Astrophotography – equipment

Sun in a new Light – Cak

Using recently acquired skywatcher ST102 refractor, see above with collapsible dark box and shroud.  Along with a Baader CaK double stacked filter 390 – 398 nm covering both CaK 393.7 nm and CaH 396.85 nm I managed to image the sun in Ca k.

The filter was attached to a DMK41 mono CCD camera with a x0.5 focal reducer to enable whole disc imaging.


The CaK filter needs an energy rejection system to be used on scope, it comes packaged with 3.8 OD Baader film, but a Herschel wedge can also be used.

Other CaK systems like those available from Lunt contain both Cak filter and energy rejection system, hence the cost.

I missed the early morning activity recorded by Nick and Roger and by this afternoon there was little prominence activity according to Gong, so I just concentrated on Sunspot AR2670, imaging using CaK filter and the Baader 590nm Contiuum filter.

Whole disk in White light, continuum filter.

Whole disk in CaK, showing Plages

Colourised CaK whole disk.


Left white light image without x0.5 focal reducer.

Centre CaK without focal reducer.



Below colorised Cak



















With x2 Barlow (below), smaller image white light. Trying to dodge between clouds meant that the sun was getting lower during the session and subsequently I was imaging over my neighbours roof and the garage roof, started to get lots of atmospheric wobble. However I was reasonably pleased that different detail could be imaged with the CaK filter, couldn’t take H alpha (656.78nm) at same time as I’d used the vixen rail I normally attach it to, to mount the ST102 on the HEQ5. Compare the rese CaK images with Rogers H alpha.

The white light image shows what is happening on surface of suns photosphere, the observeable surface at 5500k, H alpha shows what  is happening in the chromosphere, the layer above the photosphere where the temperature rises to 50000K at its upper level. CaK images show what is occurring between the upper photosphere and lower chromosphere.

At 393.37 nm CaK is not visible to eye , in fact there is a lot of UV being passed, not good for the eyes, so this filter is for imaging purposes only.

Future activity will compare Herschel wedge / Baader film combinations with CaK filter and comparison with H alpha images from Coronado PST.

Pete H

Nice All Sky Camera timelapse

Hi Folks,

Here’s a nice little timelapse from a few days ago, edited using a free bit of software for windows called Shotcut ( It’s a bit like Windows Media player and VLC player but it allows you to export a speeded up video, which is very handy

This one is effectively running at 60fps and was a timelapse recorded on my All Sky Camera with iSpy recording at 1 frame per minute over about 6 hours, although, I’ve cropped this much shorter as it was getting light

It’s quite nice as you can see the Plough moving down the screen, and the after about 20 seconds you’ll see Cassiopeia coming in at the top right near the tree . You can also faintly see the Milky Way moving down the screen after that.

I think for a cheap DIY camera it’s not bad

Ed Mann

07802 350187

A Challenge to the Quarkers out there – – –

To quote Holmes: “When you have eliminated the impossible, whatever remains, however improbable, must be the truth”

I have been musing over my recent post concerning the apparent lack of fine detail on my solar images ( While they are comparable with other LS35 images I have seen, and with GONG images, they do lack the fine detail you sometimes see in other published images. I am not 100% convinced it isn’t a stacking artifact, but setting this aside what else could it be?

Daytime observing suffers from atmospheric turbulence big-time, and you need a fast shutter speed to reduce this. I wonder if I simply have not got the sensitivity to employ an appropriately fast speed.

Simple optics would inform me that a Quark with an 80mm scope has the potential of being at least 2 stops faster than my LS35, everything else being equal.

So, the challenge to the Quarkers – I know that there are at least 3 of you out there, and one of them at least (mentioning no names, Andy), has a Mikrokular, the same as I use:

Can you get finer detail than I get using a fast shutter speed? Simple stacking is likely not to help, as the images you stack will be slightly displaced due to the turbulence, thus blurring the final stack.



NASA salute A.S.B.O successful installation with flypast!

NEWS FLASH – Wednesday 24th May 2017

NASA scientists can be seen here celebrating the success of their latest endeavour…

It was all systems ‘GO’ at A.S.B.O Headquarters last night as final checks took place for this historic event:

The site was deemed clear for operations around 9pm

Due to cables on-site, all Perimeters were secured from any invading – ‘Andrews!’ > CHECK!

Comms > CHECK!

Visuals > CHECK!

Data storage > CHECK!

At 00.58am BST, A.S.B.O picked up the link and the NASA ‘flypast’ commenced……. the ISS (plus some stray plane getting in on the action – possibly the RAG Chair flying back from ESA) !

Pass took over two minutes, the movie is speeded up x4

The ISS passed through Bootes (Arcturus to the left) and headed through Hercules and just north of Vega in Lyra before comms cut-off.

With thanks to Heavens-Above, below !

Damian ( a pyjama clad ‘Operations Director’ at A.S.B.O)

All Sky Camera Workshop

A massive thanks to Ed Mann for his RAG ‘All Sky Camera Workshop’ run on Saturday 13th May.

The amount of work he’d put into this event was incredible – what started as a load of bits at 10am turned into a working unit by the time we finished….. around 3pm – still in Saturday!

We left with a set of printed instructions, tips and tricks, and now need to explore just what can be achieved with the software and unit…



I wonder what happens when I do… this!


Bags… of Bits!


Ed’s view of the proceedings – his ‘class’ 😉


The build in progress…


Unit complete!


It’s…. ‘ALIVE’!

Archive Resources

A question arose last night concerning the PD (Phil Dyer) camera that I use. I suspect that not many of our newer members realise that there is a vast resource of data, images, hints and tips, accessories etc etc (including the PD camera) archived in the “old” web-site that you can access using the link at the top of this page. I would urge members to have many happy hours browsing there!

Observing log:2/Jan/2017

Hi, all the forecasts said clear, the satellite pictures concurred, all the visitors had gone time to get out into the winter sky.

Set 9.25 Celestron SCT up on HEQ5 pro, aligned N, levelled and balanced early and waited for dark. Venus, moon and mars showed above the roof and a quick look at venus with 70mm celestron refractor showed beginning of crescent phase, looked with Binoculars for Comet 45P, but too low in relation to surrounding houses, will need to go further afield.

Powered up mount at 7:45 pm, attached Telrad and carried out 3 star alignment and went in search of some Messier favourites before reacquainting myself with the PD camera. M42 showed up nicely as did M31, M33 however did not show up, even with averted vision. M81 , M82 but not as bright as seen on other occasions, still somewhat low, noticeable also that could not get in to same field of view as possible with 8″ Newtonian, this highlighted the smaller field of view produced by the SCT ( focal length 2.35m), which had already made carrying out alignment, even with Telrad and 9×50 celestron right angled finder, a bit trying!

Then disaster, probably due to “finger trouble” and getting use to the SCT, handset managed to reset , this required another alignment set up, which having completed I then managed to rest again!!!, anyway, got going again, M1 showed as a very faint fuzz, back to M42 as I intended to try out PD camera with the SCT tonight.

Tonight was also the first real “test” of my “power box”, large plastic box with lid (weather-proof), with 3 x 12v cigar lighter plugs and internal 300W inverter, connected to 55AH leisure battery with clip on connectors. The inverter runs the laptop and the 12 v outlets ran Dew heater on Dew shield on SCT, power for PD camera and the 12V hairdryer when required on a couple of occasions to demist the Telrad.

Once reacquainted with PD camera, had a go at imaging M42, by this time 10:30 pm the camera showed definite atmospheric turbulence, very difficult to focus even using Bahtinov mask, looking around sky , there was a lot of “twinkling” stars! Using the sense up setting at x32 was the best compromise any higher image was far too bright and blew out all detail. The final image below was produced from a 20 sec .avi video , staked in Autostakkert, wavelets in Registax 6,final tweaking in Photoshop.6m42x32As always it’s bit of a compromise trying to get the detail in the nebulosity, vs the brightness of the stars. Even visually I couldn’t resolve any more than 4 of the trapezium stars. Now 11pm, the unstable conditions did not bode well in trying to pull out any other images, so time to pack up, made myself popular laying everything out on dining room table to defrost and dry out!!

Having previously used the SCT for imaging / viewing Jupiter, the advantage of adding a x.63 focal reducer when viewing deep sky objects has become obvious, as it will increase the field of view, making location easier and include more of the target, the smaller field of view being more appropriate for planetary imaging. The “power box” worked well and the battery had recharged by lunchtime today (on 2A trickle charge).

Meteor counts have been low over the first two days of January, a peek at the log showed a marked increase for today ( 3rd Jan), the Quadrantid peak is at 14:00 UT today , peak is not spread out as Earth enters stream at right angles, passing through quickly, so if you didn’t see any in the early hours this morning (thro’ the cloud)  you will have unfortunately missed it!



Pete Hill