CCDSPEC Spectrometer - review

[athornett]

Wow! Incredible! Amazing! I wish I had got one of these earlier.

I have seen this advertised at Astrofest over the last two Februaries in Kensington, London, and felt tempted but did not purchase one. Then, a few weeks ago, I came across a flyer I had bought home from Astrofest this year. I contacted Peak2Valley Instruments to find that there was one only left. Faced with the prospect of never owning one, I bought it....and I don't have any regrets - quite the opposite! I wish I had bought this earlier. I have a Daystar Hydrogen Alpha Quark & a Calcium-H Quark. Nothing beats the H-Alpha scope/filter as an upgrade to your standard night time scope but if I had a choice between one of these CCDSPEC's and the Calcium-H Quark, I would definitely go for the spectrometer. Don't get me wrong = the Calcium Quark is a great bit of kit - it is just that the spectrometer gives a real sense of immediate satisfaction and opens up a new world of observation to its users. So if you own a hydrogen-alpha scope and now want something more, consider getting one of these if you can.

However - one step at a time. The spectrometer arrived neatly packed in an aluminium case. Dr Elliott had aligned and calibrated the QHY6 camera that came with it so this job was not needed. Good - because I would not have known where to start. This is quite different to other manufacturers.

It is housed in a beautiful yellow CNC-machined housing - nice enough to impressive my Takahashi-owning observing buddy Damian. Guiding is part of the design so does not need to be added separately. There is a place to connect an eyepiece separate form the camera. This differs from the ALPY-600 spectrograph which costs around £2000 by the time you purchase the guiding module as well as the spectrometer and connectors. This one was only a fraction of that cost.

After care from Dr Elliott has been nothing short of incredible. The poor soul has been bombarded with my e-mails and always promptly and politely responds with clear instructions and explanations. I wish every astronomer vendor was like this! He clearly knows his stuff and is happy to share his experience and skills with others.

In use – during the day it is incredibly easy to take a spectrum of any light – just point it at it. For the sun you point out the window at any part of the sky (just avoid the sun) and a lovely solar spectrum appears of your computer. At night, my first try disobeyed all the instructions in the manual -I used my Sky Watcher Pro 80mm scope on Manfrotto alt-az mount and hand guided for 30 second exposures of Vega and a couple of other stars. I also took a spectrum of the Moon and Mars – shorter exposures and equally as easy. It does not matter if the star slips on and off the slit – all you need is enough light collected and a spectrum appears as if by magic! I am sure it will work a lot better on my EQ6 tracking or guided and with my Sky Watcher Pro 120mm which is a proper match of F7.5 for the spectrometer but even with the wrong kit spectrums just kept appearing and lines matched up with those on sample spectrums off the internet – amazing! I am not used to stuff working first time when I use it – and straight out of the box. Dr Elliott needs to be thanked for achieving this, as some other spectrometers are not like this.

A word on hand guiding – a spectrum appears when the star is on the slit, so you know it has dropped off the slit in the eyepiece when the spectrum turns into a round star, so I just moved the star back on to the slit then.

The spectrometer can use any combination of cameras and a range of software. However, it comes with propriety software called PCSpectra which works well and is covered extensively in the manual. If you buy the QHY6 camera at the same time as I did then Dr Elliott will calibrate it for you – and even (as I have proven) help sort out the mess you make when you don’t realise the camera should not be taken off again and take it off to take a peak inside! We’ve had calibration files going back and fore like yoyos and all I can say is he has been a marvel putting up with the mess I’ve created...But then my history with astronomy equipment is a bit of a legend in our astro club.

Dr Elliott recommends using Nebulosity 4 to capture the FITS images – certainly they integrate well with the QHY6 and PCSpectra and purchasing Nebulosity helps to keep the system working “out of the box” so I would recommend it to an y purchaser.

I have posted images of spectra and my experiences of using the spectrometer at https://roslistonastronomy.uk/category/spectroscopy/ccdspec-spectroscope

This is such a great piece of kit – and British made – that it is a shame that this is the last one available. I hope that there will be so many folks wanting to buy it that either Dr Elliott will make some more or someone will take up the mantle and continue to provide a UK-built spectrometer for UK astronomers – one that works just as intended and works for novices but is also a serious instrument capable of serious spectrometry work for advanced astronomers.

I don’t have any personal relationship to Dr Elliott or anything to gain from this review – I think I met him once at Astrofest……

[Merlin66]

Welcome to the exciting world of spectroscopy!

Sounds like you're off to a good start.

You might want to consider using other pre-processing software like BASS Project or VSpec. These packages contain some comparison spectra which can be used to produce an Instrument response curve and subsequent corrections to your spectra.

Onwards and Upwards

 

[andrew s]

Yes, welcome to the fascinating realm that is spectroscopy. The key to the Universe ?

Regards Andrew

[robin_astro]

On 28/07/2018 at 22:15, athornett said:

This differs from the ALPY-600 spectrograph which costs around £2000 by the time you purchase the guiding module as well as the spectrometer and connectors. This one was only a fraction of that cost.

I think to be fair it should be pointed out  that the ALPY 600 spectrograph is actually ~1400ukp for the equivalent core and guiding module which is similar to the price of the CCDSpec when it was launched, though it may now be discounted.  

Robin

[Demonperformer]

Checked Peak2Valley website and the CCDSPEC is also discontinued. 

[Merlin66]

There’s not too many commercial spectrograph available.

The sole suppliers are Shelyak in France and Baader in Germany. All the others have fallen by the wayside.....such is life.

 

[AKB]

1 hour ago, Merlin66 said:

The sole suppliers are Shelyak in France and Baader in Germany. All the others have fallen by the wayside....

I really know very little about spectroscopy, but had been looking at this:

https://www.firstlightoptics.com/starlight-xpress-accessories/starlight-xpress-spectrograph-with-built-in-lodestar-x2-guide-camera.html

Does that not count?

[Merlin66]

Possibly.....

we’re still waiting on any current user feedback on performance.......

[robin_astro]

2 hours ago, Demonperformer said:

Checked Peak2Valley website and the CCDSPEC is also discontinued. 

Yep and the website has been abandoned. 

http://www.elliott-instruments.co.uk/

The patent application is also out of time

http://www.ipo.gov.uk/p-ipsum/Case/ApplicationNumber/GB1120579.6

(To prevent the possibility of a whole raft of existing spectrograph designs being outlawed, I submitted a comment pointing out Prior Art, though  I doubt it would have got through any way)

Robin

[robin_astro]

On 28/07/2018 at 22:15, athornett said:

I hope that .......   someone will take up the mantle and continue to provide a UK-built spectrometer for UK astronomers

There is the Star Analyser of course, and the grisms at the heart the ALPY (and the CCDSpec) are also made in the UK

Robin

[athornett]

Thanks folks for all your comments.

I have had an interesting issue with interlacing on the QHY6 camera attached to the CCDSPEC - although I think I may now have sorted the problem.

Photos and details at:

https://roslistonastronomy.uk/issue-with-interlacing-on-fits-images-taken-in-nebulosity-4-with-qhy6-camera-on-ccdspec-spectrometer

Following on from analysis at the link above, which suggests that the interlacing occurs in association with oversaturation of the camera chip, I carried out some test shots to look at the effect of overexposure on the quality of the spectra produced, which suggested that over-exposure was potentially more dangerous that slight under-exposure:

https://roslistonastronomy.uk/effect-of-altering-exposure-on-spectra-of-daylight-and-compact-flourescent-bulb-1-8-2018

Andy

[athornett]

I would also like to ask other members what they use to calibrate their spectrographs.

In my study I have some compact fluorescent bulbs on a stand for lighting the room - I found this on Wikipedia and so far have used this for calibration - is this adequate or do I need something else?

https://roslistonastronomy.uk/spectrum-of-fluorescent-light-to-use-for-calibration-of-spectrometers

Here are more photos of the CCDSPEC spectrometer:

https://roslistonastronomy.uk/photos-of-my-ccdspec-spectrometer

My first astronomical spectra:

Vega: https://roslistonastronomy.uk/spectrum-of-vega-using-cccspec

Couple unknown stars in Cassiopeia: https://roslistonastronomy.uk/spectra-of-two-stars-in-cassiopeia-with-ccdspec

Mars and Moon (turned out to be same as sun but there you are!): https://roslistonastronomy.uk/spectrum-of-mars-using-ccdspec

I am really quite excited by this aspect of our hobby!

Andy

[robin_astro]

Hi Andy,

The RELCO lamp starter as discovered by Swiss amateur Richard Walker and used in the Shelyak and starlight Xpress instruments is commonly used.  See here for example

Cheers

Robin

Edited August 2, 2018 by robin_astro

[robin_astro]

28 minutes ago, athornett said:

 

Mars and Moon (turned out to be same as sun but there you are!): https://roslistonastronomy.uk/spectrum-of-mars-using-ccdspec

They are similar as we are seeing reflected sunlight but not identical as the planet superimposes its own spectral features. These are subtle for the rocky planets (mainly a change in overall shape (eg the lunar spectrum is less blue than the sun) but the gas giants show clear bands from Methane for example. eg as here

Cheers

Robin

Edited August 2, 2018 by robin_astro

[robin_astro]

1 hour ago, robin_astro said:

Hi Andy,

The RELCO lamp starter as discovered by Swiss amateur Richard Walker and used in the Shelyak and starlight Xpress instruments is commonly used. 

Alternatively you can use a star with known lines to make an approximate wavelength calibration (eg using the Balmer lines in your Vega spectrum) provided your spectrograph is stable enough (ie the lines do not move significantly due to flexure as you move between targets)

Robin

[robin_astro]

1 hour ago, athornett said:

Couple unknown stars in Cassiopeia: https://roslistonastronomy.uk/spectra-of-two-stars-in-cassiopeia-with-ccdspec

Star I looks like an A class star like Vega. The Balmer absorption lines are very clear in the image but don't seem to have come out very well in the profile. I suspect your software is not doing a good job for some reason. (The dip you identified is probably  H beta at 4861A)

Star II is much more interesting. Note the bright spot at the red end. This looks like Hydrogen alpha emission. This is seen in various types of interesting stars, for example among others, Be stars and Novae.   Is their any chance you can identify it's location ?

Robin

[robin_astro]

19 minutes ago, robin_astro said:

Star II is much more interesting. Note the bright spot at the red end. This looks like Hydrogen alpha emission. This is seen in various types of interesting stars, for example among others, Be stars and Novae.   

I made a quick analysis of your spectrum images for star I and II on your blog using Visual Spec

Note how the H alpha and H beta emission lines in star II (in pink) line up with the absorption lines in star I (in blue)

If they were bright stars in Cassiopeia, I suspect star II is Gamma Cas a well known Be star. The other star might be Delta Cas.  

Interestingly these were two targets I used on a Sky at Night programme back in 2005, taken with a prototype of the Star Analyser

http://www.threehillsobservatory.co.uk/astro/spectra_12.htm

[athornett]

Hi Robin,

Thanks for all your replies. I have been carefully looking through what you've said. I apologize for not having responded for last couple weeks but been away on holiday.

Unfortunately, I can't positively say which 2 stars they were in Cassiopeia as I just pointed the scope manually at them and manually guided.

My "observatory" is a log cabin and I bring my scopes out on to the grass. So, not permanently set up. So far, only tried aligning EQ6 once without success because I made the mistake of trying to do so using the guiding eyepiece on the CCDSPEC for the purpose and of course that uses highly polished mirror so you can only see very bright stars and it also has small field of view.

So next time I will try adding 2nd refractor to top of Sky Watcher Equinox Pro 120mm (I have spare ST80 hanging around in shed somewhere and some rings!)

Thanks for your efforts trying to identify those two stars - just goes to show how much information can come out of a "simple" spectrum - did a demonstration at my astro club (www.roslistonastronomy.uk) on Friday night and got lot of wows just pointing it at the lights in the room.......

Re neon lamp circuit with RELCO starter - do you have a circuit diagram I could use? I went to the neon lamp thread you linked to - the main article listed there on a German website appears not to be available any more - I believe that was the one with circuit diagram

Andy

 

 

[robin_astro]

47 minutes ago, athornett said:

Re neon lamp circuit with RELCO starter - do you have a circuit diagram I could use? I went to the neon lamp thread you linked to - the main article listed there on a German website appears not to be available any more - I believe that was the one with circuit diagram

Ah yes Richard Walker has updated the document since then and the link address has changed. ( Despite his English sounding name he is actually Swiss)  Here is the latest version 

http://www.ursusmajor.ch/downloads/sques-relco-sc480-calibration-lines-5.0.pdf

from this page

ttp://www.ursusmajor.ch/astrospektroskopie/richard-walkers-page/

There he uses mains power so is a bit risky out in the field so I used the flash circuit from an old disposable camera as devised by an Italian amateur

http://www.marcellocucchi.altervista.org/html/neonlamp.html

You can use a neon indicator lamp instead but unlike the relco starter spectrum which is a mix of several gasses (mainly  neon and argon), neon does not have any lines at the blue end.  The lines which would be best  for your spectrograph are shown in the spectrum on page 22 (DADOS 200l/mm)

It is not bright enough to use in front of the telescope aperture so I injected the light via a flip mirror before the spectrograph, mounted the wrong way round.  (This was before Shelyak brought out the calibration module for the ALPY.)

 The ALPY calibration module also has a flat lamp. It might even be possible to adapt it for use with your spectrograph. 

Cheers

Robin

Edited August 27, 2018 by robin_astro
added ref to spectrum

[robin_astro]

49 minutes ago, athornett said:

Thanks for your efforts trying to identify those two stars - just goes to show how much information can come out of a "simple" spectrum - did a demonstration at my astro club (www.roslistonastronomy.uk) on Friday night and got lot of wows just pointing it at the lights in the room.......

Yes, when I am giving talks on spectroscopy I use artificial stars. (A box with pinholes in front of 3 hidden lamps Tungsten incandescent, Compact Fluorescent and warm white LED.  The pinpoint light sources all look like stars of with same colour but when you look at them through a grating they have very obviously different spectra, just as real stars do.

Cheers

Robin

[athornett]

I have purchased RELCO lamp starter to make a neon calibration light.....however it appears I can only buy them in 25's! So I have a lot of spare ones - is any one interested in buying any off me at cost price?

Andy

[robin_astro]

Hi Andy,

Probably worth hanging on to a few.  There is some variability in how well they perform and they dont last so long unless used in a more sophisticated current controlled circuit with a particular DC polarity that Shelyak use for example . 

http://www.spectro-aras.com/forum/viewtopic.php?f=8&t=606#p2392

Shelyak supply selected ones as  spares for their spectrographs but at 30 euro for 3 your 25 probably still worked out cheaper.

https://www.shelyak.com/produit/se0148-argon-neon-spare-bulbs/?lang=en

Robin

[robin_astro]

More info from Marcello Cucchi on how to drive the RELCO using the photo flash circuit here on astronomical-spectroscopy

https://groups.yahoo.com/neo/groups/astronomical_spectroscopy/conversations/topics/7811

and some hints and tips from Francois Cochard of Shelyak in this thread on spectro-l

https://groups.yahoo.com/neo/groups/spectro-l/conversations/topics/14084

Robin

[athornett]

I have started to make my RELCO starter based calibration light - my first version is driven by 240V through inverter in field. At our Astro club, earlier in the year one of our members (Ed) made some fantastic leisure battery based battery packs for us and hence we have access to ready supply of low amp 250V in field.

click on link below to view photos of this first stage of RELCO fluorescent starter calibration light:

https://roslistonastronomy.uk/modifying-relco-fluorescent-light-starter-to-create-neon-calibration-light-for-spectrometry

Next step is to house it all in something safe to stop getting electrocuted when used outside!

I also intend to use a circuit breaker in line with the plug.

NB I am not a qualified electrician so if anyone follows in my footsteps please ensure you are qualified to do the job or ask someone who is to do it for you.

Andy

[Merlin66]

Many of the amateur spectroscopists use both the Neon and Relco reference lamps. No major issues, no drama.