Jump to content


Skywatcher different scopes different reducers/flatteners?

Recommended Posts

Hi folks

Any views on the following: I have a Skywatcher 0.85 reducer/flattener made specifically for a Skywatcher Evostar ED80 scope. I recently acquired a secondhand Skywatcher Equinox ED 120 scope and decided to try it with my reducer sold for the ED 80 scope. I can see nothing wrong with the images taken that suggest I need to pay out another £150 to purchase the reducer sold specifically for the ED120 scope.

Any views on the above would be welcome, thanks for feedback

Link to comment
Share on other sites

Have not looked recently as I have the reducer required for mine but 4 or5 years back a reducer/flattener was specified on the f number of the scope. In effect you bought a reducer for an f/6 scope or an f/8 scope. Since I would guess that the 2 scopes referred to are similar f numbers I could quite understand the reducer operating well on either of the scopes.

Also at the time I was looking I recall that the general wording was if the Reducer/Flattener was for an f/6 scope but would operate well on an f/5 or f/7. As in one either side.

There is I suspect very little difference in the 2 items, which is also what you appear to have found from the more direct approach of simply trying it out.


Link to comment
Share on other sites

Thanks Ronin

I read an article some where that the curvature radius (CR) of the scopes lens required different reducers/flatteners to take account of the different CRs. The ED120 having a bigger piece of glass an a different CR to the glass in the smaller ED80. Hence I thought there would be a noticeable difference.



Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.