5” app refractor what to expect

[Antares_856]

Having so far viewed through an 8” sct, what can I expect from a good quality 5” apo?

can you give descriptions/ comparisons with 8” sct for the various types of target I.e. globular and open clusters, double stars, galaxies, nebulae, planets and moon?

wider field of views and sharper stars appeal to me which I know I would get, but what are all the pros and cons?

thanks

[John]

I have an excellent quality 5 inch apo refractor but I've not compared it with an 8 inch SCT directly having not owned one of those recently.

Given how the 5 inch compares with my 12 inch dobsonian I would say that the 8 inch SCT should show more resolution of the stars in globular clusters, fainter stars in open clusters, pick up fainter galaxies and show a little more extension in the brighter galaxies, similarly on nebulae. On double stars the overall performance is likely to be similar but the refractor will show tighter star images which may aid splitting close / uneven brightness pairs. On the moon and planets, assuming that the 8 inch SCT is well cooled and collimated, the performance could be quite similar. The refractor might show low contrast features a little more clearly and fine features possibly a little sharper but the conditions will also play a large part in that. With planets in unfavourable positions (ie: low in the sky) the refractor might have the edge.

Obviously these are not detailed descriptions but might give you some idea.

 

[Peter Drew]

I have an excellent 5" F15 triplet APO and three 8" SCT's and I can confirm exactly what John has said.  Saved me a lot of typing!    🙂 

Edited November 15, 2020 by Peter Drew
typo

[JeremyS]

What John said. And what Peter would have said if John hadn't already said it

🙂

 

[dweller25]

I have directly compared a 5” APO to a C8 with XLT coatings and can also confirm what John and Peter said and what Jeremy tried to say but was too late 😁

Edited November 15, 2020 by dweller25