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Re: Celestron Telescope Driver with Sharpcap
Posted: Sun Sep 07, 2025 7:54 pm
by TheAstrophotographer
Robin,
A new issue

- again just to lay the foundation, I have a NexStar 8SE alt/az mount without a wedge using a starsense hand controller and using the Celestron Telescope Driver 6.1.7350 Within ASCOM Hub Device and now when I start SharpCap Pro 4.1 it seems to indicate that the time of the mount is different than the computer by usually 30-40 minutes.
Please note, I have a Celestron 93969 SkySync GPS Accessory connected to the NexStar 8SE alt/az mount which should provide not only the location of the mount but also the time. Please note, I have made sure on the starsense hand controller that for the Set Time/Location Source to GPS I have already used the Select Time/Location Source to GPS and press ENTER which I presume should make it automatic.
Therefore, can you please let me know what is going wrong and why SharpCap Pro 4.1 seems to not be able to get the time and likely location of the mount?
Thanks,
Edmund
Re: Celestron Telescope Driver with Sharpcap
Posted: Mon Sep 08, 2025 2:40 pm
by admin
Hi,
SharpCap will ask the ASCOM driver for the mounts current UTC Time when you connect to the mount in SharpCap. In theory, that should report the time that the mount hardware is using, but the implementation of that function does depend on the ASCOM driver in use. Anyway, SharpCap will pop up a warning if there is more than a 1 minute difference between the PC time and the mount time at that point. That tells you what is happening, but not really why...
I don't have experience with the Celestron GPS accessory, but I have noted in the past that weird values come back from the co-ordinates of a Celestron SE mount if you haven't done the sky alignment procedure when you connect to it via ASCOM. Is it possible that could be part of the problem?
I would also suggest taking the GPS gizmo out as a test and setting the handset time/location manually to see if that is reliable or if you still see the error from time to time.
cheers,
Robin
Re: Celestron Telescope Driver with Sharpcap
Posted: Mon Sep 08, 2025 4:34 pm
by turfpit
Edmund
I use the Celestron Telescope Driver 6.1.7350 on a Celestron AVX mount and a Celestron CG5 Advanced GT mount - both having Nexstar+ hand controllers. I have no GPS. These are the settings in Sharpcap Settings > Hardware > Mount for the CG5.

- Celestron_Setup.JPG (26.98 KiB) Viewed 1329 times
The mount is in my study and no alignment has been performed. Latitude and Longitude are stored in the hand controller, having been set up in Setup Time Site (GPS co-ords from an iPhone). When a camera is selected, the mount connects and SharpCap alerts to the time difference between the hand controller and the current time on the laptop. I agree to the time update and the hand controller now has the same time as the laptop.
The hand controller works under UTC and I have the laptop set as Time Zone UTC+00:00 with adjust for daylight saving time turned off.
It is at this point I would normally start the alignment process.
I have no experience with a StarSense controller but what I would do here is:
- disconnect the mount from the PC
- Check the site co-ords and time in the hand controller
- Check the time in the PC, including Date and Time settings in Windows (Time Zone & Daylight saving Time)
See what comes out of that. Because the 2 devices are isolated you should be able to see what is happening. Something might come to light to report back.
Dave
Re: Celestron Telescope Driver with Sharpcap
Posted: Tue Sep 09, 2025 5:40 am
by TheAstrophotographer
Dave,
Although I was not able to get into the mounts ASCOM propertied per the attached pic file, I was able to confirm the information is on my mount.
I was just wondering if there is another way to confirm that the information is getting into SharpCap Pro 4.1 besides the Celestron properties methodology?
Thanks,
Edmund
Re: Celestron Telescope Driver with Sharpcap
Posted: Tue Sep 09, 2025 7:48 am
by turfpit
Edmund
Search for
ASCOM Device Hub User and Technical Information and download the manual. There may be some enlightenment in there, page 4
Telescope Setup looks promising:

- Telescope_Setup.JPG (46.46 KiB) Viewed 1311 times
I don't use Device Hub as I control my mount and filter wheel using their own setup facility. The scope properties are used by plate solvers.
I still think you need to start off with the bullet points I listed and report the findings at each step. Complexity reduction is usually a big help in problem solving.
Dave
Re: Celestron Telescope Driver with Sharpcap
Posted: Tue Sep 09, 2025 3:32 pm
by TheAstrophotographer
Dave,
Based on this, I can use the Celestron Unified Driver directly in SharpCap Pro 4.1 to access its properties and in PHD2 as the Aux Mount for non-control purposes (e.g., mount status) while using ST-4 guiding for mount control.
I like - simpler is better - you sound like my college AiCHE transport professor

- always remember the KISS method - Keep It Simple Stupid

.
Based on this, the ASCOM Device Hub is recommended to prevent driver conflicts, especially for simultaneous use of SharpCap and PHD2 which is not the case for me.
Also beyond this, for other software like Stellarium, I think I should be able to use the Hub for multi-program setups or the direct driver for standalone operation. As always, I need to test the setup to confirm guiding accuracy and mount responsiveness.
Thanks,
Edmund
Re: Celestron Telescope Driver with Sharpcap
Posted: Tue Sep 09, 2025 6:09 pm
by turfpit
Edmund
With the following:
- Handset connected to laptop USB via RS232 to USB converter
I managed this 7x1200s of M27 in Ha. It was actually 10x1200s but the Aurora last October affected the last 3 frames.

- Ha_7x1200s.jpg (344.2 KiB) Viewed 1290 times
Good luck with the project.
Dave
Re: Celestron Telescope Driver with Sharpcap
Posted: Tue Sep 09, 2025 6:16 pm
by TheAstrophotographer
That is amazing - my goal after Saturn is M31 but not sure if my ZWO ASI676MC on an alt/az mount has enough exposure time per sub to achieve a good image. What do you think?
Re: Celestron Telescope Driver with Sharpcap
Posted: Tue Sep 09, 2025 7:01 pm
by turfpit
Best thing to do is have a trial run one night. With m31 I think you are going to need mosaics. At 2Β΅m pixels size it would do well with lunar imaging.
Dave
Re: Celestron Telescope Driver with Sharpcap
Posted: Tue Sep 09, 2025 7:14 pm
by TheAstrophotographer
Dave,
I presume due to small size of the pixel size of the ZWO ASI676MC, you are referring to the process of stitching together multiple individual images of the sky to create a single, high-resolution, panoramic-style image.
I first need to get the first image so that I know I am in the neighborhood and once that occurs I can move on to mosaics

. I still canβt get any portion of M31 so need to get SharpCap all setup to take images

. Like my mother told me when I was a kid, baby steps!!
Edmund