BrendanC

Thanks! Looks promising. I don't currently have CdC installed, although I used to. I guess that, even if this doesn't work directly with Stellarium, I might be able to run CdC in the background to power the graphics. Although AVG has blocked the executable unfortunately, for it to be 'thoroughly examined' in their 'Threat lab'. Hopefully when the Threat lab has done its thorough examination I'll be able to use it...!

This is probably what I once saw, looks like it's nothing to do with EQMOD. https://www.siriusimaging.com/Help/APCC/threed_scope_editor.htm Would be cool if there was something though, or if this could be made to work with it.

Hi all, On Wednesday I'm giving a virtual presentation, taking some people on a Zoom tour of the skies. I've done it before 'live' - as in, sharing my screen during the Zoom session, actually slewing the scope to objects in APT, showing Stellarium to indicate where the scope is, and taking shots, which I then shared with them afterwards. It went really well as a live session, mainly because we did it at very short notice when I realised we had a small window in the weather and we were up and running in minutes. However, this one is a scheduled talk, this Wednesday, and the weather (as always) is forecast to be terrible. So, no live scope, but I've been looking into the EQMOD Simulator. It works well in Stellarium - I can show exactly where the scope is, and show it slewing to different objects. This is actually good enough as it introduces a bit of 'virtual realism' to the proceedings. However, it would be even cooler if there were some sort of CGI scope I could also hook up to the simulator, by which I mean, a small 3D graphic of the scope, that I could have in the corner of the screen, that slews as the real one normally would. I've looked around and can't find anything, but I could be using the wrong search terms. Obviously it would be even cooler if such a thing were to exist that could let me choose the mount and scope! So I could pick an NEQ6 mount, and a 130PDS scope, and that would slew, while the crosshair slews in Stellarium. Any ideas? I'm sure I've seen something like this before but cannot find anything. Thanks, Brendan

I'd probably be cleaning the whole mirror while I'm at it. I've ordered distilled water just to be on the safe side, and then I think I'll probably try the 'no touch' method by letting it mostly dry on its own then using a hairdryer to get any excess off.

Hi all, So it looks like an insect may have met an untimely death on my primary. There's a small splodge, and it's noticeable on my subs, so I need to clean it. I've only ever cleaned a primary once before so I'm a bit scared. I know how to do it, but the question is as per the title: for rinsing it, I see deionised water for sale everywhere, but distilled water seems much harder to find. Is distilled water an absolute must, or would deionised water be ok? Thanks, Brendan

Btw @tooth_dr, just to be very clear, that was a joke...! You've been very helpful again.

Not you again...! That's a great idea actually - I could just copy the flats into a separate folder for each group. Very nice. Thanks! Now, will you please stop stalking me...

I just realised, I don't know what I'm doing. It's a strangely frequent experience... So, in Deep Sky Stacker, which I've been using for quite a while now, I always put my flats and dark flats into the Main Group, because my understanding is that everything in the Main Group gets used across all groups. Then I bring my lights and darks into Group 1, 2, 3 etc for each temperature, seeing as I'm using a non-cooled DSLR. That way, my lights match my darks in each group, and the light and dark flats are used across them all because they're in the Main Group. I'm pretty sure that's how it should be done, so if I'm already wrong, let me know! I've just tried however, to bring together subs from two separate sessions, in which I took two different sets of flats. So, now I don't want the flats to be used across all the groups, so I can't put them in the Main Group. However, I do still want the dark flats to be in the Main Group, because they haven't changed. So, I thought the way to do this would be to have dark flats in the Main Group, then the lights and darks in each group according to temperature, as before, but also including the flats from that session in each group too. This would mean I'd be duplicating flats in groups, but I didn't think that would be a problem. As I was merrily going along compiling all of this, I realised that DSS wasn't registering the flats in all the groups, just the first one I imported them into. So, for some reason, DSS will only let me bring in one set of flats, into one group, not use those flats again in other groups. So it seems to me the only way around this is go back to square one: have all the flats and dark flats in the Main Group, and all the lights and darks in subsequent groups, and stack them for each shoot, just using the one set of flats and dark flats. Then, in a second round of DSS, stack the stacked output from each shoot, but not using any calibration files at all. Does this make sense? Am I right about how DSS behaves? And would this be the best workaround? Or does none of this make any sense whatsoever?

Not a problem! Just so long as you're not stalking me...! Totally take your point and this question has indeed been asked a bazillion times. The answer can only be as generic as 'long/high enough to beat the read noise and short/low enough not to clip stars'. So, close eye on the histogram from now on then. Thanks for the help! Again!

Which would be best? As per the title of this post? I know different cameras have different characteristics, quantum efficiencies, resolutions, pixels sizes, well depths etc. And each object/location/night sky might require different settings. But in general, say I took 10 mins at ISO200, and 5 mins at ISO400 (even, for the sake of argument, 2.5 mins at ISO800)... which, generally, would be better? Which would be more likely to have a better S/N ratio for example? I also know this is something I need to test for myself! And I will do (and have to an extent but not very deeply). But, given the scarcity of good weather I'm reluctant to experiment too much - I just want to take photos. So, if someone can definitively answer this, that would be great. I expect there's a mathematical argument for long exposures at low ISO versus equivalent shorter exposure at higher ISO? Thanks, Brendan

Thank you, I should have been more observant!

Hi all, I thought I wanted a clip-in EOS filter because that was the best way to fit a filter with my EOS1000D and Skywatcher 0.9x coma corrector (see https://www.firstlightoptics.com/coma-correctors/skywatcher-coma-corrector.html). However, I just thought: is there a way to attach a much cheaper 2 inch filter to the coma corrector? For example, this: https://www.banggood.com/SVBONY-2-inch-CLS-Light-Pollution-Broadband-Filter-Suitable-for-Visual-and-Astronomical-Photography-p-1688255.html?cur_warehouse=CN I've noticed that the coma corrector has a thread both internally and externally, neither of which would change the focus distance. It would make sense that a 2 inch filter might simply screw into either of these threads quite nicely. Can anyone who uses this coma corrector with a 2 inch filter confirm or utterly refute this? Thanks, Brendan

Just thought I'd pop up, seeing as someone had 'liked' my earlier comment, to say that everything's been going perfectly fine since stopping polar alignment! I might check it from time to time, but it's been working well with good guiding and results... Cheers! Brendan

Ahhh, that would explain it. I did not know that! Another learning for the day.

Thanks all. Btw, I think Adam is referring to the kit list in my signature. Great to know someone who had virtually the same kit can advise!

OK, in which case I'll probably stick with it then - not least because the vendor is out of stock with the CLS version. It costs a bit more but then again it's worth it for immediate gratification. Thanks again.

Yes, that's the problem - he doesn't state what type of mod. Now, here's the catch - I've already ordered the CLS-CCD filter. Yep, I may as well come clean: everything I read said I should get that one, not just the CLS one, so I ordered it last night. Then, tonight, after a bit of browsing, I started coming across contrary advice and started to worry somewhat. I've emailed the vendor asking their opinion (and how I stand if I need to return the filter, unopened), and even emailed the guy who did the mod, for their take on it. Given your advice, I was all set to return it. But are you saying that the CCD might still be beneficial? All I want, is a filter to lessen the sky-fog from light pollution on longer exposures. I took a look at that page you linked to and honestly, I really don't understand much of it.

Ah, posted before I saw your reply! So, I need the CLS version, right? Not CLS CCD? In which case, AstroBackyard is a tad misleading: The CLS-CCD filter improves the visibility of deep sky objects while blocking out a great deal of city glow. This version is suitable for modified DSLRs because of the built-in UV/IR block filter. This produces smaller, sharper stars. From here: https://astrobackyard.com/canon-astrophotography-filter/ Thanks for helping out.

Here's where I'm confused: "the only difference between the two filters is that the CCD version has IR cut, which you don’t need on an a unmodified Camera, but you also don’t need on a modified camera either unless you have the full spectrum mod which removes both filters in the camera, the “normal” Astro mod leaves one of the filters in the camera which has excellent IR cut, so hence why the CCD version is not needed with the normal Astro mod...the CCD version is really for a CCD Camera that Has nothing in front of the sensor." From here: https://stargazerslounge.com/topic/307670-cls-or-cls-ccd-for-unmodified-500d/?tab=comments&fbclid=IwAR2m8ebSHJi9yYpnYDWb9LTG3QZYtl-9eUsBlEG4Zssdt4LI8MrZzacrlhU#comment-3364531

OK, I guess I'm showing my ignorance here about exactly what the astro mod involved! I bought it modded, as a hot mirror removal, which I thought meant the filter had been removed. So, I was confused about whether I should get a CLS or CLS-CCD filter. I get that CLS filters the light pollution. But I'm thinking the CCD filter is for full-spectrum modded DSLRs, not IR-cut modded DSLRs... and that's where my understanding ends. If you think CLS-CCD is the way to go, could you explain why?

No idea, that's why I'm asking! My DSLR has had the IR filter removed. So, why would I need a CLS CCD to cut IR? That's where I'm confused - a lot of people say the CLS-CCD is better for a modded camera, but I don't understand why I'd need the IR filter if I already have the IR filter removed.

I'm considering getting a CLS clip filter to help with light pollution on longer exposures, on my modded EOS1000D. It's had a hot mirror removal astro modification which, as I understand it, means the IR filter has been removed, so not a full spectrum mod. Now, a lot of what I read says that the CLS CCD filter is what's needed for a 'modded DSLR'. However, for this specific mod, I'm wondering whether it should be the CLS version only, as I don't need the IR cut of the CCD version. Am I making any sense here? Could someone advise please? Thanks, Brendan

I'm pretty certain that error message in APT is because you don't have the telescope remote plugin activated on Stellarium. Go through this page and you should get set up properly: https://www.lightvortexastronomy.com/tutorial-setting-up-an-equatorial-mount-on-ascom-with-eqmod-stellarium-and-cartes-du-ciel.html

I knew that ASCOM had been incorporated into Stellarium, but I thought you still needed Stellarium Scope for the CTRL buttons to work to align your scope?

Thank you once again Vlaiv! I think it's fair to say that you definitely 100% absolutely know the answer!