Optical resolution—what is it, and how does it affect the examination?

The image matters

Imaging plays an increasingly important role in dermatology. Dermoscopes, videodermoscopes, and full-body documentation systems allow for the observation of structures that are not visible during a standard clinical examination, aiding in the assessment of pigmented lesions, neoplastic lesions, and many other skin conditions.

As technology advances, manufacturers are increasingly emphasizing image quality specifications. Marketing materials now include information on the number of megapixels, zoom capabilities, and sensor quality.

At the same time, optical resolution remains one of the most important diagnostic parameters—a concept often confused with digital resolution.

It is this factor that determines how many actual details a doctor is able to see during an examination.

What is optical resolution?

Simply put, optical resolution refers to an imaging system’s ability to distinguish very fine structures that are close together.

In other words, it answers the question:

How small does a detail have to be before it can still be seen as a separate element of the image?

The higher the optical resolution, the more actual diagnostic information can be obtained during the examination.

This parameter depends primarily on:

• the quality of the optical system,
• lens design,
• the quality of the sensors,
• the system’s ability to resolve fine structures,
• lighting quality.

In practice, this means that two devices can take photos with the same number of megapixels, yet provide a completely different amount of useful diagnostic information.

Optical resolution vs. megapixel count—they’re not the same thing

This is one of the most common mistakes people make when comparing devices.

The number of megapixels simply indicates how many pixels make up a digital image.

However, this does not automatically mean that the device can capture more detail.

If the optical system is unable to distinguish very fine structures, increasing the number of pixels will not improve the diagnostic quality of the image.

In dermatology, this can be compared to taking a photo of a birthmark with a very large unit, but through a low-quality lens. The image will have high digital resolution, but it will not necessarily reveal more clinical details.

Therefore, when selecting skin diagnostic devices, it is important to consider not only the sensor specifications but also the quality of the optics and the device’s actual ability to image fine structures.

Why is optical resolution important in dermatoscopy?

Modern dermatoscopy is based on the analysis of subtle morphological features of skin lesions.

Among other things, the doctor assesses:

• pigment network,
• vascular structures,
• dots and globules,
• regression areas,
• white and blue structures,
• the limits of change.

The higher the optical resolution of the device, the easier it is to see fine details that may affect the interpretation of the dermatoscopic image.

Therefore, the quality of the optics plays a key role not only in everyday dermatological practice but also in dermato-oncology.

Dermatoscope—Why Do Optics Matter?

With conventional dermatoscopes, image quality depends primarily on the optical system used.

One example of a device designed to maximize optical capabilities is the Illuco IDS-9100 dermatoscope.

The device is equipped with a high-quality optical system that ensures highly detailed imaging of skin structures. In practice, this translates to greater comfort during use and the ability to evaluate dermatoscopic images more accurately.

In the diagnosis of pigmented or neoplastic lesions, the difference between a good image and a very good image often comes down to the quality of the optics.

Videodermatoscopy—When Every Detail Counts

The importance of optical resolution is even greater in the case of videodermatoscopy.

The image is not only viewed in real time, but also archived, analyzed, and compared during subsequent visits.

Systems such as the Canfield D2 videodermatoscope allow for a detailed assessment of skin lesions using high-quality digital imaging.

In practice, this means the ability to:

• more detailed documentation of the changes,
• monitoring the progression of moles,
• assessment of vascular structures,
• conducting comparative analyses during subsequent visits.

The higher the quality of the source image, the greater the diagnostic value of the collected documentation.

Optical resolution in whole-body imaging

Similar rules also apply to systems designed for full-body imaging.

When monitoring patients with numerous moles or an increased risk of skin cancer, it is extremely important that the image retain sufficient detail even after significant magnification of selected areas.

That is why, in systems such as Canfield’s IntelliStudio, it is not only the number of images captured that is crucial, but also the quality of the optics and the ability to detect subtle changes visible on the skin’s surface.

It is precisely thanks to high-quality imaging that it is possible to effectively monitor changes that occur between consecutive examinations.

How can you assess the quality of a device?

When choosing a dermatoscope or videodermatoscope, it’s important to consider more than just the stated magnification or the number of megapixels.

The following are of much greater importance:

• the quality of the optical system,
• actual optical resolution,
• rendering of details,
• lighting quality,
• work ergonomics,
• image documentation and archiving capabilities.

It is these parameters that determine how much diagnostic information the doctor will obtain during the examination.

In skin diagnosis, it is not only the image that matters, but also the amount of information it conveys

Optical resolution is one of the most important parameters affecting the quality of dermatological diagnostics. It determines a device’s ability to visualize fine skin structures, blood vessels, and pigmented lesions.

Whether we’re talking about classic dermatoscopy performed using the Illuco IDS-9100 dermatoscope, advanced videodermatoscopy performed with the Canfield D2 videodermatoscope, or full-body documentation using Canfield’s IntelliStudio, it is the quality of the optics and the optical resolution that directly influence the diagnostic value of the image obtained.

Because modern skin diagnostics isn’t about seeing the bigger picture. It’s about seeing more details.