Digital cameras in dermatology

This page describes the different types of products available for dermatological imaging. For a full review of the most popular dermatoscopes on the market, visit Dermatoscopy.

On this page:

• Important parameters affecting the quality of dermatological imaging
• Smartphones or tablets for dermatological imaging
• Point-and-shoot cameras for dermatological imaging
• Interchangeable lens cameras for dermatological imaging

Digital cameras and technology have come a long way in the last 10 years. Nearly any camera, no matter the pixel and sensor size, will provide a sufficient image resolution for most applications in dermatology.

There is no one perfect device or camera for dermatological images. All have strengths and weaknesses, and different people have different priorities in terms of what they look for in their imaging devices. For example, many people tend to favour easily available and small-sized handheld devices, such as smartphones and tablets with cameras.

In general, as size increases from smartphones and tablets through to cameras with interchangeable lenses, absolute image quality improves steadily with the increasing size of the camera sensor. If there is no need for reproduction or the viewing of images at very large sizes, then most readily-available consumer devices will suffice. With good lighting, good image quality is almost guaranteed if a good technique is used to compose and capture the image. The factor that probably most affects image quality is the ability of the person taking the images to use the available functions and features of their device and their ability to compose and choose the right parameters to use to capture the image optimally with the available light and conditions (or to compensate for these variables).

Every year to 18 months, new models of devices are released, with incremental improvements in functionality and image quality. Significant cost savings can also be made by choosing last year’s model or a ‘runout’ model, or buying during sales periods.

Smartphones or tablets have now been widely adopted as day-to-day cameras, with a resulting marked reduction in the sale and use of compact digital cameras (‘point and shoot’ cameras) and also a reduction in the sale and use of cameras with interchangeable lenses (both digital single-lens reflex [SLR or DSLR] and mirrorless interchangeable lens cameras).

There is a misconception that more pixels in an image equates to better image quality, but this is not always true. What adequate image quality (not the same as resolution) and image resolution and detail entail depends largely on what the images will be used for and what size they will be viewed at (eg, web-based viewing requires a much lower image resolution and quality in general compared to printing a fashion spread or billboard).

Important parameters affecting the quality of dermatological imaging:

The following parameters affect the quality of dermatological imaging and should be considered when you are looking to buy a new device:

• Resolution — how many millions of pixels (megapixels) the camera’s image sensor captures to produce the digital image
• Low-light capability — the ability to capture images and retain detail without ‘noise’ (visual distortion and fluctuations in colour and intensity of light) and loss of resolution, with ever decreasing available light
• Dynamic range — the ability to capture gradations of shades of colour, particularly at the extremes of bright and dark areas of an image (the highlights and shadows) and, as a result, fine details
• Camera lens quality — increased clarity of focus, detail and depth of field are seen with higher quality lenses
• In-camera processing — where the camera is able to manipulate captured images (eg, applying filters, noise reduction, changing colour tones and contrasts etc) to produce final images, usually in JPEG format, before they are moved off the camera onto a computer
• Colour fidelity — the accuracy with which a camera reproduces the colours of the photographed subject in the digital image; most cameras don’t have a neutral rendition of colours with standard or even so-called ‘neutral’ or ‘faithful’ colour settings (avoid cameras that reproduce skin tones too pink or red)
• Post-processing — the manipulation of images with software after they have been moved off the device onto a computer; this usually applies to images captured in RAW or variations of it (RAW is a file format that contains all data recorded by the camera sensor when an image is taken; in comparison, when shooting in a format like JPEG, image information is compressed and lost).

Additional considerations when choosing a device

• Device size/portability
  • Ergonomic layout of buttons
  • Dial placement
  • Menu control layout — which all affect usability
  • Device connectivity — USB, wireless connectivity, storage media type(s)
  • Video capability
  • Remote control functionality — camera and/or flash
  • Presence of manual controls — to affect parameters critical to taking images (eg, of film speed [ISO], aperture, exposure compensation, exposure bracketing, flash output modification)
  • Availability of accessories
  • Range of lenses available — interchangeable lens camera systems only
  • Cost
  • Battery charge duration in use
  • Durability
  • Warranty and service
  • Intended use outside of dermatology image capture
  • Always check compatibility with adaptors/step up rings to allow attachment to dermatoscopes if you are intending to attach a dermatoscope to a smartphone or tablet

Smartphones or tablets for dermatological imaging

The advantages

There are advantages for using smartphones or tablets for dermatological imaging:

• Availability — everyone has one, usually on hand
• Small size
• Ease of use (eg, automatic exposure settings, ease in altering point of focus and capturing images by touch, ease of sharing images)
• Able to take clinical and dermoscopy images easily — adaptors for dermatoscopes slide in, clip on or magnetically attach to the device via adaptors or are imbedded with the device
• Some dermatology devices are compatible with Apple products via adaptors
• Low relative cost (compared to interchangeable lens system cameras)
• Easy-to-charge battery
• Acceptable-to-good battery life (depending on how much screen, GPS, Wi-Fi or Bluetooth functionality is used)
• Adequate image quality — some image acquisition applications allow customisation of image parameters (eg, white balance selection, exposure compensation)
• Built-in security as data is encrypted (eg, Apple products)
• Good for general photography for the majority of people
• Dedicated macro, telephoto and wide-angle attachments are available for general photography.

The disadvantages

There are disadvantages when using smartphones or tablets for dermatological imaging:

• Usually only average to good optics
• Sometimes small is ‘too small’ (although smartphones are growing in size with each generation of phones produced)
• Average image quality if cropping, reproducing or printing large images
• Limited user adjustability of image acquisition parameters
• Limited support for dermatoscope devices with some brands (eg, HTC, LG, Google, Xiaomi, Huawei, Asus, etc)
• Not built for long-term durability with frequent use (compared to some DSLR cameras), but might be durable enough due to the lack of moving parts
• Built-in obsolescence (eg, fixed/soldered-to-circuit-board non-user replaceable batteries in Apple and Samsung Galaxy S7/S7 Edge devices, rapid model turnover and product cycles)
• Operating system software updates sometimes lead to dermoscopy image acquisition applications not functioning until the developer can release a compatible update
• Need to use an adaptor to mate the device to camera and dermatoscope
• Security is dependent on the device operating system and can be bypassed in some cases (eg, the android system is more open than the Apple system)
• General photography macro, telephoto and wide-angle attachments are usually of average optical quality.

Point-and-shoot cameras for dermatological imaging

The advantages

There are advantages of using point-and-shoot cameras for dermatological imaging:

• Still relatively small
• Able to use point-and-shoot modes (eg, macro or program modes)
• Most devices are able to alter image acquisition parameters
• Good image quality — some models have relatively large imaging sensors compared to standard compact camera models with resultant better image quality (eg, Panasonic Lumix DMC-LX100, Panasonic Lumix DMC-LX10/LX15, Nikon DL series, Sony RX series, Canon G-X series devices)
• Good optical quality
• Some devices have ergonomically designed layouts and menu structures, ensuring easy control
• Some devices have dermatoscope-compatible adaptors (eg, 3Gen DermLite DL2, DL3 and DL4; Heine Delta 20T; Canfield VEOS HD1 and HD2; VisioMed microDERM Luminis 58-mm threaded camera adaptor; Opticlar VisionMed devices)
• Some devices are purpose-designed for both clinical and dermoscopic imaging in one device (eg, 3Gen DermLite Cam)
• Most have wireless image transfer ability
• May support tethered shooting
• Good battery life.

The disadvantages

There are disadvantages of using point-and-shoot cameras for dermatological imaging:

• An additional device
• Cost (extra over smartphone or tablet costs)
• Not built for long-term durability with frequent use (compared to some DSLR cameras)
• Some controls may be too small and fiddly with those with large hands
• Need to use an adaptor to mate device to camera and dermatoscope — these are sometimes fiddly to attach, although some now have quick-fit magnetic attachments
• No inbuilt dedicated image acquisition, labelling, storage or sharing applications
• Built-in obsolescence — the compact camera market share is declining rapidly as a whole
• Accessories may be expensive
• Now fewer models to choose from — although mid-to-high cost point-and-shoot cameras have the appropriate controls and functionality required to take good images
• Require good photography knowledge to make the most of available functionality when adjusting image acquisition parameters.

Interchangeable lens cameras for dermatological imaging

(These include Nikon 1 series, micro 4/3, Advanced Photo System type-C [APS-C] mirrorless, full-frame mirrorless, APS-C DSLR and 35-mm full-frame SLR cameras)

The advantages

There are advantages of using interchangeable lens cameras for dermatological imaging:

• Image quality — almost always excellent
• Good ergonomics (eg, easy to hold, user-friendly layout of buttons and dials)
• Some interchangeable lens cameras have adjustable screens that allow easy image composition
• Some devices have touch screen focus-point selection
• Adjustability — nearly all image acquisition parameters can be adjusted to suit the conditions or be left in automatic mode
• Most brands have a ‘system’ — that is, the camera constitutes the core of a system and comes with interchangeable components such as complementary lenses and accessories (eg, flashes for suboptimal ambient lighting conditions) or there are third-party providers of complementary lenses (eg, Sigma, Tamron, Zeiss, Tokina, Rokinon) and accessories (eg, tripods, flashes)
• Some devices can be connected to a computer to allow the instantaneous transfer of images (tethered or wireless transfer options exist)
• Some devices have excellent high definition (HD) or ultra-high definition (4K) video functionality
• Some devices can provide ultimate image quality in other forms of use (eg, sports, event, fashion and landscape photography by enthusiast or professional photographers)
• Generally, battery life is excellent for DSLR cameras and good for mirrorless cameras.

The disadvantages

There are disadvantages of using interchangeable lens cameras for dermatological imaging:

• Size and weight are much larger than smartphones, tablets or point-and-shoot cameras
• Higher costs
• Some ergonomics and menu structures are not user friendly
• Some have only fixed screens and/or no touch screen focus-point selection
• Need to use an adaptor to mate a dermatoscope to the camera to allow image acquisition — can be fiddly
• No inbuilt dedicated image acquisition, labelling, storage or sharing applications
• Require accessories (eg, camera adaptors and/or stepping rings) to fit with dermatoscopes, such as the 3Gen DermLite, Heine Delta 20T, Opticlar VisionMed and VisioMed microDERM Luminis dermatoscopes
• Accessories may be expensive (eg, flashes, tripods)
• Some devices have limited or no 4K video functionality
• Built in obsolescence — this is less obvious with system cameras as they tend to have good durability
• There is a trend to reducing market share with interchangeable lens cameras and a move towards mirrorless interchangeable lens cameras away from DSLR cameras
• Some, but not all, high-end system cameras are professional-grade cameras made for repeated heavy use
• Require significant time to learn how to use the device to utilise all its functionality
• Require good photography knowledge to make the most of available functionality to adjust image acquisition parameters
• Mirrorless cameras have small camera bodies, large LCD screens and continuous autofocusing so can only fit physically small batteries — meaning they have a poorer average battery life in normal use compared to DSLR cameras.