Thalestris24

Yeah, as I say, I can platesolve via the guide scope though it might get complicated using 3 cameras at once! The guide scope isn't precisely lined up with the imaging scope and it's bolted in place and can't be easily adjusted. It is nice and rigid though! So to find a particular, individual star will likely be tricky. But where there's a will... Thanks for the advice Louise

Maybe I'll try the Atik383l+ first (assuming I can otherwise get everything working!). It's a lot less sensitive and more noisy than the qhy183m, and has slightly lower resolving power and spectral resolution, but it will be fine on brighter stars, I think. A problem I do have, though, is in precisely finding targets. I'm used to plate solving. I guess I could use the guide scope with a different (probably new...) camera. It's hard to line up with the imaging scope but I could probably calculate a fixed offset. It's something I'll have to fiddle with! I take it there's no advantage to using a reducer/flattener for spectroscopy? The scope is 115mm, f6.96 without a reducer. Louise

Oh ok - as it happens, I was in fact just looking at the 'back slit illuminator' image in your book That gives me the impression it might be useful for positioning the target star in the slit but it doesn't reference reflective slits. I'll try without first! I've got most of the Lowspec done and assembled but need to finalise the optics and the cameras. I'm not sure which cameras I'll be using yet. I expect just a qhy5l-IIm for guiding. I was thinking about the qhy183m for imaging but maybe that will be a bit heavy - I'll have to think about it. Thanks Louise

I was wondering... How useful/necessary is a slit illuminator? What does the camera see exactly with/without the slit being illuminated? There is an optional illuminator on the Lowspec. I'm just printing the part out in white PLA. There is a connection (a hole) to facilitate attaching and using a Baader Illuminator. They are quite expensive, though - would an adjustable LED do instead or am I being naïve? Thanks for any explanation/advice Louise

Thorlabs are kindly sending me a replacement grating. Great service from them. I just have to return the 610 within 30 days. Relieved Louise

No - I'm happy just to print from sdcard - I don't need anything else. I've probably already done the biggest/longest print that I'm likely to do - the lowspec case which took some 24 hrs or so. I have a Pi from 2017 but really don't have the time or inclination to mess around with it. Printer is working fine as is! Louise

Hmm... that seems out of date? There's no mention of version numbers that I could see though I'm not too well up on these things! Anyway, for the amount I'm likely to use it I won't worry about it. I wouldn't leave it running unattended. Louise

It's a bit confusing as they only mention 1.1.61 on their web page: https://creality.com/info/ender-3-ender-3-pro-ender-5-firmware-source-code-upgraded-i00025i1.html Where on GitHub is the firmware code? Thanks Louise

Hi Steve I'm a 3D Noob and I bought an Ender 3 Pro Specifically for printing the Lowspec spectrometer, though I'll use it for other things too. It has taken me about a month to get to grips with the printer and to print out the Lowspec design. I've been teaching myself Fusion 360 in order to be able to create slightly different parts and to edit the .stl files because things don't necessarily fit precisely. It's been a challenge but quite an interesting one. I'm not a mechanical engineer, lol. I tapped my first ever thread the other day! Fusion 360 is really good, is free too, but there is quite a learning curve. I've been able to use it to make T2 rings and custom holders for lenses. Of course, there are many videos on YouTube though some are a bit old. Some of the optical parts for the Lowspec are quite expensive (for me!) but if you have an Alpy 600 I'm guessing you don't want to actually build another spectrometer? Louise ps I started a separate thread for the Lowspec:

It says 1.1.6.2 on the About menu...

Yes but is there any way I can tell what version of firmware I have?

Ok. How can I tell what firmware version I have? Thanks Louise

Are Creality lying on the Amazon link above?

I've seen that but the recent posts (above) suggest Creality has updated it since August. How can I tell? Louise

Oh well, never mind! Anyway, I just want mine to print parts fairly accurately

Creality say the Ender 3 Pro does have (some flavour of) thermal runaway protection but I don't know how to confirm it? https://www.amazon.co.uk/ask/questions/Tx37GPPGCUY989Z/ref=ask_ql_ql_al_hza Louise

Oh ok, mine does sound like R2D2/morse code ha ha but I quite like I I just have an otc Ender3 Pro but it does what I ask of it. I've no idea what Martin 2.x is either... Thanks for the info Louise

What are the 'BLTouch' and the SKR board? Louise

Yeah, I have asked them if I can exchange it, otherwise it's an expensive mistake. It was so easy to click on gr25-610 instead of gr25-605... I just wondered if it might be of any use at all Louise

Ken? @Merlin66

Unfortunately, it is I'm in a red zone... I have a qhy183M which has a QE of about 84% but even with narrowband I'm up against it. Louise

Sorry, I was confusing you with Calzune's OP. My bad, though same principles apply The 50mm finder will be fine. You really don't want a barlow on your guide scope - better off having the wide field of view to select guide stars. PHD2 is very good at sub-pixel guiding because it calculates the star's centroid. As regards calibration and guiding, make sure you manually select a star with good snr and not clipped. Adjust guide exposure to be around 2-2.5s. The small pixel size difference between 8.4 and 9.8um won't make any difference, I don't think - lots of people use Lodestars. When calibrating find a star at about 30 deg and in the region of the sky in which you are imaging. When guiding monitor the bullseye - if there's an offset to one side it's likely you are out of balance. If you can't get a decent calibration you'll have to investigate why that is. The Guiding Assistant can give you a lot of info. Louise ps make sure none of your cables are dragging on the scope!

It shouldn't matter whether target and guide images are centered. Have you entered the focal length of your guide scope into PHD2? Are you displaying the basic PHD2 tools that you need - guide star profile, bullseye target etc. What PHD2 settings are you using? If you're imaging with the Evo 72, that's a short focal length so guiding requirements are fairly minimal and should work beautifully on your mount (If your seeing is good you should get guiding accurate to with an arc sec or 2, run the PHD2 guiding assistant to see how your mount behaves without guiding). Balancing out the dslr might be tricky. I take it you are pulse guiding with Ascom/Eqmod? I've no idea what you mean by "the photosite size of the guide camera was not accurate", and why are you using a Barlow - not a good idea! Maybe you can get a log file and/or a screen clip showing it all in action? Louise

I think I made a boo-boo with the diffraction grating. I only just noticed that I inadvertently bought one with a blaze wavelength of 1um rather than 500nm. Tut. I'd just looked at the lines/mm I assume it won't work too well (if at all) in the normal visible range? I've not opened the case so maybe Thorlabs will let me exchange it... Louise

Yeah I use Ha filters, either 7nm or 3.5nm, to no avail Louise