Comparing between 2 newtonian reflectors!
Comparing between 2 newtonian reflectors!
I am looking at the Celestron Astromaster 114eq and Orion starblast 4.5'' I was wondering what most people would choose. Please give me some suggestions! And why..
-
weixing
- Super Moderator
- Posts: 4708
- Joined: Wed Oct 01, 2003 12:22 am
- Favourite scope: Vixen R200SS & Celestron 6" F5 Achro Refractor
- Location: (Tampines) Earth of Solar System in Orion Arm of Milky Way Galaxy in Local Group Galaxies Cluster
Hi,
Base on the focal length and the length of the tube, I believe Celestron Astromaster 114eq is a Newtonian with a so called "corrector lens" at the focuser. I haven't had a chance to look through this type of telescope yet, but this type of telescope doesn't seem to perform well base on old review. Not sure whether the modern version will be better than the older version.
Anyway, I also think the Orion starblast 4.5" will be a better choice... the reviews and feedback are quite good. I had seen through a few times and the image quality is quite good... just avoid using very low magnification as the coma are very obvious which is very common for a F4 scope.
Good luck and happy shopping.
Have a nice day.
Base on the focal length and the length of the tube, I believe Celestron Astromaster 114eq is a Newtonian with a so called "corrector lens" at the focuser. I haven't had a chance to look through this type of telescope yet, but this type of telescope doesn't seem to perform well base on old review. Not sure whether the modern version will be better than the older version.
Anyway, I also think the Orion starblast 4.5" will be a better choice... the reviews and feedback are quite good. I had seen through a few times and the image quality is quite good... just avoid using very low magnification as the coma are very obvious which is very common for a F4 scope.
Good luck and happy shopping.
Have a nice day.
Yang Weixing
"The universe is composed mainly of hydrogen and ignorance."
"The universe is composed mainly of hydrogen and ignorance." 
Celestron Astromaster 114eq - this probably has a built-in 2x barlow & erecting prism; compared with the starblast it probably has not so good axial optical performance, but probably better off-axis field correction. I had sold off a similar Meade 114 before.
Orion starblast 4.5'' - this probably has better on-axis optical performance than the above, but suffers from off-axis coma, unless you use a coma corrector and/or premium eyepieces. The other drawback for beginners is the need for critical collimation. It is quite fine as a grab-n-go small second scope for more seasoned observers. I still keep one as an alternative travel scope.
Equatorial (EQ) mounts are quite bulky, heavy and tedious to setup, but allows tracking if motorised. Altazimuth (AZ) mounts are light, fast and easy to carry & use, but usually no motorised tracking. For a beginner, I would think an AZ mount would be easier to move, use and learn star-hopping with.
If you have a limited budget, another alternatives for a first scope is to check under "Buy & Sell" for a second-hand 70-80mm refractor, or 3"-5" Schmidt Cassegrain (SCT) or 3"-5" Maksutov Cassegrain telescope (MCT). Standard 'cheap' eyepieces perform better optically on 'slow' f/10 scopes like SCTs and MCTs.
Orion starblast 4.5'' - this probably has better on-axis optical performance than the above, but suffers from off-axis coma, unless you use a coma corrector and/or premium eyepieces. The other drawback for beginners is the need for critical collimation. It is quite fine as a grab-n-go small second scope for more seasoned observers. I still keep one as an alternative travel scope.
Equatorial (EQ) mounts are quite bulky, heavy and tedious to setup, but allows tracking if motorised. Altazimuth (AZ) mounts are light, fast and easy to carry & use, but usually no motorised tracking. For a beginner, I would think an AZ mount would be easier to move, use and learn star-hopping with.
If you have a limited budget, another alternatives for a first scope is to check under "Buy & Sell" for a second-hand 70-80mm refractor, or 3"-5" Schmidt Cassegrain (SCT) or 3"-5" Maksutov Cassegrain telescope (MCT). Standard 'cheap' eyepieces perform better optically on 'slow' f/10 scopes like SCTs and MCTs.
rlow
-
weixing
- Super Moderator
- Posts: 4708
- Joined: Wed Oct 01, 2003 12:22 am
- Favourite scope: Vixen R200SS & Celestron 6" F5 Achro Refractor
- Location: (Tampines) Earth of Solar System in Orion Arm of Milky Way Galaxy in Local Group Galaxies Cluster
Hi,
The Az mount is easier to use and lighter, but the problem is that a lots of Az mount in current low cost, beginner scope is very lousy... cannot hold the position you point properly after you release you hand.
The disadvantage of EQ mount is as the above mention... heavy compare to Az mount, take more time to assemble and disassemble. The advantage is most of the eq mount (even low cost one) can hold the position you point properly.
Just my $0.02.
Happy shopping and have a nice day.
The Az mount is easier to use and lighter, but the problem is that a lots of Az mount in current low cost, beginner scope is very lousy... cannot hold the position you point properly after you release you hand.
The disadvantage of EQ mount is as the above mention... heavy compare to Az mount, take more time to assemble and disassemble. The advantage is most of the eq mount (even low cost one) can hold the position you point properly.
Just my $0.02.
Happy shopping and have a nice day.
Yang Weixing
"The universe is composed mainly of hydrogen and ignorance."
"The universe is composed mainly of hydrogen and ignorance."