New Scope : The Stellarvue SVX130T
The Company has currently have completed a number of 130 apo triplet objectives at better than .99 Strehl.
Air-spaced lenses that are 5" and larger are often mounted in aluminum cells. These cells expand and contract many times more than the glass. The larger the lens is, the more important it is to have it mounted in a cell with a similar coefficient of expansion (CTE). LZOS in Russia has always provided their 130 mm and larger lenses in a steel cell for this reason. Many other 127 - 130 mm refractors use simple aluminum cells which expand and contract around the glass many times more than our cells, distorting the image. Using a material that closely approximates the expansion and contraction rate of the glass is heavier and much more expensive, but it maintains the performance of the lens despite dropping temperatures.
What is the Gibraltar Amateur Astronomers Society, and who was it founded by?
After obtaining a Master’s Degree in Astronomy, I decided to create the GAAS back in 2013 with the help of a small group of fellow astronomers. The aims were and are to provide a forum for discussion of astronomy matters and share knowledge, as well as to meet other fellow stargazers, whether just getting started in astronomy or as a seasoned observer and/or astrophotographer. It’s also a great way to learn about telescopes, eyepieces, cameras, and the Universe.
How many members are there? When/where do you meet? What do you do?
Since its founding in 2013, membership in the society has been limited to members interested in astrophotography, and currently, we meet in Spain at least once a month. We have a Facebook page of nearly 700 followers, and Facebook groups of over 2000 members. I would like to establish a club locally to develop and create awareness of the sky above us, bring together local people from our community to share our passion for astronomy and the wonders of the Universe. I receive many requests from local parents asking how their children can join the society, but without premises, it’s difficult.
I REMEMBER THE EXCITEMENT I FELT SEEING IT.
When did your interest in astronomy begin?
When I was in school from a very young age, I was interested in all kinds of science things. There weren’t many books on astronomy at the time, but I read all the ones in John Mackintosh Hall library. TV series like Star Trek and Lost in Space when I was growing up did influence me quite a bit. I do remember the first trips that were made into space, like the Gemini and Apollo missions. It wasn’t until later in life when I could afford a telescope, that I saw for the very first time a close-up of the Moon; I remember the excitement I felt seeing it.
What do you love most about it?
I had to think about this for a long time. But I think the best thing is being able to share what I have learned about the Universe with others and enjoy their enthusiasm and amazement.
What has been the most significant/exciting discovery, in your opinion?
There have been many significant discoveries, mostly in the past fifty years. Still, I will stick with last year’s breakthrough and one in particular, which proves a theory going back decades. I am talking about the first image of a black hole, taken using Event Horizon Telescope observations of the center of the galaxy M87, published in April. This shows the supermassive black hole at the center of the Messier 87 galaxy, which is about 54 million light-years away from Earth. The black hole’s mass is equivalent to 6.5 billion suns.
Scientists struggled for decades to capture a black hole on camera to prove it exists, since black holes distort space-time, ensuring that nothing can break free of their gravitational pull — even light. That’s why the image shows a shadow in the form of a perfect circle at the center.
How do you see our knowledge of the skies advancing over the next decade?
In the next decades, we will see a global competition between nations and the private sector to reach the Moon and Mars to establish colonies within the next twenty years. India will send astronauts into space in the next few years. Late this year ESA with Roscosmos aims to discover life in Mars. SpaceX by 2024 plan to send a crewed spacecraft to Mars. China expects a spacecraft landing on the far side of the Moon. We mustn’t forget the USA and Russia, whose sole interest is in the Moon’s minerals.
Would you take part in the Mars mission, given the opportunity?
Sure, wouldn’t you? I can picture a special tour: First a stop on the Moon, wearing spacesuits and exploring all its splendor. Second stop, Mars. There are lots of places to visit there — the Grand Canyon of Mars, the ice caps, strolling along in the morning in the ice fog. Our imagination has no limits. Even if there are no tour ships yet, it will come, but we will need to wait for some years before this is a reality. I would also like to mention that space is a dangerous place, from cosmos radiations to super-speedy dust grains that can damage spacecrafts and astronauts, to gravitation forces that affect our bodies.
WE WILL SEE A GLOBAL COMPETITION BETWEEN NATIONS TO REACH THE MOON AND MARS.
How much of the observable Universe do we know about? What is it comprised of? What do you think lies beyond?
Ahh, the million-dollar question. Of the many ideas that have been discussed over time, the one theory that I feel is most likely is that outside this Universe, there are a bunch of others all expanding just like ours, or contracting.
The Universe is expanding. Space itself is expanding. That much we know from the cosmic redshift of distant galaxies in every direction and which is measurable. The fact it is expanding means it was once smaller, and carrying that to its finality is to recognise that it must have at some point been unified in some form or way. Although I have read a lot about this subject, there is no concrete answer yet.
Now, to make everybody aware of how little we know about the Universe. All the stars, planets, and galaxies that can be seen today make up just 4% of the Universe. The other 96% is made of stuff astronomers cannot see, detect, or even comprehend.
What planets/constellations are best seen from Gibraltar/Spain, and in what spots?
Gibraltar’s uniqueness makes it difficult for seeing. We have a big rock and quite a lot of light pollution, and there are only a few places you can appreciate the cosmos with your naked eye; one spot is on the top of the rock, but only if you’re lucky. Remember the night sky changes throughout the year and constellation position changes as well. If you look towards the North (North Star-Polaris) you will see Constellations like Perseus, Cepheus, and a few others rotating around Polaris. Spain is a vast country, and there are quite a lot of pitch-dark sites nearby. My observatory, for example, is in Istan (Malaga) mountainside with a night sky reading of 21 SQM.
What equipment would one need? Or where can we borrow it/use someone else’s?
The simple answer is minimal to get started. A clear night and a star chart are enough. Star charts can be bought from most of the larger book shops online, such as WH Smith. As you gather sky knowledge, buy a reasonably low budget telescope with a GOTO mount. This will be your starting point, and remember, do not run before walking, or it will cost you eventually.
Do you have a favourite constellation?
Not sure, I suppose Orion given its spectacular colorful nebule images once processed. I have been observing and imaging the night sky for years. For me, the Universe is my favorite space.
Do you have any advice for someone who is interested in getting into the field of astronomy?
Amateur astronomy should be calming and fun. If you find yourself getting wound up over your eyepiece’s aberrations or a planet’s invisibility, take a deep breath and remember that you are doing this because you enjoy it. Take it only as fast or as slow, as intense or as easy, as is right for you.
I purchased the Flip-Flat for my FSQ-106 and like it a lot. It’s well-made, and it's a necessary for my camera images, thou I found the included plastic strap for mounting is a bit loose, I can replaced it with a large metal “hose clamp.” if necessary. Using with SGP for automation while I sleep, it’s very handy that it will record flats and close to cover the scope at the end of the night. As others have said, I don’t trust it for bias or darks in daylight, because it seems light will leak in, so I simply record those with the camera unmounted and capped during the night.
This equipment can be a bit over prices I disagree that it is a luxury item... any more than filters, reducers/correctors or PixInsight.
Good quality flats are a requirement and anything that makes taking good flats consistent and reliable is worth every penny. Look at the hundreds of posts on CN about problems processing lights with flats, the majority of which have to do with the quality of the flats in the first place. High quality, astro-dedicated like the Flip Flat eliminate that problem. iPads, cheap LED panels from Amazon and the like are NOT valid substitutes.
Observatories/ Sheds are highly individualistic; they reflect the interests, equipment, and personalities of their owners. Unfortunately, this also means that one individual's dream observatory might be a white elephant for someone else. As a result, the more specific observatory plans become, the less useful they are.
To store my telescope I used PVC/Aluminium walls with an insulation foam between the internal and outside walls. to move the shed I connected four wheels with brakes, the front of the shed has a rolling shatter that lifts with a cable, this way its easy to just move back the shed from the semi-fixed mount/telescope.Having the shed will safely guard my equipment from the elements better than the previous telescope covered that I had
I've been using my ASI1600MM for last month or so, along with the PixInsight BatchPreProcessing script.
I've read multiple posts to try to understand what should be the proper settings, and at this stage my conclusions are:
1- All exposures should be longer than 0.2 seconds, as the sensor is not consistent under that.
2- Take light frames as usual, at lowest temperature reasonable (-15C for me these days), with proper gain and offset (gain 200 and offset 50 for me, as I do narrowband), and for me exposures are determined using help from the tables in this post.
3- Take matching dark frames: same length, same gain, same offset, same everything as the lights.
4- Take flat frames: adjust gain as needed so that exposures of over 0.2s are achieved, giving a SGP ADU readout of around 12,000-16,000
5- Take dark flat frames: same gain and offset as the flat frames, and same length. For me, this means one set of dark flats per filter.
6- No bias frames
7- In BPP, put Dark Frames in Darks, Dark Flat frames in Darks, nothing in Bias, Lights in Lights, Flats in Flats. Dark Optimization set to OFF. What I understand this does is:
a. Create a master dark of same length as light frames
b. Create a master dark flat of same length as flat frames, for each filter
c. Flat frames for each filter are calibrated with the master dark flat that corresponds to the length of each filters' flat exposure
d. Flat frames for each filter are calibrated into a master Flat
e. Light frames are calibrated with Master Dark (from step a.) and Master Flat (for each filter)
f. Light frames are star aligned/registered
g. Light frames are integrated into a Master Light
8- If needed, manually perform a drizzle or Local Normalization integration
For flats I am using a technique using the daylight instead of a light panel, tests have proven that the quality is much better then a light panel, and its easy to do.
Cover the telescope, Filter Wheel and camera to avoid light penetration to the sensor.
CMOS sensors have undergone significant upgrades in recent years, in many cases surpassing CCD sensors. Their high speeds (frame rate) and resolution (number of pixels), their low power consumption and, most recently, their improved noise characteristics, quantum efficiency, and color concepts have opened them up to applications previously reserved for CCD sensors.
The improvements to CMOS technology and the strong price/performance ratio in these sensors make CMOS sensors increasingly attractive for industrial machine vision. In particular, the very high frame rates that can be achieved, almost without any compromise in image quality, are one of the primary hallmarks of the current generation of CMOS.
CMOS development over taking CCD
There are two types of image sensors for industrial cameras on the market: CCD and CMOS sensor. The right sensor for any given job is a case-by-case question. At the same time, the trend seems to be toward CMOS sensor technology as the wave of the future. This should come as no surprise, as CMOS sensors have made major strides in recent years in two important parameters for area and line scan cameras, namely image rate and noise level. Since the beginning of 2015, it has become official that CMOS technology will be the future technology.
My New CMOS Camera
My new mount 10Microm GM2000 replaces my old AP 1100, my motivation for the upgrade grew out of the realization that my astrophotography quality needed a with dual decodes which lack the replaced mount. Two things matter to me: avoiding wasted time during an overnight session (caused either by images thrown away due to tracking errors or by time spent repeatedly trying to properly frame the desired variable star), and image quality (which affects photometric – brightness measurement – accuracy). This is a personal expression, but never got the reliability to the point where I could trust it to work during unattended overnight sessions.
What made the GM2000 so attractive is that it uses absolute encoders on both the declination and RA axes, which virtually eliminates periodic error. The company claims that tracking error is routinely less than 1 arcsecond, What appealed to me is that 10Micron doesn't sell any version of the GM2000 without absolute encoders, which has permitted them to optimize the entire control system around the use of the encoders.
Installing the GM2000 onto my pier was straightforward, just requiring a few holes and bolts. The most difficult part of the installation was wrestling the 30 KM of mount up onto the pier. The image below is a picture showing the new mount, telescope, and camera.
It then took a couple of weeks to finish upgrading my software to handle the computer interface to the GM2000 and to build a "mount model" in the GM2000 firmware.
To build a mapping points model there are third parties software , this are ModelCreator or Mount Wizzard. It a be tricky to setup the communication channel , but once you connect it a great program.
The firmware has a very nice polar alignment tool, eventually 5 arcseconds away from perfect.
This time I used Polemaster to assist me , thou you need first to do a three stars alignment followed by the polar alignment and if you use the mount PL you would need again to do the three stars alignment.
The general "feel" of the mount is wonderful. The GM2000's firmware seems solid. When you execute a goto, the mount does it quickly and accurately, the same every time. When things go wrong, you don't need to cycle power to get the mount working normally again; instead, just fixing the problem makes the mount happy again.
The mount performs "two-axis tracking," with both the declination and RA motors involved in the tracking process. The mount's pointing model is translated by the firmware into both a declination tracking rate and a RA tracking rate. Thus, the two-axis tracking is able to compensate for all of the known elements of small misalignment. I've run the mount last week for the first time given that when setting up the connection to SGP it platesolving was not aligned with the mount RA/DEC coordination. The issue was the mount software memory stick firmware version, thinking that it was latest in reality its was old, quite old (1.22) when the current update with 1.5. After realizing this and quite annoyed that they sold me a nearly two year old mount (new , but old if you know what i mean) I did a fully automates of five hours overnight sessions, connected and sync to the dome.
For my exposures (up to about 6 minutes), there is no visible tracking error. Typical star images have FWHM widths of about 1.9 pixels.
The QHY PoleMaster
The QHY PoleMaster electronic polar scope was designed to make your polar alignment routine easier, although I do have the RAPAS scope by Astro-Physics, this scope is very versatile and can be use jointly with any other polar alignment software like the SharpCap (which I will talk later) or PoleMaster . One point to mention is no matter which camera tracker or telescope mount you’re using, when it comes to astrophotography, accurate polar alignment is critical.
If you have ever struggled to polar align your telescope mount with the north or south celestial pole, the QHY PoleMaster or SharpCap may just be your new best friends.
The QHY PoleMaster delivered exceptional results for me on my first night out with it. The dedicated polar alignment software was easy to use, and the camera produced a crystal clear image of the star field surrounding the north celestial pole, you just have to be patient as you will need a dark sky before starting.
Polar Alignment speed, accuracy and experience improvements with the QHY PoleMaster:
I can polar align faster, at dusk
I using the PM to improve the current method I use with the RAPAS for alignment which was fast, this one is faster.
I can monitor and confirm my polar alignment at any time
No more 2 or 3-star alignment routines if necessary but again is a personal choose
The spot-on accuracy of the PoleMaster means that my AP mount 1100gto will only need to swell to a star at zero declination (South sky) and once centered on the scope finder or PC do a Recal (press bottom left hand corner button once and press 9). QHY PoleMaster Alignment Camera Specifications:
Field of View: 11 degrees by 8 degrees
Interface: Mini USB 2.0
Resolution: Approximately 30 Arc seconds
Weight: 115 g (0.25 lb)
What’s included in the box .This PoleMaster was sent to me from High Point Scientific for review. The team at High Point made sure to include the necessary adapter for my EQ telescope mount. Here is a look at everything that comes with the PoleMaster:
PoleMaster camera body
Lens cap with a lanyard
Mini USB 2.0 cable
Mount adaptor cap
M4 hardware for attaching the adaptor
Allen key for lens focus adjustment
Fastening the PoleMaster to your telescope mount
The PoleMaster I am using is for my Astro-Physics 1100GTO EQ mount, and I have fastened it to the mount using the dedicated QHY adapter for this model. The hardware was easy to install, and the materials used and overall finish of this device is attractive.
The adapter for my mount came with a tiny Allen key to adjust tension, so I could securely lock the PoleMaster into the front of the polar axis scope of the mount. The QHY PoleMaster adapter for the AP Mount 9000 & 1100
There are two parts to the mount adapter for the PoleMaster, the camera base disc that attaches to the camera body, and the camera mount ring that you need to secure to the mount. You secure the camera base disc to the mounting ring using a thumb screw.
For the mount adapter I used, there were three tiny grub screws to tighten using the supplied Allen key to lock the adapter into place.
The device connects to my Hub via a Mini USB 2.0 cable, with miniature locking screws to avoid yanking the cable out by accident. I wish more of my device connectors had this. The manual instructs you to position the USB port of the PoleMaster to the left hand side when looking at the device head on.
I ran the mini USB 2.0 cable from the PoleMaster into my recently Pegasus powered USB hub, which consolidates the various astrophotography devices I have running to a single USB cable into my laptop.
The adapter allows you to take the PoleMaster off of the mount while not in use or in storage, but I think I’ll leave it right where it is. The tiny camera adds no weight to my rig and maintains a low profile.
I’ll just have to make sure I don’t bang anything against the device by accident when setting up. The included lens cap should stay on the PoleMaster when not in use to protect the lens.
Software and Downloads
All of the software and drivers needed to run the PoleMaster device were found on the QHY website. The company has recently updated their site, which lead me on a bit of a wild goose chase.
Rather then using the URL printed on the green card that came with the camera, I simply “Googled “QHY PoleMaster Driver” to find the appropriate section of the QHY website. Here, I downloaded the latest stable driver for the PoleMaster, along with the dedicated software needed to communicate with the camera and control parameters such as gain and exposure length.
With the 2 downloads unpacked and installed, I ran the PoleMaster software on my field laptop with the camera connected. The QHY PoleMaster manual was to-the-point and helpful through this process, and instructed me to click the “connect” button. I heard the reassuring “new device connected” chime on my Windows 10 OS after plugging in the PoleMaster, so I new the camera was successfully recognized by my PC.
After hitting the “connect” button, the PoleMaster delivered a live-view loop of the stars in the northern sky. My mount was already partially polar aligned to my latitude at 36 degrees north, and pointed towards Polaris from my observatory.
The PoleMaster camera lens has an 11 x 6 degree of field of view. This means that the pole star should be visible if the mount has been roughly polar aligned.
Even though it was not completely dark out yet, I could see a formation of stars in the display screen right off the bat. After zooming out to 75% view, the north star, Polaris was obvious.
Using the PoleMaster Software
The PoleMaster software user interface.The first thing you’ll want to do is adjust the gain and exposure settings so that it is easy to identify the pole star and a of adjacent stars in the field.
The software walks you through a simple process of identifying and confirming the pole star. The process involves matching an overlay of star positions with your current view of Polaris and surrounding stars.
The rotate tool on the left hand sidebar lets you rotate the star pattern overlay using your mouse or using the computer arrows to move the sidebar level.
Then, you are asked to rotate the RA axis of your telescope mount to determine the rotation of the mechanical axis. By rotating your mounts right ascension axis by 15 degrees or more, the software can confirm this value.
This can be confusing the arrow showing on your screen shows an clockwise rotation, the star rotation must be moving anti-clockwise, so when using the Hand_Control/HandPad move the stars anti-clockwise. when the manual clearly states that this must done using the hand controller or mount control software.
Fine tuning my the polar alignment accuracy of my telescope mount using the QHY PoleMaster.
Next the on-screen prompts tell you to confirm the center of rotation. Eventually, you will get to a point where the application displays a small green circle. This is exactly where the pole star needs to be. At this point, the ultra-fine adjustments you make to your polar alignment are far beyond what’s possible with the naked eye.
The PoleMaster has an option to enable a feature called atmospheric refraction to further improve your polar alignment accuracy. This feature asks you to input your coordinates, temperature, and pressure. For atmospheric refraction to work correctly, the USB connector on the PoleMaster must be facing east.
Owners of the PoleMaster have recommended to start the polar alignment routine with your telescope to the west instead of the home position. 2 moves or more than 30 degrees can be difficult from the home position, so if the telescope starts in the west it is not an issue.
If you do not remove the PoleMaster from your telescope mount between astrophotography sessions, you can reuse the centering procedure from your previous polar alignment. However, if you are using the atmospheric refraction feature, you’ll need to remember to adjust the temperature and pressure settings for that night.
Some weeks back I began to hear about Sharpcap’s polar alignment tool. Sharpcap is compatible with just about any camera out there as long as there is an ASCOM driver for it. Best part? Sharpcap is free.
A visit to the Sharpcap website revealed I had everything I needed to give this Polar Alignment Tool a try: a compatible camera (guess what my QHY polemaster camera!!) and all I needed was one of those increasingly rare clear nights to give it a try. I read over the instructions a time or two in preparation, but, frankly, there isn't much to the procedure once the camera is connected to Sharpcap. Press an onscreen button a few times, move the mount once, and adjust the polar alignment with the mount’s altitude and azimuth adjusters.
That nice night finally came, and saw me setting up my AP-1100GTo mount. I put the telescope in normal “home” position, that is, pointed north with the counterweight “down.” (NOT Tracking) the QHY polemaster was already was inserted into the guide scope and connected to the Pegasus USB hub/ computer.
First task was getting an image, a focused image.
Once I was close to focus, the sensitive QHY was producing more than enough stars to meet Sharpcap’s requirements in a mere 1 seconds of exposure. To work, the program needs 15 stars within 5-degrees of the pole, and according to the information on the first polar alignment screen, I was getting around 20.
Ready to go, I clicked Sharpcap’s Tools menu and selected “Polar Align.” I was then presented with Screen 1, shown here. Stars marked in yellow are the ones Sharpcap is using for plate solving the star field (figuring out which star is which). I didn’t worry about that, just let the program think for a little while as the frames rolled in. Shortly, the “Next” button was enabled, meaning I was ready for step 2.
After pressing “Next,” screen 2 was presented and I was instructed to rotate the mount 90-degrees in right ascension. I did, so, moving the mount roughly 90-degrees to the east. (remember NOT TO USE the hand-control to rotate the scope).
Sharpcap then studied a few more frames in order to determine where the Celestial Pole was and what I needed to do to aim the mount there. Once it knew these things, the Next button was enabled again.
After pressing Next for a final time, a star was highlighted in yellow and there was a yellow arrow connecting it to a circle, my target . The task was to move the mount in altitude and azimuth so as to position the star in the little circle, not unlike what you do with a polar bore-scope (by the way, you don't need to return the mount to home position before adjusting; leave it rotated 90-degrees). As you move in the proper direction, the yellow arrow gets shorter and shorter and eventually disappears. It is then replaced with a pair of brackets around the target to allow fine tuning. As you center the star in the target circle, the brackets will move closer and closer together.
How easy was this to do? Quite easy AFTER I understood exactly how to do it. In the beginning, I was fairly far from the pole, with the arrow extending off screen. I’d been told that at this stage it was best to adjust while watching the error numbers Sharpcap displays instead of worrying about the arrow.
These numbers (degrees, minutes, and seconds) indicate how far you are from the pole. They aren’t labeled as altitude and azimuth; instead they read “Up/Down” and “Left/ Right.” Sounded easy to me. I’d adjust the mount’s altitude until the Up/Down number got smaller, and the azimuth till the Left/Right went down. Alas, that didn’t work at all.
It turned out there was a catch, and until I understood what it was, I was all at sea. Up/Down does NOT mean the mount’s altitude, and Left/Right does NOT equal azimuth. Instead, these error numbers relate to directions onscreen (that's what I thought, anyway; see the addendum at the end of the article).
In just a minute or two, I had the program indicating my distance from the pole as under a minute (it when from 55sec to 15 sec) showing as an 'excellent' Polar Alignment!!
The accuracy? I swell to a star at zero declination south and just need to move the star with my hand-control a bit to the centre of the screen to calibrate my AP 1100gto mount.
Advantage above Polemaster
Basically, SharpCap takes two pictures near the pole and analyzes them to judge the accuracy of your Polar Alignment. SharpCap uses plate solving to scan the images and then tells you how much you need to move your mount to increase the accuracy of your Polar Alignment. It connected to APCC automatically using it plate solve and altitude position.
Almost one year after my first try to build an amateur observatory in my garden this was unfortunately discarded due to poor location both in light pollution and water log coming form a nearby golf course grounds. The current location is situated in Istan Mountain around 270m from the sea level and away from light pollution. I am installing the observatory using a Pulsar 2.2M (https://www.pulsarastro.com/).
The Pulsar Observatory Dome provides a high quality, secure and practical housing for your telescope. Providing excellent weather protection for you and your telescope, it allows you to have your instrument ready for use at all times. Whether imaging or visual, having the convenience of a permanent set up adds greatly to your enjoyment of exploring the night sky.
The Pulsar Observatories 2.2 metre full height dome benefits from the following advanced features:
Finest quality, weather proof GRP finish
High quality locking system
Simple design for self assembly
Motorised dome rotation available
Motorised dome shutters available
Accessory storage bays available
Available in white or sage green (other colours - please call)
Total Height approx 2.47 metres
Dome Diameter approx 2.2 metres
Door Height approx 1.1 metres
Dome Aperture approx 0.6 metres
Ideal for up to 12" telescopes and a variety of installations.
Next Step - Internal Equipment Installation
The mounts will follow the apparent movement of the stars in a smooth arc: ideal for imaging, but through the course of the imaging session, the telescope starts on the west side of the pier pointing east and ends up on the east side of the pier pointing west.
This non-linear pointing has to be accounted for to ensure that the telescope points through the dome’s aperture at all times, requiring some complex mathematics.
It is the job of the dome control software to do this for you.
However, to do this correctly, the software must know exactly where the telescope is mounted in relation to the centre of the dome, so your first task is to make some careful measurements to obtain the dimensions required.
Using the spreadsheet available below will make it easier to get all the dimensions correct and ready for insertion into your software.
Install the ASCOM software and enter the offsets from your spreadsheet, ensuring the correct signs (positive or negative), into your choice of control software – we used MaxIm DL and POTH (Plain Old Telescope Handset) and my personal choose is Sequence Generator Pro.
Once the above is completed, your telescope and dome aperture will be in sync.
An example below using my AstroPhysics 1100GTO mount, the dimension is obtained from the mount (see below)