2nd Telescope Recommendation - Balance between portability, EAA capability, 1st contact with AP & Visual

[JediScp]

Although I’m an avid reader of this forum, this my first post ever. Perhaps the 1^st of many others.

So, I’m now having a dilemma in choosing a secondary telescope and I would appreciate if the community could advise me on the best option.

My primary telescope is a 10-inch dobsonian (254/1250 | F/4.92) equivalent to a GSO Deluxe. Due to its relatively large weight & since I also wish to do the first steps in EAA and eventual very basic deep sky astrophotography (achieving better results than an untracked dob should not be really that hard!) , I’m looking for 2^nd scope (to be installed in a computerized EQ mount).

My aims:

- valid for visual although it should not be the its main objective as the dob has this slot

- ideally a native focal ratio of 5 or 6 or a slower scope with a focal reducer to achieve those ratios so it can be used in EAA and basic astrophotography

- portable (OTA up to 5/6 kg)

- 150mm aperture

- Focal length preferably over 700mm (main targets will be globular clusters/medium-small nebulae & dozen of galaxies or more)

- Easy collimation (preferably using star collimation or the tools I have: Concenter Eyepiece and Rigel Collimation Cap).

- Preferably an open tube due to dew problems

- Budget under EUR 600.00 / GBP 500.00 / USD 700.00 (OTA only)

 

I’m narrowing the telescope designs/models to these two:

·         150/750 | Newton F/5 namely the Orion Optics VX6 with mirror surface quality 1/10 | 97% reflectivity | 4.5 kg

·         152/1370 | Ritchey-Chrétien namely the TS Optics RC6 (by GSO) | 99% reflectivity | 5.4 kg

 

Regarding the mount I would prefer to consider a SW NEQ5 / EQ5 (budget issue) but I know that many of you will suggest a HEQ5 or EQ6. I will in the future which one can I afford.

Concerning camera an APS-C  DSLR will be used namely a Pentax K-30

Which one would OTA model should I buy?

I’m totally aware of coma issues regarding the Newton (I already have a budget GSO CC) and tricky collimation / large secondary mirror obstruction in RC but I may not be aware of other issues as eventual tracking problems in EQ5 in larger focal lengths. I would prefer a newton /RC rather than a small (70/80mm) ED/APO due to their higher focal lengths. Larger ED/APO are too expensive. Catadioptric telescopes are not being considered as the dob handles very well planetary, moon & sun both in visual & AP.

 For wide field AP & milky way shots I have the DSLR with the Astrotracer feature + lenses .

I know there is no ideal telescope to serve all the purposes (AP & visual) and especially with my budget restraints, but I’m looking to a telescope that can give me a step forward in EEA/AP and step backward in visual not being too steep in either way.

 

Thank you so much for your inputs and clear skies

[nfotis]

Can I suggest a Skymax 150? The closed tube construction and Maksutov design offer less problems with dust etc on the primary mirror, and reflector-like contrasty views on planets and the Sun/Moon. It's the smallest model which accepts 2" diagonal and eyepieces and covers a full frame sensor.

If that's too large, the Skymax 127 offers a large enough view to shoot with an APS-C camera sensor. A dew shield should help (and you can use an insulator like Reflectix in order to reduce air turbulence inside the tube, which often is a problem when air temperatures change too fast).

RC scopes are usually very fickle when collimating, many users have been unhappy with this aspect (these are easy to mess up, and they are recommended for experienced astrophotographers).

N.F.

Edited November 8, 2021 by nfotis

[JediScp]

Thank you very much for these useful suggestions. Indeed these Skymax are very interesting in aspects as you say, portability, for being a closed tube, contrasty views, OTA weight (127 would fit wonderfully in a EQ5) & high focal length. Nevertheless they are more targeted for planetary (visual & AP). I'm more interested in deep sky objects (1st steps in AP/EAA and visually whenever the dob is not around)  and therefore I decided for a safe path avoiding the RC and choosing an aluminum OTA F/5 reflector (Orion Optics VX6 Advanced 150/750). I hope the NEQ5/EQ5 GoTo can handle it with a minimalist set of accessories. Thank you so much for the tips.