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I'm considering the 250PDS. The main use is visual, and the second is EAA (I currently use a zwo183mm).
What I'm hesitant about is the primary focus. since It's mostly for visual, I'm wondering on how much back focus it has compared to the standard Skywatcher 10" dobsonians? with the standard dobsonias with the same optics and focuser you already need an extension tube for most eyepieces...
Also, there's probably a "bigger" obstruction (bigger shadow on primary)?
After many hours of fiddling round with Registax wavelet settings to process my own solar system images, I've always been curious as to how it actually works. In doing so I've put together my own image sharpening program which does something similar to Registax wavelets. For comparison, I've also added some general purpose deconvolution techniques which you'll probably be familiar with from other image processing software (like Wiener inverse filtering, Richardson-Lucy, etc). In choosing a point spread function to deconvolve with, one suprising result was that the typical stack outputs from Autostakkert work best with a Lorentz point spread function (with a minor modification). Deconvolving with a Gaussian point spread function doesn't really work. Deep-sky images seem to deconvolve best with a Moffat point spread function (which is to be expected - it's already well established that star profiles in long exposures are best approximated with a Moffat function).
On the whole, it's unlikely that you can sharpen solar system images much more in this program than you already can in Registax. You can see results from Registax wavelet (sharpening layers), inverse filtering (e.g. Wiener), and iterative deconvolution (e.g. Landweber) below. They all give very similar results. In all the techniques there's a similar trade-off between less noise but less detail vs more noise but more detail.
There are some quick start notes on the first page of the Readme here:
There are some examples of deconvolved images here (move mouse over image to see before/after):
Image credits are on the hyperlinks
The Windows download is here:
Example solar system tifs to experiment with are here:
And the project page is here (with Source code in the src folder)
If anyone finds it useful, do post here how it compares to other tools you use for solar system image sharpening.
The download and the source code are free, you can use it unrestricted for any purpose. The OpenCV and OpenCVCSharp components which my program use have licence information at the end of the Readme.pdf.
I have a SkyWatcher AZ-EQ5 mount. It’s all working fine, except I have an issue with alignment. This applies whether I’m in EQ or Alt-Az mode.
I set it up using one or two star align without problems.
However if I use the handset to GoTo another object, I usually need to do fine tuning adjustments to centre on the new object. But the mount disregards these adjustments, so if I use the GoTo system to centre on a nearby object, or revisit the original object a second time, it’s still off by the same amount.
How do I tell the mount that I have centred on the new object and that it should now be aligned with that object ?
My iOptron MiniTower has a feature that does exactly this – once set up correctly and aligned, for each new object I go to there is an “ALIGN” option, and if I use this it now knows the correct position. Can I do this with SkyWatcher and Synscan ?
This is a photo accurate representation of how I've seen the conjunction through a Skywatch 14" f4.6 Dobsonian, using the 17mm Ethos eyepiece combined with the 2X Powermate during the observation of the great conjunction of Jupiter and Saturn, and how well both of the planets fit into the eyepiece field of view.
My location on the east coast of Australia was totally overcast for the last week and this evening I had a small window of opportunity to actually have a glimpse of the rare event, which no doubt, I will not have a another chance of experiencing in my life time.
This happened about 17 hours after the actual closest point between the planets, and most likely the difference would be so small that it wouldn't be noticeable without direct comparison.
This image was composited by first taking a series of shots through the eyepiece using an iPhone, I chose the best frame of the series than superimposed the overexposed planets with images of the planets captured separately with enough transparency as to accurately show how the planet details looked in the eyepiece.
Observation time was 22 December 2020 @ 09:51 UTC.