Many amateur astronomers start their journey with Celestron Alt-Az telescopes, especially the popular Schmidt-Cassegrain models like the NexStar SE, NexStar Evolution, CPC, or CPC Deluxe HD. These Celestron Alt-Az systems are among the most appreciated telescopes ever made — combining excellent optical performance with lightweight, portable, and easy-to-use Alt-Az computerised mounts. Just power on, align to a couple of stars, and you’re ready to observe. No polar alignment, no counterweights, no meridian flip — astronomy made simple. However, when users become curious about astrophotography, many believe they need to switch to an equatorial mount or add a wedge. That’s often where things get complicated: now you need to polar align, balance the mount, and deal with increased setup complexity — losing the very simplicity that made the Celestron Alt-Az telescope so enjoyable in the first place.
A new approach to Alt-Az astrophotography
At PrimaLuceLab, we wanted to explore a different idea: can we make an Celestron Alt-Az telescope ready for astrophotography — while keeping it simple and easy to use?
The answer came from our new SESTO SENSO 3 SC focusing motor, designed specifically for Schmidt-Cassegrain telescopes. By connecting SESTO SENSO 3 SC and the ARCO 2” rotator to your telescope, and controlling them with our PLAY astrophotography software, you can achieve precise focusing and even automatic field de-rotation — all without a wedge! This means that your Alt-Az telescope can now be used not only for visual observations, but also for planetary and even deep-sky astrophotography — maintaining the same intuitive experience.
Three configurations with your Celestron Alt-Az telescope
Depending on how you want to use your telescope, you can easily switch between different configurations. Below we show three practical examples that demonstrate the versatility of this setup.
1. Visual observation configuration
This is the classic visual setup for observing the Moon, planets, or deep-sky objects with your favorite eyepieces. It keeps the telescope light and perfectly balanced for manual or computerised use. Components:
- Celestron Alt-Az computerized telescope
- 2” Visual Back
- 2” Mirror Diagonal
- Eyepiece
This configuration is ideal for visual sessions — you can still take advantage of SESTO SENSO 3 SC for precise focusing, even controlled via WiFi by using the Virtual HandPad on your smartphone or tablet (this way not requiring it to be connected to a Windows PC with USB.
2. Planetary astrophotography configuration
With just a few adjustments, your telescope becomes ready for high-resolution planetary imaging. This setup allows you to record videos of Jupiter, Saturn, the Moon, and other bright targets. Components:
- Celestron Alt-Az computerized telescope
- 2” Visual Back
- ARCO 2” (optional connection in this configuration) with 2” nosepiece (PL3600413) and 2” visual back (PL8410001)
- Optional Barlow lens to increase magnification
- Camera with 2” nosepiece (or 1.25” nosepiece with 50.8mm/31.8mm adapter)
In this configuration, ARCO can also be left unpowered, acting purely as a mechanical adapter if you prefer. Thanks to SESTO SENSO 3 SC, you can finely adjust focus remotely while capturing planets — an important improvement over manual focusing.
3. Deep-sky astrophotography configuration
Here’s where things get really interesting: you can use your Alt-Az telescope for deep-sky astrophotography — without an equatorial wedge! By combining SESTO SENSO 3 SC with ARCO, the system can automatically compensate for field rotation during long exposures. Components:
- Celestron Alt-Az computerized telescope
- Focal Reducer
- 2” Visual Back
- ARCO 2” with 2” nosepiece (PL3600413) and 2” visual back (PL8410001)
Camera with 2” (or 1.25”) nosepiece
The PLAY software takes care of controlling SESTO SENSO 3 SC and ARCO together, enabling automatic field de-rotation while tracking the target. This configuration maintains the simplicity and portability of your setup while opening the door to true deep-sky imaging. We explained how to control Celestron computerized telescope with PLAY in the article “How to remotely control your Celestron equatorial or alt-azi mount with PLAY”.
Example images captured with Celestron Alt-Az NexStar Evolution 8 HD and Player One Astronomy SATURN-C
Below you can see a few example images captured using the same Celestron NexStar Evolution 8 HD telescope and the Player One Astronomy SATURN-C camera, controlled by PLAY software. These results show what can be achieved with SESTO SENSO 3 SC and ARCO 2” when using an Alt-Az mount — from the Moon and planets to deep-sky objects.
Important notes and recommendations
Before configuring your Celestron Alt-Az telescope for astrophotography, please consider the following important points:
- Compatibility: The SESTO SENSO 3 SC is not compatible with the Celestron EdgeHD 9.25 optical tube. If your Alt-Az computerised telescope uses this tube, you cannot install SESTO SENSO 3 SC (and therefore cannot use ARCO 2” for field de-rotation). In this case, we recommend using the ESATTO 2” focuser instead of SESTO SENSO 3 SC. More generally, ESATTO 2” can be used as an alternative to SESTO SENSO 3 SC with any Celestron SC-type optical tube, providing even higher focusing precision, since focusing is performed through the external focuser rather than the telescope’s internal focusing mechanism. However, this solution comes at a higher overall cost compared to SESTO SENSO 3 SC.
- Control system: The example shown in this article was created using the EAGLE control unit, which provides excellent integration, advanced functions, and improved cable management. However, the PLAY software can also be installed on any standard Windows 10 or 11 computer, such as a laptop.
- Mount precision: For long-exposure astrophotography, mount precision is a key factor. Using a Celestron Alt-Az computerised mount does not provide the same tracking performance as a mount specifically designed for astrophotography (even an equatorial one). This means that while SESTO SENSO 3 SC and ARCO 2” make long-exposure imaging possible, results will not match those of a fully dedicated astrophotography setup.
- Backfocus and clearance: Depending on your telescope model, it is essential — especially when using a focal reducer or EdgeHD optics — to set the correct backfocus distance from the corrector or reducer. This may result in the camera coming close to the mount base when pointing near the zenith. Since this depends on both the telescope and camera dimensions, we recommend checking your setup carefully. For best results, use compact planetary cameras with side USB ports to minimize clearance issues.
A bridge between simplicity and performance
The combination of Celestron Alt-Az telescopes with SESTO SENSO 3 SC, ARCO 2”, and PLAY software creates a unique bridge between traditional and modern “smart” telescopes. You keep the freedom and upgradability of your existing equipment, while gaining automation and astrophotography capability — without sacrificing ease of use. This technology developed by PrimaLuceLab offers this new possibility at an affordable price, allowing more users to experience advanced telescope automation and astrophotography features. Whether you’re observing visually, capturing planetary details, or experimenting with deep-sky imaging, this setup adapts to your needs — all while staying simple, modular, and Made in Italy.