metering

[AO Tercan]

Sevgili Arkadaşlar,

 

Sizin de bildiğiniz gibi bir yandan Türkçe başlangıç seviyesi fotoğrafçılık kurslarımız devam ederken diğer yandan da İleri Kurslarımızı ve ingilizce Digital Photography for Beginners kurslarımızı hazırlıyoruz.

 

Bu kursların hazırlığı yapılırken sizin kurslarınızın paralelinde o derslerin de anlatımları hazırlanıyor. ‘Aperture’ yazısını da bu bağlamda hazırladım ve Türkçesini yayınladık. Yine böyle açıklayıcı yazılar, ayrıca terminoloji- glossary de yazıları yayınlamak istiyorum ama hem ingilizce hem de Türkçe zor oluyor. Birşeyler hazır oldukça parça parça yayınlayacağım. Nasıl olsa herkes ingilizce biliyor.

 

Önemli bir hatamız olursa düzeltmekten de, eklemekten de çekinmeyin lütfen. Biz mutluluk duyarız. Yani öncelikle Sürç-ü lisan edersek affola diyoruz.

 

Konumuz ‘METERING’ en son aktivitede anlattığımız konudur.

 

 

Metering (for light amount): 

 

The metering in photography means, measuring the amount of light in the scene and calculating the best-fit exposure value based on the metering mode explained below.

Photographic exposure may be based on the measurement of either light falling on a subject or light reflected from it. The first method is called INCIDENT light measurement and the latter REFLECTED light measurement.

For many years, the reflected-light method was popular with photographers, amateurs and professionals. But knowledgeable professionals soon realized that exposures based on reflected-light were seriously in error whenever the subject was predominantly either dark or light. While these errors were not too apparent in black-and-white, because of the wide latitude of the film, they could be disastrous in color photography.

Today, the incident meter is popular with any photographer (still or cine) who has to work in a hurry without evaluating the effect of the relatively unimportant surroundings or misleading subject or background brightness on his exposure. The incident meter is highly important and practical meter.

So many cameras have excellent built-in meters today that, for many photographers, the thought of owning another hand-held meter might seem odd. Nonetheless, built-in camera meters are generally the reflected-light type. As any professional photographer will tell you, there are many situations that can baffle and confuse even the most advanced reflected-light meters. In fact, there are many important lighting situations that are simply beyond the scope of any built-in meter.

In our case, we recommend our beginners to use cameras built-in Automatic exposure system which is a standard feature in all digital cameras.

The metering method defines which information of the scene is used to calculate the exposure value and how it is determined. Metering modes depend on the camera and the brand, but are mostly variations of the following three types:

Matrix or Evaluative Metering

 

This is probably the most complex metering mode, offering the best exposure in most circumstances. Essentially, the scene is split up into a matrix of metering zones which are evaluated individually.

In matrix metering, the overall exposure is based on an algorithm specific to that camera, the details of which are closely guarded by the manufacturer. Often they are based on comparing the measurements to the exposure of typical scenes.

Center-weighted Average Metering

Probably the most common metering method implemented in nearly every digital camera and the default for those digital cameras which don't offer metering mode selection. This method averages the exposure of the entire frame but gives extra weight to the center and is ideal for portraits.

Spot  and Partial Metering

             

Spot metering allows you to meter the subject in the center of the frame (on most cameras at the selected AF point, if applicable). Only a small area of the whole frame is metered and the exposure of the rest of the frame is ignored. One of the most common applications of partial metering is a portrait of someone who is backlit.  Metering off of their face can help avoid making the subject look like an under-exposed silhouette against the bright background.  On the other hand, care should be taken as the shade of a person's skin may lead to inaccurate exposure if it is far from neutral gray reflectance-- but probably not as inaccurate as what would have been caused by the backlighting.

Spot metering is used less often because its metering area is very small and thus quite specific.  This can be an advantage when you are unsure of your subject's reflectance and have a specially designed gray card (or other small object) to meter off of.

Spot and partial metering are also quite useful for performing creative exposures, and when the ambient lighting is unusual.  In the examples to the left and right below, one could meter off of the diffusely lit foreground tiles, or off of the directly lit stone below the opening to the sky.

    

MANUAL METERING

The way to correctly meter a sunset is to meter on a small part of the sky away from the sun, any part of the sky that you want properly exposed, and then use those exposure settings while taking a picture of the sky with the sun (or other very bright parts of the sky) in it.

This technique requires that the camera either has some kind of exposure-lock (meaning you can lock the exposure settings while you move the camera to a different part of the sky), or that it has manual exposure.

 

 

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