Excellent review & tutorial!👍👍At the risk of discussing stuff you already know (and my apologies if that is the case), there is one significant issue that I shall point out. It is as follows: Because our sensors are flat rectangles, our field of view is like a flat rectangle. This poses a problem, because the sky (and RA/Dec coordinates) forms a sphere around us. So, when we create a mosaic, the rectangles that we thought had parallel sides in our mosaic will not keep their orientation when they are projected onto that sphere. Consequently, if we want to end up with a perfect rectangle around the outside of our x by y mosaic (i.e. the individual panels end up with sides parallel to each other, so we don't end up cropping 'lost space' after stacking & merging panels....), the rotation angles for all of the panels actually need to be slightly different. This becomes more of an issue with (a) mosaics further from the celestial equator, (b) mosaics made with large sensors & short focal lengths, and (c) large x by y mosaics. If there is a large amount of overlap (20% or more), then generally smaller mosaics (4x4 or smaller) won't be problematic...however, with larger mosaics, one runs the risk of having gaps between the panels, due to improper rotation angles and/or one runs the risk of having to crop a huge amount from the panels that make up the corners of the desired final rectangle. I don't know what sensor you were using to take those wonderful shots, but I suspect that it is APS-C or smaller, as you didn't have to crop out a lot to make the final mosaic perfectly rectangular. However, if you made a 2x2 mosaic of the same area of sky with a full frame sensor, I think you would see the problems caused by using identical rotation angles on all four panels. FYI, Telescopius.com has a good mosaic planner, and it gives you the option of planning mosaics with all panels having identical rotation angles, or having individual panels with different rotation angles so you will get a perfectly rectangular final mosaic. Give it a try with 4x4 & larger mosaics, and the mosaic planner will show you how significant the issue of rotation angles can become. Last, but not least, one very good reason for using the same rotation angle for all panels is that you only have to take one set of flats. However, if the rotation angle for each panel in the mosaic is different, then you need to take a set of flats for each rotation angle, and apply each set of flats to the data for the corresponding panel. That may not be a big deal if you have an accurate, precise & sturdy rotator & you can automate the entire process, but it will be a bit more time consuming if flats are done manually, and it may be impossible if you are manually rotating the sensor. I hope this is helpful. cheers...and clear skies!
Thanks Derek! Yes, I was aware of that. The intent of the workshop was to review the Falcon Rotator so I didn't want to make the video longer than necessary. Your comment has some great info on the subject so I pined it to the top for the astro community. Thanks for posting. Cheers! Richard
Great review! I own 2 of these and have been using them for about a year and a half. They are indeed amazing units. They easily handle my heavy IMX571 + 7 position wheel without tilting. The software is solid and ASCOM drivers are solid.
Really well done, Richard. You packed this full of great little insights and tips. I'm just in the process of setting up a Pegasus Falcon on my 5" refractor and this video was a huge help. Thank you!
Hi Richard, another great review, thank you very much! I have the Pegasus USB Hub Controller which is a well made great device, it powers the USB dew heaters(2.5amps per socket) that I use on my current rig as well as allowing the USB devices to connect through to my PC using just the 1 cable, its pretty tidy and reliable. I suspect that Pegasus are going to become a big player in this area and if they can keep the build quality going forward they will be a well recommended company to buy from. I have been looking at their focuser and the rotator itself. I think the icing on the cake is the software and the fact it just works with no buggy feel to it. Whilst I found the workshop useful for the rotator, I am also taken by your use of NINA to create automation in your setup. I'd be interested to see you do a little workshop for mosaic imaging, something I have not tried yet. My setup isn't wide enough to capture the North American/Pelican Nebula all in one shot, so that would be the one I am looking to hopefully do at some point over the next year. Thank again for the workshop and clear skies to you in South Dakota!
Hey Robert, That Pegasus USB Hub controller sound pretty sweet. Cables are certainly a challenge. They seem to grow all over the mount like a grape vine. :) I'll keep that NINA mosaic workshop in mind. Thanks!
Thanks for this useful, practical video. My dream is to make motorised mosaics like this, especially since my next sensor is the small ASI533MC pro and I’m used to a full frame DSLR sized sensor - so mosaics is the workaround. In Australia the falcon is now version 2 and the price has gone up to $1350 AUD, which is a lot 😢Will practice first with a manual rotator and NINA.
Greetings to you all in the southern night skies! 🦘💫 Nice choice on the ASI533MC. A couple of guys I know, including myself, got one. It's a great little cam! 😊
There are three ways you can do that. You can shoot your flats before shutting down. Shut down but leave your camera in the same rotation; then take them the next day or night. Or, you can make note of the rotator position, by reading the FIT file data later or just writing it down before closing the rotator program, then send the camera to the home position. Dealer's choice. :)
@@DakotaStarryNights correct me if I am wrong, but doesn't the rotation stay the same for your different panels? In NINA, you could also shoot flats at the completion of each panel, if there is a slight difference.
@@timmyers3428 I guess that would depend on how you arranged your mosaic. A sure way of knowing is to check the rotator position in the image FIT file. I typically shoot my flats and dark flats in the afternoon of the next day.
Yes, I've seen this before. What's important is the framing matches what was generated in NINA or whatever program you may be using. Sometimes I've reset the rotator's home position or removed the camera, which can cause a difference in the number displayed. But the great thing about using a rotator with NINA, the frame will rotate until it matches the sky quadrants entered. 💫
How did you handle the backfocus with the filter wheel attached? What are the connections from your scope to your camera? I have a QHY268C and I intend to use a filter wheel along with the rotator. So I need to know your configuration and compare notes.
Hi Lynx, As I'm sure you know, each telescope has a different amount of available backfocus. So, what I can do is provide the backfocus available with the TSQ-80APO I use. It has a working distance between 65 mm and 135 mm from the M68 thread and 90 mm of travel for the focuser. If you look at 11:07 in the timeline you can see there's plenty of backfocus to add an off-axis guider in my case. Backfocus for the Falcon is 18mm (1:50 in the timeline) My setup is Camera, Rotator and Flatner: better explained at 5:50 to 7:55 in the timeline, along with some adapters you may need. Thanks for posting!
Excellent review & tutorial!👍👍At the risk of discussing stuff you already know (and my apologies if that is the case), there is one significant issue that I shall point out. It is as follows:
Because our sensors are flat rectangles, our field of view is like a flat rectangle. This poses a problem, because the sky (and RA/Dec coordinates) forms a sphere around us. So, when we create a mosaic, the rectangles that we thought had parallel sides in our mosaic will not keep their orientation when they are projected onto that sphere. Consequently, if we want to end up with a perfect rectangle around the outside of our x by y mosaic (i.e. the individual panels end up with sides parallel to each other, so we don't end up cropping 'lost space' after stacking & merging panels....), the rotation angles for all of the panels actually need to be slightly different.
This becomes more of an issue with (a) mosaics further from the celestial equator, (b) mosaics made with large sensors & short focal lengths, and (c) large x by y mosaics. If there is a large amount of overlap (20% or more), then generally smaller mosaics (4x4 or smaller) won't be problematic...however, with larger mosaics, one runs the risk of having gaps between the panels, due to improper rotation angles and/or one runs the risk of having to crop a huge amount from the panels that make up the corners of the desired final rectangle.
I don't know what sensor you were using to take those wonderful shots, but I suspect that it is APS-C or smaller, as you didn't have to crop out a lot to make the final mosaic perfectly rectangular. However, if you made a 2x2 mosaic of the same area of sky with a full frame sensor, I think you would see the problems caused by using identical rotation angles on all four panels. FYI, Telescopius.com has a good mosaic planner, and it gives you the option of planning mosaics with all panels having identical rotation angles, or having individual panels with different rotation angles so you will get a perfectly rectangular final mosaic. Give it a try with 4x4 & larger mosaics, and the mosaic planner will show you how significant the issue of rotation angles can become.
Last, but not least, one very good reason for using the same rotation angle for all panels is that you only have to take one set of flats. However, if the rotation angle for each panel in the mosaic is different, then you need to take a set of flats for each rotation angle, and apply each set of flats to the data for the corresponding panel. That may not be a big deal if you have an accurate, precise & sturdy rotator & you can automate the entire process, but it will be a bit more time consuming if flats are done manually, and it may be impossible if you are manually rotating the sensor.
I hope this is helpful.
cheers...and clear skies!
Thanks Derek! Yes, I was aware of that. The intent of the workshop was to review the Falcon Rotator so I didn't want to make the video longer than necessary. Your comment has some great info on the subject so I pined it to the top for the astro community. Thanks for posting. Cheers!
Richard
@@DakotaStarryNights Awesome! Thanks! 👍👍
NINA can adjust this automatically. There is an on/off toggle in the mosaic section to do this.
That Celestron telescope intercalated at 6:58 😍
Thank you Richard for a comprehensive video. Your review convinced me to pull the trigger on ordering the rotator. Many thanks!
I glad you found it helpful!
Great review! I own 2 of these and have been using them for about a year and a half. They are indeed amazing units. They easily handle my heavy IMX571 + 7 position wheel without tilting. The software is solid and ASCOM drivers are solid.
Yeah, the Falcon Rotator is a winner in my book, too. Thanks for posting!
Really well done, Richard. You packed this full of great little insights and tips. I'm just in the process of setting up a Pegasus Falcon on my 5" refractor and this video was a huge help. Thank you!
Thanks Dave! Glad it was of help.🙂
Great video! Thank you!
Thanks! Glad you found it useful. 💫
Hi Richard, another great review, thank you very much! I have the Pegasus USB Hub Controller which is a well made great device, it powers the USB dew heaters(2.5amps per socket) that I use on my current rig as well as allowing the USB devices to connect through to my PC using just the 1 cable, its pretty tidy and reliable. I suspect that Pegasus are going to become a big player in this area and if they can keep the build quality going forward they will be a well recommended company to buy from. I have been looking at their focuser and the rotator itself. I think the icing on the cake is the software and the fact it just works with no buggy feel to it.
Whilst I found the workshop useful for the rotator, I am also taken by your use of NINA to create automation in your setup. I'd be interested to see you do a little workshop for mosaic imaging, something I have not tried yet. My setup isn't wide enough to capture the North American/Pelican Nebula all in one shot, so that would be the one I am looking to hopefully do at some point over the next year.
Thank again for the workshop and clear skies to you in South Dakota!
Hey Robert, That Pegasus USB Hub controller sound pretty sweet. Cables are certainly a challenge. They seem to grow all over the mount like a grape vine. :) I'll keep that NINA mosaic workshop in mind. Thanks!
Thanks, the back Focus situation always terrifies me as that was hard to do. I think , I'm buying the Focuser today...
Back focus is a tough nut to crack sometimes. I'm glad the video help! :)
Thanks for this useful, practical video. My dream is to make motorised mosaics like this, especially since my next sensor is the small ASI533MC pro and I’m used to a full frame DSLR sized sensor - so mosaics is the workaround. In Australia the falcon is now version 2 and the price has gone up to $1350 AUD, which is a lot 😢Will practice first with a manual rotator and NINA.
Greetings to you all in the southern night skies! 🦘💫 Nice choice on the ASI533MC. A couple of guys I know, including myself, got one. It's a great little cam! 😊
Great video! What focal length is your telescope?
Thanks! 545mm🔭
How do you deal with flats after a rotation?
There are three ways you can do that. You can shoot your flats before shutting down. Shut down but leave your camera in the same rotation; then take them the next day or night. Or, you can make note of the rotator position, by reading the FIT file data later or just writing it down before closing the rotator program, then send the camera to the home position. Dealer's choice. :)
Thanks
@@DakotaStarryNights correct me if I am wrong, but doesn't the rotation stay the same for your different panels? In NINA, you could also shoot flats at the completion of each panel, if there is a slight difference.
@@timmyers3428 I guess that would depend on how you arranged your mosaic. A sure way of knowing is to check the rotator position in the image FIT file. I typically shoot my flats and dark flats in the afternoon of the next day.
Interesting video again, thank you
But shouldn't your flattener also be behind the rotator to have the best result ?
Yes, I believe that would be better. Thanks for pointing that out. :)
Gday
That was a great review of the rotator.
Cheers
Thank you, Ben!
I'd love to see how this does as a derotator for alt-az mounts.
I understand it was built with that in mind also. So...
During your live demo, the requested angle was 35° but the rotator went to 37°. Why was there a 2° discrepancy? What am I missing?
Yes, I've seen this before. What's important is the framing matches what was generated in NINA or whatever program you may be using. Sometimes I've reset the rotator's home position or removed the camera, which can cause a difference in the number displayed. But the great thing about using a rotator with NINA, the frame will rotate until it matches the sky quadrants entered. 💫
How did you handle the backfocus with the filter wheel attached? What are the connections from your scope to your camera? I have a QHY268C and I intend to use a filter wheel along with the rotator. So I need to know your configuration and compare notes.
Hi Lynx, As I'm sure you know, each telescope has a different amount of available backfocus. So, what I can do is provide the backfocus available with the TSQ-80APO I use. It has a working distance between 65 mm and 135 mm from the M68 thread and 90 mm of travel for the focuser. If you look at 11:07 in the timeline you can see there's plenty of backfocus to add an off-axis guider in my case. Backfocus for the Falcon is 18mm (1:50 in the timeline) My setup is Camera, Rotator and Flatner: better explained at 5:50 to 7:55 in the timeline, along with some adapters you may need. Thanks for posting!
Lose the flag stick. The constant tapping on the equipment is distracting and annoying. Couldn’t even finish watching.