ZWO ASI 183 MC and the first lunar light

[astrolulu]

Finally... One of our colleagues on CN tempted me for so long with his great photos of the Moon taken with this camera. That I finally had to try.

The first effects ... - well, difficult. Not because of the camera itself, but because of its 20 mpx resolution. Both the transfer speed to the laptop and the subsequent processing by AS! turned out to be a real challenge. I need to develop a new workflow to minimize stacking time, because currently it is well above the acceptable standard. Meanwhile, the first effects obtained with the Celestron C8-N 200/1000 mm newtonian:

[astrolulu]

And now the moment of truth... The disk of the Moon photographed in its entirety, as a single frame, directly in the focus of the 200/1000 Newtonian telescope. Without combining smaller frames into a mosaic. But what about the coma?

Unfortunately, there are no miracles. An uncorrected f/5 newtonian must show traces of coma on such a large sensor and you can see them here in the form of blurring, increasing towards the left part of the image. Perhaps this is to be adjusted or at least reduced with fine collimation. This effect is also confirmed by the photo of M42 taken as a quick test - also directly in the focus.

 

 

[neil phillips]

Congrats on the camera. Good first images

[astrolulu]

In my free time, I continue my experiments with processing the first photos taken with ASI 183, working out a new strategy for dealing with color, zoom and sharpening.

As usual, there is a conflict of interest between the ambition to obtain the largest possible image area and the desire to achieve perfect sharpness of details - one that would not give the impression that the image is artificially enlarged. So far - despite the relatively large field of view provided by the ASI 178 camera - I had to compromise and accept a larger image scale, at which the precision of details was "acceptable" at most. In the 1:1 scale, however, it was clear that the details are not perfectly sharp, and the image is slightly larger than the need dictated by the practical resolution.

The gigantic ASI 183 sensor avoids this conflict of interest. The image can be reduced to the size at which the precision of drawing small details is perfect, and yet the image retains a large area, which does not fit in the 1:1 scale on most monitors - which I treat as a condition and measure of success 🙂

The image below has been stacked with the drizzle 1.5x option, then scaled down to 53% - and finally to 77%, so it's 61% of its native size in total and at this scale it doesn't feel like the details are unnecessarily enlarged. In fact, after such a reduction, some of the smallest details are lost or barely visible. But we don't take part in any sports competitions! For me, the goal is to get an image that feels natural - like a good quality image in an eyepiece when visually observing. The large sensor seems to be a step in this direction.

 

[Fay]

Superb!!

[Astrophysical Graffiti]

I am glad that 183 is working out for you, Lukasz. I do love mine for the Moon, even with its quirks and difficulties.

 

[astrolulu]

Thank you! This is a more demanding camera, if only due to the fact that there is a much larger area in the frame. And the larger the area, the greater the variation in the brightness of objects, and the more difficult it is to set the exposure correctly - so as not to burn out the brightest ones, and at the same time not to lose too much in the shadows. Well - I have to learn and experiment 🙂