Deep Focus in Digital Photography is a technique where a large depth of field is obtained by using wide angle lenses and the smallest possible aperture. There three photography specific terminologies; that is – Focus in Photography, Depth of Field in Photography and Wide Angle Lens has been discussed in details before. Interested readers can read the above mentioned articles if needed for the purpose of understanding. Deep Focus is not only used in Digital Still Photography but is used in cinematography as well. We will discuss Deep Focus only in case of Still Digital Photography, in this article. In the article, basics of Optics in Digital Photography we referenced to 16 must to be understood points for any level of photographer and Aperture was mentioned there as hyperlink to the article specifically on Aperture. We want that the starters read that article for better understanding of the topic Deep Focus, thus we have avoided direct linking to the article on Aperture.
Basics of Deep Focus in Digital Photography
Focus stacking or focus blending is a software level post processing work, whereas deep focus is a fully optical method where the foreground, mid-ground and background are remains in focus. This effect is usually achieved by using the hyperfocal distance of the particular camera lens, usually a wide angle lens. From the definition of optics, hyperfocal distance is the closest distance at which a lens can be focused to produce an image on a screen (sensor in our case) while keeping the objects of infinity to an acceptably sharp quality. In the typical American movies from 80’s to the 90’s you will get an ‘sense’ where in the master shots three were two or more characters in a conversation. This trend in case of movies has went off as with time, focus on an individual with the background blur effect appears to be more effective trend now. However, deep focus in still photography, from the posters for promoting a movie to just our digital photography has remained in the same place.
Deep focus, deep space and issues with sensor formats
Deep space is synonymous with deep staging. In deep space the subject to be shoot and props within a planned or studio setup remained in different planes. The seasoned photographers can use this deep space without really using the optical deep focus.
As because depth of field is dependent on focal length plus the aperture and focal distance settings, kind of deep focus is easier to achieve with a smaller size of film sensor. Shallow focus is just the reverse of deep focus. We often face this issue of shallow focus in case of Macro photography, where Focus stacking or focus blending is used to make the image more better or shallow focus is used to add the artistic background blur effect or bokeh.