Dear friends,
Yesterday I took one frame of 10 minutes using a Ha filter (6nm) because of the proximity of the Moon, of the bug nebula.
The camera was a SX-694 and the scope, as mentioned before, a Skywatcher Newtonian Quattro, in Carbon Fiber, 10" f/4.
This version is cropped and reduced to be uploaded here.
My question for you is this: by looking at this image, the result is something that you guys would expect, or there are much room for improvment ?
The shot looks slightly out of focus to me and pretty noisy for a camera with that cooling potential. I think more shorter subs would be a good idea to start. I'd try five minutes, and stack at least ten with corresponding darks. Good luck.
woohoo. What a great first image Fernando - you must be very pleased.
The resolution is excellent and detail is exceptional for something so small. The stars look a little out of shape, but nothing too bad - maybe a slight tweak on collimation would be a good idea?
Overall though, very nice. Regards Ray
edit: just a tip - watch out for dew inside the OTA tube - the paint runs if it gets wet (or at least mine did).
Hi Ray,
Thank you very much for yor feedback. As for the collimation, I have not retuned it after to connect the coma corrector in the optical train. Do you think I should do that ? Just secundary mirror or both ?
Thanks again Ray,
Fernando
Hi Ray,
Thank you very much for yor feedback. As for the collimation, I have not retuned it after to connect the coma corrector in the optical train. Do you think I should do that ? Just secundary mirror or both ?
Thanks again Ray,
Fernando
Hi Fernando. FWIW, I found that collimating with the coma corrector in place was best and that both mirrors needed to be adjusted. The other thing I found that helped was to round off the ends of the 3 secondary adjusting screws. Mine had sharp raised ends that cut into the surface of the hub and made fine rotation difficult - it is easier with the ends of the screws smoothed off.
Hi Fernando. FWIW, I found that collimating with the coma corrector in place was best and that both mirrors needed to be adjusted. The other thing I found that helped was to round off the ends of the 3 secondary adjusting screws. Mine had sharp raised ends that cut into the surface of the hub and made fine rotation difficult - it is easier with the ends of the screws smoothed off.
If you use a piece of a plastic milk bottle as a washer between the secondary holder back face and the threes screws you'll get a smoother motion as well.
Ray,
Thank you so much for the valuable inputs.
If I am not abusing I would have one more question: once the coma corrector is in place and threaded to the CCD, I can understand the collimation of the secundary, as I have the feedback provided by the defocused star on the computer's screen, but the primary, what would be the feedback ? Should I, by the chance, displace a collimated star in the center to the corners to check if the colimation remains at the 4 corners ?
Thanks again Ray
Marc:
Great suggestion, I will implement it.
Thank you very much,
Fernando
Good work Fernando. I've recently picked up one of these too, and will also use it with an ICX-694 sensor (QHY22). But due to weather, and observatory construction underway, it's not yet seen first light! A few months for me...
