I've had my OAG and scope set up for eleven years, but here in the south of the U.K., telescope time has been trashed by cimate change. The trend, particularly over the last 5 years has been for increasing cloud cover at night. I've created control electronics, written ASCOM drivers, worked out my FOV, but it's all just sitting in the obsrvatory waiting for some clear sky. Tonight it's 55 MPH winds & rain (again).
Dude, you have no idea what you just solved for me. I inherited a ZWO OAG (same as yours) from a friend. The manual for the OAG states that the adjustment for the prism is one of the 2 long screws on the body. Well, maybe I'm an idiot, but I loosened the screw, and carefully tugged and twisted everything I could, with no result - everything stayed firm. Now, thanks to your video, I now know that adjusting the prism is done by loosening the small hex screw that you showed. As far as focusing, I'm going to use an ASI120mm-ss regular body camera, which, I understand, screws directly to the top of the guider, so we'll see. But thank you for shedding the light on this. I hope ZWO will refigure their manual so that guys like us will not pull out what hair we have left! - - Steve
I appreciate your video! Thanks! I have the ZWO OAG with the ZWO ASI120MM Mini with a ZWO F107 (749 Focal length) telescope. What did you put into the ASIAir for the focal length of the ASI120MM mini/OAG combination?
I put in the focal length of my imaging scope. Also you can get asiair to figure it out on its own by putting zero for the focal length. Hope this helps!
Thanks for sharing. How does it compare with the traditional setup of guiding i.e. polar scope? Have you seen any improvement in auto guiding performance? There are two versions of ZWO OAG available. Any recommendation on which one to buy?
OAG's are great and back then there was a major difference in guiding performance. With multistar guiding now common there isnt as much. Where it will benefit you is balancing if your mount requires it and a simpler set up. Unless you shoot with aps-c type sensor or larger the Large OAG is for those cameras. The smaller OAG is for cams smaller than APS-C.
Thanks so much for your excellent tutorial. To compound problems with setting up guiding, I bought a Svbony 205 as a guide camera (to save some money) to work with my Skywatcher GTi mount (modded for EQ) and controlled by my ASIAIR Plus. Now, I'm hearing that the ASIAIR will not recognize the 205. Do I have to buy a ZWO camera (ASI120) for all this to work properly? Thanks, Michael
no problem! At least the ASI120 is a great guidecam I own 2 of them and have been using them for 3 years. Hope you get things sorted soon and wishing you clear skies!
The threads are M42 on the c6 looks like the askar oag comes with the hardware for that. I don't own a askar oag so just double check the proper ring size is installed
Another question, please sir: Is there a recent book or catalog out that shows all the best deepsky objects, what focal lengths to use, best sensor size, and what filters to use? Charles Bracken has Deep Sky Imaging Primer, 2022 thats looks decent. Thanks for your thoughts, Michael
That's a great question. I've actually only used stellarium and sky atlas on the computer. It's planetarium software and has a catalog of most DSO's .what's helpful is you can input your scope and camera and you can see what the FOV will be like not to mention what time and where your target will be in the night sky.
My experience with OAG did not end well. I achieved the correct spacing/BG and got focus on both the primary imager and the guide scope. However, my OAG had significant offcenter vignetting (on an f5.5 Esprit 100ED). Seems to something of a known issue on the ZWO forum and CN - apparently the prism is just a friction fit without positive alignment guides which can allow the prism alignment to be off which creates misshapen stars. I also had to withdrawn the prism further than your image seems to indicate to get sufficient stem length to reach focus with the guide camera. But I had the helical focuser which does add some space.
I have the QHY 268m with oag-m and cfl-l. I had to put 14 mm between the oag and cfw to achieve focus on both. Matching focus points can be frustrating!
Thanks. Does this work well for a Celestron 9.25 scope? I have an external Moonlite Focusing Flange attached to the tube. And I also have a 0.63x Meade reducer. Would there be any issues in focusing? My guiding camera is ASI 174mm.
I don't have the Cestron 9.25 but I did have it momentarily on my c6. It fit fine but I found the stars very dim at f6.3. Might be due to the focal ratio and small prism the zwo oag. 174 is a better cam than the 120 tho so you may get better results than I did
So regarding orientation of the prism and sensor. Should the relationship remain fixed or will it be rotated in the field to find a guide star? I realize the whole optical train could be rotated to maintain the orientation, but target framing would be an issue.
@@astronotna So the advantage to your method would be not having to re-calibrate the guidecam (ie, in PHD) however, you may not get the framing you want.
Yet another great and educational video, thanks! I have a question though. I have the ASI585MC Pro and the ASI120MM and I recently bought an SVBony filter drawer (same focal length as ZWO, 21 mm). I plan to initially get the simpler ZWO OAG like in your video. My question is then, is this the correct order of installation?: ASI585MC Pro (with the standard extension of 11mm, making the focal length only 17,5mm)- SVBony filter drawer (21mm)- ZWO OAG (16,5mm) to make it 55 mm. OR should the "first" extension ring of 11 mm be moved closest to the telescope?
I have the 11mm attached to the camera which is attached to the filter drawer. if you can screw the camera on the drawer and move the 11mm closer to the telescope side by all means do as closest to the filter is better for the cam. Yes the OAG before the filter drawer so it can get the most light to the prism. Thanks for watching this one!
Excellent video and appreciate your clear instructions. I am a new subscriber now. I would like to try OAG with my ASI Air (and thanks to you, with the EAF) on my Z71 telescope. I realized that you didn’t mention focus and backfocus distance with OAG camera. As others suggested, do you ensure equal backfocus distance with OAG camera or just focus OAG camera after main camera is focused and not worry about backfocus distances. Sorry for such basic question, I’m still a beginner with new challenges emerging every clear night.
Hey Bruce glad this video helped you out in someway and thanks for checking my channel out! Yes after the main camera is focused then focus your guide camera in the oag. It should only take small movements up and down to focus. The guide camera has a small window of focus so use small movements. You will be able to view where your focus is in real time on your ASI AIR guiding screen in the app. you can also focus it during the day using trees at a distance to give you an idea where the camera should be placed. The you can then make your final adjustments at night on the stars. If you don't need to remove the guide camera after imaging you can just leave it in there until your next session and not worry about it. After some time with it you will just know instictively where to place it for focus. Since you will be repeating this process alot. On a side note If you have a ZWO astrocam the OAG takes the place of your 16.5mm spacer ring that is needed to achieve proper backfocus between the camera and telescope. This also ensures proper back focus of your guide camera as well. No need to apologize everything about this hobby is complicated. LOL I have challenges too that surprise me all the time! I think everyone of us has stories! Reach out anytime! Hope you get clear skies and enjoy your Z71 it's an amazing scope! Sounds like you have great set up! Congrats!!
Hello! D diver! I don't have the helical focuser for my oag but as I understand the ring where the cam slides in can be removed and you should be able to attach the helical focuser to the threads where the ring was removed. Yes you can use an oag with that focal length.
I do like the edge. I was lucky to borrow one from a friend for a few nights to see how I would like it. I am interested in hyperstar and getting closer to some targets with one scope. I looked at the RC's but I heard they were a little finicky with collamation but I would love to try one. Price is much better. I have some time before I decide clearly now is a horrible time to buy a scope. Prices are outrageous right now
Thanks just great to see someone actually going through the steps of assembling your image train.
Glad it was helpful!
I've had my OAG and scope set up for eleven years, but here in the south of the U.K., telescope time has been trashed by cimate change. The trend, particularly over the last 5 years has been for increasing cloud cover at night. I've created control electronics, written ASCOM drivers, worked out my FOV, but it's all just sitting in the obsrvatory waiting for some clear sky. Tonight it's 55 MPH winds & rain (again).
Oh no! Here's to wishing you some better weather and clear skies
Thank you for this! My ZWO OAG came with no instructions so this video was super helpful!
Your welcome! Glad this helped
Dude, you have no idea what you just solved for me. I inherited a ZWO OAG (same as yours) from a friend. The manual for the OAG states that the adjustment for the prism is one of the 2 long screws on the body. Well, maybe I'm an idiot, but I loosened the screw, and carefully tugged and twisted everything I could, with no result - everything stayed firm. Now, thanks to your video, I now know that adjusting the prism is done by loosening the small hex screw that you showed. As far as focusing, I'm going to use an ASI120mm-ss regular body camera, which, I understand, screws directly to the top of the guider, so we'll see. But thank you for shedding the light on this. I hope ZWO will refigure their manual so that guys like us will not pull out what hair we have left!
- - Steve
That's awesome Steve! Glad this helped you out!!
Thanks, I just bought that exact OAG and this was very helpful.
Niice!! Glad this helped out and enjoy it! Clear skies to ya!!
Good explanation. The only thing I do differently is I loosen the screws instead of untightening them .
Thank you and thanks for visiting my channel!!
I appreciate your video! Thanks! I have the ZWO OAG with the ZWO ASI120MM Mini with a ZWO F107 (749 Focal length) telescope. What did you put into the ASIAir for the focal length of the ASI120MM mini/OAG combination?
I put in the focal length of my imaging scope. Also you can get asiair to figure it out on its own by putting zero for the focal length. Hope this helps!
Thanks for sharing. How does it compare with the traditional setup of guiding i.e. polar scope? Have you seen any improvement in auto guiding performance? There are two versions of ZWO OAG available. Any recommendation on which one to buy?
OAG's are great and back then there was a major difference in guiding performance. With multistar guiding now common there isnt as much. Where it will benefit you is balancing if your mount requires it and a simpler set up. Unless you shoot with aps-c type sensor or larger the Large OAG is for those cameras. The smaller OAG is for cams smaller than APS-C.
Thanks so much for your excellent tutorial. To compound problems with setting up guiding, I bought a Svbony 205 as a guide camera (to save some money) to work with my Skywatcher GTi mount (modded for EQ) and controlled by my ASIAIR Plus. Now, I'm hearing that the ASIAIR will not recognize the 205. Do I have to buy a ZWO camera (ASI120) for all this to work properly? Thanks, Michael
Yes unfortunately that is the case. Asi air past dslr and mirror less cameras only recognize zwo gear.
@@astronotna Well, there we are. Guess I need an ASI120 mini mono camera to use with my Svbony 30mm guide scope. Thanks for your help, Michael
no problem! At least the ASI120 is a great guidecam I own 2 of them and have been using them for 3 years. Hope you get things sorted soon and wishing you clear skies!
Hello ! very interesting. What do you use as an adapter to join an OAG Askar to the Celestron 6 SCT?Thank you!
The threads are M42 on the c6 looks like the askar oag comes with the hardware for that. I don't own a askar oag so just double check the proper ring size is installed
Very nice instructional video. Very clear. Excellent tips. Thank you!
You're very welcome John. Glad this helped! Thank you so much for watching!
Another question, please sir: Is there a recent book or catalog out that shows all the best deepsky objects, what focal lengths to use, best sensor size, and what filters to use? Charles Bracken has Deep Sky Imaging Primer, 2022 thats looks decent. Thanks for your thoughts, Michael
That's a great question. I've actually only used stellarium and sky atlas on the computer. It's planetarium software and has a catalog of most DSO's .what's helpful is you can input your scope and camera and you can see what the FOV will be like not to mention what time and where your target will be in the night sky.
My experience with OAG did not end well. I achieved the correct spacing/BG and got focus on both the primary imager and the guide scope. However, my OAG had significant offcenter vignetting (on an f5.5 Esprit 100ED). Seems to something of a known issue on the ZWO forum and CN - apparently the prism is just a friction fit without positive alignment guides which can allow the prism alignment to be off which creates misshapen stars. I also had to withdrawn the prism further than your image seems to indicate to get sufficient stem length to reach focus with the guide camera. But I had the helical focuser which does add some space.
I have the QHY 268m with oag-m and cfl-l. I had to put 14 mm between the oag and cfw to achieve focus on both. Matching focus points can be frustrating!
Very well explained. Really helpful. Thank you!
Glad this helped!
Thanks. Does this work well for a Celestron 9.25 scope? I have an external Moonlite Focusing Flange attached to the tube. And I also have a 0.63x Meade reducer. Would there be any issues in focusing? My guiding camera is ASI 174mm.
I don't have the Cestron 9.25 but I did have it momentarily on my c6. It fit fine but I found the stars very dim at f6.3. Might be due to the focal ratio and small prism the zwo oag. 174 is a better cam than the 120 tho so you may get better results than I did
Very helpful-thanks for making it.
Glad this helped!!
Great practical video.thanks heaps
Thank you!! Glad you found this useful
So regarding orientation of the prism and sensor. Should the relationship remain fixed or will it be rotated in the field to find a guide star? I realize the whole optical train could be rotated to maintain the orientation, but target framing would be an issue.
Great question. I rotate my imaging train so the orientation prism is always I'm the same place in relation to the sensor.
@@astronotna So the advantage to your method would be not having to re-calibrate the guidecam (ie, in PHD) however, you may not get the framing you want.
Well having the imaging train in conjuction with an angle rotator will allow you to frame it up how you like. The camera and prisim always follows!
Nice video thank you.
Glad this helped!
Yet another great and educational video, thanks!
I have a question though. I have the ASI585MC Pro and the ASI120MM and I recently bought an SVBony filter drawer (same focal length as ZWO, 21 mm). I plan to initially get the simpler ZWO OAG like in your video. My question is then, is this the correct order of installation?:
ASI585MC Pro (with the standard extension of 11mm, making the focal length only 17,5mm)- SVBony filter drawer (21mm)- ZWO OAG (16,5mm) to make it 55 mm. OR should the "first" extension ring of 11 mm be moved closest to the telescope?
I have the 11mm attached to the camera which is attached to the filter drawer. if you can screw the camera on the drawer and move the 11mm closer to the telescope side by all means do as closest to the filter is better for the cam. Yes the OAG before the filter drawer so it can get the most light to the prism. Thanks for watching this one!
Nice video and good warning. I also have the ASI 120 guide camera. May I ask what is the focal length of you imaging scope?
Hey B thanks and thanks for checking this out! I image with a z61 @360mm and a Z73 @430mm.
Hi Sir ! I don have any filter drawer and wheel like you have , so can you teach me how to install my filter before the OAG ? thanks
What telescope do you have?
Thanks that was a big help
Your welcome glad it was helpful!!
Excellent video and appreciate your clear instructions. I am a new subscriber now. I would like to try OAG with my ASI Air (and thanks to you, with the EAF) on my Z71 telescope. I realized that you didn’t mention focus and backfocus distance with OAG camera. As others suggested, do you ensure equal backfocus distance with OAG camera or just focus OAG camera after main camera is focused and not worry about backfocus distances. Sorry for such basic question, I’m still a beginner with new challenges emerging every clear night.
Hey Bruce glad this video helped you out in someway and thanks for checking my channel out! Yes after the main camera is focused then focus your guide camera in the oag. It should only take small movements up and down to focus. The guide camera has a small window of focus so use small movements. You will be able to view where your focus is in real time on your ASI AIR guiding screen in the app. you can also focus it during the day using trees at a distance to give you an idea where the camera should be placed. The you can then make your final adjustments at night on the stars.
If you don't need to remove the guide camera after imaging you can just leave it in there until your next session and not worry about it. After some time with it you will just know instictively where to place it for focus. Since you will be repeating this process alot.
On a side note If you have a ZWO astrocam the OAG takes the place of your 16.5mm spacer ring that is needed to achieve proper backfocus between the camera and telescope. This also ensures proper back focus of your guide camera as well.
No need to apologize everything about this hobby is complicated. LOL I have challenges too that surprise me all the time! I think everyone of us has stories! Reach out anytime! Hope you get clear skies and enjoy your Z71 it's an amazing scope! Sounds like you have great set up! Congrats!!
Hello sir,,,if you have the zwo helical focuser how do u attach it? Also, I have a telescope with a 628 mm focal length, can I still use oag? Thanks
Hello! D diver! I don't have the helical focuser for my oag but as I understand the ring where the cam slides in can be removed and you should be able to attach the helical focuser to the threads where the ring was removed. Yes you can use an oag with that focal length.
Which camera were you using and did you remove the tilt plate from it?
Hey TheGalaxyGael I used the Asi183mm pro in this video. Also the standard (smaller) zwo OAG was used here so no tilt plate.
Prob best to put the OAG after the filter drawer or wheel. So they are not affected by the filter and reduced light etc.
Exactly! I explained that at 3:50 thanks for watching this one
great video
Thanks Ethan!!
Of course, you will find guide star with your telescope. It is problem for long focal range (>1500mm) telescopes
Indeed my friend. As I got interested in the edge hd series this has become more apparent
@@astronotna Do you like edge? Why did you selected it, but not RC? Thanks
I do like the edge. I was lucky to borrow one from a friend for a few nights to see how I would like it. I am interested in hyperstar and getting closer to some targets with one scope. I looked at the RC's but I heard they were a little finicky with collamation but I would love to try one. Price is much better. I have some time before I decide clearly now is a horrible time to buy a scope. Prices are outrageous right now
@@astronotna Thanks