Skip to content

Celestron EclipSmart Solar Filter for 70 mm Refractors - 94221

SKU: CEL-94221
This Celestron 70 mm EclipSmart Solar Filter has been discontinued and is no longer available. You may find a suitable alternative in our selection of similar sized solar filters. If we can be of assistance, please don't hesitate to call us at 1-800-266-9590 or send us an email, and we will be happy to help you. Thank you!

To ensure that the solar filter you buy will fit properly, please take a few moments and measure the outside diameter of your telescope, spotting scope or binoculars before you order. Remember, the solar filter needs to fit snugly around the front of the tube assembly that holds the optics. If the filter is slightly larger than its diameter, the filter can be made to fit by the addition of self-stick felt spacers to the inside of the cell. However, if the filter is too small it will not fit, and that would be a shame. So please, measure before you order. Thanks.

Celestron 70 mm EclipSmart Solar Filter


  • Transforms Celestron Powerseeker 70AZ and 70EQ, as well as the 70 mm Travel Scope, instantly into a telescope capable of white light solar viewing.
  • Proprietary material used for this filter is ISO certified Solar Safe to allow safe direct viewing of the August 21, 2017 North American Total Solar Eclipse.
  • Made from the lens cap of the telescope to enable a safe, comfortable fit using three safety screws. Comes with a safety cap for protecting the exterior surface of the filter when not in use.


With this ISO-compliant Celestron EclipSmart Solar Filter for 70 mm refractor telescopes, you'll be able to safely view the Sun, enhancing your overall observing experience. Adheres to your telescope via three nylon safety screws and will not slip off for continuous Solar Safe viewing.

Suitable for use with the following telescopes:

  • Powerseeker 70AZ - 21036
  • Powerseeker 70EQ - 21037
  • Travel Scope 70 - 21035


Celestron 70 mm EclipSmart Solar Filter Specifications


  • Telescope Compatibility: Celestron PowerSeeker 70 AZ and EQ; Travel Scope 70
  • External Filter Diameter: 105.1 mm
  • Internal Filter Diameter: 100.6 mm
  • Filter Thickness: 22.9 mm
  • Clear Aperture: 42 mm
  • Filter Weight: 1 oz.
  • Filter Material: Celestron proprietary Mylar film
  • Three nylon safety screws


Solar Safe Technology

Solar Safe filter technology is incorporated into all EclipSmart solar products for maximum protection from damaging UV and IR light, and filtering 99.999% of powerful visible light. This technology, independently tested by SAI Global Assurance Services, makes it possible to directly observe the sun in a GUARANTEED SAFE manner.

What About Your Finderscope?

Adding this solar filter to your telescope will adequately filter the light coming through your focuser, but have you considered what you’ll do about your finder scope?

Here are some suggestions for dealing with your finder that will assure you do not damage your eyes (or anyone else’s) by looking at the Sun through your telescope’s unfiltered finder:

  • Remove Your Finder. Ditching your finderscope when solar viewing will remove the possibility of someone accidentally looking through it to spot the Sun. Of course, not having a finder makes centering the Sun in your eyepiece more difficult, but with practice, it can be done. Set the mount down so the telescope is pointing in the direction of the Sun. Put the main solar filter on so you can check your progress, and then move the telescope around until it casts a shadow that produces a nice, sharp silhouette of the scope. The OTA will look circular. Now move your telescope up or down with your hand controller, slow motion controls, or very carefully by hand if required while looking through the eyepiece. You will not get a warning when you are close, but you should be able to align with the Sun using this method. Practice ahead of time before any big event, like an eclipse, to make sure you’ve got the process down.
  • Filter Your Optical Finder. This solution is not recommended for a reflex or red dot finder since it is too easy to accidentally look around the window. If you have one of these finders we recommend you either remove it or replace it with a dedicated solar finder (see below).

    To make your optical finderscope safe for solar viewing you’ll need to buy a piece of Baader Solar Film for Visual Use. This film comes in different size sheets and cuts easily with scissors, allowing you to make your own filter. You can go super low-tech and use a rubber band to hold a piece of the film firmly around the finder or you can get fancy and build your own slip-on solar filter. However you attach the solar film, you need to make sure there are no light leaks at all and that it doesn’t accidentally fall off when you move your telescope around. Any unused film can store flat between two pieces of cardboard and will keep for years. It is nice to have around, just in case of a solar emergency :-)

  • Buy a Dedicated Solar Finder. Check out the Tele Vue Sol-Searcher Solar Finder. This special finder can only be used when observing the Sun, but it works very well. The Sol-Searcher is reasonably priced and can be attached to your telescope with Velcro or with #10-32 screws (user supplied).