Skywatcher different scopes different reducers/flatteners?

[alcol620]

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

[ronin]

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.

 

[alcol620]

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.

Regards

Alec