saac

I purchased my Ender 5 round about October last year and I cannot fault it. It's worked straight out of the box without any tweaking and the print quality has been excellent.  It was sourced from Amazon and the price was very competitive. 

Jim 

That is a lovely photography . I love the way it just melts away into the darkness - really moody/soulful. 

Jim 

1 hour ago, Craney said:

... and you would be able to see what is beyond infinity !!!!......

 

more infinity  

Love it , well done. Looks like you all enjoyed that .  

10 hours ago, Davey-T said:

Colonel Tom now 

Dave

He made me laugh today on radio - he replied to a reporter's question on what it felt like to be 100 with "I don't know I have never been 100 before" .   What a guy, modest as ever he said I will always be Cpt Tom, he's having the time of his life.  What an example of life to the full. 

Jim 

On 28/04/2020 at 19:50, Gina said:

WOW!!!  That is some DEEP hole!!

That's exactly what I was thinking - I'd be frightened that something might crawl out of that from the other side  

12 minutes ago, David_Scotland said:

well i basically have mossmorran to the east, with flaring NE to SE, to the south i have the damn pesky lights from the bridges (and glow from Edinburgh) to the west i have my house plus streetlights, so basically i have a narrow corridor roughly NNW to image, off course there is always UP ☝️

 

Thanks for the friendly welcome messages guys and gals, appreciated

I feel for you,  Loch Leven then or the Lomonds as Watcher suggested may work.  For my school sessions I use the foothills of the Lomonds and Kings Barns beach. 

Jim 

On 23/04/2020 at 23:34, Merlin66 said:

Jim,

Promising start....

I'm a little surprised it was a 40 sec exposure, I would have though much less.....

What slit gap were you using? Around 20 micron would be a good start......

Have you checked the focus of the collimator to slit plate?

With a large chip (DSLR?) concentrate on the centre of the FOV, don't worry about the edges (yet!)

Softly, softly....I'm sure you'll have success.

Ken

 

Thanks for the suggestion to recheck the collimator position Ken, I'll have a go at that. Yes I was a bit surprised by the exposure times as well - I was using the narrowest slit position.  I've installed my new lens (fl 100mm) so focus should now be achievable with the spacers I have.  I've also swapped out the focusing screw for a micrometer head - it's a lot smother and in theory will provide better control. Silly question, when attached to the telescope does position of the draw-tube have a role to play on providing focus. I'm guessing it should be set to focus at infinity would that be correct?  From playing around with it today I have a feeling that my focus position is on a knife edge  - quite tricky finding it!

Jim 

3 hours ago, WatcherF said:

Hi David, and welcome.

I'm in Fife too (Leven) and also new to the hobby having just bought my first scope last week.

Once lockdown is lifted a couple of good viewing sites (bases just on online googling) seem to be around Loch Leven and East Lomond.

I'll be checking them out myself so I'll let you know.

HI David I'm another subject of the Kingdom (NE) - as Watcher said above there are plenty of dark sites around us. Having said that you don't really need to travel that far our skies here are generally good unless I guess if your in the middle of one of the towns or in line of sight of  Mosmoran.  Have fun buddy and welcome to the forum.

Jim

Neat solution and well executed, looks solid. 

Jim 

3 minutes ago, andrew s said:

Hi @saac your scope is looking good. I  donhave a spare  Thorlabs 50x25mm echelle grating you can have if your current spectrograph is not up to the job. Mind you you will need to build the rest of it. 😛

Regards Andrew 

Andrew you do realise I would need to make it out of plywood and it would be oversized and overweight by a factor of 10 at least.    I'm really hopeful for the spectroscope coming together , Paul Gerlach's Low Spec  design is brilliant.  I know you work a lot on that area and I really find it fascinating; it offers a potential to come close to some real science in our astronomy.  I did some earlier work with the Star Analyser grating about 2 years ago (DSLR video of Vega using the grating) .  I used RSpec and managed to generate the curve but stopped short at properly calibrating the thing.  I desperately need to retire so that I can spend more time on stuff that really matters  

Jim 

6 hours ago, JonCarleton said:

Ships & Stars::  Off topic...to your avatar.  I am a gyroplane CFI and a good friend of mine flew the gyroplane in that Mad Max movie.  Funny story..he sold gyroplanes in Australia and was approached by the film company to purchase one.  They arrived a few days later with a stuntman and asked him to "tell the stuntman how to fly it."  He replied, "OK...it'll take about 6 weeks to explain properly."  They hired on the spot to fly the shots, because they planned to start shooting that afternoon.

My apology for misdirecting the thread...but then, it is my thread start

 

Jon, back to part of your original question regarding which camera.  I started with a DSLR (Conon 500D in my case). Yes DSLRs have limitations but, and this was important to me, you can use them for general daytime photography. I simply found it hard to justify spending a large sum of money when I was starting out on this on a camera I could only use for a limited application. Given our weather of late that case is still as strong as ever. There are some  fantastic astro software applications available for DSLR use and with Cannon  "Backyard EOS" is amongst the best.  I would say go with DSLR first, and if you get the bug you can work up to a dedicated astro camera while honing your processing skills with the DSLR. 

Jim

4 hours ago, Macavity said:

💡Always thought it might be interesting to try a really LARGE Dobsonian
with a (real time) integrating Video Camera... Watec 910HX etc. You may
not like the idea of using a screen, but iit's multi-user - No need for ladders? 🥳

You could also split the Video stream... to write data to disk for subsequent
stacking - while you are observing & nudging... whatever it is Dob users do! 😛

P.S. I sense the above EEVA will be better on smaller / brighter (surface!)
targets in specific parts of the sky (less motion blurring). It's always good
to image *different* (less popular?) targets... GC's, OCs, PNs... maybe? 😎

That's a good point Chris and something that Andrew had also suggested, in fact he also donated a video camera and monitor as part of the package.  It's  definitely on the list of next steps and it would be well matched to  small group use viewing. 

Jim 

1 hour ago, Ships and Stars said:

Thanks Jim! I'd love to double the number of subs for each of these but the weather has gone quite cloudy for the duration. I think if I add darks flats etc they will be decent, and they are still quite high resolution images, even after a heavy crop. 

I looked at an EQ base, but I think at my/our latitude the whole thing would fall over! I'd have to pour some kind of concrete pier and bolt the base to it or something, but will revisit that idea again after the past few weeks. 

If you have a 16" with tracking or a EQ platform etc and a DSLR, I'd say give it a go. Focus is very important of course, and stability, etc etc. A little practice saw a lot of improvement in my images in a short span of time. 

Although I want an EQ mount an refractor/astro cam now, it's fun to see what a dob can do.

This is our 16 inch Dob,  built as school telescope with a mirror gifted by Andrew S (forum member).  It's a bit heavier than perhaps it needs to be and at F5 it calls for a stepladder but the views are fantastic. It's a sight to behold when I have it in the classroom the kids are mesmerised by it. My long term aim is to try to get some spectra with it to maybe confirm the blue shift  of Andromeda as this would link in really well to our Higher physics curriculum. I don't know how practical that may be but your photographs with your 20 inch Dob have inspired me.  The lock down will give me some time to experiment. 

6 hours ago, Ships and Stars said:

After spending almost two weeks imaging with a 20" SW dob with goto  it's hit and miss and you will be taking thousands of exposures and deleting a lot of them at times. With a 10" dob (still a fairly large scope) you'll need two to three times more exposures to capture the same amount of light and/or detail presumably. 

I'm using a full frame camera but the image circle only really covers about half the total sensor area. I shoot in 5:4 mode and crop heavily, maximum 8" subs at ISO 400 or 800. At least 75 really to get enough decent data for an image, and upwards of 200 is not uncommon, plus darks/bias and flats (which I've yet to do).

Sometimes the mount tracks nicely for short exposure photos, sometimes it's jerky and all my subs get deleted. Not designed for imaging as Olly says, but possible if you are determined. It's fine for visual, which of course a dob excels at. The only thing going for my setup is sheer aperture, I can get in 30 minutes integration what would take a refractor or small reflector 2-4 hours I'm guessing, but there can't be any wind and the mount has to perform near perfectly. Plus taking subs near zenith can be impossible. It's a fun experiment and if you have a go-to dobsonian and a DSLR laying around with a remote release or intervalometer or interval setting, go for it, but you'll have to be patient! Otherwise look at a proper imaging rig. Hope that helps.

PS still working on getting the colours right, so sticking with B&W. Images below are lights only, between ten and twenty minutes total integration I think, no darks, dark flats, bias or flats. 

I love those images; never thought you would have managed that with a Dob, well done. Any plans to experiment with DIY equatorial tracking base, I think they can give 30 minutes worth of useful eq tracking.  That said your images are already impressive -  you have given me some food for thought with our 16 inch dob.  

Jim

That is cool; it would be a brilliant setup to use in a school or outreach setting where you are looking for a quick uncomplicated setup that simply works. Hope you have fun with it. 

Jim 

New lens now fitted and after a very quick play against a bright sky I managed to refine the focus. Still not perfect and not focused over the entire field but I feel I'm getting there. I'll hopefully have more time to play around with it this coming weekend. Any tips on refining the focus would be greatly appreciated; the exposures are approximately 40 s. 

Jim 

My new lens has arrived together with some more Thor Lab snacks   Hopefully I will find some time today to get it installed and try it out.   

Jim 

14 minutes ago, theeruditefrog said:

@Cornelius Varley that now makes perfect sense. If the tube is set too far back, it will hit the stand.

Also - while I'm here...

With  a Synscan - how accurate do I need to be with my Polar Alignment? Does it need to be perfect on the etched ring for the time - or is there some leeway that the motor system will adjust for?

If you are just doing visual observation then don't waste too much time over your polar alignment. Better to save the time you would have spent tweaking alignment to use on actual observation. A rough alignment will be good enough for the handset to get the object you want to view into the field of view of your low power eyepiece.  If you were looking to do astrophotography, especially with guiding, then a more accurate alignment would be needed. 

Jim 

3 hours ago, Deep_Space said:

Hello. My brain is frazzled trying to understand this. My handset has a choice of E or W and its asking for longitude. Mine is 51.2949744, and my Latitude is -1.9736615. I am so confused as its asking for E or W then a 3 digit number followed by a 2 digit? I am a complete novice. Any help would be good 👍🏻

I find this app really useful when using the syncscan handset - just feed the details (includes gps coordinates) straight from the app into the handset makes it really easy.  I think it is only available for android though .

Jim 

Syncsan App

9 hours ago, Merlin66 said:

What's the latest status on the various LowSpec builds?

Been quiet for a while.

 

Mine is waiting for a replacement lens (camera) from Thor Labs.  I was close to focus with my original two element (two separate lenses not joined) lens (f95 mm) but I couldn't quite get it nice and sharp not even after playing around with spacers following help from Paul. I think the two separate lens may have not have been properly aligned. Anyway, the new lens should arrive tomorrow so hopefully I'll be able to post a nice sharp solar spectrum.  

Jim 

Brian that is a cracking find giving you the makings of very sound 12 inch Dobsonian telescope; that would be a very capable beast.  Constructing a Dobsonian would not be as challenging as perhaps you may think and it's certainly and enjoyable and rewarding project. If you think you may be interested in going down that line then this site would be a good starting point https://stellafane.org/  . 

Jim 

What a wonderful app Helen, thanks for sharing that.

Jim

6 minutes ago, Carbon Brush said:

Hi Jim.

I don't at all mind you downloading the file. That is what it is for!

If you want to edit, then I can provide a file in SKP (sketchup) or STL format.

David.

David that would be great if it isn't too much trouble. I'm mounting it on a flat surface (Square pier) so I was going to cut off the rectangular standoff on the rear of your bracket. Im using Fusion so an STL file would be great. 

Jim 

On 28/10/2018 at 16:14, Carbon Brush said:

I am part way through fettling a Skywatcher 10" dob.

When supplied, it had the basic handset and has at some point been upgraded to a GOTO handset.
The original handset bracket is of course too small for the new handset and a bracket does not seem to be readily available.
OK I could have used a bit of velcro. But I thought a 3D printed bracket might do the job better.

The attached photos show the prototype bracket. The screw holes match those already on the mount and the handset just drops in.
I suppose I should make the finished item in  black or white to match the mount.

The OBJ file can be opened using windows 3D viewer, or similar to get an all around look.

A rainy afternoon spent doodling on the computer.

David.

Handset Holder-4.obj 62.72 kB · 39 downloads

 

 

David I hope you don't mind but I've just downloaded your design and fired up my 3d printer. This one is destined for my the permanently mounted setup (fed up with the controler just hanging by its cord).  I was just about to start my own "doodling" to design one when I thought I'd better do a quick search first, somebody has bound to have solved this before    You have saved me some time, thanks for sharing the file. 

Jim