SteveBz

OK. Got GIMP 2.9.5, quite easy to install.

I'm torn then between getting this from China for £65, which I guess will do the job:

http://www.ebay.co.uk/itm/50mm-Guide-Scope-Finderscope-CCD-Image-Bracket-1-25-Helical-Focuser-Astronomy-/172274032837?hash=item281c5520c5:g:q-gAAOSwbYZXVjtn

And a cheap old scope off ebay or somewhere.  Maybe I should do both.  Buy the cheap scope quickly locally, try it out, and then, if I need to, go for the proper guide-scope from China. 

The nice thing is that an old frac could also be used as a grab and go.

For me, my light pollution is not SO bad, that I need monochrome cams and narrow-band filters.  I have a friend who lives near the local Cinema complex who has 974 street lights within 500 metres of his house and he can only do astrophotography with monochrome cams and Ha, OIII filters and whatever the green one is and recombine after stacking. 

Steve.

Here is the plugin:

http://hennigbuam.de/georg/gimp.html

I don't think it's maintained, but I might have another cracking at compiling it. I'll also look at gimp 2.9.

Steve

Actually, I think that's the dss stacking. Gimp doesn't produce those jitters, it's just time consuming.

Both pictures are about 45 secs to one minute.

Hi Bob,

Thanks for your reply.  The info about focal lengths is interesting.  Really, I think you're saying if I don't have a sensitive camera, then go for a short focal length.  It's a good point.  Yes I use DSS and GIMP too, both have their problems.  Have you managed to get the astro-exension to GIMP installed?  If so I'd be pleased to hear how.  So far it has resisted all my attempst!!

Here is a single unprocessed picture of the Flame Nebula, the only thing I've done is to convert from raw to .png.  No match for yours:

Here is a fully processed picture of the Orion Nebula, about 8 images cleaned for noise and manually stacked with GIMP:

The noise levels is not as bad as some, but I feel UHC filters and guiding is the way forwards.

Tell me what you think.

Regards

Steve.

Really excellent project.  I'm trying to do a similar job, but I'm struggling with the cost of the guidescopes.  I've decided to buy any old frac from ebay as long as it's less than a tenner.

What are your skies like? Once I go over about two minutes, my photos are all washed out by light pollution.  I'm probably going to have to use filters.  Any thoughts?

Regards

Steve.

2 hours ago, Robd said:

If you intend using arduino based do as I did, I based mine on TekkyDave's, elsewhere on here.

I added functions to PC and arduino code to allow setting of backlash compensation. This is then applied within the arduino logic every time movement direction is changed. I think I ended up with a 100 step correction. 

Oh, wow.  Does it not matter however bad the backlash is?  You just put in a correcting factor?  I've seen TekkyDave's thread before.  I'll look it up.  I just recall it being very ... very ... longggggg.

Amazing.  I'll look it up

Regards

Steve. 

4 hours ago, Davey-T said:

Most commercial motor focusers have a backlash setting that you can set.

Dave

It has a screw you can tighten, but it just stiffens the whole mechanism and doesn't wholely cure it.

It seems to me I need to go down one of those astronomy-shed style solutions: ie take it apart and re-line it with PTFE.

I don't really want to do that and I wondered if you guys have done this?

Regards

Steve.

Hi Guys,

I've been watching this thread with great interest.  I have an Arduino "Goto" for want of a better word and I was thinking of adding a focusser based on this thread to my set up.  So I do have a SkyWatcher focuser attached to a celestron C8-N with a belt and a sort of home-made coupling.  It could be better but it works fine.  My main issue is the slack/wobble in my focusser.  I imagine all new telescopes start with some slack and you find a way of removing it, otherwise automating it with an Arduino is a bit superfluous.  How have you managed to deal with the slack?

Regards

Steve.

Hi Magnus,

What a simply fantastic setup you have.

How have you automated getting flats and biases?  Do you just close the observatory lid and film?

Do you know roughly how much it cost excluding optical equipment? It seems I probably need to sell the house to fund something like this.

Regards,

Steve

2 hours ago, Gina said:

I've only used stepper motors.

Do you mean you haven't converted an existing electric focuser, you've built it from scratch?

I've just done the ST4 connection to my Enhanced Dual Drive with an Arduino using a project from Hackaday (https://hackaday.io/project/4386-arduino-st4-telescope-control). 

It works just by by-passing the buttons on the handset (ie the Arduino shorts the contacts on the button thus "pressing" them).  The LEDs are direction indicators.  Could focusing not work the same way?  Just by-pass the buttons, then you don't need any additional circuitry at all.  As there are still several pins unused on my Arduino nano, I thought I'd try the same thing on my focuser handset, drill a hole, insert grommet and cable, solder to contacts, add arduino.  Then it would be a combined focuser and navigation system.  Eventually adding other electrics like the dew-heater controller, fans, etc. onto a dashboard on my PC.

Oh, whoops, wrong thread.  Too many tabs open!!

1 minute ago, cjdawson said:

might even be a driver thing!

I was hoping so.  I use Linux, so with any luck I can probably hack into the driver and modify.  There might even be a flag to switch it on and off.  There is a user group dedicated to linux drivers, so I'll post there.

Regards

Steve

12 hours ago, cjdawson said:

All that I'm saying here is to manage your expectations as to what to expect from a real time view from a camera.   If you throw enough money at the problem, I'm sure you can get a great image in real time.  However most budgets, means that you'll be extended your exposure time.   That's all.

Hi CJ,

My budget is meagre in the extreme.  Really I want people to pay me to take stuff off their hands!!

I did however buy (as I may have mentioned earlier) a Bosma TCE-200 CCD 2MP Camera for £20 off eBay.  However, it has automatic brightness control and noise reduction, both of which get in the way of viewing DSOs.  I'm trying to get into the low-level electronics and control of it all, because I'm fairly sure that with the right intervention I can turn off these features and make it a more useful tool.

Regards,

Steve.

9 minutes ago, Waldemar said:

It all depends on your expectations... A dedicated modern video camera for astro use is far more sensitive than our eyes, but costs alot. Maybe you are looking for very hightech equipment like this: http://nightvisioncameras.com/ ?

Whoops forgot to quote:

Nice. Do you have any of these?

So i could use an Astro scope for Canon age intensifier?

It doesn't mention prices, do you know how much they cost?

Steve

Nice. Do you have any of these?

So Soi could use an Astro scope for Canon age intensifier?

It doesn't mention prices, do you know how much they cost?

Steve

I

1 hour ago, cjdawson said:

The root issue here is that objects in the night sky are dim.  Most cameras are designed to work in daylight, so the exposure times that work are are a fraction of what is needed to be able to clearly see night objects.   You can get cameras that are very sensitive compared to about 20 years ago.  However if you take a look at the threads of people capturing images, you will quickly see that the exposure times they are talking about for a single frame is around 2-10 minutes depending on settings.  Then you'll also notice that the same people are talking about that single image being part of a set of 20-100 images.    This can mean that for a single photo, there will be something in the region of 60 mins or more exposure time on the object.    This simple won't happen in real time.

 

that said, if you are only looking to see feint fuzzy blobs, it can be done with exposures of 10 seconds or less.

Hi CJ,

So are you saying that no camera can see live what you can see through the eyepiece?

Regards

Steve

19 hours ago, wuthton said:

The slight wrinkle here is that much like when using eyepieces if you want to change your field of view (magnification) you need to use a different camera and/or telescope.

You're right. so it seems if I want a 4mm or 6mm. Ie a lens for planets, then I can use a planet cam. If I want 20mm for deep space, then I need another one, but if I want to see for instance the ring nebula with the same 4mm, the planet cam can no longer see it.

Regards

Steve.

On 09/28/2016 at 19:33, Waldemar said:

Or use ep projection, preferably with a zoom eyepiece. The Baader Hyperion zoom is really well suited for that. 

Many 'electronic eyepieces' are available...

Waldemar

The issue is that many electronic eyepieces are really just planet cams.  I bought a cheap one on ebay and it can only see seethe brightest stars. The others get cancelled as noise.

Hi Mark,

Thanks for that, so if I get a DSLR (any DSLR?), as long as I have the right software I can use it do see pretty much what I would see through my eyepiece?

Nice.  Presumably I'd need some sort of connector too. 

Thanks and regards

Steve.

Hi Guys,

I'm sure this must have been asked dozens of times, I just couldn't find the relevant thread(s).

Is there a camera out there that will allow me to look through the telescope or finder as if looking through an eyepiece.  The main options seem to be planetary cams which pick up bright objects but not faint ones, or DSLRs which require long exposure and passing through Registax.

I'd like a relatively economical camera that I can strap to my focusser and sit elsewhere to look through the telescope. 

Maybe I'd use something like EQMOD and a game console to steer the scope.

I don't really want to experiment with a whole list of £100 plus cams to find the right one.

Thanks in advance.

Regards

Steve.

4 hours ago, jambouk said:

It won't matter if the mount isn't level. I was going to say "roughly level" will be good enough, but that isn't even true, you could have the one leg 10cm fully longer or shorter than the others and have the mount cockeyed, but as long as your polar alignment is good (and that will is achieved independently of how level or not your mount is) you'll be tracking fine. And if you are using GOTO then the star alignment process compensates for any wonkyness.

So I would save yourself the hassle of trying to get this perfect. You'd be far better stripping the mount and cleaning the innards and greasing them nicely.

James

 

So should I fill in the hole? Or expand it and use it for something else, like a socket for a dew heater?  I'm distracted by the fact that it is there and not working.

I've already stripped the mount, wetndry'd the worm gear and regreased it.  It's taken several weeks, and because that now works so beautifully I can't bear other bits not to work equally well.

Any suggestions for it's new use gratefully received.

Steve.

1 hour ago, SteveBz said:

PS I'm gonna go and pull off the rubber bit and see what I find.  Report back later.

Ok. This is what I found, a nice rubber bung, an old bubble level and some bits of expanded polystyrene :

I got a small tap washer, drilled it and used it to replace the expanded polystyrene like this:

It's better than before but not perfect.

I'll try again later, but the bottom line is that I think it's fixable.  If I improve it sny more I'll say so.

Thanks all.

Regards

Steve.

6 minutes ago, wuthton said:

Level by eye is more than accurate enough, even if you're only wearing one shoe. 

Nice post.  I still have an unhealthy attachment to my cg5.  I've nursed it back from the edge of the wheelie bin (see my other posts) and I don't want it to walk with a limp if it doesn't need to.

It's just me being obstinate not that there is any real need to fix this.

Thanks for your post.

Steve.

P's I'm gonna go and pull off the rubber bit and see what I find.  Report back later.