IT8 targets ?

[screeny]

dumb simple question: what is it, these IT8 targets?

[klaus.sailer]

IT8 Targets... can be bought. They are sheets, posters or transparencies with defined, known, measured and published properties. On these sheets there is a set of colors and contrast scales with known color values and brightness. When you scan, photograph or otherwise process IT8 targets, the workflow can be adjusted to yield the correct color/luminance values further down in the processing pipeline.

 

See this link - http://www.ddisoftware.com/prism/help/it8.htm

[john_murphy1]

Also check out <a href="http://www.targets.coloraid.de/">Wolf Faust's site</a>.

[ellis_vener_photography]

IT-8 targets are used in profiling scanners. They are color charts made on E-6 film and are

to be used in conjunction with tables of the Red, Green and Blue values for each patch for

that target. small and medium format IT-8 targets are batch measured while large format

(4x5 IT-8 targets should be hand measuered. Yo uscan the target and then use profiling

software that reads each patch and compares the scanned value for each patch

againsttheactual value . A profile is then created which compensates for the characteristics

ofthe scanner and neutralizes (within the limits of what is possible for the scanner) those

characteristics. Once installed this profile works in the background to make sure you are

getting a scan which is essentially an accurate reproduction of the slides you are scanning

assumng the work space (a special class of color space in whioch equal amounts of red,

blue and green create a neutral tone of gray at all densities from shblacks through

midtones to highlights) you are using is large enough to contain without lipping the color

range of the transparency. Adobe RGB(1998) is a relatively large workspace that is quite

common but clips some of the potential range in a transparency. ProPhoto is large

enoughto contain all of the range of a transparency (slide) but is too large for scanning.

My preference is the Ektachrome 100 workspace from http://www.josephholmes.com but

the free Ektaspace workspace from http://www.josephholmes.com works very well too and

is free. These workspaces are just large enough to contain all ofthe colors a trnsparency

film is capable of recording short of writing color directly to the film with a color laser.