Abstract: An apparatus for the desludging of baths includes a separation part with an oblique sieve filter containing a plurality of essentially horizontal slots. A side of the slots over which soiled liquid runs is covered by a filter cloth placed on the sieve plate and consisting of a polyester monofilament filter fabric with a mesh width smaller than the width of the slots between the sieve rods of the oblique sieve. The combination of the filter fabric of the filter cloth and the slots of the oblique sieve yields in spite of the filtering of small solid particles, a high liquid throughput.

Abstract: A composite plate contains a core layer with a honeycomb structure between two cover layers, the first cover layer of which carries a decorative panel and the second cover layer of which carries a rear protective plate. The adhesive bonds of the composite plate consist of a layer of a relatively nonflammable adhesive. The protective element, made of a silicate base (but without asbestos) or a non-combustible mineral substance base, is adhesively bonded to the rear side of the composite plate.

Abstract: Tetrahydrothiopyran compound of the formula I ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, X and n are as defined in claim 1, are effective stabilizers for dyes and dye couplers in photographic layers. In particular, they provide protection from damage by light. They are preferably used in combination with a phenolic antioxidant.

Abstract: Salts of 1-phenyl-3-pyrazolidinones which are useful photographic silver halide developing agents.

Abstract: Reflection holograms are described and are prepared from a transmission hologram. The reflection hologram is divided into a plurality of sequential parallel notional strips each of which is divided into bands, the bands and strips extending across the hologram from one side or end to the other and being parallel. Each band of a strip contains information derived from a respective notional strip into which the transmission hologram was divided during production of the reflection hologram. Thus each strip of the reflection hologram contains information derived from the whole of the transmission hologram. The reflection hologram is produced from the transmission hologram by a process in which each band of a notional strip of the reflection hologram is exposed in turn to a respective notional strip of the transmission hologram.

Abstract: New phenols are described containing an alkyl substituent containing a functional group; as well as a process for the production of such phenols. The new phenols are useful e.g. as stabilizers in organic or aqueous systems.

Abstract: In a laser layout, a rapid photodiode is coordinated with a fully reflecting mirror of a laser, the output signal of which is compared in a comparator with a reference voltage that may be set on a potentiometer, so that if the power density detected in the resonator of the laser by a photodiode exceeds the reference voltage, the laser is deactivated to protect a frequency doubling crystal by actuating a Q-switch and/or a shutter.

Abstract: This invention relates to layers for photographic materials, which comprises a polysaccharide which is formed extracellularly by bacterial fermentation of glucose, maltose, sucrose or xylose, if appropriate in the presence of yeast, yeast hydrolysate or casein-hydrolysate, and with mono-, di- and/or tri-valent metal ions, forms gels having a solidification temperature between 24.degree. and 25.degree. C. Gellan gum has proved to be a particularly advantageous polysaccharide for use in the layers according to the invention.

Abstract: A gripper head for connection with a suction device includes an air permeable suction plate having selected portions covered by a readily replaceable cover mask so that only the uncovered portions of the suction plate are suctionally active. The uncovered portions of a perforated object to be gripped by the gripper head having relatively few perforations.

Abstract: A process for producing masked positive color images by the silver dye bleach process using a developer solution which contains 0.3 to 1.0 mol/l of a bromide.

Abstract: A method for processing exposed and developed photographic silver dye-bleach materials, in which the exposed and developed material is treated with aqueous bleaching preparations which contain (a) an acid component, (b) a silver complexing agent, (c) one or more bleach catalysts, (d) optionally an antioxidant, (e) optionally a water-soluble oxidizing agent and (f) optionally a bleaching accelerator.A water-soluble and as a rule solid adduct of an acid amide or a lactam and a strong mineral acid is used as acid component (a).

Abstract: In a process and apparatus for the production of photographic images of transparent masters, the master is reproduced in a first beam path by means of a light source and optical means on photographic material, and in a second beam path for color and contrast correction by means of a CRT controlled by image measuring means and a computer unit as a mask in a coincident manner. The mask is produced by a feedback loop formed by the CRT, master, image measuring unit, computer unit and again the CRT, whereby in particular the geometric image distortions of the CRT are eliminated. In each location of the screen of the CRT, in which the light point is present, the brightness of the image point is calculated and immediately corrected. By the above described measures the effect of any distortion of the CRT is coupled out, whereby a sharper image is obtained. The part of the light of the CRT used for exposure is not weakened by the master. The process is intended primarily for the photographic copying of color slides.

Abstract: The processing of exposed silver dye bleach materials by applying, to the uppermost layer of the material, an amount of processing liquid which corresponds to not more than the swelling volume of the material, followed by a heat treatment.The process is particularly suitable for the production of positive colored images, especially in automatic copying or photographing machines.

Abstract: Holographic film material which comprises in a silver halide emulsion layer an amount of a water-soluble compound, which does not affect the photographic properties of the silver halide emulsion and which is non-light scattering.

Abstract: There is disclosed a photographic four-color material for the silver dye bleach process, which material, in addition to containing the customary yellow, magenta and cyan image dyes, contains a black layer which is sensitive to infra-red light.The material is suitable e.g. for testing dotted or continuous tone color separation positives.

Abstract: New hydroquinones have the formula: ##STR1## wherein p is 1 or 2 and q is 0 or 1, provided that p+q is 1 or 2; R is a residue of formula: ##STR2## wherein Q is (i) -OX or (ii) -PO(OR.sub.11)((O).sub.x R.sub.11); and salts thereof with organic or inorganic acid bases.The groups X and R.sub.11 and x are defined hereinafter.The compounds of formula I are useful as stabilisers in photographic materials.

Abstract: In a room-light load cassette, a web of photographic material is wound on a reel core, and the core is rotatably supported, by means of two core hubs, in hub seats provided in two opposite cassette end walls of a light-tight casing. Each of the hubs which are firmly mounted in the core, comprise a hollow sleeve part which is supported in the respective hub seat. In order to secure the web roll of photographic material in the cassette against unwinding during shipping and storage, a core lock comprising a locking member is provided in one of the end caps. The locking member bears an external gear and is connected via connecting means breakable at a desired rupturing zone, with the hub seat of the respective end cap. The teeth of the external locking member gear engage an internal gear in a sleeve part being part of the corresponding core hub, and prevent the core from rotating as long as the connecting means, preferably in the form of small stays, between the locking member and the hub seat remain unbroken.

Abstract: Method of preparing a hologram which is of the silver halide in gelatin binder type, which method comprises exposing, developing and bleaching the holographic material, where a water-soluble halide and a ferric salt of an acetic acid derivative are used in the bleach bath.

Abstract: Multicolor holograms using gelatin as the binder and having interference fringes lying in layers parallel to the substrate, the colors of which are visible by reflection in incident natural light, by treating the holographic material which has been holographically exposed and processed to produce a hologram therein, by applying to the selected areas of the gelatin which contains the interference fringes a solution of a compound which causes the interference fringes to separate permanently and produce a bathochromic shift in the replay wavelength.

Abstract: There is described a method of determining the contrast grade of the paper to be used to print a black and white photographic negative which comprises placing a photocell in the darkest significant area of a projected negative image and noting an indication of the light received or calibrating the photocell so when the photocell receives light of the same level it will indicate this, then placing the photocell in the lightest significant area of the projected image of the negative and reducing the light reaching the photocell using graduated steps until the light reaching the photocell is of the same level as the light which reached the photocell when it was placed in the darkest significant area of the projected negative image and noting the step employed to achieve this equivalence and selecting the contrast grade of the paper which is indicated by the step which achieved equivalence. The method can be performed using an enlarger or by use of a modified light exposure meter.