Astrophotography Setup

[Mattjohnson1978]

I'm looking for some feedback on a whole new setup for astrophotography. I've currently have an explorer 150p on a motorised eq3-2 mount. I am now looking for a setup that would be more for imaging rather than observing and have a budget of about £2000 to play with. I struggled with accurate polar alignment so would like a computerised mount that could make this easier. Does anybody have anything they could recommend or any hints on what is important for a setup with this in mind?

Many thanks

Matt

[rowan46]

the heart of any imaging set up is the mount so you will need heq5 minimum or better still eq6. the larger mount gives you more flexibility for whichever scope you wish to put on it. you will need a camera for autoguiding and a guidescope plus of course bits to add on your guide scope t-mount adaptors and things

[Arushin]

the heart of any imaging set up is the mount so you will need heq5 minimum or better still eq6. the larger mount gives you more flexibility for whichever scope you wish to put on it. you will need a camera for autoguiding and a guidescope plus of course bits to add on your guide scope t-mount adaptors and things

Hi,

I couldn't agree more!

If I was starting again I would still invest in the NEQ6.

Your canon should give good results so no worries there. I would go with an ED80 and an ST80 as a guidescope. The Orion Starshoot Autoguider worked straight out of the box for me.

Mount £960 last time I looked from FLO

ED80 around £400

ST80 (OTA from FLO) £90

OSA around £250

Should leave you a decent lump of change for any other little extras.

Regards Tony

[ollypenrice]

If you want an electronic alignment process isn't there something in the EQmod series called EQ align? I don't use it but plenty of folks on here could advise. Or there are other pc based alignment pacages to help wth the EQ series mounts. If you are mobile and opting (wisely) for a small refractor I would put the case for the smaller HEQ5 which is no less accurate than the NEQ6.

It's a shame nobody else uses Takahashi's polarscope alignment routine because it wipes the floor with all other polarscope systems. In second place is the iOptron IEQ45 but that is a lot dearer than a SW mount and maybe tracks no better once aligned.

Olly

[chrisshillito]

Despite its name EQAlign isn't one of the EQMOD Project applications.

EQMOD does have its own inbuilt polar scope alignment routine which will accuratly position the polar scope reitcule for you and indicate where within the reticule bubble you need to position the pole star to compensate for precession (the current reticules are getting rather out of date now).

Of course you may find that polar scope based alignment is not sufficent for your astrophotography needs in which case EQAlign, Alignmaster and the like may be of interest - they all have different strengths and weaknesses (i,e require views of certain areas of the sky, or restrictive combinations of stars, zero cone error, perfectly level mount etc.)

Chris

[Mattjohnson1978]

Thanks guys. The mount is going to be my main priority. I was also considering the ED80 refractor. The lack of aperture concerns me but then are the rules different for these types of scopes?

As for polar alignment, I am hoping that a more stable mount than my eq3-2 and with auto guiding, super-precise polar alignment wont be so critical. The adjustment bolts are quite cumbersome and the retro-fit motor drives don't fill me with confidence so for all I know I am actually quite good at alignment....just need the right tools!

Can I ask what sort of exposure times to expect from a well aligned, auto guided neq6?

Cheers.

Matt

[Spikey]

I can get 30 min guided subs only using EQMOD's built-in polar alignment routine, so it gets a big thumbs up from me.

[swag72]

Have you been using your current setup for astroimaging? I ask, as if not, a good place to start would be getting the book 'Making Every Photon Count' in the book section of the FLO website.

I am less than 2 years into the wonderful hobby that is astrophotography, and here are my thoughts and pitfalls thus far.

For Polar alignment - I absolutely hands down recommend PEMPro. It is a great programme, does it all for you once you've put in a couple of parameters and is accurate. You need to be using EQMOD though and something like Maxim for capture. This has taken the guess work out of PA that I found nothing else really sorted.

£2k sounds like a massive budget, but in reality will go very quickly indeed. For example the NEQ6 mount will be better future proofing if you want to change scopes later down the line for something bigger, but the HEQ5 is good value if you think you'll stay put with a smallish refractor. For a scope, I would recommend a small ED80 refractor, the short focal length is very forgiving for your mount and guiding. For guiding I'd personally go down the finder guider route and connect it to a QHY5 for example. I use this and can easily get 30 minute subs with no problem at all. If you get an ED80, you may want to think about changing your camera for a CCD. The Atik 314L+ gives you a very pleasing field of view, which you can check out using CCDCalc from New Astronomy Press. Then you can factor in filters and a filter wheel should you decide you want a mono camera. If you are guiding in the field, then you may opt for either a standalone guider or the route I suggested above. The QHY5 will require a PC to run it as well. With an ED80 and a DSLR for example, you'll need a focal reducer, which will again set you back at least another £100-120.

Probably one of THE best things I ever did was build an observatory - Life is so easy once everything is setup night after night and I can be up and imaging within 5-10 minutes.

Sorry but it's all a little rambling, but hopefully you can take out the main bits and put them into some semblance of order! I started off with a £2k budget a couple of years ago - I was given what I now consider to be bad advice about a scope / mount combo - and I have spent many more £££'s in trying to get it right. I think I am almost there now and I can finally see the light at the end of the tunnel!

[Mattjohnson1978]

I haven't long since bought my DSLR and although I haven't spent out on the mod (yet) I wasn't planning to upgrade that part of my setup just yet. Is there an issue with hanging a camera of this size off the back of a ED80?

As for the autoguiding, I was considering the orion miniautoguider which apparently is basically a qhy5 camera and a finderscope. It would sit conveniently in the finderscope bracket without having to sort a piggyback system for say, the ST80 but would love to find out if the system has worked for anyone else.

My mind is pretty made up for the NEQ6 pro synscan for my mount. Will start to look into this EQMOD and see what its all about. 30 minute subs sound incredible compared to my usual 30-60 seconds!!

Thanks again for all the feedback

Matt

[swag72]

Absolutely no problem with sticking your DSLR onto the back of an ED80. Lewis (Shibby) is getting some cracking DSLR images if you check in the DSO imaging section.

Don't forget that you will need to factor in a reducer with that to stick between the camera and the focuser. You may find that that the focuser struggles to hold the weight, or you may be lucky and it will be OK. Personally I'd be looking at a scope with a decent R&P focuser and avoid the usual ED80 offerings from Skywatcher et al with their Crayford focusers. There are many who get them to work, but I think that they are mediocre at best, so I'd never purchase another scope with one ever again.

WO scopes are offering R&P focusers as standard now - That would sway it for me.

[ollypenrice]

Apologies to Chris Shillitoe for confusing the EQ Align with the EQ Mod I think he masterminds. Sorry Chris.

With good PA you can expose for as long as you like with an autoguided SW mount at small apo focal lengths. I can't think of anybody going over thirty minutes but thirty minutes is fine if you have the dark sky to support it.

I like small apo imaging but would say that when DSLRs approach CCD standard, which occasionally they do, it is in very fast optical systems. However, these fast systems bring their own challenges in terms of focus, orthogonality and collimation.They are highly intolerant.

Olly

[Mattjohnson1978]

You got me worried about combining a dslr + focal reducer to the focuser. I did a bit of calculating and wouldn't mind if you or anyone could check the maths.

Using the formula of 206.265 * pixel size / focal length I worked out the resolution of a 500mm FL scope with my pixel size of 4.3 to be 1.77 arcseconds/pixel. With my maximum size being 5184 x 3456 pixels, M31 (being probably the biggest thing I'd photograph at this stage) just misses out at just over 6000 pixels across its widest axis.

This still would be a massive improvement on what I currently can get (1.18 arcseconds/pixel making M31 9000 pixels wide) but also means that objects like pleiades and M42 which as a novice, would consider being large, would easily fit onto my camera sensor. With this in mind, the use of a focal reducer may not be necessary at this moment in time and I could address the issue at a later date.

Does that make sense or have I overlooked something critical?

Many thanks

Matt

[swag72]

What you have missed is that without a reducer, you will most likely get bad elongated stars at the corners. They're not just for making your filed of view bigger, they really do serve a very important purpose when you have a large chipped camera (such as a DSLR). It's all to do with field curvature and that the light is bent. A reducer / flattener works to flatten the field.

I can't get into the technicalities of how they work, but I know that they do and I know that if you want nice pinpoint stars over your entire image, then they are the way forward.

[Mattjohnson1978]

Thanks Sara. I find I always overlook something!

What I think I am going to do is get my NEQ6 pro mount, ED80 scope, Orion guiding and a reducer for my camera and see how it goes. Like you said, I may get lucky and not have a problem with it holding on to the scope.

A good CCD camera will be next on my shopping list, it's just a little out of my budget. I don't want to just spend £400 on an entry level one now when I can save for a little longer and get something a little nearer the top end. I'll still have my trusty 150p to use with my DSLR on my nice new guided mount should it be worst case scenario but I think even if it means skipping the reducer on the ED80 for a while, it's still going to be a big improvement on what I am achieving at the moment.

I guess experience is the only true teacher....just hope I learn before it costs me £££'s!

Thanks everyone for your comments......wish me luck!!

Matt