ISO/TC 42/WG 3 - Image measurement, viewing and sensitometry

This document provides information and examples of measurement methods for evaluating the image quality of digital photographic reflection prints, including prints produced by ink jet, thermal dye transfer, electrophotography and silver halide (chromogenic) technologies. These measurement methods are intended especially to be applicable to small prints with a size of available picture area ranging from 35 mm × 45 mm to 360 mm × 450 mm, a popular and basic application of photographic print technology. NOTE The definition of "digital print" here is print made directly from digital data when there is no intermediate image carrier, or when the image carrier is refreshed for each impression, and thus each impression can be different in content if desired.

This document specifies the measurement methods and specification of image quality of lenticular prints that are used for changing images. This document does not cover lenticular prints that are used for 3D images. NOTE Lenticular prints for 3D images can be measured with the same types of procedures. However, it needs more information, such as the dependence of the measurement distance, to evaluate the 3D performance. This document specifically describes measurement methods for cross-talk, viewing angle range, angular misalignment from the designed viewing angle and the uniformity of the image within the printing area of the lenticular print images. These are critical for the image quality of lenticular prints for changing images. This document is applicable to lenticular prints produced by printing technologies that include impact and non-impact printing. Examples of the former are off-set, gravure and flexography, while the examples of the latter are silver halide, inkjet, dye diffusion thermal transfer and electrophotography. The multiple laser images (MLI) and changeable laser images (CLI) process of using a laser to write through a lenticular screen at different angles to create multiple images is also used.

ISO 10505:2009 describes a method for determining the intrinsic root mean square granularity (rms‑granularity) of photographic films. Intrinsic rms-granularity refers to those density fluctuations produced solely by the distribution of developed image forming centres in the photographic emulsion. Continuous-tone monochrome (silver absorbing species) and colour (dye absorbing species) materials coated on a transmitting support can be measured by the procedures described in ISO 10505:2009. ISO 10505:2009 is intended for imaging systems with viewing magnifications between 5x and 12x (see Annex A). The following kinds of granularity measurements are not covered by ISO 10505:2009, even though they are photographically important: reflecting materials (photographic papers); materials having emulsion coated on both sides of the support (e.g. some X-ray films); the estimation of the noise power spectrum (Wiener spectrum).

ISO 9236-1:2004 specifies methods for the determination of the sensitometric curve shape, average gradient and speed of a single sample of a screen/film/filmholder/processing system for medical radiography. It is not applicable to special radiographic applications such as mammography, dental radiography and direct-exposing medical radiographic systems (see for example ISO 5799). The filmholder can be any means that ensures close screen/film contact and prevents the film from being exposed to ambient light. In particular, the filmholder can be a light-tight vacuum bag, as often used in the laboratory, or a radiographic cassette as used in medical radiography.

ISO 9848:2003 specifies a method for determining the ISO speed and ISO average gradient of black-and-white camera negative photographic films used for first generation microfilming of source documents at exposure times typically found with tungsten sources. These source documents include any handwritten or printed alphanumeric and line documents such as books, periodicals, business correspondence, and engineering drawings. The value-rating system described in this ISO 9848:2003 is only useful to the consumer if his exposure illumination is from an incandescent tungsten source. It is not intended to include pictorial or continuous tone reproduction, computer output microfilm (COM), reversal processed or direct positive films or other films exposed by non-tungsten sources such as laser or cathode ray tube. The ISO speed and ISO average gradient values obtained by applying this ISO 9848:2003 are intended for practical use in comparing film/process combinations and for computing exposures.

ISO 2240:2003 specifies the method for determining the ISO speed of colour reversal camera films producing continuous-tone pictorial images that are intended to be viewed on transparency illuminators or by projection as slides. It also applies to 8 mm and 16 mm motion-picture films used in non-professional applications. ISO 2240:2003 is not applicable to professional motion-picture films regardless of their applications.

ISO 7004:2002 specifies methods for determining sensitometric curve shape, ISO speed, ISO average gradient and ISO gradients G2 and G4 for industrial radiographic systems consisting of film and film processing when exposed directly to X-rays and gamma-rays. The measurement of characteristics of film systems used in industrial radiography with fluorescent intensifying screens is not specified in this International Standard.

This International Standard specifies the spectral characteristics of illuminants for sensitometry appropriate for evaluating camera films used for pictorial photography in natural daylight, studio tungsten and photoflood, including colour and black-and-white films, both reversal and negative types, and for evaluating black-and-white papers used with incandescent tungsten printers. It also describes methods for evaluating the acceptability of illuminants for sensitometry and specifies tolerances. It does not include illuminants for use with colour papers, since this would need to take account of the coloured mask of the negative material, for which no standard information is at present available.

This International Standard defines a common set of reporting parameters and describes the methods to be used in the determination and presentation of individual densitometer performance and manufacturer-reported performance specifications. This International Standard applies to transmission and reflection densitometers typically manufactured for and used by the photographic, graphic arts and radiographic trades.

This International Standard specifies the methods for determining the maximum exposure time that a given sensitized material can receive from a given safelight without affecting the quality of the final image. It also specifies the records which shall be maintained for the components of a safelight and its operating environment.

The colour negatives obtained with these films are assumed to be primarily used for making reflection-type colour prints but may also be used to make colour transparencies. The specifications do not apply to colour negative films for motion-picture and aerial photography.

Describes a method for determining the speed and average gradient of black-and-white negative films used in aerial photography. Depending on the processing conditions, a single film product may have several speed and gradient values. The specifications do not apply to infrared aerial films.

This International Standard specifies a method for determining the resolving power of photographic films, plates and papers, including black-and-white films, black-and-white printing papers, colour-reversal films, colour-negative films, and colour-printing papers. Materials designed for X-ray and other high-energy radiation are excluded, as are photographic materials used in medical radiography where the exposure source is an intensifying screen in contact with the film (sensitized on one or two sides). Also excluded are materials having photo-polymer, diazo, etc. light-sensitive layers.

This part of ISO 9236 specifies methods for determination of the sensitometric curve shape, average gradient and speed of a single sample of a screen/film/filmholder/processing system in mammography. The filmholder may be any means which ensures close screen/film contact and prevents the film from being exposed to ambient light. In particular, the filmholder may be a light-tight vacuum bag, as often used in the laboratory, or a radiographic cassette as used in mammography. NOTE — Hereafter, screen/film/filmholder combinations will be referred to as "combinations", and will be referred to as "systems" when the processing is included.

Describes a method for the determination of the ISO speed of materials for direct-positive colour-print cameras. Does also apply to diffusion-transfer and conventional colour-print materials directly exposed in cameras.

The principle of the method specified is exposing and processing samples as specified, obtaining density measurements from the resultant images to produce a sensitometric curve from which values are taken and used to determine ISO speed and ISO range. The method applies to vesicular microfilms which have their principal spectral sensitivity in the region of 350 nm to 450 nm and are used to produce negative-appearing images from positive originals and positive-appearing images from negative originals.

Specified is a sensitometric method for determining and expressing the speed of photographic negative materials.

Pertains to all conventional silver-halide contact and enlarging papers used for continuous-tone or pictorial photography. The method is based on exposing and processing samples, performing density measurements from the resultant image to produce a sensitometric curve from which measurements are taken and used to determine ISO speed and ISO range values. Annexes A to C deal with the relationships between the paper range and the effective density range of the negative, log exposure range and contrast, and log exposure range and average gradient.

Specifies measuring methods so that the film/process system can be obtained reproducibly and can also be compared with those of other systems. Describes sensitometric procedures for films exposed directly to X-rays. This second edition cancels and replaces the first edition (1981).

The colour negatives obtained with these films are assumed to be primarily used for making reflection-type colour prints but may also be used to make colour transparencies. The specifications do not apply to colour negative films for motion-picture and aerial photography.

Describes a method for determining the speed and average gradient of black-and-white negative films used in aerial photography. Depending on the processing conditions, a single film product may have several speed and gradient values. The specifications do not apply to infrared aerial films.

Specifies a method for calculating a spectral distribution index to evaluate the ability of expendable flash and electronic flash units to produce photographic colour results comparable with those obtained with daylight-type films exposed to daylight illumination.

Describes the spectral characteristics of an ISO standard camera lens and a method for determining the contribution of spectrally selective lenses to the colour of the final film image. The procedure can also be applied to other optical elements in the camera.

Methods for the determination of the sensitometric curve shape, average gradient and speed of a single sample of a screen/film/filmholder system in medical radiography. Does not apply for special radiographic applications such as mammographie and dental radiography.

Specifies spectral conditions for the measurement of several types of densities used in photographic image reproduction. Has been expanded to include additional spectral types. Replaces the first edition which has been technically revised.

Cancels and replaces the first edition (1983). Specifies the geometric conditions for measuring the reflection density of photographic and graphic art materials. Specifies illumination at all azimuth angles. Does not cover those situations where light has been deliberately polarized. Also applicable to the measurement of these characteristics for other materials.

Cancels and replaces the first edition (1982). Gives the method for determining the ISO speed of colour reversal camera films producing continuous-tone pictorial images that are intended to be viewed on transparency illuminators or by projection as slides. Also applies to 8 mm and 16 mm motion-picture films used in non-professional applications. Does not apply to professional motion-picture films regardless of their applications.

Replaces "G" with "G bar" throughout subclause 6.2.2, table 2 and subclause 7.2.

The method of determination specified is based on exposing and processing samples, measuring density from the resultant images to produce a sensitometric curve from which values are taken and used to determine ISO speed and ISO average gradient. Applies to black-and-white camera negative photographic films used for first generation microfilming of source documents at exposure times typically found with tungsten sources.

The specifications apply to industrial radiographic film/film process combinations when exposed directly to X and gamma rays. The evaluation of films used in industrial radiography with fluorescent intensifying screens is not specified.

Specifies the method of test for determining the condition for handling sensitized material, which is defined as that condition which provides less than half the maximum safelight exposure which can be given to sensitized material without producing a detectable change in the final image.

Specifies the spectral characteristics of illuminants for sensitometry appropriate for evaluating camera films used for pictorial photography in natural daylight, studio tungsten, and photoflood, including both reversal and negative colour and black-and-white films. Describes also a method for evaluating the acceptability of illuminants for sensitometry.