Focal reducer for aps camera

[GrampyG]

I have a modded Canon 600D which I use with a focal reducer for my Newtonian.

However, it has been suggested that a reducer is not required for scopes like the Redcat 51/Zenithstar 73 with aps-c sensors

Most grateful for any advice

[Davey-T]

Do you mean a reducer or reducer / flattener ?

Dave

[MarkAR]

Shouldn't need a reducer with either as the FOV is pretty wide.

This is a handy tool

https://astronomy.tools/calculators/field_of_view/

[PEMS]

Redcat no need as it is in effect flattened and adding a reducer makes little sense and would counter the in built flattener system at the rear. 2 flatteners do not result in flatter, they result in curvature.

On a Z73 there is a dedicated flattener - worth getting the WO adjustable - and WO do what may be a reducer/flattener. They say flattener but the images of the item have 0.8 on the side also implying it flattens and reduces.

Do you need to reduce? Often seems people think they "have" to reduce but have no reason to do so, except to make a system faster and even then you need to ask Why?. Many seem to assume they have to do so because they read about the items.

[alan potts]

I'm not exactly in love with reducers. I have a reducer on the back of my Borg 77EDll, this seems to make it a nightmare to focus at F4.3. I also have a TS Red .79 reducer I use with my bigger APO, which even at the exact 55m backfocus is not that great at the edges. However the flatener I got from FLO, Hutech, is absolutely spot on.

Alan

[GrampyG]

Thank you for your replies.

I think I mean a flattener rather than a reducer for an aps. Looking at the Zenithstar 61/73 for the 600D.

G

[GrampyG]

Looking through a box of old photography stuff just found  "Meade Series 4000 f6.3 focal reducer/field flattener". Would this be suitable on those scopes (Zenithstars)?