Stub Mandrel

1 hour ago, Pullock said:

Good call, it's roughly the size of the front ring on my DSLR, won't fit this one but certainly the right size, thanks.

Try one of these, actually I only paid £7 for it!

https://www.ebay.co.uk/itm/18Pcs-Lens-Filter-Ring-Adapter-Step-Up-Down-37-82mm-For-Nikon-Canon-Camera/372681098810?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

I have no idea what the cutter picture means....

23 minutes ago, Pullock said:

I figured that... but don't know of anything that is a 62mm/2.4 inch fit

I had a set of about 17 step up and step down adaptor rings, about £12 off eBay. I should now be able to fit a lost anything to anything.

Wizard Ha combined with OSC from last year:

My 130P-DS inages from last night are here:

I've added a bit of noise reduction in Astra image:

These are two images from last night, both 5-minute subs using my cooled 450D with the 130P-DS and a 7nmn Ha filter. They have been stretched in FITS Liberator and very lightly adjusted in photoshop. This is because they subs were very dark so I wanted to make full use of FITS Liberator's ability to stretch 32-bit data.

The wizard is 30 frames, the Crescent is 22. There's quite visible 'posterisation' if you zoom right in with the faintest areas, so if it's clear again tonight I will repeat the exact sequence with the hope of doubling my subs and doubling the range of pixel values. Very pleased with the lack of noise. Now to dig out my RGB ones and try making LRGB versions.

Good question Alan! I'm in an area that Clear Outside describes as Bortle 5, but I'm pretty sure it's not as good as that, except straight up.

Last night I got good results using 7nm Ha, butI found that even a basic moon and skyglow filter makes a huge difference to my RGB images so I expect it to work well here.

But... I also expect it to make nebulas 'pop' more if used under good skies - my (limited) understanding is they can be used as a luminance layer with rodinary RGB to get a more accurate colour balance.

I've successfully printed the enclosure and now fitted the heatsink to the peltier and fan for a test and it works.

Tomorrow I will photograph all the bits and assemble it, then I have to make lids for the electronics and desiccant chamber (just a box to put silica gel in) then make a carrier to take 1.25" filters to seal the sensor chamber.

I've gone for the Optolong one, it may have a few percent less pass at the peak frequencies, but it's the only one that really explains what it does with examples - and it appears to do what I want!

So the effect of these is a bit like doing Ha, then (sort of) doing OIII using a  wide-band visual filter and combining them, except you do them at the same time?

Still a bit confused... the Optolong, Altair and IDAS NB2 appear to pass HB, Ha and OIII, but the NB3 only passes Ha and OIII?

56 minutes ago, Hertford Stargazer said:

I'm intrigued, although it's an earth as such (I assume) in practice its insulated from the ground when in use by the rubber feet on the tripod so as far as I can see its just linking the tripod to the DC negative.

It's a 'chassis' connection for the purpose of shielding/reducing interference than an 'earth' for the purpose of protection against electrical faults.

But I would say it's pretty pointless

10 hours ago, dyfiastro said:

Managed to get out again last night and try out a few changes. I still need to pull the scope off at some point and do a strip down, flock and re-collimate but I am hoping I work out most of the major issues.
I do not normally image when the moon is up but it was a good chance to get out and test things out.

Borth! Must be great for astro, I used to live in Talybont, a lifetime ago...

Unboxing...

*

I should be grateful; I urgently needed a 10A fuse so ordering yesterday afternoon and getting delivery before 8:00am is impressive. All for £1.62.

But perhaps this would have been better sent in a small padded envelope?

(Still not as impressive as Farnell, they once sent me a single microchip, about 15mm square, in pair of plastic waffles about 30x20cm, inside bubble wrap, inside a box, inside more wrap, inside an outer box about 60cm square - but I suspect this was someone in despatch who was a bit bored!)

Ah. In that case it's probably to help minimise electrical noise, it's not needed for safety with a 12V system. If you get glitching, add an earth wire.

Fuzzed out Skywatcher Logo, how very Blue Peter!

I think the cheapest route for you is to go back to your data, I think you have moved the black point across too aggressively and clipped some fainter nebulosity; but even so my stretch of a screen grab shows there's more data in there. Also worth looking for a gradient removal action/plugin  for your imaging software.

Sorry, can't resist doing a bit more, hope you don't mind and this inspires you to do more processing!

1 hour ago, Hertford Stargazer said:

How important is it that I find a way of replicating that earth on the pillar.

Can't be that important for two reasons:

1   On my HEQ5  Pro the handset sits in a holder on the tripod spreader with no such earth point

and

2   The handset is designed to be use out of the holder and in your hand...

43 minutes ago, Astro_Ben said:

Forgive me if I’m being dim but I don’t see how moving the counterweight 6 inches towards the already heavier side of the rig would make it any better? Never experienced that before, I always have it slightly east heavy but never by a distinct amount. 

It's hard because we don't know the details of each other's setups or the exact amount of any imbalance  but I have found what I would judge to be about a kg of imbalance works best for me. I do track past the meridian because of my situation and if I have too little imbalance the guiding degrades when the counterweight side is higher than the scope side.

Linking to that:

I received a large small pile of electronics components  - resistors and voltage pump IC.

55 minutes ago, Gina said:

I used it yesterday and can offer comments.  Worked fine on grass but ate string on weeds and the so-called heavy duty fixed twin strings wore out in a few seconds.  I've bought a new spool of string but will probably refill spools with loose string in future.  100m of 2mm string costs about the same as a B&D spool of 6m, from Amazon and there are probably cheaper sources.  I did try some unwanted ABS 3D printer filament in 1.75mm size but that didn't work.  I think the "proper" stuff is nylon and a bit more flexible.

I did wonder whether it would be cheaper to use strimmer filament in a 3D printer or vice versa! 🙂

I had another go last night, with a different rig, but I only got four subs.

34 minutes ago, Starwiz said:

At the time of imaging it was at about 30 degrees, so less than perfect but obviously not as bad as the UK.

Luxury! We're having to grab a few frames as it dodges between the  grass tussocks... 🙂

Sorry @FLO but I am not able to untangle the different IDAS filters you sell. Each one seems to claim to be better than all the others.... and not all of them have transmission graphs.

I have Skyglow and 7nm Ha filters. What third filter would you recommend for use with a DSLR? Specifically to tease out more and fainter nebulosity under Bortle 5-ish skies.

OIII?

One of the IDAS nebula filters?

One of the IDAS Light Pollution filters?

It has a big effect, but I always use a moon & skyglow or a Ha filter. When its up I only go for brighter objects.

Tonight its RISES at 11:11 and will be up all night, it set at 10:59 this morning!

So tonight I'm doing Andromeda which is fairly bright and sticking to two-minute subs. Not expecting earth-shattering results as it will have a fair gradient from LP and the moon, but at least its something.

Earlier on I did M25 and Pluto, both low down and would be washed out by light pollution but open clusters (and star like planets) should be OK with shortish exposures