Stub Mandrel

Is it any less meaningful than having a 'boarding pass' and my name burnt into a memory card that's being sent to Mars?

Probably not, although Mars ticket was free I had to print it out myself.

On 04/12/2018 at 08:38, fwm891 said:

Managed to get a short run with the Lodestar installed last night (need to look at SharpCap settings!), anyway sequence of 50 frames shot with a gap of 4 secs between frames.

I've stacked the first and last frames in Photoshop CS3 with an image of M1 to approx. same scale (not my image). The arrow shows the drift in 4 mins 7 sec (from timestamp). Drift is mainly due to poor north alignment. I made no adjustments later when viewing M1 at x62 (1250 fl with 20mm ep) for 5 mins.

So need to sort the north alignment and fine tune the tracking speed (Oh and remember to re-set the platform when it ends a run... ?)

This is definitely in my long-term plan list!

13 hours ago, aatdalton said:

I was wondering what options people have used most successfully to mount a guidescope?

I got some aluminium U-channel, fitted to the top of the rings at each end using 3D-printed adaptor blocks, held ina 3D printed bracket so very similar to @Susaron's approach.

The Redcat is a Petzval lens.

Some frantic googling suggests that the design lacks a flat field, whioch can be corrected with a field flattener, at the expense of introducing coma.

As the Redcat is marketed as being flat full frame, perhaps some  residual coma is an inevitable consequence of the design?

This is a 'pixel peep' of the bottom right corner of one of the (stunning) example Redcat images on the Williams Optics website. The coma looks worse than some examples above...

The ASI294 looks good... but not available as mono!

2 hours ago, Rusted said:

At the risk of starting an endless argument:

Modern piping is often plastic. Rural homes are almost certainly fed by miles of plastic hose.
Connecting the indoor metal pipes, if any, as an earth, will be lethal and based on a lack of basic electrical knowledge.

Discussions on forums, which have US members, suggests that the rules for earthing are as varied as the soils on which the building stands.
I claim absolutely zero knowledge and nobody should ever follow anything suggested on a forum.
Your "expert" advisor might be a trolling, psychopathic, serial killer!

ALWAYS seek EXPERT advice from a local, fully qualified electrician with experience of your local conditions.

Your having moved on from your own installation leaves those who follow on in a very precarious position.
Which through their own ignorance, of what they only think they should trust, might easily kill them.
This doesn't even begin to deal with the matter of lightning and adding extra earthing rods to an existing electrical system.

We had a professional survey done of our electrics.

He said the best bit was my workshop, which I wired up myself - ring main, spur lighting + spur for the heater, all off a dedicated distribution box with RCB.

This is the camera that tempts me, but it is quite a lot smaller than a DSLR sensor.

I would like the ASI1600 sized sensor - as that is the biggest that works with 1.25" filters and I already have a filter wheel and filters (but not narrowband ones) for planetary. But it is even more expensive and there are horror stories of strange things happening to bright stars.

That said, at £1000 it's still a lot to invest when my biggest purchase so far has been a secondhand HEQ5 at a third of that.

Nice one.

You do realise the lifetime cost of starting astrophotography at age 10...?

On 15/06/2019 at 22:46, AstroFin said:

Very impressed after a glimpse of Jupiter! 😎

Cripes! Does it get over the horizon up there?

2 hours ago, Vangelis said:

And how do you set up the clutch to slip Stub? Just not tighten it too much. But then the scope moves?????

If the scope is balanced, or nearly so, it should be easy to get it tight enough to keep it steady while still allowing you to move it by hand. It is on the HEQ5.

2 hours ago, Vangelis said:

Does anyone know if, other than killing the power, there is a way to stop the mount slewing incase it is about to hit a tripod leg?? Will you damage the motors if you try and stop it manually?

Not if you have the clutch set so it will slip if you stall it. That's why they have clutches, not locks.

On 15/06/2019 at 19:23, cloudsweeper said:

Nice acquisition, John!  I also feel my collection is now complete with the recent 20mm 100 deg Myriad - total now is 20 EPs (3 to 42mm; 50 to 100deg AFOV) - PLUS an 8-24mm zoom and a x2 ED Barlow.  All 2" or with an adaptor, and the adaptors are all protected by the bottoms of Aldi Luxury Desserts pots!

Doug.

As used by grey aIiens...

NGC193 is easily found using google!

https://en.wikipedia.org/wiki/NGC_193

Magnitude 13.25

4 hours ago, McPulsar said:

how was the other stars like antares named if they only using numbers? 

It was named before people started numbering stars. Even teh numbering systems are a horrendous mess (IMHO). Take your choice from Wikipedia:

Quote

"α Scorpii (Latinised to Alpha Scorpii) is the star's Bayer designation. Antares has the Flamsteed designation 21 Scorpii, as well as catalogue designations such as HR 6134 in the Bright Star Catalogue and HD 148478 in the Henry Draper Catalogue. As a prominent infrared source, it appears in the Two Micron All-Sky Survey catalogue as 2MASS J16292443-2625549 and the Infrared Astronomical Satellite (IRAS) Sky Survey Atlas catalogue as IRAS 16262-2619. It is also catalogued as a double star WDS J16294-2626 and CCDM J16294-2626. Antares is a variable star and is listed in the General Catalogue of Variable Stars but as a Bayer-designated star it does not have a separate variable star designation.^[16]"

I ran 7 amps through Piers Morgan. It didn't work my mount but it did make me feel better :-)

I've got an old 10D,  it's not very good - low bit depth,. high noise, old fashioned cards etc.

2 minutes ago, JamesF said:

I think the USB2 120MM used an older sensor than that in the USB2 120MC, but as far as I'm aware the USB3 mono model uses the mono version of the sensor in the colour camera.

James

Correct, I've updated my post to make it clearer.

22 minutes ago, JamesF said:

I'm not sure that's a clone, at least for the colour model.  I think the 120MC uses the AR130 sensor.  The pixel size is also wrong the the sensor they claim it has, but perhaps that's just a typo.  Surprising how many vendors are selling the same camera on AliExpress though.  I wonder if they're actually just one of the older Touptek models?

James

The irony is that the Touptek mono and colour have the same sensor as the  original 120MC, but the 120MM has a slightly lesser sensor. [From ZWO's discontinued product section:  Sensor: 1/3″ CMOS AR0130CS(Color) / MT9M034(mono) }

So the mono ZWO is actually slightly less sensitive than the Touptek!

The -S versions of the ASI120 both have an AR0130CS

That said, having used a mono Touptec side by side with the ASI120MC it seems to be less sensitive, but I suspect that is a gain-related issue or in the firmware? I discovered this doing planetary where I was needing longer exposures with the Touptec.

For that budget a Canon 450D or 1100D are a sort of 'step change' better then the 400D and 1000D. If you can find one for your budget the 600D is often praised.

For planetary the ZWOASI120 series are not far beyond you budget and can do small DSPOs like planetary nebulas, distant galaxies and globular clusters.

If it's like the HEQ5 you can only see through the polarscope when the ALT movement is oriented one way.

It's not critical that the zero is at the top, it's only an aid to counting.  Make sure the main cross lines are horizontal and vertical and treat the reticle as if the 0 is at the top..

Not astro... a twin-valve preamp for less than £8(!) https://www.ebay.co.uk/itm/6J1-Valve-Pre-amp-Tube-PreAmplifier-Board-Bass-on-Musical-Fidelity-X10-D-Circuit/152894986169?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Very little gain apparently (about x2) but can be used to add the elusive 'valve sound' to other amplifiers, or as an overdriven front end for guitar amps.

A 3D printed case might be nice 🙂

Yes, I mix and match my HEQ5 and EQ3 counterweights.

+ Film!

All-in-one camera challenge (no DSLRs or astro cameras allowed).

Education Challenge - make an annotated image that explains something astronomical.

Spirit of astronomy - picture that best shows one or more people enjoying the hobby

Lucky shot - a single image that catches an event - meteor, satellite trail, Betelgeuse going supernova etc.

Mercury Transit

Animations - asteroids, jupiters moons, moon phases etc.

Low alt planets - a planetary challenge to encourage long-suffering UK imagers and all of us north of 50n latitude!

Apollo Demi-Centenary - images to mark fifty years.

Tiny DSOs - images no more than ~ 1 mega-pixel (or even smaller) to encourage photographing small planetaries or galaxies etc.

Narrowband DSLR - a challenging challenge!

Urban Image - has to be from a light polluted area, severity of LP to be taken into account.

19 hours ago, Rusted said:

A wheelbarrow and a rake never did me any harm when it came to mixing concrete. 

I  always mix in a wheelbarrow. Less mess and you can move it around easily too 🙂