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Hello to all,
I've just acquired my first tracking mount, a Skywatcher Star Adventurer, having dabbled with AP some years ago with a Celestron Nexstar 5SE which I still own but quickly realised back then that I needed an EQ mount. I captured my first ever planetary images this week with the 5SE and my new ZWO ASI290MC - Jupiter and Mars -which I was pleased with as a first stab but clearly need more work and knowledge. Looking forward to contributing more on the forums.
By Anthony RS
I'm selling these 2 filters since I'm getting a mono astro cam. The filters are barely used and in perfect condition, no scratches, no fingerprints, not even dust. They are both amazing filters, probably the best investment I've made. I've attached some images
taken with these filters, using a 100$ celestron newtonian, a 250$ Canon 500D and the infamous AVX. Also attached are images of the filters showing their perfect condition.
Astronomik CLS-CCD Canon Clip in Filter: https://www.astronomik.com/en/filter-gegen-lichtverschmtzung-filters-against-lightpollution-lpr/cls-ccd-filter/clip-filter-eos-mit-astronomik-cls-ccd.html
Original price including VAT is 155 Euros (around USD 182). I got it for around USD230 including VAT, shipping and custom taxes.
Selling for USD 120.
Astronomik Ha 12nm Canon Clip in Filter: https://www.astronomik.com/en/clip-filter/clip-filter-canon-aps-c/clip-filter-eos-mit-astronomik-h-alpha-ccd-12nm.html
Original price including VAT 194 Euros (around USD 228). Got it for around USD 270 including VAT, shipping and custom taxes.
Selling for USD 180
I am willing to ship them on my own expense using LibanPost (from Lebanon). Shipping might take time; if you would like to use some other shipment method please contact me to discuss the price.
Feel free to buy one or both together.
Let me know if you have any questions.
You can also contact me on <private email address removed>
I have already posted my first astrophotographic session report in the telescope review thread: Tecnosky 80/480 APO FPL53 Triplet OWL Series - Review. But since that is more of a general review/diary of my experience with the new telescope, I feel some of the issues I am having are being buried and they will probably get more visibility if I post them - in a more synthetic version - in a dedicated thread.
So, a few nights ago (October, the 5th) I took out my new telescope for its first light. All the photos have been taken with the 0.8x flattener/reducer and the Optolong L-Pro 2" filter attached to the reducer. The camera is an astromodified Nikon D5300. The only processing the following pictures have consists in this:
Here we have a 90s shot of M31.
And here's a mosaic generated with the AberrationInspector script.
What I do like:
- tightest, smallest, roundest stars I have gotten since I started doing astrophotography at the end of January. Obviously comparing it to what I have been achieving with a kit 70-300mm zoom lens, these can't be anything else but better by orders of magnitude
What I don't like:
- star shape not consistent in all areas of the image
- residual chromatic aberration, especially on stars that are not round: there's clearly some red and blue edges visible
I didn't expect this from an apochromatic refractor, but maybe it's just because the stars are kinda "smeared", so not all light is focused at the same spot? I don't see this around the center of the image (or, at least, the problem is less pronounced). Maybe I have some tilting in my imaging train/sensor?
I have been doing some reasoning about it and it seems like a combination of tilting and/or backfocus spacing. According to the following image about backfocus spacing:
if the stars are elongated radially, the sensor is too close, if they are elongated tangentially, the sensor is too far. But to me it seems I have a little bit of both: in the top right corner, for example, the stars look radially elongated, in the bottom right, they look tangentially elongated. Top left they look tangentially elongated, bottom left also, but a little less. Seems like there has to be some tilting as well, otherwise they would all have a symmetric shape on all corners, correct?
How do I determine - is there even a way - if the issue is due to tilting only, backfocus only, or the combination of the two? Is there a sure proof way of checking for tilting? Like, rotating the camera and taking pictures with, say, the camera at 0°, 90°, 270° and 360°? If there's tilting, the pattern of the star shapes should follow the camera, correct?
I also tried splitting the channels in R, G, and B components, doing a star alignment of the blue and red channels with the green as a reference, and recombining the channels. The blue and red edges become a lot less evident, which is good, but obviously the star shapes remain the same.
In my Telescopius gallery you can also find two other images, Capella and Capella Mosaic showing pretty much the same issues.
Also, one issue with the guide camera: ZWO ASI 224MC. When attached to the guide scope (Artesky UltraGuide 60mm f/4), I can't seem to get a "sharp" focus, I even tried on the Moon, and the best I got was a soft lunar disc, with some major features visible, mainly by change of color/brightness (the maria, for example), but no details. The image still seemed blurred/bloated. Is it because of lack of IR blocking filter? I tried the same camera attached to the main refractor, with the L-Pro filter (which blocks UV and IR, as well) and I could focus perfectly. Do I need an IR block filter for guiding or even if the stars appear a little soft, the camera guides just fine?