Overview: We quickly reviewed the Exposure Triangle and dove right into Depth of Field and shutter speed. We did some activities and looked at Focus points, including Back button Focus.

Depth of Field (DoF) calculator | PhotoPills

1. Definition
   • The zone from the nearest to the farthest point in your scene that remains in focus. Imagine you’re taking a portrait: DoF determines whether just the subject’s eyes are sharp or if their entire face is in focus, along with the background.
2. Key Points about Depth of Field
   • Acceptably Sharp: The term “acceptably sharp” is subjective. It depends on factors like how you’ll view the image (print, screen, etc.) and your vision.
3. Factors Influencing DoF
   • Aperture: The size of the lens opening (measured in f-stops) significantly affects DoF. Larger apertures (smaller f-stop numbers) create a shallow DoF, where only a small slice of the image is in focus. Smaller apertures (higher f-stop numbers) result in a deeper DoF, where more of the scene is sharp.
   • Camera-Subject Distance: The closer you are to your subject, the shallower the DoF. Conversely, greater distance increases the depth of field.
   • Focal Length: Longer lenses (higher focal lengths) tend to have shallower DoF, while wider lenses (shorter focal lengths) provide more depth.
   • Sensor Size: Larger sensors (commonly found in full-frame cameras) generally yield shallower DoF compared to smaller sensors (like those in crop-sensor cameras).
4. Visualizing DoF
   • Imagine a narrow DoF as a photo where only a small sliver is in focus (like a blurred background behind a subject).
   • Conversely, a large DoF means much more of the scene is sharp (think landscapes where both foreground flowers and distant mountains are clear).

1. Practical Tips

   • Portraits: For creamy backgrounds and subject isolation, use wider apertures (e.g., f/1.8 or f/2.8).

   • Landscapes: Smaller apertures (e.g., f/8 or f/11) help keep everything sharp from foreground to background.

   • Experiment: Play with different settings to see how DoF changes. It’s a creative tool!

Focus Point Options – you may not have all of these! They are camera dependent. Use these is telling the camera what you want it to focus on. 

1. Single-Point AF
   • Description: This mode allows you to select a single focus point manually. The camera will focus on the subject located at that specific point. This is my usual go-to.
   • When to Use: Ideal for precise focusing, such as in portrait photography where you want to focus on the subject’s eyes. It’s also useful for still subjects and when you need to control exactly where the focus should be1.
2. Dynamic Area AF
   • Description: You select a single focus point, but the camera also considers surrounding points to maintain focus if the subject moves slightly.
   • When to Use: Great for photographing moving subjects, such as children playing or animals in motion. It provides a balance between precision and flexibility.
3. Zone AF
   • Description: The camera divides the frame into zones, and you can select a zone where the camera will focus. It uses multiple focus points within that zone.
   • When to Use: Useful for subjects that move within a specific area of the frame, such as sports photography or events where the action is concentrated in one part of the scene. Best if you don’t care what the camera focuses on (random people on a team, in a crowd, a flock of birds, etc).
4. Auto-Area AF
   • Description: The camera automatically selects the focus points based on the subject’s position and movement. It often uses advanced algorithms to detect faces or subjects.
   • When to Use: Best for quick snapshots or when you need to capture a moment without having time to manually select focus points. It’s convenient for casual photography and situations where the subject is unpredictable. When in doubt, don’t use this.
5. Group-Area AF
   • Description: This mode uses a cluster of focus points to track a subject. It’s more focused than Zone AF but covers a larger area than Single-Point AF.
   • When to Use: Ideal for tracking larger subjects or groups of people. It’s useful in wildlife photography where the subject might move unpredictably, or when your subject (or kid) is kinda far away and you just need their head to be in focus.

Summary of When to Use Each Focus Point Option (remember to keep depth of field in mind)

• Single-Point AF: Portraits, still subjects, precise focusing.
• Dynamic Area AF: Moving subjects, children, pets.
• Zone AF: Sports, events, concentrated action.
• Auto-Area AF: Quick snapshots, casual photography, unpredictable subjects.
• Group-Area AF: Wildlife, groups of people, larger subjects.

Tips for Using Focus Points

• Focus and Recompose: For static subjects, you can use the focus and recompose technique. Focus on your subject using a single point, then recompose your shot while keeping the focus locked. This advice is often given to beginners, but remember depth of field – if you shift your plane when you recompose, your subject might not still be in focus. I never got this to work, your mileage might vary.
• Back-Button Focus: Consider using back-button focus to separate focusing from the shutter release. This can give you more control, especially in dynamic shooting situations. This is what pros use.
• Make subject speed changes in Focus Menu
• If camera won’t focus, step back a step (you maybe too close)

Focus Modes – Telling the camera how to focus.

1. Single Shot Autofocus (AF-S or One Shot AF)

• When to Use: Ideal for stationary subjects like landscapes, portraits, buildings or still life.
• How It Works: The camera focuses when you half-press the shutter button and locks the focus until you take the shot. This ensures your subject remains sharp as long as it doesn’t move.

2. Continuous Autofocus (AF-C or AI Servo AF)

• When to Use: Best for moving subjects such as sports, wildlife, or children playing.
• How It Works: The camera continuously adjusts focus as the subject moves, ensuring it stays sharp even if it changes position. It can hunt for focus or eat up your battery or both!

3. Automatic Autofocus (AF-A or AI Focus AF)

• When to Use: Useful in unpredictable situations where subjects might switch between being stationary and moving.
• How It Works: The camera automatically switches between single and continuous autofocus modes based on the subject’s movement. My camera used to have this and it was my favorite. 

4. Manual Focus (MF)

• When to Use: Ideal for precise focusing needs, such as macro photography, low-light conditions, or when autofocus struggles.
• How It Works: You manually adjust the focus ring on the lens to achieve sharpness. This mode gives you full control over what part of the scene is in focus if you can see it! You may need to look at your Live View and zoom in if you camera has that capability. Cameras are much better at focusing than we are as a general rule.

Tips for Using Focus Modes:

• Portraits: Use AF-S to lock focus on the subject’s eyes.
• Action Shots: Use AF-C to track and maintain focus on moving subjects.
• Low Light: Switch to MF if the camera struggles to find focus.
• Mixed Situations: Use AF-A to let the camera decide the best mode based on the situation.

Bonus material: File handling basics (so you don’t lose photos)

• Don’t format until you’ve confirmed import + backup
• One simple folder structure
• One copy is the same as having zero copies – try to back up your photos to three places. 1) a cloud backup service, 2) a second copy on your computer, 3) your card until you know it’s been backed up to the cloud.