Toolkits

Digital Camera - DSLR - Assessment Process Guide

 The DSLR camera is generally a higher cost, low volume purchase for a telehealth program. This is the case generally speaking, however, there are many use cases for large programmatic deployments. That being said, anytime you are dealing with a higher cost item it is prudent to assess the technology to make sure that you make the proper selection that will best serve your telehealth programmatic need. Purchasing this equipment without any form of assessment could be a costly mistake. The cost associated with this technology is not related to one specific component, rather the costs of all the supporting pieces and parts. The DSLR camera market is relatively stable, so if you make a technology selection you can be assured that it will not be obsolete in the near future, as opposed to the point and shoot digital camera market. The features of the DSLR camera for medical imaging purposes are fairly comparable across manufacturers, which can make selecting a DSLR camera that is going to best fit your telehealth program a daunting process without some basic guidance. Determining a programmatic need, conducting a market review, planning to test, conducting testing, and selecting a candidate are all components of a thorough DSLR camera assessment.   

Determining Minimum Requirements

Establishing a minimum set of program requirements is critical when starting any technology assessment. The DSLR camera is a very technical piece of equipment, with many feature sets and many additional pieces of supporting technology. It is a piece of equipment that is available on the general consumer market and offers a wide range of uses to that market alone. The use cases for a DSLR camera in telehealth spread across many specialty areas and have many varying potential uses within each specialty area. With that in mind, it is very important to know your specific program's needs, or how this piece of technology needs to work for you, before moving forward with a technology assessment to determine the best DSLR camera for your program. One DSLR camera can also be purchased to meet several programmatic needs; it just comes down to knowing what they are.

Some ideas for determining programmatic needs include defining the users of the equipment, reviewing the proposed deployment plan, determining the required functionality, and listing any additional hardware, software, or equipment necessary.

Define the Users

Knowing about the potential users of this technology will serve you in determining the best fit for your programmatic need. This technology inherently possesses a level of technical difficulty and requires a certain level of technical knowledge from the user. The potential users for this technology do not already have to possess this knowledge; it can be your plan to train them, but knowing this will help you when thinking about ability to train on the equipment as a requirement. Knowing the general photography-related knowledge set of the potential users will help give you an idea of where you will be starting with your training, as well as how durable and how forgiving the equipment needs to be. If you have a set of expereiced users, knowing what, if any, equipment preferecnes they might have. Knowing which specialties want to use the DSLR camera is important, each specialty can have potentially different lens needs and different supporting hardware and equipment needs. Specific specialties may have specific supporting equipment needs. The manufactures of the supporting equipment may only support certain camera bodies, so this also needs to be taken into consideration.

Define the Deployment

Establishing where the cameras will be deployed, as well as how they are supported, can help set limits and expectations for how to purchase, configure, and support a DSLR camera in a telehealth program. You need to know basic things, such as how many sites you are deploying and how many DSLR cameras and supporting equipment sets will be needed at each site. Will the cameras be maintained by the users or by a centralized body/service? How and by whom the DSLR camera and equipment will be supported are important considerations, knowing this can help determine things such as warranty needs and additional equipment stock needs.  Will the DSLR cameras be in a set location, or will they need to be made into a mobile solution? You will also need to know, if in either a fixed location or with a mobile solution, the dimensions of the area that will be used for imaging. Knowing the areas available for imaging will help you determine what additional costs can be allocated to setting up an imaging area. The type of imaging area will affect the type of lens that can be used, the type of lighting that will be necessary, if wireless imaging acquisition tools can be used to transfer images, and if a tripod will be utilized or necessary.

Define the Required Functionality

There are dozens of features and many pieces of supporting hardware, software, and equipment that can be associated with the DSLR camera. The feature sets on the camera bodies are relatively similar, so a large part of the functionality of the DSLR camera assessment will potentially be related to supporting and additional equipment. Knowing which of these features, functions and additional piece and parts will be useful in a clinical setting is important to ensuring that the right camera and supporting equipment is chosen for a telehealth program. You will need to determine what the imaging needs of the telehealth program are, which will help you determine the functionality required. The imaging needs will help determine the required lens, additional lighting, supporting hardware, supporting software, data storage needs, and data transmission needs. If a clinical program has already existing equipment that they might want to use, compatibility issues also need to be taken into consideration.  

The Market Review

A market review for a DSLR camera will generally require looking at camera bodies, lens, and light sources at a minimum. It most likely might also require reviewing tripods, wireless image transfer devices, image storage options, supporting software, image review software, image reviewing hardware, and image reviewing hardware calibration tools.

Being equipped with a set of minimum requirements will make the market review process much simpler. That being said, there is still a lot of work that must be done before cameras should be ordered for review. An important first step in a DSLR market review would be to know what, if any, existing equipment your program may already have access to and the preexisting camera preferences of the imagers that are going to be using the equipment. Knowing about such details may help you greatly narrow your market research time. For example, if you have the bulk of your experienced users that have a certain manufacturer preference, you may want to select that manufacturer when making a camera body selection. You may ultimately select a different camera body then some are used to working with, but if an imager is familiar with feature sets of a certain manufacturer, they will most likely be comfortable with any camera body from that manufacturer. Likewise, if you already possess lens from a certain manufacturer that are in good working order, you may decide to select camera bodies that are compatible with the existing lens, which will help you narrow down to a specific manufacturer or a specific few camera bodies. If you have specialists that have additional specialized equipment necessary, and that equipment limits users to a camera body or a manufacturer, that might also help you narrow your research. Equally important in a market review for DSLR cameras, is to look at which cameras have been slated for release in the current year. There are online resources that host camera reviews, and also include chronological lists of cameras that have been released by all manufacturers.

The process of elimination can begin once a list of cameras has been compiled. DSLR cameras and supporting equipment that do not meet the minimum requirements should be removed from the broad list. The lists of equipment should be reduced to a manageable number by this point, although with all of the potential supporting equipment the lists still might seem unmanageable. For the DSLR camera body selection, the choice of manufacturer may inadvertently be made for you based on your minimum requirements.  If you are considering multiple manufacturers for camera bodies, you may need to narrow this selection first. If you have selected a manufacturer for the camera bodies, you may still want to assess several camera bodies for use. Once a manufacturer has been arrived at, it will be easier to narrow down the supporting equipment lists. If the list sill seems insurmountable, consider reducing the number by using online resources, camera specifications, price and existing sample images to further narrow down the number of equipment slated for assessment.

Planning For Testing

Once your market review has been completed, it is time to bring in the equipment in for the assessment. With the potentially large numbers of equipment that you will be bringing in, it is extremely important to be very methodical and organized moving forward. It will require logistical organization to get all the equipment and staff in at the same time, and have the space and knowledge sets to set all the equipment up, to stage it, and test it. It will require planning for what tests you want to perform and how you want to perform them. Furthermore, due to prices and working with consumer available equipment, it will most likely require some ingenuity on how to actually afford to do the assessment and testing of the equipment, hoping that you have already budgeted for this expense as part of your technology selection.

As you plan for testing, the tests that you plan for may not be the features that you end up assessing in the end. However, the process of planning them out can be invaluable to help you think through what all you will need to be successful in your evaluation. With DSLR cameras you will need a plan to select a camera body. You will also need a plan to select the lens and lighting that you will use for your imaging. You will need to plan to test any additional supporting equipment options that you might be entertaining. You will need to plan for the logistics involved with testing the equipment, things as simple as making sure you have enough batteries in house for the equipment you will be testing.  All of the tests should also be planned around the already determined minimum program requirements.

Once you have decided on the specific test and/or assessments that you want to conduct, then you need to come up with a standardized documentation system. You may want to create forms to record the data that you will be collecting. You may also want to want to have a place to keep additional notes about what occurs during each assessment. You need a place to document all the settings used, measurements recorded, and any other pertinent data about your tests. If you are planning on capturing image data sets as part of your testing, you may want to define and record what the subjects will be, how the shots will be framed, and what the goals of the images captured will be. You may also want to decide on any associated photography data that you might want to record about the tests that are performing, and come up with a way to keep those photos separate from the photos that are part of your actual tests. You will need to think about backing up this data and how you will record the data at the time of the tests and even who will be doing the documenting.

When thinking about these tests you need to consider who to involve in the planning process and who to involve in the testing process. At the TTAC, we found it important to involve subject matter experts (SME), as well as people with technical, networking, clinical, photography, and general telehealth program knowledge sets in the planning phases of our assessment. When it comes to actually doing the testing, you will need a consistent group, but fewer individuals, to be involved.

You will need to plan for space requirements for where you physically plan to do the testing. It would be most useful to test the equipment in an area that has similar size and lighting compared to the location where the DSLR cameras will be used. This can be difficult with general space constraints in most clinical areas. You will need a space that has space to receive all the equipment. You will need a space that has enough power outlets to charge batteries and support equipment that needs plugged in. You will also need a place that supports wireless networking and computing, if you plan to work with any associated wireless devices. During the actual testing process, you will need a physical space big enough to accommodate all of the equipment, the assessment team and a documenter.

You will also need to spend a bit of time planning on how you will handle the equipment as it arrives. It is best to plan to have it all in at the same time, if at all possible, for consistency’s sake. You will need a system to label and organize all the equipment. You need a plan to keep all of the parts with their corresponding additional parts, to know how to repack borrowed equipment when it comes time to ship it back, a way to keep all of the associated paperwork straight and organized, and a plan of how to deal with equipment that might malfunction during your assessment. 

As far as the financial challenge of procuring equipment is concerned, there may be a few solutions. One solution, permitting that your budget will support it, is that you simply purchase all of the equipment that you will be bringing in for testing. Another option is that you work with vendors to obtain as many demo units as possible. This market may present some challenges when considering working with vendors. For the equipment that is generally considered to be consumer oriented, the manufacturers may be less inclined to work with you for demo units. For this segment of the market, the price of the units compared to the volume of business that they are dealing with are not particularly motivating factors to gain vendor cooperation. Also, the risks that the vendors could incur when loaning demo units will most likely outweigh the benefits for them. If it is cost prohibitive for you to purchase camera bodies, lens, lighting solutions, and wireless file transmitters for your assessments, another available option is using professional photography equipment rental companies. For the supporting equipment that is more specific to the medical community, we would encourage you to try to establish relationships with these vendors and utilize demo units in your assessments when possible. Again, when you are dealing with lower volumes you might incur some difficulty, but generally vendors are reasonably motivated to work with programs to meet their needs.

The general idea is that this planning phase will allow you to step back, think all aspects of the assessment through, and allow you to anticipate what the testing will be like. When you actually start the assessment, you will likely make changes to the plan as you go, but having a plan will make sure you have the right material and people available and hopefully serve to decrease the chaos involved. 

Setting Up For Testing

After you have done the hard work of determining minimum requirements, completing a market review, selecting equipment for the assessment, and planning for all aspects of the testing, you are ready for the fun part-the actual assessment of the equipment. Organization is crucial from the moment the equipment arrives at the testing location. It is very tempting to jump right in a play with the new shinny toys. It will help you tremendously to have planned how you will organize the equipment. At the TTAC, we immediately catalog all equipment as it arrives. For boxes that we will need to reship, we take pictures as we unpack, so we will know how to repack. We check off that we have received all equipment that we have ordered or rented against our purchase orders. We have clear plastic totes that the contents of each box go into. Each separate item gets its own tote. We separate out the associated paperwork in file folders; such as instruction manuals and additional electronic contents. We keep all returned shipping labels and shipping paperwork. Once you have organized all the contents you will need to temporarily label like parts in order to keep them straight. For example, the batteries and cords that go with each camera body.

Once you have received and organized the equipment, you are ready to stage it for your testing purposes. This will require plugging in a charging all equipment that requires a battery charge. You will need to gather the necessary additional equipment required for you testing, such as subject matter models, subjects, and other additional supplies. Gather testing staff and procure the testing physical space that you planned for.

Next you actually need to physically set up for the features that you have planned to assess. The TTAC team chose to assess features of the camera bodies, lenses, external lighting set ups, and wireless file transmission systems. We planned on the features we would be testing and set up standardized ways to capture the data. We set up a documentation station in the testing area, where a member of the team could readily be documenting on our created forms while the testing was in progress.

Assessing the DSLR Cameras

Now that you have done all the hard work that goes into the planning, it is time to sit back and learn from the tests that you are performing on the equipment that you have in house. In order to assess DSLR camera bodies, you need to have skilled photographers as part of the image capture process, and you need to have the features you want to test specifically planned for.

At the TTAC for our DSLR assessment we decided to focus our testing on 3 DSLR related components: camera bodies, lens and lights.

Camera Bodies

As far as the top competitors on the DSLR camera body manufacturer market are concerned, especially for medical photography needs, the camera bodies are extremely comparable. It will most likely come down to compatibility with addition equipment necessary, photographer preference, and any equipment that you might already have available for use before you make a purchase (ie lens and light sources). For this assessment we decided to bring in all the camera bodies in the Canon Line at the time of our assessment and then bring in a comparable camera or two at the prosumer level across all manufacturers. For the comparable cameras we stuck to comparable features and to a relatively comparable price range, approximately on par with the Canon T3i.

To assess the camera body functionality, we elected to capture to 9 subject shots for all camera bodies. We subjects shots were obtained were of the: eye, oral cavity, oral frontal view with retractors, head & neck, posterior torso, wound, first three finger tips, right hand, and elbow.  We designed the shots to see how comparable the camera bodies were with macro and zoom lens, and with room light and external lighting for each lens type. For the zoom lens the external light source was the onboard flash when present and for the macro lens the external light source was the Doctors Eyes ring and bilateral wing light with diffusor present. The zoom lens shots were all taken at approximately 55mm and all shots were taken in landscape mode. We designed these shots sets to bring out the strengths and weaknesses for each camera body. We planned for each subject to be framed with similar predefined boarders. We were looking at how the camera bodies could perform, and wanted photo sets that could be compared. We were trying to obtain the best possible shots that the camera bodies could take, while in automatic mode. All shots were captured in the same physical location utilizing the same imager and subject. Every effort was made to capture all the shots in one setting, however due to the extremely large number of shots being obtained the images were taken over the course of a period of 4 consecutive days.  

As we captured images we meticulously documented all details. We had a shot documentation note set where we captured general procedures and notes. We had an image table where we captured camera body, lens type, lighting type, measurements for each shot taken, and each shots file name for future reference. As we ran across variations from our planned norms, we documented them in the shot documentation.

Please see all of our images obtained in the Sample Media section of this toolkit. If you want to see further details regarding the subject shots, see the camera body comparison table and the batched comparison shots by subject matter.

Lens

As far as lens were concerned, we wanted to be able to show the difference between macro and zoom lens for clinical imaging, as well the difference in image quality related to the quality and expense level of the lens. We brought in an assortment of lens for each camera body that was part of the study. Additionally we were trying to address the question that many programs may have, can you go with the lens that come with DSLR camera kits and get high enough quality clinical images.

For the purposes of our evaluation, we had already seen the functionality of a general macro and zoom lens with each camera body in the camera body evaluation, so we designed our assessment to address the lens quality question. Because macro photography is so important to clinical photography, we elected to compare macro lens. We planned to compare shots across 5 subject areas on one camera body with 3 macro lens. We utilized the Canon EOS 7D camera body with the Canon EF-S 60mm f/2.8 Macro USM lens, the Canon EF 100mm f/2.8L Macro IS USM lens, and the Canon EF 180mm f/3.5L Macro USM lens.  We designed the shots to see how comparable the lens were. The external light source was the Canon Macro Twin Lite MT-24EX flash, which had new batteries placed in it before the imaging session. Each lens was cleaned prior to shooting. We planned for each image to be shot for specific framing with similar predefined boarders. We metered each shot, and adjusted camera settings in hopes of obtaining the best possible shots possible. We had set image priorities prior to shooting that guided camera setting selection. We also elected to capture three of the subjects in portrait mode (full body, Torso, and head & neck) and two in landscape mode (eye, oral). All shots were captured in the same physical location utilizing the same imager and subject. Every effort was made to capture all the shots in one setting, however due to the extremely large number of shots being obtained the images were taken over the course of a period of 4 consecutive days.  

As we captured images we meticulously documented all details. We had a shot documentation note set where we captured general procedures and notes. We had an image table where we captured camera body, lens type, flash power level, F metered, F set, measurements from the camera lens end to the subject matter, and each shots file name for future reference. As we ran across variations from our planned norms, we documented them in the shot documentation.

Please see all of our images obtained in the Sample Media section of this toolkit. If you want to see further details regarding the shots, see the lens comparison table and the batched comparison shots by subject matter.

Light Source

It is our position that proper lighting can make almost any camera body and lens shine. There are many types of light sources on the market, at a variety of quality levels and pricing levels. We wanted to provide a good representation of all the options on the market that could be suitable for clinical imaging.

For the purposes of our evaluation, we designed our assessment of the lights to capture sets of images taken at specific distances with vague framing guidelines for comparison purposes. Because light quality decreases exponentially as it moves away from the subject, we felt it was important to see not only how each light functioned near the subject, but at incrementally increasingly far distances as well. Each light source image was captured at a set distance, measured from the end of the camera lens to the subject. The distances for each light source image were: 6 inches, 1 foot, 2 feet, 3 feet, 5 feet, 8 feet, and 10 feet. All the shots in for this image comparison were primarily taken on the Canon EOS 5D Mark II camera body utilizing the Canon EF 100mm f/2.8L Macro IS USM lens. The additional cameras used were the Canon SD3500 point and shoot and the Canon EOS 7D, and they were used to support features that were not able to be demonstrated with the Canon EOS 5D Mark II. The lens was cleaned at the beginning of shooting and thereafter as necessary. The images were taken at a shutter priority of 1/125, the ISO was variable for each shot, and each shot was metered. All shots were captured in the same physical location utilizing the same imager and subject. Every effort was made to capture all the shots in one setting, however due to the extremely large number of shots being obtained the images were taken over the course of a period of 4 consecutive days.  

As we captured images we meticulously documented all details. We had a shot documentation note set where we captured general procedures and notes. We had an image table where we captured camera body, lens type, light source used, ISO, shutter speed, F metered as appropriate, F set, and each shots file name for future reference. As we ran across variations from our planned norms, we documented them in the shot documentation.

Please see all of our images obtained in the Sample Media section of this toolkit. If you want to see further details regarding the shots, see the light source comparison table and the batched comparison shots by distance.

Additional Supporting Equipment

A DSLR camera assessment can potentially utilize quite a bit of additional equipment. This equipment may be supporting to the assessment, but not the point of the assessment. However, you may have a programmatic need to find additional supporting equipment as part of your overall DSLR camera assessment.

The types of supporting equipment will be based on your specific programmatic needs, but might include: a tripod, a light meter, remote flash triggering devices, step rings, wireless file transmitting devices, screen calibration tools, and picture comparison software. You can find information about the additional equipment utilized by the TTAC in the Product Information section of our website. Additional equipment not formally evaluated by the TTAC that might also be a programmatic need associated with DSLR cameras could include: lens T mounts, lens C mounts, colposcopes, and image transmission software.

Image Review

Being able to have a technical solution that will allow you to do batch reviews of your images is highly valuable. The TTAC has used home grown tools for this in the past, as there was nothing on the market that could meet our needs and we had the programing staff available to design the tool. For this image assessment we added yet another component, image review software, to our market review. We were able to find the tool Adobe Photoshop Lightroom 3 as an acceptable tool. This tool allowed us to mark up each photo based on its characteristics and gave us the ability to call the images up in batches for review. The program requires some familiarity with the Adobe creative suite software, but with online tutorial and experience can fairly easily be learned. This software allowed us to categorize over 1000 images. The keywords can be set prior to imaging or after imaging has been completed. This software allows you to view 2 images side by side, zoom in tandem, and assess the same location in two photographs. This tool creates a catalog, which allows you to pull originals from the raw file data when necessary. This software has mechanisms that allowed us to randomize the images and control for certain variables when evaluating images.

After we had a way to review the images in a timely fashion, we had to find a technical solution that insured that all image reviewers would be “seeing” the same images for review. With the plethora of monitors and TV’s currently on the market that can be used for image reviews, we needed to make sure that we were going to be seeing the same image between viewing devices. How an individual reviewer perceives color is variable enough, not have to have color issues introduced by the technology we were using. Each viewing screen can have potentially different color profiles. Each individual color profile can affect how an image looks to individual viewers. There are screen and TV calibration devices on the market that can be utilized to remove this variable. Based on our market research and needs, we elected to use the Spyder 3 Elite and the Spyder3TV products in our lab.  

For the purposes of the TTAC image review, we were not looking to compare image quality, rather potential usability as a clinical image. We reviewed all images sets to find an example of a clinically useful and non-clinically useful images. For the purposes of your own technology assessment, you may be reviewing images for image quality, color accuracy, depth of field, appropriate lighting, and true representation of the subject matter. Reviewing image details is important, and often requires zooming in on the original image to look for sharpness and clarity in the subject matter. Try to find points of detail to compare between images, such as fine lines in the hand, body hair, and mole appearances. It is important to document the individual reviewer’s findings as well as the group consensus agreed upon at the conclusion of each reviewing session. Utilizing Likert scales with agreed upon 1-4 ratings can be extremely valuable. Rating these aspects of image quality should happen on a 4-point scale, as opposed to the 5-point Likert scale, because this forces the reviewer to decide if an image is good or bad, and removes the possibility of many images being placed as simply “okay”.  Additional notes of why you decided what you decided are invaluable when you go back to re-review images.

Select the Technologies

Once images have been reviewed, look at the scores of the cameras, and, if multiple people are involved, discuss differences in how cameras were rated. Decide which ratings are most important to the intended users. You can always spend additional time with a smaller number of cameras, looking at them as a group or with outside participants if possible. Give the cameras to people who have never used them before, and see if they can perform basic tasks without extensive guidance. The extra time spent reviewing the cameras, especially if end-users are included, can help to make a final decision on which camera is best suited for a particular program.  

Compile all the data that you have obtained to make the final product selections that meet your programmatic needs. If you have stayed true to your planning and eliminated candidates based on your programs requirements of the technology, this difficult decision should be much easier. You will be able to eliminate candidates based on the fact they don’t meet needs, and then for the camera bodies and additional equipment that all meet needs you will have your image review data to help with candidate elimination. The familiarity that you will gain during your assessment will allow you to be able to select a technical solution that will work for your program.   

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