Wet plate photography ice flower texture imaging process with controllable crystallization effect

Abstract

The invention discloses a wet plate photography ice flower texture imaging process with a controllable crystallization effect, which comprises the following steps of: after developing, applying a crystallization control method on the surface of a photosensitive plate to carry out crystallization induction; and placing the processed photosensitive plate in a controlled environment with the temperature of 20-30 DEG C and the relative humidity of 50-60%, promoting crystallization and migration of a silver core and a fixing agent, diffusing silver particles to an image contour line, enabling crystals to grow radially along the image contour line of a negative film, and forming an ice flower-shaped silver crystal image with a three-dimensional structure. Specifically, a crystal with silver particles as a core is directionally diffused to form a radial crystal dendrite structure, a negative film image and crystalline salt diffusion crystallization are combined, the two-dimensional plane limitation of traditional wet plate photography is broken through, a three-dimensional crystal image structure with the average height of 50-200 microns is formed, and the three-dimensional depth feeling of the image is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of wet plate photography imaging, and more specifically to a wet plate photography ice flower texture imaging process with a controllable crystallization effect. Background Art

[0002] Wet plate photography, an ancient photographic technique, was invented by British sculptor Frederick Scott Archer in 1851. Before the establishment of the modern photographic system, wet plate photography was the most mature of the ancient photographic techniques. Compared with the early daguerreotype and calotype photography, wet plate photography not only overcomes their many shortcomings, such as insufficient detail, limited size, high toxicity, high cost and slow photosensitivity, but also combines the advantages of both, forming a photographic technique with rich details, flexible size, low toxicity, relatively low cost and fast photosensitivity.

[0003] The film of wet plate photography usually uses an aluminum plate as the film base, and a layer of photosensitive liquid is coated on it. This layer of photosensitive liquid must remain wet before, during, and after exposure until development. Once the photosensitive coating dries before development, the desired image cannot be obtained through subsequent means, and the film will become invalid. This characteristic makes every shot of wet plate photography a unique artistic creation process.

[0004] The imaging principle of wet plate photography is based on the photochemical reaction of silver ions. During the exposure process, light energy acts on the silver halide (AgX) crystal, causing the halide ion (X~) to lose an electron and become a halogen atom (X), while generating free electrons. These free electrons move in the crystal, and when they encounter a photosensitive center, they are attracted by the center, causing the silver ions in the photosensitive center to be reduced to silver atoms. As the exposure increases, the photosensitive center becomes a developing center due to the expansion of the range of reduced silver, generating a latent image.

[0005] The development process is the key step to turn the latent image generated by exposure in the wet plate into a visible image. The reducing agent (such as ferrous sulfate) in the developer continues to reduce the silver halide at the development center to silver atoms until the human eye can clearly observe the image.

[0006] When the wet plate is exposed to a low temperature, high humidity environment, the water will quickly freeze on the surface of the film, causing the silver ions to crystallize uncontrollably. These randomly formed crystal structures are similar to ice flower patterns in nature.

[0007] See also Figure 1-2 As shown, Figure 1 and Figure 2This is a silver particle crystallization image in an uncontrollable state. Currently, the silver particle crystallization imaging in wet plate photography is in an uncontrollable state, which limits the creator's ability to express specific intentions. Since the result of each imaging cannot be fully predicted, it is difficult to achieve a high degree of control over the image details, which increases the unpredictability of the imaging results and affects the quality of the final image. Summary of the invention

[0008] In order to overcome the shortcomings of the prior art, the present invention provides a wet plate photography ice flower texture imaging process with a controllable crystallization effect, which combines the film image and the diffusion crystallization of the crystal salt to achieve regular extended crystallization, thereby breaking through the two-dimensional plane limitation of traditional wet plate photography, not only retaining the unique texture of wet plate photography, but also adding visual layering and three-dimensional effect through the ice flower texture.

[0009] The technical solution of the present invention is as follows: A wet plate photography ice flower texture imaging process with controllable crystallization effect, comprising:

[0010] After development, a crystallization control agent is applied to the surface of the photosensitive plate to induce crystallization;

[0011] The processed photosensitive plate is placed in a controlled environment with a temperature of 20°C to 30°C and a relative humidity of 50% to 60% to promote the crystallization and migration of silver nuclei and fixers, diffuse the silver particles toward the image contour, and make the crystals grow radially along the film image contour, forming an ice flower-like silver crystal image with a three-dimensional structure.

[0012] Furthermore, the crystallization control agent includes sodium thiosulfate and potassium citrate, and the mass ratio of sodium thiosulfate to potassium citrate is 1:2.

[0013] Further, the following steps are included:

[0014] Substrate pretreatment: Clean the substrate surface with a cleaning agent, then rinse with distilled water and dry;

[0015] Colloid coating: In a bright room environment, the collodion emulsion is evenly coated on the surface of the substrate to form a wet adhesive film with a thickness of 80μm to 120μm;

[0016] Silver halide formation: Immerse the coated substrate in a silver nitrate solution with a concentration of 8% to 12%, and react for 3 to 5 minutes at 18°C ​​to 25°C to generate composite photosensitive crystals of silver bromide and silver iodide in the collodion layer to obtain a photosensitive plate;

[0017] Selective exposure: Place the halogenated photosensitive plate in a film holder and perform gradient exposure control in the camera, where the exposure time of the highlight area is 15s to 30s, and the exposure time of the shadow area is extended to 2min to 4min;

[0018] Dynamic development: staged development in developer, first at 20°C for 20 seconds, then heated to 28°C for another 10 seconds;

[0019] Crystallization induction: Apply a crystallization control agent to the surface of the developed photosensitive plate. The amount of crystallization control agent applied is 0.5 mL / cm 2 ~1.2mL / cm 2 ;

[0020] Directed crystallization: Place the processed photosensitive plate in a controlled environment with a temperature of 20℃~30℃ and a relative humidity of 50%~60% to promote the crystallization and migration of silver nuclei and fixer, diffuse the silver particles toward the image contour, and make the crystals grow radially along the film image contour, forming an ice flower-like silver crystal image with a three-dimensional structure.

[0021] Furthermore, the substrate is a transparent glass or metal substrate.

[0022] Furthermore, the crystallization control agent also includes polyvinyl pyrrolidone in an amount of 0.5% to 1% by mass.

[0023] Further, the directional crystallization process comprises the following steps:

[0024] Step 1, promoting the dissolution of the silver complex in an environment with a temperature of 30° C. and a relative humidity of 60%;

[0025] Step 2: Slowly cool down to 25°C and simultaneously reduce humidity to 55% to induce crystal nucleation;

[0026] Step 3: Cool down to 20° C. and maintain the humidity at 55% to accelerate the growth of dendrites along the image gradient direction.

[0027] Furthermore, the silver nitrate solution includes nano titanium dioxide with a mass fraction of 0.01% to 0.1% and a particle size of 20nm to 50nm.

[0028] Furthermore, in the substrate pretreatment, specifically: an alkaline cleaning agent with a pH of 8.5 to 9.5 is used to ultrasonically clean the surface of the substrate, and then the substrate is rinsed with distilled water with a resistivity greater than or equal to 18 MΩ·cm and dried.

[0029] Furthermore, in the colloid coating step, specifically: in a bright room environment, the collodion latex is evenly coated on the surface of the substrate to form a wet adhesive film with a thickness of 80 μm to 120 μm, wherein the collodion latex contains 2% to 5% by mass of ethyl acetate.

[0030] Furthermore, in the production of silver halide, the mass ratio of silver bromide to silver iodide is 1:(1.2-1.5).

[0031] The present invention according to the above scheme has the beneficial effect that: the present invention provides a wet-plate photography ice flower texture imaging process with a controllable crystallization effect. After development, a crystallization control agent is applied to the surface of the photosensitive plate to induce crystallization; the treated photosensitive plate is placed in a controlled environment with a temperature of 20°C to 30°C and a relative humidity of 50% to 60%, promoting the crystallization and migration of silver nuclei and fixers, causing the silver particles to diffuse toward the image contour, so that the crystals grow radially along the negative image contour, forming an ice flower-shaped silver crystal image with a three-dimensional structure. Specifically, the radial dendrite structure is formed by the directional diffusion of crystals with silver particles as the core, combining the negative image with the diffusion crystallization of the crystal salt, breaking through the two-dimensional plane limitation of traditional wet-plate photography, forming a three-dimensional crystal image structure with an average height of 50μm to 200μm, and significantly improving the three-dimensional depth of the image. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 This is one of the crystallization diagrams of silver particles in an uncontrollable state;

[0034] Figure 2 This is the second picture of silver particle crystallization in an uncontrollable state;

[0035] Figure 3 Silver particle crystal imaging prepared by a wet plate photography ice flower texture imaging process with controllable crystallization effect provided by an embodiment of the present invention Figure 1 ;

[0036] Figure 4 Silver particle crystal imaging prepared by a wet plate photography ice flower texture imaging process with controllable crystallization effect provided by an embodiment of the present invention Figure 2 . DETAILED DESCRIPTION

[0037] The following detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments.

[0038] In order to better understand the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0039] Traditional wet plate photography has the problem of missing dimensions. Specifically, the traditional silver halide process is limited to two-dimensional plane imaging and lacks physical three-dimensional structure, resulting in insufficient image layering.

[0040] In the wet plate photography process, after the development and fixing steps are completed, the inventors found that some aluminum plate surfaces will show irregular crystallization phenomena, such as Figure 1 and Figure 2 As shown, although it has a certain artistic beauty, it will cause the film image to be blurred and the image outline cannot be presented. At the same time, the inventor came up with the idea of ​​combining the film image with the crystallization phenomenon to enhance the three-dimensional depth of the image.

[0041] Based on this, after continuous research, a wet-plate photographic ice flower texture imaging process with a controllable crystallization effect was proposed. Specifically, after development, a crystallization control agent is applied to the surface of the photosensitive plate to induce crystallization; the treated photosensitive plate is placed in a controlled environment with a temperature of 20℃~30℃ and a relative humidity of 50%~60% to promote the crystallization and migration of silver nuclei and fixers, so that the silver particles diffuse toward the image contour, and the crystals grow radially along the film image contour, forming an ice flower-like silver crystal image with a three-dimensional structure.

[0042] Specifically, by applying a crystallization control agent and controlling the ambient temperature at 20°C to 30°C and the relative humidity at 50% to 60%, the silver particles are directed to diffuse to form a radial dendrite structure, and the film image and the diffusion crystallization of the crystalline salt are combined, breaking through the two-dimensional plane limitation of traditional wet plate photography, and forming a three-dimensional crystal image structure with an average height of 50μm to 200μm, thereby significantly enhancing the three-dimensional depth of the image and solving the problem of dimensionality loss in traditional wet plate photography.

[0043] See also Figure 3 and Figure 4 As shown, Figure 3 and Figure 4 This is an image of silver particle crystallization under controllable conditions.

[0044] For further explanation, this embodiment also provides a specific step of a wet plate photography ice flower texture imaging process with a controllable crystallization effect, as follows:

[0045] Step 1: Substrate pretreatment: clean the substrate surface with a cleaning agent, then rinse with distilled water and dry;

[0046] Specifically, the substrate can be a transparent glass or metal substrate. In the present embodiment, the substrate is preferably an aluminum plate. During cleaning, an alkaline cleaning agent with a pH value in the range of 8.5 to 9.5 is used, and the cleaning effect is enhanced by ultrasonic technology. After cleaning, the substrate is rinsed with high-purity distilled water with a resistivity of not less than 18 MΩ·cm to ensure that the residue is removed. Finally, the substrate is dried to complete the pretreatment process.

[0047] Step 2, colloid coating: in a bright room environment, the collodion emulsion is evenly coated on the surface of the substrate to form a wet adhesive film with a thickness of 80 μm to 120 μm;

[0048] The collodion latex contains ethyl acetate in a mass fraction of 2% to 5%.

[0049] Step 3, silver halide formation: immerse the coated substrate in a silver nitrate solution with a concentration of 8% to 12%, and react for 3 to 5 minutes at 18°C ​​to 25°C to form composite photosensitive crystals of silver bromide and silver iodide in the collodion layer to obtain a photosensitive plate;

[0050] The mass ratio of silver bromide to silver iodide is 1:(1.2-1.5), and the silver nitrate solution includes nano-titanium dioxide with a mass fraction of 0.01%-0.1% and a particle size of 20nm-50nm, which serves as a heterogeneous nucleation site for the crystallization of silver particles.

[0051] Step 4: Selective exposure: Place the halogenated photosensitive plate in a film holder and perform gradient exposure control in the camera, where the exposure time of the highlight area is 15s to 30s, and the exposure time of the shadow area is extended to 2min to 4min;

[0052] Step 5: Dynamic development: Perform staged development in a developer, first develop at 20°C for 20 seconds, then heat to 28°C and continue developing for 10 seconds;

[0053] Step 6: Crystallization induction: Apply a crystallization control agent to the surface of the developed photosensitive plate. The amount of crystallization control agent applied is 0.5 mL / cm 2 ~1.2mL / cm 2 ;

[0054] Among them, the crystallization control agent includes sodium thiosulfate and potassium citrate, and the mass ratio of sodium thiosulfate to potassium citrate is 1:2. In this embodiment, by applying the crystallization control agent (composite system of sodium thiosulfate and potassium citrate) after development, the silver particles are complexed into soluble [Ag(S2O3)2]3-, delaying random nucleation. At the same time, potassium citrate adjusts the pH of the solution to weak alkalinity (8.5-9.0), enhances the stability of the complex, and drives the silver particles to diffuse to the contour line of the negative image (density mutation area) through the ion concentration gradient.

[0055] Specifically, due to the difference in the concentration of silver particles in different areas of the film after development (high silver particle concentration in the highlight area and low silver particle concentration in the shadow area), citrate ions tend to diffuse to the area with low silver particle concentration (shadow area) to balance the charge. This diffusion causes the citrate concentration in the shadow area to be higher than that in the highlight area, forming a reverse citrate concentration gradient. According to the principle of electrical neutrality, cations migrate with anions to maintain charge balance, causing silver particles to diffuse to the contour line of the film image (density mutation area).

[0056] Specifically, the crystallization controller also includes 0.5% to 1% polyvinyl pyrrolidone by mass. Polyvinyl pyrrolidone serves as a crystallization directing agent, and its long-chain molecules are preferentially adsorbed at the edge of the image (density mutation area) to form a local hydrophilicity difference, which is used to inhibit the random branching growth of silver dendrites.

[0057] Step 7, directional crystallization: Place the processed photosensitive plate in a controlled environment with a temperature of 20℃~30℃ and a relative humidity of 50%~60% to promote the crystallization and migration of silver nuclei and fixer, diffuse the silver particles toward the image contour, and make the crystals grow radially along the film image contour to form an ice flower-like silver crystal image with a three-dimensional structure.

[0058] By placing the processed photosensitive plate in a controlled environment with a temperature of 20°C to 30°C and a relative humidity of 50% to 60%, the crystallization and migration of silver nuclei and fixers are promoted, and the silver particles are diffused toward the image contour. When the silver particles are crystallized and nucleated, the radial crystal dendrites formed expand along the concentration gradient formed by the density distribution of the film image. The density distribution in the film image reflects the unevenness of silver deposition during the exposure and development process. The high-density area corresponds to a higher silver particle concentration, while the low-density area corresponds to a lower silver particle concentration. The crystal dendrites expand along the concentration gradient determined by the image density distribution, so that the crystals grow radially along the contour of the film image and are confined to the contour of the film image, presenting a radial structure consistent with the contour of the film image, thereby strengthening the edge characteristics of the image and forming an ice flower-like silver crystal image with a three-dimensional structure.

[0059] The directional crystallization process includes the following steps:

[0060] S1. Promoting the dissolution of the silver complex at a temperature of 30° C. and a relative humidity of 60%;

[0061] S2, cooling to 25°C and simultaneously reducing humidity to 55% to induce crystal nucleation;

[0062] Specifically, such a design can accelerate the decomposition of the complex by cooling, release silver particles and induce crystal nucleation; at the same time, reduce the humidity (from 60% to 55%) to increase the supersaturation of the solution, so that the crystals grow radially along the contour of the film image.

[0063] S3, cooling to 20°C and maintaining the humidity at 55% to accelerate the growth of crystal dendrites along the image gradient direction to form a three-dimensional ice flower texture matching the film image.

[0064] In this embodiment, the directional crystallization process lasts for 2 to 3 months. In the above step S1, it generally takes 5 to 7 days under an environment with a temperature of 30°C and a relative humidity of 60%, and tends to be stable after 7 days. In the above step S2, this stage usually lasts for 3 to 7 days. If the time is too short, the number of crystal nuclei is insufficient, which easily leads to sparse crystal dendrites; if the time is too long, the crystal nuclei grow excessively, which easily destroys the image contour matching. In the above step S3, this stage generally lasts for 30 to 40 days. It should be noted that in actual applications, the specific reaction time of these three stages is not limited to the scope listed in this embodiment. Those skilled in the art can judge and adjust by observing the surface crystallization state of the aluminum plate, thereby flexibly adjusting the reaction time of each stage.

[0065] The wet-plate photography ice flower texture imaging process with controllable crystallization effect provided by the embodiment of the present invention has the following advantages:

[0066] (1) Traditional wet plate photography is limited to two-dimensional plane imaging and lacks a three-dimensional structure at the physical level, resulting in insufficient image layering and loss of dimension. The wet plate photography ice flower texture imaging process with a controllable crystallization effect provided by the embodiment of the present invention forms a radial dendrite structure through the directional diffusion of crystals with silver particles as the core, combines the film image with the diffusion crystallization of the crystal salt, breaks through the two-dimensional plane limitation of traditional wet plate photography, and forms a three-dimensional crystal image structure with an average height of 50μm to 200μm, which significantly improves the three-dimensional depth of the image.

[0067] (2) In the traditional wet plate photography process, the migration rate of silver particles is too fast (3μm / s~5μm / s), and the crystallization direction is random, which easily leads to blurred image contours. The wet plate photography ice flower texture imaging process with controllable crystallization effect provided by the embodiment of the present invention promotes the crystallization and migration of silver nuclei and fixers by placing the treated photosensitive plate in a controlled environment with a temperature of 20℃~30℃ and a relative humidity of 50%~60%, so that the silver particles diffuse toward the image contour. When the silver particles crystallize and nucleate, the radial dendrites formed expand along the concentration gradient formed by the density distribution of the negative image, so that the crystals grow radially along the contour of the negative image and are confined to the contour of the negative image, presenting a radial structure consistent with the contour of the negative image, thereby strengthening the edge features of the image, forming an ice flower-shaped silver crystal image with a three-dimensional structure, and making the crystal growth accurately match the contour of the negative image.

[0068] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

[0069] The above is an exemplary description of the present invention in conjunction with the accompanying drawings. It is obvious that the implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made by adopting the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A wet plate photography ice flower texture imaging process with controllable crystallization effect, characterized in that: After development, a crystallization control agent is applied to the surface of the photosensitive plate to induce crystallization; The processed photosensitive plate is placed in a controlled environment with a temperature of 20℃~30℃ and a relative humidity of 50%~60% to promote the crystallization and migration of silver nuclei and fixers, diffuse the silver particles toward the image contour, and make the crystals grow radially along the film image contour, forming an ice flower-like silver crystal image with a three-dimensional structure.

2. A wet plate photography ice flower texture imaging process with controllable crystallization effect as claimed in claim 1, characterized in that: The crystallization control agent includes sodium thiosulfate and potassium citrate, and the mass ratio of sodium thiosulfate to potassium citrate is 1:

2.

3. A wet plate photography ice flower texture imaging process with controllable crystallization effect as claimed in claim 2, characterized in that: The following steps are involved: Substrate pretreatment: Clean the substrate surface with a cleaning agent, then rinse with distilled water and dry; Colloid coating: In a bright room environment, the collodion emulsion is evenly coated on the surface of the substrate to form a wet adhesive film with a thickness of 80μm~120μm; Silver halide formation: Immerse the coated substrate in a silver nitrate solution with a concentration of 8% to 12% and react for 3 to 5 minutes at 18°C ​​to 25°C to generate composite photosensitive crystals of silver bromide and silver iodide in the collodion layer to obtain a photosensitive plate; Selective exposure: Place the halogenated photosensitive plate in a film holder and perform gradient exposure control in the camera, where the exposure time of the highlight area is 15s~30s, and the exposure time of the shadow area is extended to 2min~4min; Dynamic development: staged development in developer, first at 20°C for 20 seconds, then heated to 28°C for another 10 seconds; Crystallization induction: Apply a crystallization control agent to the surface of the developed photosensitive plate. The amount of crystallization control agent applied is 0.5mL / cm²~1.2mL / cm²; Directed crystallization: Place the processed photosensitive plate in a controlled environment with a temperature of 20℃~30℃ and a relative humidity of 50%~60% to promote the crystallization and migration of silver nuclei and fixer, diffuse the silver particles toward the image contour, and make the crystals grow radially along the film image contour, forming an ice flower-like silver crystal image with a three-dimensional structure.

4. A wet plate photography ice flower texture imaging process with controllable crystallization effect as claimed in claim 3, characterized in that: The substrate is a transparent glass or metal substrate.

5. The wet plate photography ice flower texture imaging process with controllable crystallization effect as claimed in claim 3, characterized in that: The crystallization control agent also includes polyvinyl pyrrolidone with a mass fraction of 0.5% to 1%.

6. A wet plate photography ice flower texture imaging process with controllable crystallization effect as claimed in claim 3, characterized in that: The directional crystallization process includes the following steps: Step 1, promoting the dissolution of the silver complex in an environment of 30° C. and 60% relative humidity; Step 2: Cool down to 25°C and simultaneously reduce humidity to 55% to induce crystal nucleation; Step 3: Cool down to 20°C and maintain the humidity at 55% to accelerate the growth of dendrites along the image gradient direction.

7. A wet plate photography ice flower texture imaging process with controllable crystallization effect as claimed in claim 3, characterized in that: The silver nitrate solution comprises nano titanium dioxide with a mass fraction of 0.01% to 0.1% and a particle size of 20nm to 50nm.

8. The wet plate photography ice flower texture imaging process with controllable crystallization effect as claimed in claim 3, characterized in that: In the substrate pretreatment, specifically: an alkaline cleaning agent with a pH of 8.5 to 9.5 is used to ultrasonically clean the surface of the substrate, and then the substrate is rinsed with distilled water with a resistivity greater than or equal to 18 MΩ·cm and dried.

9. A wet plate photography ice flower texture imaging process with controllable crystallization effect as claimed in claim 3, characterized in that: In the colloid coating step, specifically: in a bright room environment, the collodion emulsion is evenly coated on the surface of the substrate to form a wet adhesive film with a thickness of 80μm~120μm, wherein the collodion emulsion contains ethyl acetate with a mass fraction of 2%~5%.

10. The wet plate photography ice flower texture imaging process with controllable crystallization effect as claimed in claim 3, characterized in that: In the production of silver halide, the mass ratio of silver bromide to silver iodide is 1:(1.2~1.5).

Images