Meet the Achromatic+

A New Scientific, Industrial and Photographic tool

Establishing a partnership
The growing demise of traditional photographic film has even affected the scientific community. Many specialty scientific films are no longer available or are becoming increasingly difficult to acquire. This includes infrared and other scientific films that are sensitive to specific nanometer ranges in both the visible and invisible spectrums. Dealing with the chemical processes that film requires has also become increasingly difficult in the workplace.

Recognizing that these scientific requirements are becoming more difficult to deliver, Jim Taskett and Karla Johnson of Bear Images Photographic Inc., in San Francisco decided to do something about the problem. Jim put together a research consortium including both US Government and private companies and not-for -profits, all focused on finding a digital capture solution to replace scientific film and traditional processes. A 5000 square foot research center was established in 2007 in Palo Alto California to focus on workflow, technology evaluation and deployment.

The research team assessed available technologies and decided to approach Phase One to help develop and build a digital solution. As Jim Taskett explains, Phase One was a natural choice as a development partner.

“There is no question that Phase One engineering has achieved many digital capture milestones. Time and again over the last 10 years, Phase One has provided the best possible image quality from any give sensor size available at the time. The design of the Phase One backs is an industrial marvel being virtually indestructible in a traditional photographic environment. The robust design can withstand tons of weight, extreme temperature of heat and cold as well as the rigors of extreme acceleration. The backs are engineered to capture millions of images without failures. These are all traits that are required for an industrial solution.

Unfortunately, that’s not enough! Our initial project scope suggested that there would be numerous technical challenges in developing this device. Phase One maintains an extensive research team that is continuously working on new technology. Having access to the Phase One R&D team proved to be of significant benefit to our project. The availability of software that could also operate the back was the final factor in selecting Phase One to assist us in developing and building the Achromatic+ back.”

The research teams prediction of technical challenges proved to be more than true. The Achromatic+ back has taken over 2 years to develop, manufacture and deliver. The goal has been achieved. The Achromatic+ is the first commercially available medium format back that is a true replacement for almost all scientific black and white film types at much higher quality and with far more consistency.

The Achromatic+ back
The Achromatic+ is a 39 megapixel medium format digital camera back that provides wide spectrum black and white images, at an unprecedented level of accuracy. To take advantage of existing proven technology, the design is based on Phase One’s latest P+ chassis and platform. Backs are available for the Phase One / Mamiya mount, Contax, Hasselblad V-series and Hasselblad H-series mounts. Numerous off the shelf and custom adapters are available for mounting on technical or view cameras, other medium format platforms and scientific equipment. Custom capture software is available to aid scientific imaging specialists.

The Achromatic+ raw files are compatible with Phase One’s Capture One software. This utilizes all of the existing workflow and tools that are part of the Capture One solution for both Mac and PC.

The Achromatic+ results go far beyond the accuracy possible with film. There are two key reasons for the high level of accuracy, no RGB filters on the sensor and the variables of film and processing.  Variables like chemical processing; building emulsions, film storage and latent image stability have significantly varied the accuracy of film. The range of specific film emulsions is fairly limited requiring a wide range of film products. In comparison, the range of sensitivity with the Achromatic+ back extends beyond the visible spectrum into the infrared wavelengths in a single product. Filters are used to limit the Achromatic+ back to specific bandwidths required for scientific study and process control.

The Achromatic+ is built with hand picked sensors that are at the top of the quality range for consistency and accuracy. This reduces the effect of extensive correction for sensor defects.  The selected sensors are removed from the manufacturing process before the RGB filters are applied to the pixels. This gives the Achromatic+ back the unique ability to record pure black and white data with extreme accuracy.

○ Filters on the sensor pixels and a UV cutoff filter over the whole sensor limit sensitivity to the visible spectrum.

○ Each pixel site requires a color filter to create final images in color. This adds to the thickness of a sensor creating optical changes reducing sharpness and adding artifacts.

○ The range of sensitivity of a regular RGB sensor including an IR cut-off filter is from 350 to 700 nanometers (nm). Image courtesy of Eastman Kodak Company

 Quantum efficiency for color image sensor in some Phase One P+ backs

○ The removal of all filters on the pixels as well as the removal of the IR cut-off filter expands the sensitivity beyond the visible spectrum, to include infrared and ultraviolet.

○ The Achromatic sensor has no filters on the pixel sites. This design provides the truest possible data with sharper images and virtually no artifacts.

Image courtesy of Eastman Kodak Company

Quantum efficiency for image sensor in Achromatic + back
Traditionally, all sensors have a Bayer pattern of individual red, green and blue filters on each pixel site. These individual colors are then interpolated through numerous methods to create RGB data at each photo-site. The Achromatic+ back is designed to be a black and white only product with no color filters on the sensor. 

The back is supplied in two different configurations. The first configuration includes a permanently mounted IR cut-off filter that is required to allow the sensor record the human visible spectrum. The second version is supplied with no IR cut-off filter and is therefore capable of recording into the visible as well as the infrared and ultraviolet parts of the spectrum.

The back is built using Phase Ones latest P+ chassis and platform. Mounts are available for the Phase One / Mamiya, Contax, Hasselblad V-series and Hasselblad H-series medium format solutions. Numerous adapters are available for mounting on technical or view cameras, other medium format platforms and scientific equipment with custom and industry standard adapters. Custom capture software is available to aid scientific imaging specialists.

Achromatic+ raw files are compatible with Phase One’s Capture One software. This utilizes all of the existing workflow and tools that are part of the Capture One solution for both Mac and PC.

A few Achromatic+ applications
For Scientific purposes, filters are used to restrict the captures to specific wavelengths thereby recording specific information. The use of filters to record the restricted wavelengths also have the safety advantage of allowing researchers to work in full spectrum light. With Infrared film, all visible light had to be removed and the film was extremely difficult to handle and work with. The Achromatic+ back can record infrared in regular daylight or existing light because the optical filters, not the capture medium, defines the range of electro magnetic spectrum recorded.

Aerial, Biomedical, Agricultural Research  
In the medical and agricultural segments, organic specimens can be either designed to reflect a specific spectrum or may reflect differently depending on age or growth condition. All of these aspects can be documented with the Achromatic + back. Accuracy of information is much higher than film based solutions because the variables of emulsion manufacturing and chemical processing are removed.

B&W reproduction
The process of reproducing original black and white prints is extremely difficult with a full color process. The Achromatic + back can reproduce original black and white with extreme accuracy that requires little or no post-production retouching. The lack of filters on the sensor also provides the advantage of higher resolution. To take advantage of the extra resolving power, high-resolution lenses are required. Reproduction lenses are typically higher resolution thereby allowing the Achromatic+ back to provide the best quality possible. Improved optical performance can be achieved with select spectrum illumination systems, which have been developed for use with this imaging device.

Restoring original film footage
The extreme resolution capabilities combined with the accuracy and simplicity of capture makes the Achromatic+ an outstanding solution for restoring original black and white film footage. The added benefit of Phase One’s robust back design makes the multiple millions of exposures required to restore film footage, easier to achieve.

Optical research and quality control
A unique pattern is created when lasers are used to test optical elements, mirrors and assemblies. The Achromatic+ back can be used with  a filter to record the specific patterns and confirm the quality of the item. More importantly, current film solutions require this work to be done in a total darkness. The Achromatic+ back can achieve the same results in conventional work areas.

Forensic, Photogrammetry and Military Applications
Information is a critical aspect of military research and in-field situations. The Achromatic+ back through filtration can be tuned to pick out very specific information of a location or an event like an explosion or gun powder residue patterns. Detailed information about specific events is critical in analyzing the effectiveness of the particular device or event being analyzed.

Photography
The Achromatic+ can be filtered for the visible spectrum. This creates the most accurate black and white response we have ever achieved. Black and white filters provide the exact response expected and achieve exactly the same result that would be achieved with film. Using and IR filter, the Achromatic + achieves true IR images that even require a focus adjustment, just like using IR film. The consistency achieved is unprecedented since the response and result is virtually identical each time. With IR film, the emulsion coating process, special film handling, storage and chemical processing after exposure adds variables to the process and thus less controllable results.

Possibly the most unusual and most inspirational value of the Achromatic+ back photographically, is the ability to shoot with no filters and record IR and visible spectrum down to UV. The images are almost impossible to describe and truly exciting for Fine-Art Photographers exploring a new way to capture visually intriguing images.

Conclusions
The Achromatic+ back represents a whole new aspect of digital capture for both the scientific community and photographers. The extreme ability to create repeatable accurate results supersedes the abilities of traditional film. For research, scientific study and testing, the value of this accuracy is immeasurable.  The reduction in availability of research and scientific film emulsions, as well as the safety and difficulty of processing many of these films, further enhances the value of the Achromatic + back.

For the photographic community, the Achromatic+ back is a new frontier that is yet to be discovered. The ability to record beyond, and including the visible spectrum, offers significant opportunity for exploration.  Although the price will be restrictive for many, there is no doubt that artists will find a way to access the Achromatic + back and  redefine the limits of black & white and much more.