Sharpness vs. Size: Resolution vs Magnification Quiz

If light behaves as a wave, then it creates a diffraction pattern when entering a telescope. If resolution is the ability to see fine detail, then it is defined by how well the system can keep two close light sources from blurring together into one.

If magnification only increases the size of the image, and if resolution is determined by the size of the telescope's aperture, then simply zooming in (magnifying) will not reveal new details that the aperture failed to capture.

If a telescope has a fixed resolving power based on its diameter, and if the magnification is pushed too high, then the observer is just enlarging a blurry diffraction pattern; this result is known as "empty magnification."

If the ability to resolve detail is limited by the diffraction of light, and if diffraction decreases as the opening grows wider, then the size of the objective lens or mirror is the primary factor in determining resolution.

If clarity depends on light-gathering and detail, then aperture is key. If the air is moving, it distorts light. If coatings and cleanliness are poor, light is scattered or lost. The price of a stand does not change the physics of the glass.

If astronomers need to know the closest two stars can be and still be seen as two points, and if this depends on the aperture in inches, then the Dawes' Limit (4.56 / aperture) provides that mathematical threshold.

If resolution is inversely proportional to the diameter of the aperture (theta = 1.22 * wavelength / D), then a larger diameter (D) results in a smaller angle (theta); if the angle is smaller, the telescope can resolve finer details.

If the total magnification is calculated by dividing the telescope's focal length by the eyepiece's focal length, then changing the eyepiece is the standard way to adjust how large the object appears.

If you take a low-resolution digital image and zoom in, the image becomes "pixelated" because the detail wasn't recorded initially. If a telescope has low resolution, magnifying it further creates the same effect: a larger, blurrier version of the same data.

If the same amount of light is spread over a larger area (magnification), the image must get dimmer. If the resolution is fixed by the aperture, no new detail appears, even though the image is larger and the visible window (field of view) is smaller.

If light passes through a circular opening, it bends and creates a pattern of rings. If a star is a point of light, its image in a telescope is actually a small disk with faint rings; this disk is the Airy Disk, which limits resolution.

If "seeing" describes the turbulence or steadiness of the Earth's atmosphere, and if this turbulence blurs starlight, then it is a measurement of atmospheric quality rather than a telescope's magnification setting.

If light must pass through an aperture, it will always spread out due to its wave nature. If this spreading prevents perfect focus, then the resulting limitation on detail is called the diffraction limit.

If magnification is the ratio of how much a system enlarges an object, and if the objective and eyepiece act as a two-stage system, then the focal length of the telescope divided by the focal length of the eyepiece yields the power.

If clarity is reduced by the atmosphere, then going higher or using computer-corrected mirrors helps. If resolution is needed, a larger mirror helps. Objects low on the horizon look through more air, which reduces clarity rather than helping it.

If you are looking at a smaller portion of the total image produced by the telescope to make it appear larger, then you are naturally excluding the outer edges; therefore, the field of view must decrease as magnification increases.

If atmospheric conditions are perfect, most telescopes can handle a maximum useful magnification of 2x for every 1mm of aperture (or 50x per inch). If you go beyond this, the image quality degrades.

If a nebula is faint, it provides very few photons per second. If the aperture is large, it acts as a "light bucket" to catch more of those photons, making the image bright enough for the human eye to resolve.

If the atmosphere is the main source of blurring (seeing), then being in space removes that limit. If the limit is removed, the telescope can reach its full diffraction-limited resolution and use higher useful magnification.

If Magnification = Focal Length of Telescope / Focal Length of Eyepiece, and if we divide 1000 by 10, then the result is 100; therefore, the magnification is 100x.