Thalestris24

I noticed that the floodlit sports complex near me turned the lights off early. When I checked it out online it closed at 8pm until further notice. As it normally lights up the sky for miles around from dusk until around 10:30pm, it's a positive side effect for me, arising from the current anti Covid-19 measures. Perhaps other people are also experiencing some positive side effects? Louise

FWIW, I aimed to get my spacing to align close to the mid-point of where the focuser puts the lens. That gave me focusing leeway. Of course, it all changed when I swapped my camera... Louise

Maybe not far off focus. The focal length is determined by the Lowspec camera lens. I got mine close to focus by measuring from the lens to the sensor plane to get the right T2 tubes between the camera and the Lowspec body. I've not found my Lowspec focuser easy to use - my one tends to be a bit stiff 😞 Oh, I added a rotator to get the camera sensor horizontal. Louise

Ok, so, if I got one, I would just connect it back to front from normal. Not sure when/if I'll get one as Western Europe is shutting down at the moment 😞 Ta! Louise

Hi Ken I just re-read your reply and bit unsure now. Would the Vixen flip mirror let me select inputs i.e. the telescope or the calibration source? So the flip mirror would be connected to the scope and lowspec T2 scope connector? I was a bit confused by the mention of 'guide port' as that's separate and 'standalone'? Cheers Louise

Yes! I wanted to easily be able to use the nitrogen spectrum lamp. I thought the Vixen version might be reversible but wasn't sure. Thanks! Louise

Anyone know if there's a cheaper equivalent of the Baader Flip Mirror II to work with a spectrograph i.e. handles two inputs rather than just two outputs. Thanks for any input Louise

Yep. Don't worry, with a bit of practice you'll be fine. Once you have focus on a star or the Moon, you probably won't have to focus again. Good luck Louise

The camera is very sensitive. Focus can be difficult to find. So best set up during the day with qhy's EZPlanet software. You need a very short exposure - perhaps just a few ms, you have to adjust the exposure so it's nether a bright white field or a pitch black one. Once you have a reasonable exposure then you can try and focus on a distant object e.g. a pylon or church spire that is several km away. The focus point is quite critical. Louise

What scope have you attached it to? It helps to use a very short exposure and focus during the day on a distant object. Louise

Had the nitrogen spectrum tube running. I connected it up to a '400kV' 'Step-Up Boost Power Module' I got off Ebay. Input voltage was from a 12V battery via a variable DC-DC converter. The Boost module is supposed to run from a 18650 4.2V battery but I don't have anything that will properly control the 18650 voltage. Anyway, are a couple of YouTube videos I made: 1. Using a minimum voltage from the DC-DC converter: 2. Using a slightly higher input voltage: Now I just need to get the Lowspec up and running again (I still have a problem with the guide platform 😞 I've reprinted it yet again but need to tap the holes and clean it up in order to get all the parts to fit together. Louise

Well the EL Panel inverter powers the little EL panel I bought 🙂 It does just power the starter bulb but maybe not quite bright enough. I'm not sure whether that's a current limitation or a voltage one. The inverter can also give an electric shock... 😛 Panel: Starter Bulb: As I have two of the EL inverters, I might try connecting them in parallel to see if it's a current problem. On the other hand, at 120V the bimetallic contacts don't switch on and off. I'll try out the EHT source plus a power controller with the nitrogen spectrum tube tomorrow. I know the EHT source outputs a very high voltage... Louise

If you can find the data sheet for the particular starter bulb you have it will quote a non-reclosure voltage. For a Philips S10 'Ecoclick' 4-65W that voltage is 140V. So below that it shouldn't close the bimetallic contacts. I've bought a couple of EL power supplies which output 120V. I was hoping to use them without a resistor. However, I've not got around to trying them yet - they were very cheap so no great loss if they don't work. I also bought a white EL panel to maybe use for flats. I've also bought a nitrogen spectrum tube which might be better than a starter bulb as it has a limited spectrum but covers the visible range. I haven't got it working yet - I have to sort out a power supply that works. I think the tube needs around 2kV to strike. I have some power supplies (CCFL) and an alternative EHT one to try. Hopefully, will get around to trying them out soon 🙂. Louise

I just bought a Tacklife rotary tool off Amazon to help me with some 3D printing post-printing tasks. Yep, (needle) files are useful too. Having a cfl bulb is useful for initial testing as well as a neon. Building the Lowspec was my first ever experience of tapping a thread - better late in life than never! 🙂 Louise

Meant to mention before, there is quite a bit of useful info and peoples' experiences of printing and using the Lowspec on here Louise

Yeah, filament comes in 1kg reels. I think my Lowspec 2 weighs around 500g including lenses and grating (it's actually 1.18kg with cameras and t2 tubes attached but my qhy183m weighs about 450g on its own). Exact weight will depend on the density you print at. How much you actually use is going to depend on whether you have to do reprints. I've had to reprint some of the parts 3 or 4 times... But I'm not an expert 3D print person! I was a complete 3D and slit spectrograph beginner when I started. Louise

PLA has been fine for me. I would advise: 1) Calibrate your printer 2) Practice bed levelling 3) Get familiar with your particular printer. Do lots of practice test prints of rectangular pieces with holes in them to check how they come out and to be certain your bed is level Hth Louise

Ok - excellent mount! It's up to you which guide scope you go for. The finder-guider is maybe better value but either will do the job. Yes - flex is your imaging enemy so always strive for rigidity! Louise

A 50mm guide scope is fine. Most guide cams have around the same pixel sizes so a fast 50mm guide cam is great. It gives you a wide fov and bright star images. If you buy a standard finder as I linked to, you need an adapter at the rear of the finder as you have to remove the existing lens assembly viz https://www.firstlightoptics.com/adapters/astro-essentials-sky-watcher-9x50-finder-to-c-adapter.html If you'd prefer your dedicated ED guider then you won't need that adapter. However, that guide scope has a slightly longer focal length so a slightly smaller fov. It's a personal preference which one you go for really. Btw, with a 50mm guide cam you probably won't also need the Telrad as you'll be able to use the setup as an e-finder. Which mount do you have? That's the most important part for good imaging! Louise

Ok, that sounds good. It can be better to have rigid mounting to ensure there's no flex between the guide scope and imaging scope. It doesn't matter from a guiding point of view whether or not the two scopes are aligned. It may be a problem if you want to use the guide scope as an e-finder. However, using plate solving via the imaging scope is becoming a more popular way of getting on target. Louise

The SW 50mm finder guider scope is excellent. In general, though, it's best not to use the finder scope bracket. However, you'll probably get away with it as your imaging scope focal length is short (also depending on which imaging camera you use). You'll need an adapter to fit the guide camera to the finder. Are you thinking of using the qhy5-ll as an imaging camera or guide cam? The qhy5 is essentially a guide cam. What targets are thinking of using your setup for? Louise ps I just realised you were considering the ED finder. TBH that's a bit overkill - the standard one is much better value though, as mentioned, you do need an adapter https://www.firstlightoptics.com/finders/skywatcher-9x50-finderscope.html

It's ok - I sorted it. Problem was caused by loose rollers under the bed. Thanks anyway 🙂 Louise

Maybe not completely out of focus but made worse by the reflection. I adjusted the focus and used a translucent plastic sheet as a diffuser. I think the focus is still off a bit. CWL? My focuser on the Lowspec is dreadful... I hate having to use it. I'll definitely have to reprint the slit assembly. I'm tired - going to bed now. Thanks for your help. Louise ps Working in my living room I can't keep dust out - can but try and keep it to a minimum. All the optics have dust on it...

I set the grating back to normal mode but it looks completely out of focus now. Surely it should still be in focus or close to it? Louise

I think this one is maybe a bit better. I took the slit assembly out. I noticed that when looking through from the illuminator side that the bottom of the slit was being cut off! I've taken the illuminator out so this image is without it. Bin 1 this time, just the illuminated wall, 15s. There is still a tendency to cut off the very bottom. It's looking like I'll have to try reprinting the slit holder body... Another thing I noticed from looking through from the illuminator side is that if tilt the assembly such that I'm not looking through the slit itself, I can still see the cfl bulb. Maybe this is what's causing the ghosting? Maybe it's not an issue with a less bright source. Louise