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Orion Telescopes
Orion 70mm Multi-Use Finder Scope
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  • Modular large aperture finder scope optical tube can be easily customized for your specific telescope aiming needs
  • Add preferred accessories to create your own specialized finder solution for your telescope
  • Multiple potential applications for both visual observing and astrophotography
  • Big 70mm fully coated lens provides bright, clear views
  • To reach focus, a 1.25" diagonal along with a 20mm or shorter focal length eyepiece, imaging camera, video camera, or autoguiding device is required (all accessories sold separately)


Learn more
Item #  07220b

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 22x70 finder scope with powerful 22x magnification. Alternatively, you could use the Orion 20mm I.C.E. eyepiece to create a custom 14x70 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!

Warranty

Limited Warranty against defects in materials or workmanship for one year from date of purchase. This warranty is for the benefit of the original retail purchaser only. For complete warranty details contact us at 800-447-1001.

Product Support
Visit our product support section for instruction manuals and more
  • User level
    Intermediate
  • Optical design
    Refractor
  • Optical diameter
    70mm
  • Focal length
    279mm
  • Focal ratio
    f/3.9
  • Coatings
    Fully coated
  • Glass material
    Crown/Flint
  • Resolving power
    1.70arc*sec
  • Lowest useful magnification
    10x
  • Mount type
    Optical Tube without Mount
  • Tube material
    Aluminum
  • Length of optical tube
    8.2 in.
  • Weight, optical tube
    1.2 lbs.
  • Additional included accessories
    Included accessories may vary for 2nds, Substitutions may be made
  • Other features
    2nds are covered by Orion's Satisfaction Guarantee
  • Warranty
    One year

Orion 70mm Multi-Use Finder Scope optical tube assembly (OTA)
Bracket with adjustment screws

Orders received by 1pm Eastern Standard Time for in-stock items ship the same business day. Order received after noon will ship the next business day. When an item is not in-stock we will ship it as soon as it becomes available. Typically in-stock items will ship first and backordered items will follow as soon as they are available. You have the option in check out to request that your order ship complete, if you'd prefer.

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