Pin-Cushioning

What Is Pin-Cushioning and How Does It Effect Photography and Photographs? When talking about photography and taking photographs the term ‘pin-cushioning’ refers to a kind of distortion which makes images appear ‘pinched’ in the middle. The term gets its name from the effect pushing a pin into a pin-cushion has on its appearance. Pin-cushioning is a problem associated mainly with cheap telephoto zoom lenses such as those found on point and shoot cameras. The effects of pin-cushioning can be corrected in post-processing or by using higher quality equipment. The opposite of pin-cushioning is ‘barrel distortion’ which causes an image to …

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Pixel

What Is a Pixel and What Does It Mean When Talking About Photography? When talking about digital images, or methods of displaying digital images a ‘pixel’ is the smallest component within a digital image. Pixel stands for ‘picture element’, they are the individual components that collectively recreate the image captured with your digital camera on a computer monitor. Image resolution is measured by the total number of pixels within an image; A VGA image for example has a resolution of 640×480 pixels (total of 307200 pixels), the higher the number of pixels the higher the resolution of an image, or …

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PSD

What Is A PSD File? PSD stands for Photoshop Document and is the native file type created by the Adobe image editing application, Photoshop. Photoshop is a powerful editing tool that allows for a totally non-destructive editing workflow (if used correctly!). Much of the workflow centres around the use of ‘layers’ to selectively apply adjustments and add or remove content from the image. A PSD file saves all of this layer content, as well as other content such as saved selections of specific areas in your image. A PSD file can be as simple as a single image, or as …

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Retouching

What Is Retouching and How Is It Used in Photography? When talking about photography, specifically post-processing and image editing, the term ‘retouching’ refers to any process used to alter an image physically, in the case of film or, digitally in the case of digital images to improve the images appearance. Retouching can be used to remove a variety image defects for example dust or dirt on an lens or image sensor or, as is widely seen in fashion publications the physical defects of a model’s skin. Modern digital retouching is carried out in photo editing software using numerous tools such …

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Thumbnail Index

What Is a Thumbnail Index and how Is It used in Photography? A thumbnail index is an index of images comprised of thumbnails; reduced size versions of images designed to give you an ‘at a glance’ idea of an images contents. Thumbnail indexes usually replace text indexes in cameras and image editing software because of the practicality of searching visually when working with photographs. Thumbnail indexes will often contain a small amount of metadata which can be used alongside the thumbnails to quickly identify images in libraries that can sometimes contain hundreds of thousands of individual images. Thumbnail indexes can …

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Tone Map

What Is a Tone Map and How Is Is Used When Editing Photographs? When editing photographs applying a tone map means that you are changing the RGB value for pixels of a certain color or ‘tone’ within an image. Take for example a pixel with the RGB value 0,0,225 or blue; If you were to alter or ‘re-map’ the tone of the blue channel to produce a pixel with the values 0,0,180 and applied this map to all of the pixels with the value 0,0,225 within the image, you have tone mapped the image, drastically altering it’s appearance. Tone mapping …

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True Color

What Does True Color Mean When Talking About Image Editing and Photography? When talking about digital photography and image editing, the term ‘True Color’ refers to an image which is rendered in RGB color with a bit-depth of 24. 24-bit RGB allows for 256 values of each color channel, therefore creating the possibility for the rendering of a total of 16,777,216 tones. The human eye can only perceive roughly 10 million colours and so images rendered in True Color appear to be extremely realistic. Given the large amount of information contained within an image rendered in True Color related file sizes …

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Unsharp Masking

What Is Unsharp Masking and How Is It Used When Editing Photos? Unsharp masking is a techniques used when editing photographs to remove blurriness from an image. The name may initially appear confusing because it would appear to suggest the removal of sharpness, but is derived from the fact that the technique uses a blurred or ‘unsharp’ negative of an image as a mask to increase sharpness. the technique can be traced back to 1930’s Germany where the process involved the creation of a physical second negative of an image. The advent of digital photography and powerful image editing software …

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XMP

What Is an XMP File and How Is It Used in Photography? In photography, specifically in post-processing and editing, XMP Data is the data standard for Adobe’s Extensible Metadata Platform. In XMP enabled applications photographers and editors are able to embed metadata directly into popular image file formats such as JPEG files. Using XMP means that so-called ‘sidecar’ metadata files are no longer required, vastly simplifying the file organization and storage workflow for photographers. Files containing XMP data are still able to be opened and edited in applications that do not support XMP data, the metadata contained within the file …

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