it is at 125 for this shot), then I had to use a larger aperture (f3.5 here). So I should have pulled out my DOF calculator (Simple DOF). I punch in that I am roughly at 34mm on my D300s camera (51mm on a full sized sensor), I was roughly 5 feet from my subject in focus (girl). The calculator tells me that my DOF is 0.85 feet. That's 10 inches.  In other words, everything from 5 foot 2 inches to 6 feet away from camera will be the sweet spot of focus.  Because the boy was more like 24 inches away, he falls in the out of focus zone.

So what could I have done differently? Well, I could have placed them equal distance from the lens. Pull the boy closer or move the girl further, or simply repositioned myself to be equal distance from both. Well, 10 inches isn't much room for error in estimating distance.
But here is an example of the same area with the same fstop. Notice both subjects are in focus here.
Same f3.5, but I backed up a bit, maybe 10 feet away, and 55mm. Now my Simple DOF calculates the focus to be 1.4 feet. That gives me almost 17 inches of focus rather than only 10. In addition, the two subjects are almost equal distance from the camera. So that gives me the focus on both of them while still getting the blurred background, so as to not distract from my subjects.

Well, that was a lot of talk... but hopefully you've learned something about calculating the dof. Google DOF or depth of field and read up a bit. It is very critical. I will end with this one where I shot 23 people and needed them all to be in focus. Fortunately, I had my ipod with me with Simple DOF on it, I used it, and it worked out. I was about 35-40 feet from the subjects, f2.8, and 70mm. That gives me around 7-10 feet of focus. I also tried to place everyone semi-equal distance from the camera by pulling in the sides and pulling forward the people on the top row. And it was nice to still have some background blur to contrast with the focused people.

Thursday, August 19, 2010

2 light sources, one sun, one strobe

Just a note about evening light and fill flash.  Sunsets can produce nice warm lighting; but can also produce long harsh shadows.  This evening I took this one without a flash in my front yard... forgive the subject matter, it's not the most aesthetic.
I am shooting at ISO 100, f4.0 and 1/320 at 38mm.
For the record, I metered at around /125 and then stopped it down faster a few stops so that I wouldn't have the sun blowing out (too bright) on the back of the subject.  Plus, I knew I would be adding a flash to fill in the underexposed areas.  This is a nice trick, because then the background is also a bit underexposed and doesn't get all the attention it would if it too bright.  So, I add a flash to the right.  While the sun is coming in camera left, the flash was placed directly opposite.  No umbrella, just straight flash.  I put it on manual and stopped it to 1/16 power.  Here's the difference..
I could have used a reflector, but then there is the element of not knowing how much light is really reflecting.  The flash allows me to control that power.   Although the flash is cooler light than the reflector would be.
I zoomed in a bit to 55mm and found a bee for the final shot.
Notice the lighting from the right still fills in some of the shadows that would otherwise be a bit too dark for my liking.

Pick of the Day

I have added this photographers blog to my reader for some inspiration on lighting examples of weddings. He's got some good stuff. I would be interested what the source of light was for the front of this subject. Definitely the sun is behind her, but is it a flash or a bounce reflector in front??? Very possibly, there was someone holding a reflector down in the lower right, but he may have added this dark feature in photoshop to cover that person. We may never know.

Monday, August 2, 2010


An incredible evening of light and magic. When the light from outside starting pouring yellow abundantly in through the windows, I knew it was time to grab the camera and head outside last night.

Tip of the day... if you have a PC (heaven forbid ;) ) and you are looking for a good program to manage your images, I have a favorite. Thanks to Rich (whom Spence and I met in Yellowstone) for turning me on to this... it's called FastStone Image Viewer. Check it out... you may convert. I use it at work since I don't have Adobe Bridge/Photoshop.

This first shot is straight from the camera, no editing.