Depth-of-Field and Hyperfocal Distance
Everyone knows that pictures can show elements in and out of focus. That is why most cameras require focusingeither automatically or manually. Focusing sets the only distance where a picture element appears at its sharpness. Some elements closer and further from that point can also appear sharp. The distances where this is true is called depth-of-field (DOF).
It is important to know that DOF is subjective because anything not in focus is technically not as sharp as what is in focus. The further an element is from the focus distance, the less sharp it is. If an element is far enough, it will appear out-of-focus. Far enough is in the eye of the beholder and is usually interpreted with respect to viewing size. In other words, the same image seen as a 4"x6" and as a 13"x19" will appear to have greater depth of field in the smaller print.
Even though DOF is a subjective concept, a lens' aperture and focus distance will influence the perception of depth-of-field because smaller apertures cause elements to drift out of focus slower than larger apertures. It turns out that with a given aperture, a focus distance can be calculated so that the DOF is maximized. That focus distance is called the hyperfocal distance. The hyperfocal distance depends on lens characteristics. When a particular lens is focused at the hyperfocal distance for the set aperture, elements from infinity to one third of the way before the focus point will appear in focus. This property makes the hyperfocal distance very important in landscape photography. Some point-and-shoot cameras from Pentax and Casio have a focus mode called pan-focus, which automatically sets the focus to the hyperfocal distance.
To find out the hyperfocal distances for a particular lens, you can either purchase a hyperfocal chart or use the Java hyperfocal-distance calculator below. Using it is simple, fill out the actual minimum and maximum focal length Usually printed on the front of the lens of your lens, select the minimum and maximum aperturesUsually found in the instruction manual of the camera for it, fill out or calculate the focal lens multiplierDSLR cameras come with that information in their manual and fill out the number of zoom steps you wish to see. Then, press the Hyperfocal button and the applet will display a table of hyperfocal distances according to the chosen parameters. Note that the results are subjectively based on standard human vision for a 16x20 printMost hyperfocal chart are calibrated for a 8x10 print, but people can easily print larger now.
Neocamera Blog is a medium for expressing ideas related to digital cameras and photography. Read about digital cameras in the context of technology, media, art and the world. Latest posts links:
Mirrorless Camera Buying Guide - 2015 Edition
Our detailed mirrorless digital camera buying guide, fully updated for 2015. This is the best and more current mirrorless guide!
Nikon D5500 Review
Compact entry-level DSLR with a 24 MP APS-C sensor without anti-alias filter. 5 FPS drive and full 1080p HD video at 60 FPS. A 3.2" 1 MP rotating touchscreen LCD plus built-in WiFi.
Canon Powershot G7 X Review
Premium compact with a large 20 MP 1" CMOS sensor. Stabilized ultra-bright ultra-wide-angle 4.2X optical zoom lens. ISO 125-12800, 1/2000s-250s shutter-speed, 6.5 FPS and full 1080p HD @ 60 FPS. Dual-controls dials and a tilting 3" LCD.
Fuji X100T Review
The latest classically-styled fixed lens camera from Fuji packs a 16 MP sensor with built-in Phase-Detect AF and a bright F/2 fixed 23mm lens. It offers a unique hybrid EVF/OVF with Digital Range Finder in a highly mechanical design.
Panasonic Lumix DMC-GH4 Review
The most compact interchangeable lens digital camera capable of 4K Ultra-HD video. Equipped with a 16 MP Four-Thirds CMOS sensor capable of 12 FPS. Its class-leading autofocus system is sensitive to -4 EV. Fitted with a 2.4 MP EVF with Eye-Start sensor and 1 MP 3" Rotating LCD.
Fujinon XF50-140mm F/2.8R LM OIS WR Review
Fujinon XF50-140mm F/2.8R LM OIS WR Review added to the Fuji X-T1 Photographer Experience. This is the top-of-the-line X-mount lens with constant maximum aperture in a weathersealed and freezeproof body with built-in optical image-stabilization.
Fuji X-T1 Graphite Hands-On
The Graphite Edition of the excellent Fuji X-T1 adds an ultra-fast electronic-shutter with 1/32000s maximum speed and a number of improvements in a new smooth and highly durable finish.
Nikon D750 Review
The first video-optimized full-frame DSLR features a 24 MP CMOS sensor with ISO 50 - 51200 range, 6.5 FPS and full 1080p HD video at 60 FPS, with stereo sound and AF-tracking. A 100% coverage viewfinder and large 3.2" tilting LCD with 1.2MP allow precise framing.
Best Digital Cameras of 2014
The best digital cameras of 2014, selected among each class and for various types of photography.
Nikon 1 J4 Review
The smallest Nikon mirrorless packs an 18 MP high-speed CMOS sensor capable of 60 FPS drive and full 1080p HD video at 60 FPS, plus slow-motion video up to 1200 FPS.