Examining a subject in detail is commonly seen as synonymous with taking a close look at it. For this reason, macro photography has been dedicated to various fields such as medical, industrial, and research purposes. This close-up view, often accompanied by magnification of the subject, helps the user see details that are not normally visible to the naked eye. However, when a subject is magnified excessively, the term “closer look” may no longer be accurate because we encounter a world that cannot be seen with the eyes alone; in fact, often we cannot even imagine it.
The following series of texts, which discuss microscopic photography, serve as an introduction to capturing this unfamiliar world through photography.
Microscopic photography, also known as photomicrography, refers to the practice of taking photographs of objects that are typically too small to be seen with the naked eye. It involves using specialized imaging equipment such as microscopes and digital cameras to capture highly detailed close-up images of microscopic subjects. To capture microscopic images, usually a microscope is used to magnify the subject, and a camera is attached to the microscope’s eyepiece or camera attachment part. The camera may be a dedicated microscope camera or a digital camera with an adapter. The setup may also include additional accessories like specialized lighting sources, filters, focus stacking tools and stages for precise sample positioning.
In recent years, advancements in technology have led to the development of powerful microscopy techniques and improved digital imaging capabilities, enabling even more precise and visually stunning microscopic photography. But, before discussing the complexity of microscopic photography, it is advisable to familiarize ourselves with the structure of a microscope.
The structure of a basic microscope
Basic microscope consists of several key components such as objective lens, eyepiece, stage and etc. In the following, we will take a look at the description of each of these sections.
Eyepiece (Ocular): The eyepiece is the part through which you look to observe the subject or specimen. It usually contains a lens or a combination of lenses that magnify the image produced by the objective lens.
Objective Lens: The objective lens is located near the specimen and plays a crucial role in magnifying the image. Microscopes typically have multiple objective lenses of varying magnification powers, such as 4x, 10x, 40x, or 100x. These lenses can be rotated into position depending on the desired magnification level.
Stage: The stage is a flat platform where you place the specimen for observation. It often includes clips or mechanical stages to hold the specimen in place and allow precise movement.
Condenser: The condenser is positioned beneath the stage and focuses light onto the specimen. It consists of lenses that concentrate and direct light towards the specimen, enhancing the clarity and visibility of the image.
Illuminator: The illuminator is the light source that provides illumination for the specimen. In many microscopes, it consists of a built-in light source, such as an LED or halogen bulb, placed beneath the stage. Some advanced microscopes may also have additional lighting options like adjustable brightness or filters.
Coarse and Fine Focus Adjustment: Microscopes have focus adjustment mechanisms to bring the specimen into sharp focus. The coarse adjustment knob moves the stage up and down rapidly, allowing rough focusing, while the fine adjustment knob enables precise focusing by making small adjustments.
Arm: The arm is a curved structure connecting the base to the top part of the microscope. It provides a handle or grip for holding the microscope while carrying or adjusting its position.
These are the fundamental components of a basic microscope. However, depending on the type and complexity of the microscope, there may be additional parts such as a diaphragm for controlling light intensity, filters for specialized imaging techniques, or a camera attachment for capturing digital images or videos of the specimen. It’s also worth mentioning that different types of microscopes, like stereo microscopes, electron microscopes, or confocal microscopes, have variations in their structures and additional components tailored to specific applications and magnification capabilities.
In this text, we are focused on working with an optical microscope, which typically are not more complex than what was mentioned. However, there is another important part that needs to be addressed. Nowadays, with the increasing need for microscopic imaging in various fields, trinocular microscopes are very common. A trinocular microscope is a type of compound microscope that features two eyepieces for viewing and an additional third port, called the trinocular port or phototube, specifically designed to accommodate a camera or other imaging devices. This configuration allows simultaneous visual observation through the eyepieces while capturing images or videos of the specimen using the attached camera. Therefore, for photomicrogtaphy in such microscopes, there are two methods available: Attach camera to eyepiece and attach to trinocular head.
Attach camera to eyepiece
To attach a camera to a microscope eyepiece, you’ll need a specific camera adapter designed for your camera model and microscope. If you use a professional camera, you should take out the eyepiece from the microscope’s eyepiece tube to create space for the camera adapter. The eyepiece is usually threaded or has a bayonet mount, which can be unscrewed or released to remove it from the microscope.
After attaching the adapter, you should place the camera onto the camera adapter and align the lens of the camera with the opening of the adapter. To attach a DSLR camera to a microscope, you’ll typically need a T-ring adapter and a microscope camera adapter. Some camera adapters have a specific locking mechanism or set screws to secure the camera in place, while others may rely on friction to hold the camera steady.
Finally, you should use the microscope’s focusing knobs to bring the sample into focus while observing the camera’s live view or through the camera’s viewfinder. Once you achieve proper focus, you can capture images by pressing the camera’s shutter button.
Attach camera to trinocular head
Depending on your trinocular microscope and requirements, you can use a dedicated microscope camera or a digital camera with an adapter. Dedicated camera usually uses C-mount that is a standardized lens mount commonly used in scientific and industrial cameras. It has a 1-inch diameter thread. The C-mount standard allows for easy interchangeability of cameras and lenses in microscopy applications. C-mount cameras come in various types and specifications, including different sensor sizes, resolutions, and connectivity options.
It is feasible to employ high-end cameras, such as DSLRs and mirrorless cameras, in conjunction with microscopes. As it mentioned, to attach a DSLR camera to a microscope, you need a T-ring adapter and a microscope camera adapter.
Two crucial factors: optics and sensors
The quality of microscopic images depends on various factors. However, the sensor and optics can be considered the most important ones. The three images below have been captured using three different methods and tools. The first image was taken using a commercial camera (similar to a webcam) connected to an eyepiece microscope, which is an acceptable optical solution, but limitations of the camera sensor (especially dynamic range) prevented accurate capturing the details. The second image was captured using a specialized microscope camera through a trinocular port, which captures better light details. However, optical errors resulting from additional lenses in the system have caused a significant increase in chromatic aberration. Finally, the third image was captured using a photography camera and a specialized lens tube (without using a microscope), delivering the best image quality.
