inFINNity Deck

Let me add one more of day before yesterday (night of 30 to 31 July). Processing done in the beta version of APP that now has a comet option. Imaged using SkyWatcher Esprit 150ED and ZWO ASI1600MM Cool Pro, 4 x 12s subs in LRGB, so 16 minutes of data. Stacked in APP without outlier rejection. Nicolàs

I would recommend to stay at least well above 1 second (2 seconds for non-Pro models). Not only for the effects described above, but also to avoid interlacing as a result of the flat panel's (laptop's screen) flicker rate. When short exposures are taken interference will occur between the exposure length and update rate of the flat panel, resulting in interlacing effects (horizontal bands) in the flats. The skewing due to low exposure times in non-Pro models will not be very obvious when doing single panel work or when using processing software that deals with uneven illuminated subs, but it is better to avoid. Nicolàs

Hi Adam, be careful when it comes to using short exposure times for ZWO ASI1600 cameras. Depending on the type of 1600 you have and the USB interface that is used (USB2 or USB3), there is a tipping point at which the camera used global shutter or rolling shutter. You may find the following thread of interest: https://www.astroforum.nl/forum/astrofotografie/beeldbewerking-methoden-en-technieken/1438084-daar-is-dat-lastige-onderwerp-weer-flats?p=1438404#post1438404 It is in Dutch, but opening it in Chrome should provide a decent translation. Summarizing, the Pro editions of the 1600 do not have a tipping point, but all the others (ZWO ASI1600, ZWO ASI1600 Cool, both the MM and MC models) do (2s at USB3 and 5s for USB2). The method used causes the flats to be skewed (darker on one side than on the other). You stated that you use a ASI1600 Pro, so you should be safe. Nicolàs

As promised, I hereby post an image of the tool I made to loosen and re-tighten the planetary gear. I have placed additional images and explanatory text on my web-site (figures 3, 4, 7 and 8). Nicolàs

The seeing is of course also very much depending on season, latitude and elevation. Were these factors in some way included in those calculations? Nicolàs

I use APP since 2018 and am very pleased with it. Setting up a deep-sky processing action takes me now some 15 minutes, even when processing 40+ hours of data in LRGB,Ha,Oiii,Sii, after which the rest goes automatically during the following hours. After the stacks have been completed I need a few minutes for the RGB combine and then some time to enhance the image. That latter part is partially done in APP and partially in PSP and takes of course quite a bit of time. The past few days Mabula and I have been in contact regarding the new comet stacking option and the first results he showed me of my own LRGB data look very promising. Nicolàs

You're welcome! I think that not too many members have a 150mm Esprit as it is quite an unwieldy telescope, not very handy in a mobile setup. And with it's long focal length not really a wide field scope 😉 In order to tighten the nut of the planetary gear, you would need a special tool, will send you a picture later, I am currently on the road. Nicolàs

Hi Mick, I have an Esprit 150ED, but that came with a R/P focuser. Are you sure that the Esprit you saw comes with a Crayford? Not that the R/P is without issues. On mine the friction of the planetary gear drive was not sufficient to lift the imaging train when pointing towards zenith and it caused severe slippage when trying to auto-focus. To overcome this, I replaced the friction type of planetary gear with a 1:16 geared one. Later I disassembled the original planetary gear, cleaned and regreased it and assembled it again, tightening it more than it was, as a result of which it now does hold even my heaviest eyepiece (Televue Ethos 21mm of 1200gr). Still I do not use the friction gear for imaging, only for visual work. Nicolàs

Oh yes, it is green and seems to get greener by the day, or is it me? 😉 Slightly different recording than last few times. Due to heavy cloud-cover last night the luminance session failed to produce usable material, so I left that out of the processing. For the rest each colour 12 subs of 5 seconds, finished just in time before it became fully overcast. Stacked with DSS, stretched with APP, combined with PSP. Images taken with SkyWatcher Esprit 150ED, ZWO ASI1600MM Cool Pro, unguided imaging with the GM3000HPS tracking the comet. Nicolàs

Yes, I can confirm that, see my images in earlier posts: I made another image last night, but still need to process it, will try to post it this afternoon or evening. Nicolàs

If you wish to use a fibre optic indoors as an artificial star then the best way to go is by creating yourself a collimator from any other OTA of approximately the same or slightly larger diameter. You can read about it in an article I wrote about that, including some maths about the wavefront. The article is about a 12" collimator (made of a Newton and a 9μm fibre-optic cable), used for 10" CSTs and 11" RCs. It is written in Dutch, but should fairly well translate in a browser like Chrome. Nicolàs

Last night C/2020 F3 NEOWISE had a not so secret meeting with Talitha (iota Ursa Major). Apparently she, and the other stars, did not like him a bit and ran away... 😉 Imaging done with SkyWatcher Esprit 150ED and ZWO ASI1600MM Cool Pro. Lum: 29x 2s (number 30 had a plane in it), 12x 5s R, G and B, so 238 seconds total exposure. Unguided imaging with tracking on the comet using 10Micron GM3000HPS. Stacked in DSS, stretched in APP, RGB combine and post-processing in PSP. Nicolàs

At last we had a clear night again. Imaging done with SkyWatcher Esprit 150ED and ZWO ASI1600MM Cool Pro in LRGB (30x2s Lum, 12x5s Red, Green and Blue). Unguided imaging with Neowise's orbit programmed in the GM3000HPS mount. Stacked in DSS, stretched in APP. RGB combined, Lum added and further enhancement in PSP. Nicolàs

My image was indeed relative to the sky of 17 July. If you select Neowise in Stellarium and forward time in steps of 24 hours, Neowise will indeed start to plummet towards the horizon by the end of July, following the green path in your graph. Of course it will get slightly earlier dark, allowing us to see it slightly earlier, but that will not make a significant difference. In the meanwhile the magnitude also drops, so most likely there will not be much gain in the earlier sunset. Nicolàs

See attached image, according to Stellarium it reached its maximum brightness on 10 July. Nicolàs

Hi Nigella, thanks for the confirmation. During these events I have rarely more than 2 people in the observatory at the same time and for an hour, so plenty of time for everyone. But the fact that we can see more using the camera than visual only now occurred to me. When I want to image the sun I always do so with the camera, so I never noticed that visually all those features are less clear. Next year I will make the Esprit visual and the Lunt on display, that will work better. Nicolàs

Hi Nigella, indeed quite a bit of activity, once again a nice image! I did not attempt imaging the sun that day, but through the standard Lunt zoom-eyepiece we could only see granulation and a very small prominence (like the one at 12 o'clock in your image). I adjusted the single-stack pressure tuner several times, but failed to see much more than that. What we saw through a Quark on a stopped-down 150mm Newton was very similar (it was stopped down to 80mm). In addition we had two refractors with Baader filter (apertures of 110mm and 150mm, the former was used visually, the latter in combination with a ZWO ASI1600MM Cool Pro). Both of them only showed granulation. So apparently we can capture more detail with a camera on a H-alpha telescope than we can visually in both H-alpha and white-light. Is this also your experience? Nicolàs

Very nice, so much to see. Here in the Netherlands (and Belgium) it was Sun Watching Day on the 5th. On that day public and private observatories were open all day (some only virtually) to allow people to have a look at our nearest star. And guess what? There was nothing to be seen, apart from a tiny prominence the size of half an Earth diameter... a whole difference with what you have captured the past few days, thanks for sharing! Nicolàs PS: does the UK know something similar like Sun Watching Day?

If I remember well I could see the core with my C11 some 30 minutes after sunset. A decent piece of tail took half an hour more. Imaging with my Esprit was done starting from an hour and a half after sunset, the following image was taken at 21:35 UTC, while sunset was about 20:00 UTC. Nicolàs

With my SkyWatcher Esprit 150ED (1050mm focal length, f/7) I could only capture its head. Processed from LRGB in DSS, combined is PSP (image taken 'round midnight on 10-11 July). Nicolàs

Hi Mark, I am not sure if you do not have the hardware or do not know how to share live images through Zoom. If it is about Zoom, you can share your desktop with others. So all you need to do is to get video of your astro-camera on your desktop, then start Zoom and share your desktop. So if you can see it in that way, anyone can. best wishes, Nicolàs

Have you seen my article? It is in Dutch, but should translate when opened in Chrome. I use a 12" Newton in combination with a 9 micron glass-fibre artificial star. The artificial star sits in the focal point of the Newton. Mind you that when using a second scope, that the secondary obstruction of the reference scope is smaller than that of the scope to be collimated. If you scope has moving mirrors it is important that the scope it collimated as close as possible to infinity focus, this to minimise influence of mirror-shift/mirror-flop. For the rest it is quite easy, mutual distance in my set-up is about 10cm. I also recommend turning the scope over (180° rotation along its optical axis), as some scopes have terrible mirror-flop, see my second article on this (you will be surprised by the manufacturer's response). Nicolàs

Hi Ade (is that your name?), I use a ZWO ADC and the levers are normally to the right of of it. Before mounting the ADC, move the levers into the same direction and symmetrical within their combined slits. Adjust the vial so that in that position the levers are horizontal. Then mount the ADC and turn it to make the vial level. Once level and mounted I adjust my ADC using ZWO's ASICAP (click on the ADC icon within the image). There is also a tool for it in FireCapture, but that has a flaw. In FireCapture the calculated offsets vary with the position of the planet on the imaging chip, something that should not happen. In ASICAP the calculated offset are independent from the planet's position as it should. This difference makes it almost impossible to use FireCapture to adjust the ADC (for me at least). Sometimes, especially at low altitude, it may become difficult the get the right ADC setting. Adding additional length between ADC and camera helps in those cases (I added 40mm for that). So I adjust in ASICAP, then switch to FireCapture to get my imaging done. When shooting monochrome, I first mount a colour camera to adjust the ADC, the replace it with the monochrome camera, start FireCapture and do some imaging. The reason for this is, that within the RGB-filter's bandwidth the light still gets deflected, so even when shooting monochrome the ADC does help. HTH Nicolàs PS: when adjusting the levers, the planet moves over the imaging chip, that is indeed normal behaviour. For this it helps to have a guide scope that can easily be adjusted.

Hi Stephen, when using a tilt adjuster, what process do you use to adjust them? I understand that in static images the NRs are hard to see, so what is the easiest and best way (presumably these result in two answers)? I noticed that my last animation also show faint NRs, so could do with improvement, although an artificial flat would do. Nicolàs PS: Inspired by our last conversation, I created a second solar imaging tutorial on a Dutch forum, of course referring to you (should translate nicely in Chrome).

Yes, that is fine, perhaps later on we can start a thread on this. Nicolàs