Astro_Nic

Trying to understand this!

Looking at the pics above, the ipolar will be attached to the RA axis, but in my example, I would have to rotate the camera only in situ - that way it is rotating around the RA axis.  I was thinking I would then move the mount in RA - but that would move the whole camera to a different position.  Is that right or have I got it wrong?

Thanks!

The platform is a dual axis equatorial photographic platform.  The manufacturers show some great images using 180s subs for the full 110 minutes of each rotation.  So I think it is up to the job, although there are some DEC limitations as mentioned.

I attach two photos of how they suggest you polar align.  I was thinking that something like the iPolar would be significantly more accurate, but don't know if it would work.  They suggest it should.

The issue is that this is an EQ platform, not a GEM.  So using SHarpcap or other program isn't an option - It'sa real struggle to get the dob on the mount - limit of my strength, so I don't want to have to lift off the scope, move the platform 5mm, put it back, find out it should have been moved more/less etc and do that a hundred times.  I cannot move the platform with the scope on it - far too heavy.

So need something that attaches to the platform base before I add the scope and base.

Just need to know if an iPolar attached to the RA plate at the front will work, as these devices are designed to attach to a GEM in a specific way.

Thanks

Nic

Thanks

Hi everyone

Hopefully this is in the correct forum....so many to choose from!

So I have a 14 inch OO UK dobsonian on a TEPP equatorial platform.  I need a better way of getting great polar alignment for astrophotography.  Now I have a large aperture dob on an EQ platform, so I'm not expecting 300s exposures or anything and would be happy with 10s TBH.

I also have an OAG with ZWO ASI174MM mini, the platform has the ST4 guiding port, and I will be using a ZWO ASI2600MC with Antlia 5nm dual band filter with a view to using it for some DSOs.  Oh and also a Nexus Coma/ 0.75x reducer.

So far I have been playing around with placing a laser in a TEPP laser holder that I attach to the RA axis at one of the ends.  I just kinda guess using Stellarium etc where the actual celestial North is versus the North star.  I've been using a ZWO ASI678MC and 2.5x powermate for some moon and planetary action.  Realistically I'm getting about a minute at that mag before the image slowly moves enough that I re-centre and start again.  Probably fine for planetary/moon but not DSO I expect.  For visual on the moon I can have an Ethos 13mm in the eyepiece, wander off and 10 mins later there doesn't appear to be much movement.

I want the next level of polar alignment.

I was thinking of either the iOptron ipolar electronic polar scope or the QHY Pole Master.  Both have a flat base that I can attach to my RA axis like I do my laser.  I have no real idea how these devices work though and as mentioned, I'm not looking for massively long exposures as with 14 inches of F3.5 I don't think I need it.  I've seen reviews where long exposures with the iOptron is problematic, but hat probably wouldn't be an issue.

Will my idea work?  One better than the other?  Any other options?  I'm leaning towards the iOptron becase the setup of the polemaster talks about moving the mount 30 degrees then another 30 degrees to calibrate and I'm not sure this will be compatible with an EQ platform.

So my question (after all the waffle above), is will the iOptron ipolar work on an EQ platform?

Thanks you very much for your help.  Polar alignment is such a pain!

Nic 

4 minutes ago, fwm891 said:

Just put a little name badge on and ....

lol I don't want to look 'special'!  I'm a fellow OO UK user - VX14

This sounds like a great trip out.....worth going?  Although I don't really know anyone on here so I'll be the one on their own pretending I know what I'm doing!

So not going MM....

What I want to do is go MC2600MC>filter>OAG>Nexus reducer (or not if it doesn't work) - but will need a coma corrector anyway so my parracor II.  How do I calculate if this will work???? eeeek......

Then there is the issue of which new focuser will work.....

Very confused!

Thanks!

Yeah that’s what I don’t know how to calculate or what it all means! Any help appreciated! Nic

Pretty sure I'm going to get the 2600MC, unless someone says it's not appropriate.  I would go MM, but I can't see myself investing enough time initially and there are limits with the EQ platform - not like I can set up an EQ mount and leave it for 8 hours.  Pricing up the MM with good filters is also VERY expensive!

Will go OAG - is the ZWO suitable?  and pair it with the ASI174 mini for guiding.

Any advice on focuser?  Want something decent like a Feathertouch but no idea where to start.  

Thanks everyone!

Yeah that's what I have no experience of - how to work out focuser in/out travel how much focus travel I need etc......complete mystery!

I use a Paracorr II currently for visual - but not used it for photography as I read it needs dismantling and then you need certain spacing or something.....so haven't bothered yet.  I thought I wouldn't need to worry for planets, but I will for DSOs.

A reducer would be great to get some larger FOV..... 

2 hours ago, AstroMuni said:

Ask her to buy you a focal reducer too 🙂 That would greatly help IMO

Any suggestions on which one?

Thanks.  I know I don’t need a big dob, but it’s what I have and is relatively new, so not wanting to buy another scope quite yet!

wife wants to buy me a DSO camera for my birthday so not going to complain!

will certainly be practicing with the 678 before then.

cheers

The 678 is tiny - also to get the required 5x pixel size, I need a 2.5x barlow.  So essentially the Sombrero galaxy which is a tiny galaxy would take up the entire field of view/not quite fit.  Who knows how I would even find it!  It is also not a cooled camera designed for DSOs.  Cheers 

Hi everyone

Although I bought my scope for visual use - and will still be using it for visual as I love that side of it, I would like to make a move into DSO imaging with my dobsonian.   Not interested in a new scope at this time.  I'm aware it's not the best type of scope for this, so am not expecting amazing results or for it to be easy, however, it would be great if you experts could at least point me on the right path, so at least I stand some sort of chance!  I now have a dual axis equatorial platform and a ZWO ASI678MC planetary camera which I have been messing around with - but the planets are disappearing now!  The EQ platform has been great to be able to keep an object in the eyepiece!

My set-up is as follows:

 - Orion Optics UK 14" 1/10 PV dobsonian.  1600 FL. 1,860 with the Parracor II;

- TEPP dual axis Equatorial platform with support for guide camera;

- Astro Devices Nexus Pro DSC;

- ZWO ASI678MC;

- Orion ST80 'super finder' with ES24mm eyepiece for 16x mag plus standard 10x50 finder;

- Laptop with the usual imaging software etc;

- Based in the Midlands, UK.  Usual frequent cloud covering.  Bortle 5/6, but the East and South views are darker and look away from the nearby town.

So where I would like some help please is......

- I am planning on upgrading the focuser.  Was thinking of the Feathertouch - Does that sound like a decent choice?  If so, what size should I be looking at?  I know nothing about focusers/drawtube lengths/2" vs 2.5" vs 3" etc.  If that is overkill then could consider Moonlight or Baader steeltrack.  Although only the Baader appears easy to get in the UK;

- Where do I start with camera choice with my scope?  There is very little help out there for dob DSO imaging (I know - for very good reason!) - Colour vs mono - Limited opportunities to get out/Bortly 5/6 / dobsonian etc - are any of these relevant or is it really just a choice of mono - better quality, but more expensive once filters and wheels taken into account vs OSC - simple, cheaper, not as good quality?

- Which camera would pair well with my scope?  Compared to planetary cams, it looks like the more you spend, the better the camera you get - but are they all suitable for all scopes?  I was thinking of something like the ASI2600 - either MM or MC.  I do like the simplicity of the colour and the ability to get an image regardless of length of session.  But not if the quality is significantly lower.  Or with a dob set-up, is the camera really not a limiting factor and either MC or MM is fine.  Do I even need to spend up to the cost of the 2600 with my setup or are other models - 294 / 533 / 071MC / 183 etc good enough?  I was thinking with my large FL, a larger sensor would definitely help to fit targets in.  Then there's even the ZWO ASI2400 MC full size sensor.  No real budget, but don't want to chase the last few percent improvements that aren't cost effective.  But a larger sensor size looks very appealing.  Am I looking at this the right way?

- Assume I will need OAG?  Any suggestions here?

- Are there any risks that things won't reach focus etc?  How do I calculate these things?

- Anything else I have forgotten about?

- Once I have the hardware sorted, then I can think about how to operate it all!

Thank you all for your time and considered opinions and help!

Nic

14 minutes ago, johnturley said:

Don't worry about possibly over-sampling with your proposed set up.

Geoff Lewis regularly uses f22 - f24 with his C14 and ASI 462, and gets good results.

John 

Yeah but he’s not using a manual dob! 

OK so last post but the powermate does not increase magnification with distance from camera, the barlow would.  Barlow more flexible then?  Or the constant of the powermate easier as I want 2x?!

so 2.5x 1.25" powermate or the 2x 2" powermate?

5 x 2um = 10 um optimum?  Although someone has mentioned that with the ADC it might be 2.2x barlow effect so 4.6 x 2.2 =  10.16......   That's a 3,500ish FL for a manual dob.  Looks perfect sampling

The 1.25" powermate is interesting as it's sp much cheaper.  But this gives a 4,000 FL or more with ADC and a 2.5x (2.8x?) x 4.6 = 12.9....too over-sampled? and harder to use?

Over-complicating it?  Maybe I just don't need a powermate and just get a 2x televue barlow and forget it for visual?  Have 22mm (2 inch), 13mm, 9mm, 6mm, 4.5mm eyepieces

Help!

Thanks! 

39 minutes ago, johnturley said:

I generally use a 2.5x Powermate with my Esprit 150 (f7) and ZWO ASI 462 camera, which gives f17.5 and effective fl of 2650mm, I tried a 5x Powermate, but the results were not that great, although it might work ok on Mars under very good atmospheric conditions.  

With your f4.6 VX14 (fl 1600 mm), a 2.5x Powermate would give f11.5 (which incidentally is supposed to be close to the optimum for the ASI 462), and effective fl of 4,000 mm. I gather however that you were thinking of the ASI 678, which has a larger 1 /1.8 " format, so the image size would be similar to what I get with the Esprit 150 and ASI 462 with its smaller 1/2.8" format, so no a 2.5x Powermate would not be too powerful. 

John 

I was more meaning that it would be too much for manually tracking dob.  Don't want to make this anymore difficult!

1 hour ago, johnturley said:

1.25 in filters should be fine for up to 4/3" sized sensors, but 2 in for larger sizes.

If you are imaging planets you don't need a 2" Powermate, not only do these cost more, but they also add significant extra weight to the system which can result in balance issues.

Most ZWO Cameras (up to 4/3 " format) have a T thread, and come with a T thread to 1.25 in nosepiece, which is threaded for 1.25" filters.

Most observers recommend using an IR/UV cut filter for imaging planets such as the Baader one below, although cheaper brands are available. 

Baader CMOS Optimised UV/IR Cut and L Filter | First Light Optics

Hope this helps. 

Thanks.  I was after getting a powermate as I am principally a visual user and therefore want a powermate - this will also allow me to attach my 2 inch eyepieces - not likely to need it for my 1.25" eyepieces.  Although not sure if I need a barlow for visual but it gives me flexibility.

The main reason though is that the powermate on FLO website only comes in 2" for the 2x.  The 1.25" is a 2.5x powermate........is that too powerful?

Thanks

6 minutes ago, johnturley said:

With the sensor size of the ASI 678 you don't need 2in filters, 1.25" is fine.

If you were to use a camera with a full frame sensor you would need 2 in filters. 

John 

Thanks.  Would 2" future proof me?  Just wondering if it will cause any issues in the image train.  Am getting a 2" powermate and have 2" focusers etc - no idea what thread is on the camera.

Thanks for your help.

Any brand worth getting or are they all about the same?  What's the difference between IR/UV and just an IR cut?

Plus do I need any sort of T adapters to attach to the powermate?

Plus ADC or not?  Will be imaging at f10, so thinking not worth it?

Thanks

Thanks.  Excellent help.  I think I will stick with the 678.

In terms of filters, is there any benefit to a 2 inch one?  Or stick to 1.25"?  Money not an issue.

Thanks

Nic

Thanks all….looks like I might be forced down the laptop route. Don’t want to make it more difficult than it needs to be.

Thanks but I’m not just going to buy a basic laptop - it’s just me! I’d buy one that I could use for gaming when on holiday as well.  So my decision is £2,500 for a laptop or £350 Asiair.  
 

I just don’t understand what am Asiair can do.  If it’s overkill, then great, but if the laptop makes it easier (I’m a noob!) then I’ll want the laptop.

thanks

nic

Hi

Hopefully this is in the correct section.  So I have a manual Orion Optics 14 inch dobsonian.  FL 1600 (1860 with Parracor), aperture 350mm.  I am planning on buying an ASI678MC for planetary imaging and a 2x barlow.  I know a dob isn't the best for imaging, but that's what I've got so going to give it a go.  Love the visual and don't want to give that up, but would be good to get some pics at the end of a session to show the boss!

So the question is, which is the best way to get the image focused and photos taken with a manual dob - using an ASIAIR or a laptop?  So, I don't own an ASIAIR and I don't own a laptop or a tablet (although my wife owns a tablet).  I have an iphone 14 pro max.

So whatever route I take I will have to buy.  Which will be the easiest route for a beginner?  or would both work?  I really don't know how the ASIAIR works!  I kinda want a gaming laptop but realistically I don't need one and if I can get into astrophotography without dropping £2.5k on a laptop I would rather not!  Is an ASIAIR and an iphone a good substitute? or would I need a tablet?  Or do I really need a laptop?

I have a decent desktop with 55 inch 4k screen for any editing.

Thanks for your help as always!

Nic

Excellent.  Thank you everyone for your help!