inFINNity Deck

Difficult object, mine (taken with C11 EdgeHD) is not much better (and over-processed): http://www.dehilster.info/astronomy/uranus.php Nicolàs

It is possible to remove the foot/dove-tail and to replace it with two scope-rings, but my first impression is that the foot is sturdy enough to avoid flexure. That image was the result of only 40 x 30s luminance, 20 x 60s R, G en B, all unguided (should at least double the amount of integration time). Mind you that the ED80 is a fine scope, but that they do have issues. The image shown in above link was taken with my third (!) ED80. The first had pinched optics, asymmetric halos and spikes when imaging bright stars, the second had similar issues and was unable to produce a flat field (coma in two opposite corners), the third (this one) again had asymmetric halos and spike-like artefacts when imaging bright stars, but a very nice flat field. The halos and artefacts were easily solved by stopping down the scope to 79mm (making it f/5.06), which I explain in this article (open in Chrome to get it translated). Now I am very satisfied with the ED80, despite the modification. Nicolàs

Hi Gallandro, My ED80 is just a few months old. The dovetail is about 125-130mm in length (the ends are not square). Including the flattener and my ADM saddle the scope weighs 5040 grams. According to the manufacturer the saddle weighs 740 grams, so that would make the scope 4300 grams. Nicolàs

Hi Peter, were those images taken with a real or an artificial star? If I look at the last image and flip the lower left and upper right I can see there is some room, although marginal, for improvement (ignore the yellow target, only look at the outside and inside of the doughnut): As can be seen when the outer rim is nicely round, the inner rim does not match. Te ronchigrams do show several paterns: - a sand-wave like pattern - straight diffuse lines parallel to the spider in direction approximately 20° The first could be the result of seeing when done on a real star. If done using an artificial star it could indicate issues with the mirror. The second is very strange, have no idea how to explain it. Normally ronchigrams are made closer to focus, so with fewer lines (also taken with a RC10 using an artificial star): The ronchigram is not very sensitive, so errors in the inter-mirror distance of several millimetres are quickly made. The focal length of the RC10 varies by about 10-11mm per 1mm change in inter-mirror distance. In your case this could mean that the inter-mirror distance is off by slightly more than 2mm (your focal length is off by 25-26mm). HTH, Nicolàs

Did you also check the collimation of your scope prior to imaging? I usually do that on a nearby bright star, so that the scope is collimated in approximately the same position as the images are taken. In that way any flexure or mirror-shift/mirror-flop will not have a significant effect on the result (my C11 suffers from mirror-flop, which has a significant effect on the collimation). It has been a while since I attempted Jupiter and Saturn and to be honest those attempts were mediocre. Last year I improved my skills a lot using Mars as subject. With the ASI174 I can get frame-rates of over 150fps (200fps is the limit what my NUC can handle). I captured 120s SER-movies in LRGB using an ADC and the Celestron C11 EdgeHD. Each movie was processed in AS!, stacking 10% of the best frames. These four resulting stacks were then first sharpened using an unsharp mask, then RGB combined using the L as an luminance layer, enlarged by 200% with bicubic interpolation, and finally sharpened using high pass sharpen. The result is here. It has to be said that a lot depends on the seeing... Nicolàs

The screen-dump says 9180 frames (lower left of main window), so approximately 51fps. 😉 Nicolàs

From your result it seems that you are not using an ADC, is that correct? With the current low altitude of the planets an ADC is a must to get less dispersed images. For the rest it could well be that the seeing was not good enough or that the scope was still too warm. Noise Robust setting is in AutoStakkert (left hand side of main window in the Quality Estimator section). Nicolàs PS: I agree that 3 minutes recordings are too long

Hi Dave, I observe and image the Sun using a C11 EdgeHD, which is pretty close in aperture to your 12" Newton and will thus give the same resolution. The following image is what you can expect visually as well: Please note that there is ND3.8 and ND5.0 foil. The ND3.8 is not suitable for visual observing as it is 16 times less dense than the ND5.0. ND3.8 is made for imaging, although above image shows that ND5.0 can be used for imaging as well (the image was taken using a ZWO ASI174MM and ND5.0 foil in combination with a Baader Continuum filter). For visual observing I can recommend adding a polarisation filter to your set-up. Personally I find the ND5.0 filter on my C11 a tat too bright. The polarisation filter consists of two filters: one fixed filter that is attached to your EP, and a rotational one that is attached to the diagonal. The one in the diagonal has to be rotated until it allows maximum dimming, which is checked by rotating the eyepiece. During observation the eyepiece is rotated to get an acceptable intensity. The advantage of the polarisation filter is that it adds a bit of colour to the visual image (either blue or yellow, depending on the filter rotation). Nicolàs

I use the method explained in this video for my C11. The only difference is that I use odourless and colourless Kleenex tissues in the process (on instigation of Baader). Nicolàs

Hi Mike, the measurements of the RA/DEC intersection remain the same and are independent of the number of scopes on the mount. When using a side-by-side set-up you will need to measure the lateral offset and enter it it NINA, again observing the correct sign. I have built my own dome and run it using LesveDomeNet, so have no idea if there is a 64bit PulsarDome driver, you would need to check with the supplier and/or manufacturer (but perhaps other forum members know). If you are using NINA it is possible to have dome-slews in between imaging. For that you need to switch off Dome Follows Telescope and instead use the advanced sequencer to create a sequence with a Synchronise Dome trigger (let me know if you need help with that). I switched to NINA from SGP a few weeks ago and quite fond of it already, it does the dome bit significantly better. 🙂 Nicolàs

You could try to install NINA 1.11. That dome-routine works very well and directly connects to the dome's ASCOM driver. It even works for side-by-side set-ups like mine. Nicolàs

That should all be fine then. Which software are you using to slave the dome and did you correctly apply the signs to the scope-offsets? If you use SGP for slaving the dome the Observatory Settings window asks for the Diameter at Equator, while the radius is used in the calculations. So instead of providing diameter, radius should be provided here. Nicolàs

it is the intersection between the two axis, so your allan key seems about right, bit more to the right perhaps (but that could be due to perspective): Nicolàs PS: Are you using a single or multiple scope set-up?

I had a similar issue with 0.21.0. In the default Windows-key followed by typing "stel" start-up, it would freeze every half minute for several seconds, having issues with screen rendering. Then I choose several times the alternative "Angle Direct3D 11 mode", which gave no issues, and now Windows remembers that I prefer that version over the default one. Still I would like to change or remove the original one, but seem unable to do so. In the meanwhile the observatory-pc runs 0.21.1 as that version remembers that I want to connect to the mount ASCOM driver. Nicolàs

Until last week I used a paid licence of SGP. For quite some time (years in one case) I have been waiting for improvements in dome-control within SGP, but they never arrived. Then a few weeks ago I found it impossible to move the dome correctly for a new scope on my rig. I was then advised to try NINA and never touched SGP again. When I first tried NINA the dome-control was still not doing what I wished, but that was solved within a week after some extensive correspondence with the programmers, and it is now working like a charm! Yep, that is correct: SOLVED WITHIN A WEEK! Indeed, the advanced sequencer is a steep learning curve, but the nice thing is that a basic sequencer can be converted to an advanced one by a single mouse-click, which helps tremendously in understanding the advanced sequencer. Once you understand it, the advanced sequencer is very cool! So my advise is: If you want real service and progress, go NINA! 🙂 Nicolàs

Today we had excellent seeing here in the Netherlands. I imaged the Sun with three scopes in four configurations: - SkyWatcher Esprit 150ED @ f/7 with ND5.0 filter and ZWO ASI1600MM Pro Cool - Celestron C11 EdgeHD @f/20 with ND5.0 filter, Baader Continuum filter and ZWO ASI174MM - Lunt LS80THA single stack @ f/7 and f/28 with ZWO ASi174MM According to a home-built Solar Scintillation Seeing Monitor, the seeing was about 1.5-2.0" during the white-light recordings and about 4" during those with the Lunt. The active regions are AR2863, AR2864, AR2866, AR2868 and AR2869. Regions AR2866 and AR2868 are the two in the C11-image. Nicolàs

Hi Michael, Thanks for your response. This is a stack, but all individual subs show it. When I was testing the flattener-camera spacing I took 5 to 20 seconds subs to check the corners. The stack shown here is the result of 20 x 30s lum, 10 x 60s R, G, and B. Unlikely to be a guide error as the central stars are round. Also it is mounted on a 10Micron GM3000HPS with a PAE of 5 arc-seconds, so I do not expect field rotation (nor guide errors). Normally I image with a SkyWatcher Esprit 150ED without much problems, do not even use a guide scope. Nicolàs

Just wondering: Could tilt or collimation be the cause of this? Nicolàs

Dear forum members, today I had first light with a new APO in my set-up. It has a flattener and I have been tinkering with spacers to get the distance between my ASI1600MM Pro Cool and the flattener. If I look at the stars in the lower left and upper right corners I am pretty satisfied, but not when looking at the other two corners. It appears that along the diagonal all goes well, but I would expect coma to show in all four corners when it is a matter of chip-flattener spacing. Also when having tilt, I would not expect the stars be fine along one of the diagonals (but I could be wrong there). Any suggestions to the cause of this are much appreciated. Thanks in advance! Nicolàs

On the Antique Telescope Society forum there are quite a few very knowledgeable members who should be able to provide some answers. Nicolàs

I use 2" TeleVue mirror diagonals, indeed no sharp edge here. I have no prism diagonals at hand to test the filters with. Nicolàs

I use the same method with my C11 EdgeHD: the rotating one goes into the diagonal (at the scope end), the fixed one in the eyepiece. Care should be taken to properly orient the one that goes into the diagonal as the diagonal itself causes some polarisation as well, so the orientation of that filter should be checked to maximise the effect when combined with the eyepiece. This can be checked by rotating the filter while looking through the diagonal with the eyepiece and eyepiece-filter attached. Look through the diagonal from the scope end (so in reversed direction) and rotate both the eyepiece and rotating filter. You will find four positions of the rotating filter where the combined filters have no effect at all (so turning the eyepiece alone does not darken the view) and four positions where the combined effect is maximal. Choose an orientation of the rotating filter close to the darkest view, but not fully dark, as that will produce a dark beam through the FOV (but that may be depending on the FOV, I use TeleVue PanOptic and Ethos wide-field eyepieces). Finally insert the diagonal in the OTA and, as TC wrote, leave the eyepiece unlocked and rotate the eyepiece until the resulting view is comfortable, then lock the eyepiece. You will notice that the view can be made yellowish or blueish, depending on which side you are from the darkest setting. I bought the polarising filters as a set, which both were 2" and added a 1.25" fixed version for the shorter focal length eyepieces I use (those have an inner barrel of 1.25") and find them very comfortable in both lunar and solar observations (the latter in combination with a full aperture Baader ND5.0 foil filter). Nicolàs

The black spots that you see are in the eyepiece or on the Daystar. The Sun itself appears to be not focused. Today there were only two minor sunspots, see my white-light image of this morning. You can easily check the location of those black spots by rotating the eyepiece or the Daystar independently. Nicolàs

Today I was experimenting a bit, conditions were not great, but there appeared to be a vortex on the Sun's limb that I would like to share with you. Imaging done with a Lunt LS80THA, TeleVue 4x PowerMate, ZWO ASI174MM. The animation consists of 3 frames, each made of a 15 seconds recording of about 800 frames of which about 10% was stacked. Recordings of the animation made around 08:50 UTC. Full disc at 08:38 UTC. Nicolàs

I know this response is a bit late, but for those interested in these figures: today I received an e-mail from ZWO stating that unity gain for the ASI174 is 179, not 189 as written in their graph (the black arrow is correctly placed at 179). When opening the ASCOM driver unity gain is correctly given as 179. Nicolàs