Have you ever wanted a particular type of aiming device for some nights, and a different type of finder for others? The Orion Multi-Use Finder Scope is the perfect solution for all your telescope aiming needs! If you want a giant optical finder to grab those faint and fuzzy objects that can double as a guide scope, video finder or wide angle astrograph, then the Orion 70mm Multi-Use Finder Scope has the versatility you need!
Build your own custom telescope aiming device with the modular Orion 70mm Multi-Use Finder Scope. This finder optical tube allows you to customize your own 70mm optical finder scope by adding optional eyepieces, diagonals, video cameras, and more to create a complete finder solution for your telescope.
Field of view (FOV) using the 70mm Multi-Use Finder Scope with a 15mm Eyepiece (approximately 4 degrees FOV
The large, 70mm aperture of the Orion Multi-Use Finder Scope collects almost twice the amount of light compared to a conventional 50mm finder. Since light gathering is calculated by dividing the aperture (in mm) by 7mm (average dilated pupil diameter) and squaring the result, let’s compare a 50mm finder to the 70mm Multi-Use Finder below:
Light gathering power of a 50mm finder scope: (50/7)² = 51x
Light gathering power of the Orion 70mm Multi-Use Finder: (70/7)² = 100x
Since the 70mm Multi-Use Finder gathers almost twice the amount of light compared to a 50mm finder scope, you’ll be able to aim your telescope with the help of significantly brighter, more detailed views of starry skies. Six adjustable alignment thumbscrews on the Multi-Use Finder Scope’s mounting bracket make it easy to accurately align the finder with your telescope.
In order for the 70mm Multi-Use Finder Scope to reach focus, an 1.25″ mirror or prism diagonal is required along with an 1.25″ telescope eyepiece (20mm or lower focal length eyepiece is recommended), illuminated reticle eyepiece, imaging camera, video camera, or autoguiding device. With approximately 10mm of focus travel and helical focus adjustment, you’ll be able to achieve sharp focus through the 70mm Multi-Use Finder Scope with most combinations of diagonal and 20mm or shorter focal length telescope eyepiece, or diagonal and imaging accessory. (All eyepieces, diagonals, and astrophotography accessories sold separately.)
M13 region showing star magnitudes – Unprocessed, 5 second exposure using the MF70 and the Orion Starshoot Autoguider PRO
The light path distance of the Orion 70mm Multi-Use Finder Scope is approximately 80mm, so it requires a combination of accessory and diagonal that provides a similar light path distance. If focus cannot be reached with a particular combination of eyepiece and diagonal, we recommend using a 90° prism diagonal and/or different type of eyepiece which require less focus travel.
When using the 70mm Multi-Use Finder as a finder scope, we recommend using a 90° prism diagonal along with a 1.25″ eyepiece. When used as a guide scope for astrophotographic pursuits, we recommend attaching a 90° mirror diagonal along with an autoguider device. If you wish to use the 70mm Multi-Use Finder Scope as a spotting scope for terrestrial views during the day, we recommend using a 45° correct-image prism diagonal and 1.25″ eyepiece combination. We do not recommend using a 45° correct-image prism diagonal for use as a finder or guide scope due to excessive focus travel.
For visual observers, you can attach either a prism or mirror diagonal and an 1.25″ illuminated reticle eyepiece to create your own custom 70mm angled finder scope. If you use the Orion 12.5mm Illuminated Reticle Eyepiece with the f/3.9 Orion 70mm Multi-Use Finder Scope, it becomes a 22×70 finder scope with powerful 22x magnification. Alternatively, you could use the Orion 20mm I.C.E. eyepiece to create a custom 14×70 finder scope for a wider, 14x magnification view. A mirror or prism diagonal is required along with an eyepiece in order for the 70mm Multi-Use Finder scope to achieve focus. By attaching a diagonal along with a StarShoot Deep Space Video Camera II, you can make your own 70mm video-finder! You can even use the 70mm Multi-Use Finder Scope as a compact, wide-field f/3.9 telescope or spotting scope by adding a combination of a standard 1.25″ telescope eyepiece and a 1.25″ prism or mirror diagonal. (All eyepieces, diagonals and astrophotography accessories sold separately.) The 70mm Multi-Use Finder Scope may not be able to reach focus with some eyepieces longer than 20mm in focal length.
For astrophotographers, the Multi-Use Finder Scope’s big 70mm aperture is especially beneficial when used along with a diagonal and the Orion StarShoot AutoGuider for guided imaging sessions. Compared to smaller aperture guide scopes, the 70mm lens of the Multi-Use Finder significantly increases the amount of potential guide stars visible in a given area of night sky. This makes it easier to find, acquire, and utilize a guide star with the StarShoot AutoGuider in order to capture sharp, precisely guided astrophotos. A prism or mirror diagonal is required in order for the StarShoot AutoGuider to reach focus when used with the 70mm Multi-Use Finder Scope. (Diagonals and StarShoot AutoGuider sold separately.)
Weighing in at 1.2 lbs. without any diagonal or other required accessories installed, the lightweight Orion 70mm Multi-Use Finder Scope allows you to create your own unique aiming device and you can easily swap out optional accessories to alter the finder’s features. It’s like having multiple finder scopes in one!