MACRO PHOTOGRAPHY

Macrophotography is close-up photography, usually of very small subjects. Classically a macrophotograph is one in which the size of the subject on the negative is greater than life size. However in modern use it refers to a finished photograph of a subject at greater than life size.[1] The ratio of the subject size on the film plane (or image sensor plane) to the actual subject size is known as the reproduction ratio. Likewise, a macro lens is classically one lens capable of reproduction ratios greater than 1:1, although it now refers to any lens with a large reproduction ratio, despite rarely exceeding 1:1.

Outside of technical photography and film-based processes, where the size of the image on the negative or image sensor is the subject of discussion, the finished print or on-screen image more commonly lends a photograph its macro status. For example, when producing a 6×4 inch (15×10 cm) print using 135 format film or sensor, a life-size result is possible with a lens having only a 1:4 reproduction ratio.

Reproduction ratios much greater than 1:1 are considered to be the realm of photomicroscopy, often achieved with digital microscope.

depth of focus

The depth of focus Eq. 14 may be regarded as the depth of field at the film side of the lens. It has a few properties in common with the depth of field, such as that it increases with the F-number, but there are also differences. Provided that the image magnification and F-number are kept the same, there is no dependencd on the focal length whatsoever. The dependence on the image magnification is weak, a humble factor of two between infinity focus (M=0) and lifesize portrayal (M=1). The significance of the depth of focus is found in relation to the precision of camera alignment and film flatness. On the assumption of accurate focussing and a properly aligned camera, the depth of focus indicates the tolerance of the photographic system with respect to film displacement. In other words, if the film departs from its proper position by a distance which brings it out of the depth of focus the subject is imaged with a COC larger than the permissible value and considered out of focus. Overall the depth of focus is smaller for miniature (digital) cameras than it is for larger formats, which puts more stringent demands on manufacturing tolerances.

Depth of field

In optics, particularly as it relates to film and photography, depth of field (DOF) is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image. Although a lens can precisely focus at only one distance at a time, the decrease in sharpness is gradual on each side of the focused distance, so that within the DOF, the unsharpness is imperceptible under normal viewing conditions.

In some cases, it may be desirable to have the entire image sharp, and a large DOF is appropriate. In other cases, a small DOF may be more effective, emphasizing the subject while de-emphasizing the foreground and background. In cinematography, a large DOF is often called deep focus, and a small DOF is often called shallow focus.

Affecting DOF are camera-to-subject distance, lens focal length, selected lens f-number, format size, and circle of confusion criterion. The combination of focal length, subject distance, and format size defines magnification at the film / sensor plane.

DOF is determined by subject magnification at the film / sensor plane and the selected lens aperture or f-number. For a given f-number, increasing the magnification, either by moving closer to the subject or using a lens of greater focal length, decreases the DOF; decreasing magnification increases DOF. For a given subject magnification, increasing the f-number (decreasing the aperture diameter) increases the DOF; decreasing f-number decreases DOF.

When the “same picture” is taken in two different format sizes from the same distance at the same f-number with lenses that give the same angle of view, and the final images (e.g., in prints, or on a projection screen or electronic display) are the same size, the smaller format has greater DOF.

Many small-format digital SLR camera systems allow using many of the same lenses on both full-frame and “cropped format” cameras. If, for the same focal length setting, the subject distance is adjusted to provide the same field of view at the subject, at the same f-number and final-image size, the smaller format has greater DOF, as with the “same picture” comparison above. If pictures are taken from the same distance using the same

f-number, same focal length, and the final images are the same size, the smaller format has less DOF. If pictures taken from the same subject distance using the same focal length, are given the same enlargement, both final images will have the same DOF. The final images will, of course, have different sizes.

Cropping an image and enlarging to the same size final image as an uncropped image taken under the same conditions is equivalent to using a smaller format under the same conditions, so the cropped image has less DOF.

When focus is set to the hyperfocal distance, the DOF extends from half the hyperfocal distance to infinity, and the DOF is the largest possible for a given f-number.

The advent of digital technology in photography has provided additional means of controlling the extent of image sharpness; some methods allow extended DOF that would be impossible with traditional techniques, and some allow the DOF to be determined after the image is made.

RULE OF SPACE

The rule of space applies to artwork (photography, advertising, illustration) picturing object(s) to which the artist wants to apply the illusion of movement, or which is supposed to create a contextual bubble in the viewer's mind.

This can be achieved, for instance, by leaving white space in the direction the eyes of a portrayed person are looking, or, when picturing a runner, adding white space in front of him rather than behind him to indicate movement.

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RULE OF ODDS

Rule of odds – The rule of odds states that images are more visually appealing when there is an odd number of subjects. For example, if you are going to place more than one person in a photograph, don’t use two, use 3 or 5 or 7, etc. Of course this is a pretty silly notion for an engagement shoot, right? Or a wedding shoot. Or a family with only two kids. But when possible, when you are not just shooting real life but composing images (still life, family groups, flowers) remember the rule of odds. Studies have shown that people are actually more at ease and comfort when viewing imagery with an odd number of subjects. I’d be very interested to know the different opinions readers have for why that is. I’ll share mine in the comments below.

BULBING

Put simply, it's a technique of photography where the lens of the camera is left open for long enough to capture something not usually seen by the naked eye.

As far as I can tell there is no official "minimum length of time" after which a photo is officially a "bulb photo"

It is not (necessarily) a photo of a light globe or an emerging plant - although oddly enough the former is often a major contributing component in a bulb photo and the latter is often the subject of the loosely related discipline of time lapse photography (animation).

Where did the term "bulb" come from?

I don't know for sure but I can hazard a guess that it has something to do with the fact that many of the earliest cameras used an air based shutter release system.

The shutter was opened when the bulb at the end of a tube was pressed flat and stayed open until the bulb was released. This was of course a fairly inaccurate way of timing a shutter's release but was adequate for the time because longer exposures where necessary due to the limitations of the chemicals and processes used in early days.

For example, in early flash photography, it was not possible to accurately time (synchronise) the ignition of the substance exploded to create the flash, with the lens opening. Hence, subjects sat still (hopefully), the lens was opened, the flash was ignited, the lens closed and, hey presto.

It's fair to say that most photos in the early years of photography were in essence, "bulb photos".

With the advent of newer cameras, chemicals etc it was possible (and desirable) to create mechanically timed shutter releases.

I suspect the "B" setting of these cameras was retained for backwards compatibility as well as to satisfy those who wanted to take photos in low light conditions.

Happy Val's Day

You changed my world when you take off your eyeglasses B)

You changed my world when you give me your sweety smile :)

You changed my world when you laugh at me =D

So, at this special moment , I just wanna say HAPPY VALENTINE'S DAY for you and all of my friends :D