Thalestris24

Ahhh….

Oh, wait a minute.... I just reloaded the image and the chart does actually come up with wavelength rather than pixels but there are no annotated calibration lines. Should I be doing something like saving it as a reference? Louise

Hi Andrew Yeah, BASS. I did some sort of a save but it doesn't appear to have saved properly. It wouldn't reload the saved file which was a .fit but I think only a fraction of the size it should have been. I obviously did something wrong! I would have thought there would have been a warning when I chose to remove it from the display. Oh well. Louise

Oh, I was following the slit processing tutorial which says 'now that the target has its own calibration data, the reference spectra can be removed'. I assumed I'd be able to get it back? Looks like it's gone so I'll have to do the S10 all over again 😢. Louise

Oh well, ended up with these - S10 (via Eric ) and CFL calibrated from the S10: Unfortunately using the S10 to calibrate the CFL results in values that don't quite line up - there must be an error somewhere... The purple vertical lines are my attempt to add labels. Only two of them came out Upon saving the data in the label editor, the label seems to disappear. Nevertheless, the purple lines should line up with the corresponding peaks but they are a bit off. Maybe I'll have to redo the S10 calibration... I hope I don't have to do this procedure every time I need to calibrate a target even when using the same settings? That would get tedious! Louise

Thankyou very much, Eric! The above is a 120s exposure. I have a 180s exposure also but thought the red end was a bit overcooked, though I've not actually tried viewing it in BASS. I obtained Richard Walker's published lines for the Relco 480 and the Osram ST 111 starters last night. Unsurprisingly, I suppose, they are both different to the S10... I've no doubt there is commonality between them and the S10 but it needs teasing out. I'm a bit ocd when it comes to lining things up... I guess a few iterations between your calibration of my S10 and my CFL should finalise things, as Ken instructed . Happy New Year! Louise PS I was referring to the ?s on the calibration of the CFL that Ken gave me

I have that but I don't like that it has ? against most of the lines! But if you say it's ok... I have managed to find some of Richard Walkers published plates and data for various starter and fluoro bulbs so I'll peruse that as well. I should be asleep now, so off to bed! Thanks Louise

Here is my S10: CFL: Both: The S10 is a bit of a jungle at the red end! Presumably that's mostly neon plus other stuff. Anyway, I'll give it another go starting from the cfl tomorrow though different people quote slightly different wavelengths for some of the lines... Louise

Just to say, I wasn't trying to superimpose as such, just aiming to match significant lines. But it's not so easy... Louise

Ok, thanks - I'll give that a go tomorrow. Cheers Louise

Ok, thanks! What's the best easily available and reliable source of defined spectral lines? I'm probably overthinking/over-pedantic about this but different sources (ie different people) quote different values so I'm having trouble with both the cfl spectrum and the s10 starter bulb spectrum. It's driving me nuts! Although Eric kindly provided me with a detailed S10 spectrum, it's on a different scale to mine and I can't see how to reliably line them up, so to speak. How many matches do I need for an accurate calibration? Cheers Louise

Hi Ken - if you're about! I'm struggling a bit to achieve a calibrated spectrum... Trying to match more than a few lines isn't easy... A couple of questions: can I zoom into the chart to get closer to selected lines and can I change the colour of the chart spectral plots? At the moment I have one blue and one green and it's not very contrasty. Black and orange, say, would be much better! Cheers Louise

Hi Eric I was thinking of doing something similar re the calibration lamp. I was wondering whether your S10 bulb was poking down towards the front of the slit or whether you had some sort of reflector within the holder. It would seem good to have the S10 more or less permanently in place but not otherwise interfering in the light path to the slit. Oh, I see you only insert yours when you want to make a calibration. Season's greetings! Thanks Louise

Oh ok - hopefully it will all become clearer.... Thanks Louise

Hiya I have all the identified lines for the S10 bulb given to me by Eric. I just have to make sure my spectrum matches. Will have a go tomorrow Louise

Hiya Thanks! That was with the 10um slit. I left everything as was yesterday. I need to try and get a better focus, I think. Louise

Received the fluorescent starters so, excitedly, connected up the bulb from an S10 one. Here is raw spectrum: The micrometer setting was the same as yesterday so goes from ~4000A to ~7200A. Exposure was 3m so takes quite a long time. I'll try and put it through BASS Project later and compare it to the spectrum data Eric kindly provided. Louise

I recopied the fluoro reference I use to my last message.. ok, I understand what you meant now Just select the line, look up the wavelength (from the reference image I gave) and enter that, continue for the lines you can see. I don't understand exactly how to do that yet. As I say, I'll study some more. I was trying to follow the slit processing tutorial (word doc on the group page). It suddenly starts talking about a 'reference spectrum' without explaining what it is, which confused me earlier. I'll have to read through the BASS documentation... Don't rush me - I'm old and dim! Thanks Louise

I thought this short video on the relative sizes of some black holes was quite watchable. Spot the misplaced apostrophe in the text ha ha. Louise

Hiya - thanks Yes first go with BASS Not sure what you mean by 'earlier fluoro reference'? I'm obviously not really understanding/familiar with BASS. I've only used Rspec before and with the SA100. On the 'element' menu there is only elements like neon, mercury etc (as you know ha ha). So I just assumed that first brightish peak was mercury and left it at that for now. I'll have to study it some more. Cheers and Merry Christmas! Louise

I had a tentative go with BASS on a cfl spectrum. I need to spend time reading the BASS documentation... Anyway, managed to get this based on a 1 point mercury calibration and the Simspec theoretical dispersion of 1.02A/pix.: It compares to this annotated CFL spectrum: But doesn't line up exactly. I used one of the mercury lines which BASS said was 435.833nm but the annotated figure says 436.6nm. From my calibration the large peak on the right is at 620.8nm whereas the annotated one is 611.6nm. Obviously a single point calibration relies on knowing the precise dispersion. I just used the Simspec calculated value of 1.02A/pix. So may not be accurate enough. Otoh, maybe it's just a variation between CFL bulbs. I couldn't figure out how to do multiple points of the CFL. I'll have to read some more . Annoying that BASS doesn't appear to have an undo button... Still, early days! It doesn't look like I'll get any of the starters before Christmas but I might have a go with a pure neon bulb as neon is an element option in the BASS calibration procedure. Will get my soldering iron out tomorrow . Louise

That's great, thankyou so much! Lots of lines, lol. It will be interesting to compare to the S10 to the 'Vernons' brand I ordered. Yeah, I joined both the groups a while back but I've just been completely focused on learning 3d printing and building the Lowspec! It's taken up all of my astro energy!! I will sit and run BASS and try and learn how to use it. Something to do over Christmas Off to Tesco now Cheers Louise

Oh ok, thanks I just read your previous post and how you found the data on a French web site. I take it it's the one branded as S10 'Ecoclick Starter'? Louise ps: oh well, just ordered x10 of the S10s off Amazon for less than a fiver and free postage - can't be bad! (What's the worst that could happen?)

Hi Eric Thanks for that - I'm afraid I'd completely forgotten you'd mentioned the S10 (my memory capacity is dropping by the week ). I'm a bit in the dark as to how one identifies the wavelengths in these starter bulbs? As I say, I'll see what the ones I ordered are like but the s10 looks like it will be good for the blue end of the spectrum. Thanks Louise

Thanks for the offer, Steve. Hang on to them, please! I'll see what the ones I ordered are like first. Cheers Louise