Help me to justify 4"

A thought of having a 4" achromat has been visiting my mind lately. What good can 4" refractor be along with C8 and ST80 - specifically for deep sky? Can it add anything that I don't already have?

Dmitri

Dmitri Kulginov said:

A thought of having a 4" achromat has been visiting my mind lately. What good can 4" refractor be along with C8 and ST80 - specifically for deep sky? Can it add anything that I don't already have?

Dmitri

Hello there Dmitri,

In my opinion, a 4-inch APO will have maxmimum flexibility that can go from very wide FOV to very high power viewing. But since you specify "specifically for deep sky" and achromat (assuming this is what you budget for), I'd look into a wider 4-inch such as the Orion 100mm f/6 achromat.

Ron the 4-inch Tall Evangelist B[ee]

I have owned both 4" achros and an 8" SCT. The 8" SCT was significantly better on all obejcts including planets. Just make sure that your 8" SCT is collimated properly.

jeff

Dmitri,

I reworked my 8' (Orion) to give me a great combo. At an f5 it gives nice rich fields. With the refiguring and the premium secondary, the planetary views are astounding. I've pushed it to 500x when seeing allows. Usually seeing is the limit, not the scope. For me it makes for easier storage and I used to always pull the same scope out (then I built a 12.5" dob).

Ed