Comparison Sigeta Prize Novum 20x-1280x 0.3Mp vs Sigeta Prize Novum 20x-1280x 2Mp

General purpose of a microscope.

Nowadays, there are 4 main options for the appointment: children's, educational, laboratory and specialized microscopes. At the same time, different options (at least from the first three) may well be combined in one model — for example, the simplest and most inexpensive educational microscopes may well be positioned as children's, and the most advanced as laboratory ones. Here is a detailed description of the different destinations:

— Children's. The most simple and inexpensive microscopes, designed primarily for children who are taking their first steps in the natural sciences (as well as for other undemanding users who do not need particularly advanced functionality). Accordingly, such devices lack advanced features such as focus lock, Keller lighting, video outputs (for digital and opto-digital models), a trinocular with the ability to connect a camera, etc. In addition, the body can be made in bright colours, and in plastic is usually used as the body material. However, many children's microscopes are equipped with turrets for quick re-tuning of magnification, and the total magnification factor may well exceed 600x out of the box and 1000x in the top configuration.

— Educational. Microscopes well suited for teaching applications; sometimes such an appointment is even di...rectly indicated by the manufacturer. The specific functionality of such models is quite diverse, the type can also be different (both biological and stereoscopic). In general, devices of this specialization occupy an intermediate position between simple and inexpensive children's microscopes and advanced laboratory equipment. At the same time, there are many models that have a combined purpose — "children's / educational" or "training / laboratory". The first variety is simple and inexpensive, for educational purposes it is suitable mainly for school; the second option, in turn, can be useful even at the university faculty of natural sciences.

— Laboratory. The most advanced type of modern microscopes, designed for full-fledged laboratory research and other serious tasks. Accordingly, such models are not cheap, but they provide a high-quality image and, in general, have the most extensive functionality (although the specific set of features, of course, may be different). Among the features found in laboratory microscopes are a movable stage, installation of light filters, 2 types of illumination (lower and upper), Keller illumination, suitability for special microscopy methods (fluorescence, phase contrast), etc.

— Specialized. Microscopes of a specific design and purpose, one way or another different from more traditional models. These differences may vary; accordingly, the specific specialization also differs. So, recently, portable models for smartphones have gained quite significant popularity: with the help of a special clothespin, such a device is attached directly to the gadget opposite the main camera, and the smartphone screen plays the role of an eyepiece. Another popular variety is compact digital microscopes without their own screens, connected to PCs or laptops via USB, and even to smartphones via Wi-Fi (including via the Internet). This also includes professional equipment with a fairly narrow specialization: stereoscopes with special mounts for dental prosthetics, for soldering microcircuits, etc.; microscopes for metallurgical research; devices on a tripod with a remote rod, designed to inspect individual areas on general objects; comparative microscopes for ballistic and trace investigations in forensics; and etc.

Research methods applicable to this microscope model.

— Bright field. The most famous and widely used method of light microscopy. The object under consideration in such studies is placed on a light background, against which it looks darker. Note that different methods of illumination can be used for research: direct through, oblique, reflected. The first option (when the light from a lamp or a mirror under the stage shines through the sample) is optimal for studying transparent samples, the key details of which are darker than the general background. Typical examples are thin sections of animal and plant tissues. Oblique light is similar in application specifics, while it gives a grey background and is inferior to direct light in terms of backlight efficiency, but provides a more embossed image. As for reflected light, in this case it is indispensable when examining opaque objects: samples of ores and other materials, semiconductor wafers, etc. Anyway, bright-field microscopy well reveals, first of all, details that are noticeably different in light transmission or refractive index from the surrounding background (with through illumination), or give noticeable reflections / shadows (with reflected light).

— Dark field. A kind of opposite of bright-field research: the object under consideration or its individual elements are lighter than the surrounding background. However, this is not just a “negative” of the image, but a separate method with its own c...haracteristics. Illumination in dark-field microscopy is usually through, but it is carried out in a specific way: the middle of the light beam is blocked by a hood, and the light “cylinder”, passing through the condenser lens, turns into an “hourglass”. At the same time, in the narrowest place of such a "clock" there is a preparation, and towards the lens, the light cone expands so that it does not fall into the optics. Thus, the user sees in the microscope only the light scattered by the preparation and the dark background around. This method of research, among other things, allows you to identify "smooth" details that do not stand out sharply against the surrounding background and are not visible in a bright-field study. Among the applications of dark-field microscopy are the work with unstained biological preparations (cells, tissue samples, microorganisms), as well as the study of some transparent materials for small surface defects.

— Phase contrast. A method used to study transparent and colourless objects with an inhomogeneous structure, used when this inhomogeneity cannot be detected by more traditional bright-field microscopy. The idea of this method is that when passing through structures with different refractive indices, light receives different phase changes. These changes are not visible with ordinary optics, but they can be made visible with the help of special equipment — namely, a condenser and a lens of a special design. Accordingly, such equipment is necessarily included in the scope of delivery of the microscope.

— Fluorescent. This method provides the illumination of observed objects with light of a certain wavelength, under the influence of which these objects or their individual elements begin to glow, while the background remains dark. If necessary, coloring substances are introduced into the preparation to improve luminosity (a typical example is biological objects, most of which fluoresce rather weakly by themselves). For illumination, usually, UV radiation is used, therefore this method is also called ultraviolet microscopy; The image enters the eyepiece of the microscope through a filter that filters out UV rays, but freely passes the visible glow of the drug.
One of the main features of fluorescence microscopy is high resolution: it allows you to clearly see even very small objects that are not visible in the usual visible range. In fact, this method in terms of resolution is between classical optical and electron microscopy; At the same time, in contrast to electron and atomic microscopes, devices with the support of the UV method make it possible to examine even the hardware of living cells and microorganisms. And some special variants of this technique make it possible to achieve not micro, but nanoscopic magnifications. The second popular use of fluorescence microscopy is the detection of particles, elements, inclusions, etc., which are not visible under ordinary light, but stand out well in ultraviolet light. A typical example is the surface of many metals and alloys.

The design of the object stage provided in the microscope.

— Stationary. Subject table, fixed motionless; focus in such microscopes is carried out by moving up and down the tube with the objective and the eyepiece. Such systems are simple and inexpensive, but focus while looking through a constantly moving eyepiece is not very convenient. In addition, for advanced biological microscopes (see "Type") with binoculars and trinoculars (see "Eyepiece"), this option is also poorly suited for some design reasons. But the vast majority of stereomicroscopes are equipped with stationary tables — this is the most reasonable design, taking into account the specifics of the application.

— Movable. In microscopes of this type, the entire optical system is fixedly fixed on a tripod, and the stage can be moved up and down to focus the optics. This design is found exclusively in biological microscopes (see "Type"). It is somewhat more complicated and expensive than with a fixed table, but at the same time it is much more convenient: when focus, the eyepiece does not move, which allows you to comfortably adjust the image without looking up. In addition, it is the movable stage that is most suitable for advanced devices with binoculars and trinoculars (see "Eyepiece"), almost all such microscopes have such equipment.

The type of diaphragm installed in the microscope.

The diaphragm is a device that partially blocks the flow of light from the microscope lighting system. It is used mainly for adjusting lighting, as well as for some more specific tasks (in particular, changing the depth of field). When adjusting the diaphragm, the size of its working opening changes - and, accordingly, the actual light transmission; and different types of diaphragms ( iris or rim) differ in adjustment features:

- Iris. The name comes from the Latin word for the iris of the eye - similar devices work on a similar principle. The iris diaphragm consists of a set of specially shaped blades (the so-called lamellas). When moving to close, these petals move from the edges of the working hole to the center, reducing its size; when opening, they correspondingly move outward. Iris diaphragms are more complex and more expensive than rim diaphragms, but they have a number of important advantages over them. First of all, the light transmission throughout the entire operating range of such devices changes smoothly, which allows you to select the settings as accurately as possible. You can manage the settings without interrupting your monitoring of the drug; At the same time, iris diaphragms are also as compact and lightweight as possible. As a result, this option is the most popular in microscopes of the middle class and above, and...is also often found even in simpler models.

- Disk. Another name is revolver. This type of diaphragm is a rim with holes of different sizes made in it; By rotating the rim, you can place different holes in the field of view of the microscope and, thus, change the light transmission. The main advantages of such devices are simplicity of design, low cost, reliability and ease of repair. On the other hand, disc diaphragms are less practical and sophisticated than iris diaphragms - in particular, they are very bulky and do not allow for smooth adjustment. In light of this, this option is used mainly among entry-level microscopes, where advanced characteristics are not required - and an affordable price, on the contrary, is of key importance.

The presence of light filters in the scope of delivery of the microscope.

Light filters are installed in the lighting system; they can be interchangeable or built-in (usually on a turret). Anyway, such devices change the characteristics of light, adjusting it to the specifics of the situation. The types and purpose of light filters can be different, as well as their range in the kit; here are some of the most common options:

— Blue colour. Useful in cases where light from an incandescent or "halogen" lamp is used for illumination. Such a filter equalizes the colour temperature (white balance), making the shades of colours colder and providing natural colour reproduction; this is especially important for microphotography, since a properly set white balance is critical to obtaining high-quality images.

— Yellow colour. Kind of the opposite of blue: lowers the colour temperature, giving the image a warmer tint. It is also sometimes useful for adjusting white balance, but yellow filters have another important use: they are well suited for detecting imperfections in metallic surfaces.

— Green colour. Achromatic and planachromatic objectives, which are installed in most modern microscopes, are best at eliminating aberrations in the green part of the spectrum. With this in mind, similar filters are applied: an image painted in a green tint has the least visible distortion. In addition, most objectives...for phase contrast microscopy are also most effective in the green part of the spectrum (although exceptions are possible).

— Matte (diffuser). White colour filters that do not change the colour of the light, but provide additional dispersion. This can be useful, in particular, when working with low magnification lenses.

— Neutral. Filters in different shades of grey. Used to reduce the intensity of lighting without changing its other characteristics. Such devices can be especially useful when taking photographs — namely, if the camera does not have a sufficiently fast shutter speed. Note that a similar effect can be achieved using a microscope diaphragm, but this is not always the best option when shooting. So, narrowing the aperture reduces the field of view and increases the depth of field (the latter is also not always desirable), while filters do not affect these parameters; besides, in some situations, even the narrowest aperture may not be “dark” enough.

— Light filters for coloured preparations. Improve the visibility of elements painted in a particular colour. Such fixtures are especially popular in biological studies, as they are the most commonly stained specimens and are also the most susceptible to dye fading, making it difficult to view under normal lighting conditions. Note that filters of this type, in contrast to the colour filters described above, do not colour the entire image in a certain colour, but only muffle all other colours, except for their “native”.

— Fluorescent. Filters used in fluorescence microscopy. They are divided into two types — exciting (they separate UV radiation from the general backlight spectrum to illuminate the drug) and closing (protect the user's eyes from ultraviolet radiation and at the same time let the fluorescent glow of the drug pass through).

Camera sensor resolution in megapixels (millions of pixels).

The higher the resolution of the matrix, the higher the video resolution can be (see below), the more detailed the image is capable of providing the camera. At the same time, note that as the number of megapixels increases (without changing the size of the matrix), the size of each individual pixel decreases, which increases the likelihood of noise and deterioration of the overall image quality. Therefore, in itself, high resolution is not necessarily a sign of high quality — a lot depends on other points, for example, on the size of the matrix.

Ways to transfer data to other devices provided in the design of the microscope.

This parameter is relevant primarily for digital and opto-digital models, as well as for individual optical devices equipped with cameras. All described microscopes can be equipped with AV and HDMI outputs, universal USB ports, removable media card readers, and Wi-Fi wireless modules. Here is a detailed description of each interface:

— AV output. Analogue output for video signal transmission. It is used primarily for live transmission of images from a microscope camera, and in some models — also for viewing footage stored in memory. Such outputs do not support HD resolutions and, in general, are inferior to HDMI in terms of overall “picture” quality (with the same camera characteristics). On the other hand, specifically for microscopes, these moments are not so often critical; analogue connectors are still quite popular in both conventional video equipment and special equipment; and the implementation of this interface is inexpensive. Therefore, AV outputs can be found even in fairly advanced models.

— HDMI. Digital output for video signal transmission. Similarly, AV can be used both for real-time broadcasting and for using the microscope as a video player when viewing saved materials (if such...a possibility is provided for in this model at all). At the same time, such outputs are more advanced than analogue AV: HD-quality images (including Full HD and higher) can be transmitted via HDMI, and the signal is very resistant to interference. We also recall that this interface is extremely common in modern video technology — in particular, the presence of at least one HDMI input is almost mandatory for TVs and monitors that support HD standards. On the other hand, the implementation of HDMI is noticeably more expensive, and it makes sense to use it with fairly advanced cameras, which in themselves significantly affect the price of microscopes. Therefore, such outputs can be found mainly in rather expensive and advanced devices.

— USB. Universal connector that allows different applications; a specific set of these options is directly related to the functionality of the microscope. Typical examples of using USB include the following: copying captured photos and videos to a computer or laptop; live image broadcast; remote control via PC / laptop (for example, moving the parent drug); charging the built-in battery, etc. The specific type of USB connector in the microscope may vary, however, usually, an appropriate cable is supplied in the kit for connecting to a standard full-size port.

— Card reader. The device for working with memory cards is usually SD, and in miniature pocket models — microSD. Such cards usually contain materials captured by the camera. In general, this function makes it much easier to copy information to other devices that also have card readers — primarily laptops and PCs; and miniature microSD cards are also supported by smartphones, tablets and other portable gadgets. Anyway, removing the card from the microscope and installing it in another device is often easier and faster than fiddling with a wired or Wi-Fi connection.

— Wi-Fi. A wireless module, which in this case is mainly used to communicate with an external device — such as a smartphone, laptop or PC. A Wi-Fi connection allows you to at least broadcast the image from the camera and copy the photos taken by it, and often also control other functions and settings (light brightness, movement of the driver, etc.). At the same time, the absence of wires provides additional freedom of movement and overall convenience. However, note that the specific communication format may be different, it should be specified separately. So, some models support only direct connection over a relatively short distance (in fact, up to a couple of tens of metres, or even less). Others are able to connect to an external device via the Internet, and here the distance does not play a role — there would be access to the World Wide Web. Still others allow both formats of work. Also note that individual devices with this function do not have their own screens at all and are designed for use with external gadgets; This design makes the microscope as compact and easy to carry as possible.