astrolulu

It turns out that even in such vertical lighting, with practically no visible chiaroscuro, you can also get an interesting image of the lunar surface:

Hi, it's worth remembering that an SCT of this diameter is already very, very sensitive to seeing and height above the horizon. The quality of the photos increases literally in geometric progression as the conditions improve.

Great photos and an excellent, informative comparison!

Hi, I use a 180 sec exposure with a 200/2000mm setup and I don't see any traces of image blur due to rotation.

Overdue photo from November 10th. In the center, the Valles Marineris area is visible:

Anaxagoras and Plato - both claiming to control the Mare Frigoris. Who's the boss here?

Two more shots from November 10th. In the second picture at the top, the Sea of Alexander von Humboldt is quite clearly visible.

November 10 session. The classic Langrenus-Vendelinus-Petavius trinity:

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 🙂

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.

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.

Subtle and in moderation - just the way I like 🙂

Great detail. Subtle and precise for 8 inches!

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:

We climb north - towards the peaks of the Apennines and the Caucasus, passing Mons Hadley and the landing field of the brave Apollo 15 crew on the way ...

Thank you very much. I started my adventure with astronomy in the 1980s in Poland. There was no astronomical equipment at that time, I built my first refractor from a cardboard tube and a piece of PVC sewer pipe. You could only dream about amateur astrophotography while watching pictures in Sky & Telescope. Two revolutions have happened since then. Communism collapsed and astromic equipment became available also in our part of the world. The second revolution is digital photography and the amazing opportunities it has opened up for people like us. If in the 1980s someone told me that it would be possible to obtain such photos with a simple 20 cm Newtonian, I would send him to a psychiatric consultation 🙂 I still cannot believe it and I am constantly happy about every photo I manage to take. But it is a slightly different experience and a different kind of satisfaction than direct contact with the Universe during visual observations. I recently restored an old 1962 Japanese 76/1200mm refractor. I have to say that when it comes to the "jaw dropping" effect, it was this old achromat that made me feel it when I looked at Mars and the Moon through its eyepiece. Amazing feeling of "being there". The unique charm of visual observations ... 🙂

And the contiguities with the Sinus Medii at the forefront ...

Rupes Recta, Cassini Bright Spot, Tycho... pick 'n' mix 🙂

🙂

You summed up very well the most important noise function I mentioned when we discussed my photo. It is needed precisely to introduce this type of uncertainty as to the appearance of the surface where, due to the scale, we still expect to see details, but where the resolution does not allow it anymore. Thanks to the noise, you can wonder if it is not due to the presence of some small craters, for example - and without it you would see an ideally smooth surface, which at this scale of the photo would be simply untrue and it would appear artificially. This noise is obviously artificial and does not represent any detail. We see the same uniform, stohastic pattern on every bit of the smooth surface of this photo - exactly the same one that shows in the shadows, where no real fine detail is available for the camera. But the very fact that we are discussing it shows that the noise has done its job, has raised doubts - and that is its role and advantage.

I feel honored 🙂

Neil, there's no reason to argue. As I have emphasized several times, the presence of noise is nothing wrong in my opinion. On the contrary - I believe that the presence of a certain level of noise is necessary so that the photo at this magnification scale does not take on an artificial, "plastic" expression. You have just as much noise as needed - I'm sure that without it, the effect would be much worse. And the noise *is* there, you can see that I only raised what already was there - I did not create anything new in this process. Both dark and light, smooth parts of your photo are covered with the same artificial pattern caused by the noise. This must be the case, unless you are using the noise removing filters.

I meant this:

As you said yourself - the assessment depends largely on the recipient. I still prefer the more sharpened one, but both are great and if you didn't compare them next to each other, no one would probably think of accusing them of too much or too weak sharpening. Note, however, that this natural effect is due to the presence of some noise. It is delicate - but it is present. For example, the floor of the Longomontanus crater. If there was no noise and the floor was perfectly smooth, you would probably get the feeling that the photo is artificial and oversized - which is the effect I mentioned when we discussed my photo where I tried to remove some noise. So a bit of noise is in my opinion not only acceptable, but desirable if we want to maintain a relatively large scale of the photo. I must admit that I experimented several times with the deliberate addition of noise to avoid the impression of artificiality and too aggressive filtering. 🙂

This time I wanted the subject to be light rather than details that are not precisely defined with this lighting. I tried to get the effect of characteristic, lunar "luminosity". I have corrected the brightness many times and I have probably reached the acceptable limit 🙂