DLS Exercise 1 - DOF, MF

This exercise is to help you hone your understanding of DOF while practicing manual focusing.

TASK 1

Find a nice bright spot to take a picture - a kitchen, bedroom, or living room floor with lots of natural light would be ideal, or this could be done outside. Set up a series of 7 similar or identical items in a row, each about 12 - 18" apart from each other. Be as creative as you like - they could be anything from beer bottles to baby bottles, Hotwheels, Barbie shoes. You could make a train of some sort with your kids. You could put pinecones on the snow. You could ask 7 friends to stand in a row. Really, the sky is the limit...

Disable your flash, set your camera to MF, AV f3.5, ISO 200. (Remember, your zoom may need to be at the widest angle to get to f3.5!) Standing at one end of the row, focus on the object closest to you. Take one picture. Note how many of the objects are in focus at f3.5, and adjust your aperture one f-stop at a time until ALL the objects are in focus, WITHOUT readjusting your focus. How many f-stops did it take you? Note the light and what the camera set your shutter speeds at - did you have to deal with camera shake at all? If you had trouble getting pictures with higher f-stops, what would your options be for increasing the shutter speed without altering the depth of field? Hint - law of reciprocity only has 3 parts: light intensity (aperture) sensitivity (film speed) and duration (shutter speed).

TASK 2

Disable your flash, set your camera to MF, AV f3.5, ISO200. Find a long edge - your table, a countertop, the fence in your backyard, a bannister, a windowsill. Standing in the same spot at one end, manually focus so that you have 3 images with distinctly different focal points along that straight edge. If you're feeling adventurous and want to take your shooting to the street, this would be a really fun one to do in a grocery store in the soup aisle or in the library along the bookshelves! If you really want to challenge yourself, find a table or countertop that has a distinct end - something about 6-8 feet long. Try adjusting your aperture so that the entire length of the edge is in focus, but drops off suddenly at the end so everything beyond he table fades off into Bokeh oblivion...

TASK 3

Get a tape measure. This exercise needs to be done in a dark but not black room - your child's room at night with a night light, a windowless bathroom with the door partially opened, a room with the lights off and he TV on, the kitchen at night the lights off and the fridge open half an inch... if you want to know if it's dark enough, put it on AF. If it can't focus, then it's dark enough. Place a shiny object (glass, metal, plastic, no mirrors though) in the darkened space.

Set your camera on a stable surface - chair, table, tripod if you have one - and disable the flash. WITHOUT looking through your lens, set your camera to MF and place it on the chair or tripod or wherever you are going to be taking the picture from. Measure the distance between the object and your camera. Without looking through your lens, turn the manual focussing ring on your lens to that distance. Using the 2sec delay timer to avoid camera shake, take a picture. Move the object, and guesstimate the distance. If the image isn't clear, adjust your aperture until you are able to get the object in focus.

I'd love to see what you are coming up with! I strongly recommend using Picasa as both a photo organizer and for very basic editing features. It has an easy upload interface to Picasa web albums as well. Mac users can set up iPhoto to upload images directly to Picasa web albums as well. If you are using flickr or Facebook or another site for online sharing already, no worries. Send me a link to wherever you're uploading whatever you're shooting! (Or you could start a blog...)