Hello,I use the NINA program and have a question about entering the focal length: I would like to take pictures with the Celestron 9.25 with an Alan Gee Reducer (0.59). This reduces the focal length from 2350 mm to 1387 mm. What focal length do I specify in NINA for the equipment? I specified 2350mm and found that ASTAP had problems with the plate solving. Maybe someone knows their way around. Best regardsJohannes
Focal length in NINA
Hello,
You should specify the focal lenght of the complete setup, in this case 1387.
Cheers,
André
You should specify the focal lenght of the complete setup, in this case 1387.
Cheers,
André
Hello,I use the NINA program and have a question about entering the focal length: I would like to take pictures with the Celestron 9.25 with an Alan Gee Reducer (0.59). This reduces the focal length from 2350 mm to 1387 mm. What focal length do I specify in NINA for the equipment? I specified 2350mm and found that ASTAP had problems with the plate solving. Maybe someone knows their way around. Best regardsJohannes
Use the resulting focal length.
As the others have said use the 1387. I will add, if you use the framing Wizard, you will see that NINA will show you the actual field of view on an image of your target. That frame is calculated on your stated FL and your particular camera sensor dimension. If you have the camera rotation set right, your subs should look identical, or nearly so.
In any case, the FL will determine the image scale, and plate solving will want that close to work well. If you have not specified camera rotation, plate solving will return your actual rotation, which may be useful if you want to adjust. (Not sure camera sensor size is required either. My guess is the plate solve will just tell you that as well. But I may be wrong and sensor size may be a big help along with FL.)
Alan
In any case, the FL will determine the image scale, and plate solving will want that close to work well. If you have not specified camera rotation, plate solving will return your actual rotation, which may be useful if you want to adjust. (Not sure camera sensor size is required either. My guess is the plate solve will just tell you that as well. But I may be wrong and sensor size may be a big help along with FL.)
Alan
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Alan Brunelle:
(Not sure camera sensor size is required either. My guess is the plate solve will just tell you that as well. But I may be wrong and sensor size may be a big help along with FL.)
N.I.N.A. reads the FITS header to get camera and other information. Pixel size has to be entered in the camera settings in N.I.N.A. The field of view is calculated from all this information. In my setup, when doing a plate solve, N.I.N.A. always reports a different (smaller) field of view than what I give in settings.
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John R Carter, Sr.:Alan Brunelle:
(Not sure camera sensor size is required either. My guess is the plate solve will just tell you that as well. But I may be wrong and sensor size may be a big help along with FL.)
N.I.N.A. reads the FITS header to get camera and other information. Pixel size has to be entered in the camera settings in N.I.N.A. The field of view is calculated from all this information. In my setup, when doing a plate solve, N.I.N.A. always reports a different (smaller) field of view than what I give in settings.
John, thanks for reminding me of that info. It has been a while since I have had to enter the camera pixel size detail info into NINA.
That is interesting regarding your experience regarding the reported FOV. I'll have to check that again whenever I set up again. With my setup, I am getting NINA to show a FOV in Framing that is pretty close to exactly as I "see" in my actual frames. So I never really looked at the reported FOV. But I should confirm. I wondered about how accurate pixel dimensions are stated by sensor manufacturers.
But plate solving goes like a snap for me and is likely limited by my internet connection as I have it set up currently.
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Thank you for your answers, I believe that I have now made the correct settings in NINA (correct pixel size and reduced focal length). In Stellarium I have now specified the current section of the image, taking into account the reduced focal length due to the reducer.
I have now adopted the coordinates in NINA from Stellarium. In NINA I specified the focal length with the reduced size. I hope that plate solving with ASTAP does not cause any problems now.
On Monday night I would like to take photos of the Ring Nebula M57 with these settings, provided the weather remains as it is for my region in Germany.
Many greetings Johannes
I have now adopted the coordinates in NINA from Stellarium. In NINA I specified the focal length with the reduced size. I hope that plate solving with ASTAP does not cause any problems now.
On Monday night I would like to take photos of the Ring Nebula M57 with these settings, provided the weather remains as it is for my region in Germany.
Many greetings Johannes
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Thank you for your answers, I believe that I have now made the correct settings in NINA (correct pixel size and reduced focal length). In Stellarium I have now specified the current section of the image, taking into account the reduced focal length due to the reducer.
I have now adopted the coordinates in NINA from Stellarium. In NINA I specified the focal length with the reduced size. I hope that plate solving with ASTAP does not cause any problems now.
On Monday night I would like to take photos of the Ring Nebula M57 with these settings, provided the weather remains as it is for my region in Germany.
Many greetings Johannes
Johannes,
Glad to help. Let me just add one thing: to properly made the plate solve, the mount must be tracking (ASTAP is very sensitive to eccentric stars). This is also a reminder for me!...
During the setup, mount may stop tracking after slewing and in those times, I get errors.Cheers,
André
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