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I almost hesitate to ask this but ahem, here goes...
My EBay white light filter turned up today & I scurried out into the garden like an excited child on Christmas morning.
After a bit of faffing I have it clamped to the ST80 and using the equally cheap but pleasingly effective SV-Bony pinhole projector finder (can’t believe it just slotted in and is aligned as there’s no way to adjust) there is a lovely big, crisp, solar disc.
Can’t see any sunspots though - and here’s the dumb question - is there just nothing doing today or am I missing a trick?
Any beginner tips on white light observation gratefully received...
I currently have a ZWO 178MC OSC planetary camera. Everybody tells me that I need to get a mono chrome camera for solar imaging. I have narrowed it down to two cameras the ZWO ASI178MM or the ASI174MM. The ASI174MM is quite a bit more expensive and I am not sure why?
I have a Lunt 60MM HA f/7 Solar scope and looking for recommendations.
I'm posting in the hope it helps anyone else considering a Daystar Scout SS60. The video's not quite representative of what one sees looking through the scope, but gives a general idea of field of view through a 24mm EP. When observing, much more prominence detail and surface texture is visible to the eye and the colour feels less red than it appears in the vid.
I'd have taken this video sooner if I'd realised that afocal video would work so well, so I'll try again next time the sun's available earlier in the day during better seeing. The video's taken by holding an iPhone against an Explore Scientific 24mm eyepiece and adjusting exposure (i.e. afocal video photography). Although I find a Plossl as easy (if not easier) to use as a wide EP for observing, it's simpler to align a smartphone with an eyepiece that has a wider field of view, for afocal video. Hence I used a 24mm ExSc (see below for detail). It seems a fairly quiet solar day, not long after the notoriously quiet 2020 and I believe is still close to the beginning of the sun's new 11 year cycle (hopefully it will become more exciting soon but not as exciting as having any Carrington Events pointing towards us).
I spent some hours, from late morning, watching these prominences form, dissipate and reform. The prom on the Western limb was very tall and bright, looking like a large rectangular tower block, which gradually split, faded as the top looped over to the north, then the top looped back again to the south. At one point this loop appeared to join - forming the outline of the head of a man, whose figure, with arms out, was clear and rather funny. Wish I'd taken this video sooner (or had the ASI183 to hand). The prom quietened and reached its current state (3pm ish) as seen in the video.
The long group of prominences to the South - 4 main and some smaller - were more dim than the prom on the Western limb initially, but they remained impressive, ranging from good to very small and appeared at one point to be as clear row of pine trees, especially the larger right hand prom, with spiky 'branches' and a distinctive triangular fir tree shape, which gradually brightened then faded to this view. The tip of the ‘sharks fin’ to the left of the group extended out to the east then receded.
I'm afraid it's not easy to see the detail in such a simple video - it's slighly more visible to the naked eye. By the time I took this video it had gone 3pm, there was more haze and a lower sun and none of the prominences were particularly impressive.
There were No sunspots easily visible, although a Plage appeared to be visible close to the Westerly limb. Little surface detail other than orange peel, despite tuning the scope (better with the SS60s dial to left of centre for this today). I still need to lots more time with the scope to get the best from it.
I'm a Ha beginner having only observed in whitelight before and only having used this scope twice before, once in combination with a ZWO ASI 183MC astrophotography video camera. Medium seeing, 6/3/21 'third light' on the Daystar Scout SS60 Scope with fixed chromasphere quark built in - 930mm f15 60mm.
Various Eye pieces used: Plossl 40mm, Meade Super Plossl 26mm, Explore Scientific 24mm and 11mm 82 and 68 degree EPs gave good clarity and contrast, but the seeing's not good enough for close viewing of proms. ioptron motor, roughly pointed north was perfectly sufficiently good to keep the sun in view for at least 45 mins at a time. I'll edit this post to add a pic or two of the equipment setup in a moment.
3 images attached are: Afocal Smartphone still image (contrast increased in smartphont), plus two shots of the setup.
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.