DWARF Mini Smart Telescope: Full Review

Alignment

In astronomy, alignment can be referring to two different concepts. The first is known as planetary alignment, which describes the apparent proximity of at least two planets, as observed from Earth. The second concept is the precise positioning of optics to allow light through and create the best possible image.

Altitude

In astronomy, altitude is the angular distance of a celestial object from a person's observable horizon. It is measured in degrees.

Altitude-Azimuth (Alt-azimuth, Alt-az) Mount

Commonly referred to as Alt-Az mounts, this type of mount rotates in two perpendicular axes: left/right and up/down. The altitude axis alters the elevation angle while the azimuth axis alters the compass bearing angle. The two of these combined allow for a pointing to any location in the sky. As opposed to equatorial mounts, these Alt-Az mounts don’t require alignment with the celestial pole, making it easy for beginners to utilize.

Aperture

Aperture is the diameter of a telescope's primary mirror or lens listed in millimeters or inches. The bigger the aperture of a telescope, the more light it will gather, allowing the observer to see more detail on celestial objects and ascertain finer details that a telescope of lesser aperture may not see.

Astronomy

Astronomy is the scientific study of space and the celestial objects within it. It also deals with the physical universe as a whole. Astronomy can be broken up into four subcategories: astrophysics, astrometry, astrogeology, and astrobiology. The study of astronomy has helped measure time, seasons, and navigation on Earth.

Astrophotography

This refers to photography of astronomical bodies and phenomena. Astrophotography is not new, for example the popular T threading still used today harkens from Tamron’s T-mount developed for their 35 mm cameras - however it has seen a notable increase in popularity with improvements in cameras, mounts, filters, and software making astrophotography much more accessible. This is not limited to celestial bodies such as nebulae, planets, or galaxies either, as solar imaging is now more within the reach of the average consumer than ever before.

Auto-Focus

Automatic focusing utilizes software to shift the focus of a telescope in and out to determine the precise focal point of the optics. It does this by reading the star size at each focus point, creating a graph of this data, then finds the minimum star size; bringing the optics into sharp focus.

Azimuth

Azimuth is the angle between an object in the night sky and North. This angle is measured clockwise around the horizon of the observer.

Bias Frame

Bias frames are to try and capture just the noise inherent to the camera sensor, so you take them at as fast an exposure time as possible. Whether or not the camera is connected would be irrelevant, as again we're just attempting to profile the camera at this point.

Blocking Filter

Blocking filters are used in dedicated solar telescopes to reject all remaining light outside of the H-alpha wavelength. This is necessary as etalons pass harmonics of the desired wavelength. Luckily however these harmonics are far enough apart that while the filter in a blocking filter has a relatively speaking large bandpass, compared to that of an etalon, it can block them while still providing a clear view of the H-alpha light.

Blood Moon

A Blood Moon is another name for a total lunar eclipse. Due to the phenomenon where the Moon appears to be a shade of red as the shadow of the Earth covers the Moon.

Bluetooth

Bluetooth devices contain certain hardware that allows transmission of data via an antenna. The discoverable device sends out signals that are then detected by the receiving device, and their connection allows a transfer of information. This association between devices is called a piconet, where short radio waves are communicated back and forth.

Bortle Scale

The Bortle scale measures how light polluted a particular area is, and classifies the level of brightness from 1 to 9, with 9 being the brightest. This scale is incredibly helpful for astronomers, as the darker the sky, the more celestial objects are able to be discerned.

Calibration Frames

Calibration frames are types of images that are applied to light frames to remove unwanted artifacts caused by a number of different factors. Dark frames are images taken at the same temperature as the light frames, and are necessary to remove hot pixels or other fixed noise for a cleaner image. Bias frames are similar in this aspect, though their purpose is to reduce the sensor’s readout noise seen within the light frames. Another type of calibration frame are flat frames, which remove dust motes or unwanted gradients for a uniform, even field.

Chromatic Aberration

Different wavelengths of light travel at different speeds based on the medium it occupies. When white light is exposed to glass such in a telescope or lens, blue light, red light, and green light slow at varying rates. This change of speed causes each wavelength to focus at different points along the focal plane, resulting in color fringing seen within the images taken.

Computerized Mount

A telescope mount controlled by motors and software that can be used to automatically locate and track celestial targets. Typically operated with a hand controller (though sometimes remotely or via a personal computer), users can either enter coordinates or simply select the star, planet, or other object of their choice. Computerized mounts can either be alt-azimuth or equatorial and are especially useful in areas where light pollution may hinder your ability to see stars.

Contrast

Contrast, in the context of astronomy, describes the difference in brightness between the celestial object(s) and the background of the sky.

Deep Sky Object

A deep sky object is a faint celestial object that exists beyond our solar system. Deep sky objects are primarily nebulae, star clusters, and galaxies. This categorization does not include individual stars.

DSLR / Mirrorless Camera

What one may consider a “regular” camera; used for everyday photography and feature an interchangeable (removable) lens system. Popular brands from this category that also enjoy wide support in the astrophotography hobby are Sony, Canon, and Nikon.

Eclipse

An eclipse is when one celestial body blocks the light that comes from another celestial body. This causes a shadow to fall on a third celestial body. From Earth, people can observe both solar and lunar eclipses. These phenomena happen when the Sun, Earth, and Moon align in different orientations.

Equatorial Mount

An equatorial mount is an astronomy instrument that features two axes of rotation: right ascension (RA) and declination (DEC). Equatorial mounts also feature an additional axis, called the polar axis, that these RA and DEC axes rotate about. This polar axis is to be lined up with Earth’s celestial pole to accurately counteract Earth’s rotation. These mounts are ideal for astrophotography applications, as the addition of a polar axis eliminates the issue of field rotation within captured images.

Exposure Time

Exposure time is the amount of time the camera sensor is allowed to collect light. In general, the longer the exposure time, the more light collected, and the brighter the image will become. This should be selected with caution though, as an exposure time that's too long can oversaturate the pixels and blow out the image, resulting in a loss of signal. Determining the correct exposure time is highly dependent on the aperture of the optics as well as the gain settings used. A larger aperture will produce a brighter image than that of a smaller aperture with the same exposure time. In a similar fashion, an image with a higher gain setting will be brighter than a lower gain setting image with equal exposure time. Finding the perfect balance between the aperture, gain, and exposure time will maximize image quality.

Field of View (FOV)

In simple terms, your field of view is the amount of sky that is witnessed by your telescope/camera combination, or telescope/eyepiece combination. This measurement is calculated in angular degrees. To calculate how much of the sky you can image with your astrophotography rig, take the width of your camera chip, multiply it by 57.3, then divide that product by the focal length of your optics. If you want to determine how much of the sky you can view through your eyepiece, take the apparent field of view of your eyepiece (provided by the manufacturer), then divide it by the quotient of your telescope’s focal length & the focal length of your eyepiece.

Filter

A filter is an accessory that is inserted within the imaging train. These accessories allow only select wavelengths through to the camera sensor. For instance, a blue filter will only allow the camera sensor to collect blue light, while all other light is blocked out. There are a wide variety of filters, from light pollution filters to narrowband filters. The combination of data from filters is a great way to create images that highlight certain wavelengths from celestial objects.

Focal Length

The focal length is the distance, usually measured in millimeters, between the primary mirror or lens and the point at which the image comes to focus. Generally, classic refractors have a longer focal length, Newtonian reflectors tend to have a focal length that is shorter, and Schmidt-Cassegrains fall somewhere in the middle.

Focal Ratio

The focal ratio is calculated by dividing the aperture (mm) of the primary mirror or lens into the focal length. Example: 2,500 mm divided by 254 mm (10") equals an f/ratio of 9.84, which is usually rounded off, in this case to f/10. The focal ratio signifies how quickly a telescope gathers light and tells us something about the telescope's field of view, how long exposures will take during astrophotography sessions, and how much magnification the eyepiece will produce for that telescope.

Galaxy

Galaxies are massive collections of various celestial objects, and structures, that share a common orbital path around a galactic nucleus. The three types of galaxies are spiral, elliptical, and irregular.

Latitude

Latitude is one of two coordinates used to find a position on a globe. Lower latitudes are closer to the equator, while higher latitudes are closer to the poles.

Milky Way

The Milky Way is the name of the galaxy that hosts our solar system. Named for its bright milky appearance in the night sky, the Milky Way is home to countless stars, nebulae, and a even a few supermassive black holes. It estimated to be over 13 billion years old, and it would take over 100,000 light years to travel from one side to the other.

Moon

A moon is a naturally occurring object that orbits a planet or other celestial bodies (excluding stars). These are also called natural satellites. The Moon, capitalized is the Earth's only natural satellite and is the brightest object in the night sky. The Moon stabilizes the tilt Earth's orbit, causing the seasons, and tides.

Nebula

A nebula is a type of celestial body that is made up of gas and/or dust. There are 3 different types of nebulae within space. Emission nebulae have a “glowing” effect, where they absorb and emit light from surrounding stars. The colors emitted are entirely dependent on the gasses present within the nebulae itself. This type of nebula also includes planetary nebula and supernova remnants, produced by stars themselves. As opposed to emitting light itself, reflection nebulae reflect starlight from neighboring stars. Reflection nebulae are typically blue in color, such as the Pleiades or the Running Man Nebula. The last type of nebulae is dark nebulae, which blocks stars and other objects from our view, creating a dark silhouette.

Optics

In basic terms, this refers to the system that “collects” and focuses incoming light down to a smaller, brighter, magnified image that is then viewed through an eyepiece or captured by a camera. There are different ways to accomplish this, most commonly with glass elements (refractor) or with systems of mirrors (reflector). Each approach comes with its own set of tradeoffs, whether that be chromatic aberration, coma, etc. which can sometimes be mitigated with upgraded optical components (ED glass) or additional corrective components (like coma correctors). Numbers of standard optical designs have emerged as well, such as doublets, triplets, Petvals, Newtonians, SCTs, RCs, and more.

Polar Alignment

Polar alignment is the process of aligning a telescope mount’s polar axis with the Earth’s axis of rotation. By having these two axes parallel to one another, precise counteraction of the Earth’s rotation can then be achieved. While a typical process of equatorial mounts that have three inherent axes of rotation, a similar effect can also be achieved by utilizing an equatorial wedge with two-axis alt-azimuth mounts.

Seeing Conditions

This term refers to the overall clarity of the night sky at any given time and within any given location. This clarity fluctuates constantly, as it is based on numerous different atmospheric conditions, such as humidity, turbulence, high clouds, heat, and plenty more. To give an example, you may have witnessed stars in the night sky “twinkle.” This is due to our atmosphere distorting their incoming light, causing a twinkling effect. When it comes to astronomy, especially when observing the planets and the Moon, seeing conditions are very important to consider, as these distortions can cause the subjects to become blurred and unfocused. It’s best practice to observe celestial objects when the atmosphere is most stable.

Stacking

A method used to bring out what would otherwise be faint or invisible detail and contrast in an astrophotography image. When imaging a target, the longer an exposure is, generally the more faint detail will become visible. However as exposure time becomes longer several complications emerge - motion blur due to compounding small deviations or errors in tracking, increased sensor noise and glow, and overexposure of the bright areas of an image. Stacking mitigates these issues by combining a number of shorter exposure images, commonly called sub exposures, sub frames, or simply “subs”, into one image that effectively has a longer exposure time. The stacking process can further improve the resulting image with the use of calibration frames that help identify and compensate for visual artifacts introduced by the optics or sensor itself.

Star

A star is a luminous sphere of plasma held together by the collective gravitational attraction of hydrogen and helium atoms. Stars also contain various trace elements, such as lithium, carbon, and towards the end of there life cycle, iron. Stars come in many temperatures, colors, and sizes. High mass stars like Betelgeuse appear to shine red from our perspective because our eyes are only sensitive to a small portion of the electromagnetic spectrum. To see the true luminosity of Betelgeuse, you need specialized equipment designed to capture the appropriate wavelength of light.

Sun

Our Sun is the star the planets in our solar system orbit around. Like other stars, our Sun is a luminous sphere of plasma held together by the collective gravitational attraction of hydrogen and helium atoms.

Tracking

As the Earth is continuously spinning and in motion, the location of a celestial object in the sky moves over the course of a night. This becomes apparent during observation as a target moves out of view, and particularly observable in images as stars and objects quickly become a blur as exposure time and focal length increases. To compensate for this, computerized mounts and smart telescopes employ tracking techniques to keep the target centered in the optics. Depending on the motion style of the mount, the resulting image can vary. Alt-Az motion, popular in smart telescopes, keeps the object centered but can not compensate for its “spin” without what is known as a wedge. Accordingly these images lose information on the edges of the frame as they rotate out of view, leading to ever smaller, circular, images as time spent imaging increases.

Tripod

A tripod is a tool that consists of three legs, of varying thickness and materials, and is used to support cameras, telescope mounts, and other equipment through (most often) a threaded connection. It acts as a stand to increase height and stability.

USB

Universal Serial Bus or USB is a protocol for data transmission, and is by far and away the most common way astronomy equipment will communicate with a PC in a wired capacity. There are a number of USB connectors, such as USB-A (the rectangular port you’re likely familiar with), USB-B, USB-C, and micro USB; as well as a number of different revisions (2.0, 3.0, 3.1, etc.) that have brought more speed, power, and reliability to the protocol.

WiFi (Wi-Fi)

Wi-Fi, sometimes shortened to just WiFi or wifi, is a protocol for wireless communication. Primarily it is used to transmit and receive data between a device (such as a smartphone, computer, smart TV, and an ever increasing number of other household devices) and a router or wireless access point that is connected to the internet. Communication with the internet is not the only function the Wi-Fi protocol is useful for, and indeed many of the aforementioned devices can communicate with each other locally using this protocol and the router as an intermediary. Increasingly this protocol has been used for more direct communication between two devices (like a smartphone and a smart telescope), with one creating its own access point or broadcast that both devices then send and receive data on. While this does have the disadvantage of disconnecting a device’s connection to the internet, it has become necessary to transfer large amounts of data quickly that otherwise exceed what Bluetooth can accommodate.