Low Cost & Portable 50MM Refractor/ALT-AZ Mount telescope for EAA
For anyone looking for a highly portable, relatively low cost EAA refractor setup which is easily upgradeable I put together this combination of a 50mm refractor on an Alt-Az mount with a 4MP color CMOS camera. I will be testing it soon and will provide images taken with it. In the meantime I think this is a good option for anyone just getting into EAA and either on a budget or wanting something easy to setup and transport, or both. I have also listed some accessories to consider and also some upgrade options which you might prefer. Links are affiliate links which help to support my web site, YouTube Channel and my testing efforts. Please consider using them for all your astronomy purchases if you can.
Complete OTA/Mount/Camera Cost $1,100
The Refractor ($399)
I chose a Sharpstar 50mm triplet Apochromatic refractor ( available from Agena Astro or HighPoint Scientific) for its excellent optics, compact size and low cost. It uses 2 elements of ED glass for excellent chromatic aberration control. At f/5.5 this OTA provides a wide field of view of 275mm. It is compact and light weight at under 8" long and 2.2lbs. It comes with a dual speed rack and pinion focuser, 360 deg rotator, Vixen-style dovetail, retractable dew shield and a pair of 50mm M48 extension tubes.
Complete OTA/Mount/Camera Cost $1,100
The Refractor ($399)
I chose a Sharpstar 50mm triplet Apochromatic refractor ( available from Agena Astro or HighPoint Scientific) for its excellent optics, compact size and low cost. It uses 2 elements of ED glass for excellent chromatic aberration control. At f/5.5 this OTA provides a wide field of view of 275mm. It is compact and light weight at under 8" long and 2.2lbs. It comes with a dual speed rack and pinion focuser, 360 deg rotator, Vixen-style dovetail, retractable dew shield and a pair of 50mm M48 extension tubes.
The Mount ($400)
I have used the SkyWatcher AZ-GTi (available from Agena Astro or High Point Scientific) before and have found it to be very easy to transport and setup quickly. The GTe version (available from Agena Astro) is $75 cheaper and doesn't have the dual axis encoders which I don't find to be important for EAA. Both models weight just 8.8lbs but can handle a payload of up to 11lbs so eachcan easily handle the Sharpstar 50mm refractor and has the ability to handle an 80mm refractor if you decide to upgrade in the future. They come with an adjustable lightweight tripod and a pier extension which prevents the OTA from crashing into the tripod legs when pointed at the zenith. They has WiFi capability to connect to your smart phone, tablet or pc using the Synscan App which provides full mount control.
I have used the SkyWatcher AZ-GTi (available from Agena Astro or High Point Scientific) before and have found it to be very easy to transport and setup quickly. The GTe version (available from Agena Astro) is $75 cheaper and doesn't have the dual axis encoders which I don't find to be important for EAA. Both models weight just 8.8lbs but can handle a payload of up to 11lbs so eachcan easily handle the Sharpstar 50mm refractor and has the ability to handle an 80mm refractor if you decide to upgrade in the future. They come with an adjustable lightweight tripod and a pier extension which prevents the OTA from crashing into the tripod legs when pointed at the zenith. They has WiFi capability to connect to your smart phone, tablet or pc using the Synscan App which provides full mount control.
The Camera ($299)
There are multiple options for cameras to use with the Sharpstar 50mm triplet. As a compromise between cost and field of view I have chosen the ZWO ASI664MC color camera (available from Agena Astro or High Point Scientific) with a 4.15MP sensor. The IMX664 chip has 2.9micron pixels for high resolution and a diagonal of 9mm. This camera has high quantum efficiency and no amp glow. Coupled with the Sharpstar 50mm it gives a field of view of 56 x 98 arc-min which is wide enough to capture large deep sky objects like the Andromeda galaxy. Because of the small pixel size it is possible to zoom into the smaller DSOs like M27 and still get a large and pleasing image.
Camera Adapter ($19)
We will need an M42 to M48 adapter $18 - $19 (available from Agena Astro or High Point Scientific) to attach the camera to the back of the OTA.
There are multiple options for cameras to use with the Sharpstar 50mm triplet. As a compromise between cost and field of view I have chosen the ZWO ASI664MC color camera (available from Agena Astro or High Point Scientific) with a 4.15MP sensor. The IMX664 chip has 2.9micron pixels for high resolution and a diagonal of 9mm. This camera has high quantum efficiency and no amp glow. Coupled with the Sharpstar 50mm it gives a field of view of 56 x 98 arc-min which is wide enough to capture large deep sky objects like the Andromeda galaxy. Because of the small pixel size it is possible to zoom into the smaller DSOs like M27 and still get a large and pleasing image.
Camera Adapter ($19)
We will need an M42 to M48 adapter $18 - $19 (available from Agena Astro or High Point Scientific) to attach the camera to the back of the OTA.
Optional Accessories
Here are some accessories you may want to consider to enhance your overall EAA experience.
Sharpstar 0.84X Reducer/Field Flattener $99 (available from Agena Astro or High Point Scientific)
Sky-Watcher GTe/GTi Counter Weight Kit $33.50 to $38.50 (available from Agena Astro or High Point Scientific)
Sky-Watcher GTe/GTi Latitude Base $80- converts from ALT-AZ to EQ (available from Agena Astro or High Point Scientific)
ZWO Motorized Focuser $199 (available from Agena Astro or High Point Scientific)
Optolong 2" UV-IR Filter $65 (available from Agena Astro or High Point Scientific)
Optolong 2" Ultra High Contrast Light Pollution Filter $85 (available from Agena Astro or High Point Scientific)
Here are some accessories you may want to consider to enhance your overall EAA experience.
Sharpstar 0.84X Reducer/Field Flattener $99 (available from Agena Astro or High Point Scientific)
Sky-Watcher GTe/GTi Counter Weight Kit $33.50 to $38.50 (available from Agena Astro or High Point Scientific)
Sky-Watcher GTe/GTi Latitude Base $80- converts from ALT-AZ to EQ (available from Agena Astro or High Point Scientific)
ZWO Motorized Focuser $199 (available from Agena Astro or High Point Scientific)
Optolong 2" UV-IR Filter $65 (available from Agena Astro or High Point Scientific)
Optolong 2" Ultra High Contrast Light Pollution Filter $85 (available from Agena Astro or High Point Scientific)
Upgrade Options
You may want to upgrade this setup and, if so, here are some upgrade options to consider.
Sharpstar 61mm f/5.9 ED Triplet Refractor ($549) 360mm focal length 22% larger apeture
Agena Astro
High Point Scientific
SkyWatcher AZ-GTi ALT-AZ Mount with dual axis encoders Maintains alignment when disengaging clutches
Agena Astro
High Point Scientific
SkyWatcher Star Adventurer GTi Equatorial Mount $740 Enable longer exposures without field rotation
Agena Astro
High Point Scientific
ZWO ASI585 MC Color CMOS Camera ($399) 50% larger FOV 8.3MP 2.9micron pxls, 12.8mm diagonal, no Amp Glow
Agena Astro
High Point Scientific
ZWO ASI585 MC Pro Cooled Color CMOS Camera ($599) Dark Current Noise suppression 8.3MP with 2.9micron pixels, 12.8mm diagonal, no Amp Glow
Agena Astro
High Point Scientific
You may want to upgrade this setup and, if so, here are some upgrade options to consider.
Sharpstar 61mm f/5.9 ED Triplet Refractor ($549) 360mm focal length 22% larger apeture
Agena Astro
High Point Scientific
SkyWatcher AZ-GTi ALT-AZ Mount with dual axis encoders Maintains alignment when disengaging clutches
Agena Astro
High Point Scientific
SkyWatcher Star Adventurer GTi Equatorial Mount $740 Enable longer exposures without field rotation
Agena Astro
High Point Scientific
ZWO ASI585 MC Color CMOS Camera ($399) 50% larger FOV 8.3MP 2.9micron pxls, 12.8mm diagonal, no Amp Glow
Agena Astro
High Point Scientific
ZWO ASI585 MC Pro Cooled Color CMOS Camera ($599) Dark Current Noise suppression 8.3MP with 2.9micron pixels, 12.8mm diagonal, no Amp Glow
Agena Astro
High Point Scientific