Techniques et Conseils pour une Mise au Point Parfaite
Objectifs
Les objectifs de cette vidéo sont de:
- Apprendre à utiliser la mise au point manuelle et automatique
- Maîtriser les techniques de recadrage pour une mise au point efficace
- Comprendre l'impact de la mise au point sur la profondeur de champ
Résumé
Apprenez à utiliser la mise au point manuelle et automatique pour améliorer vos photographies.
Description
La mise au point, ou focus, est une technique cruciale en photographie qui peut être réalisée manuellement ou automatiquement. Le choix de mise au point peut transformer le sens d'une photographie, making it essential for photographers to master this tool on their digital SLR cameras. The photographer decides where they want the sharpness plane. Manual focus can be useful in challenging conditions, but narrow viewfinders of entry-level digital SLRs can make the process laborious. In situations with very shallow depth of field, such as macro photography, a technique known as 'focus trapping' can be employed for greater precision. This involves locking the focus at a certain distance and moving back and forth to perfect it without touching the focus ring.
Automatic focus (autofocus) is now available on all digital SLRs. Understanding how to use focus points and the re-composing technique is crucial. Viewfinder focus points are represented by small squares or rectangles, ranging from 3 to 45 or more. Photographers can either let the camera automatically choose the focus point or manually select it using a combination of buttons. Using the central focus point, which is often more sensitive, and then re-composing the shot by half-pressing the shutter button to lock focus is a common practice. The focusing speed may vary depending on the camera model.
Pre-focusing by half-pressing the shutter button allows for quicker shutter response, essential for capturing precise moments. Choosing the exact focus point can significantly impact the photo's appeal. Unlike compact cameras, digital SLRs offer more control over depth of field due to their larger sensors. For example, focusing on poppies in the foreground versus trees in the background creates entirely different images. Maximizing depth of field by closing the aperture results in sharpness across all planes. The observer's eye is drawn to sharp elements, making focus control vital for successful photography.