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NEQ6 and MN190 versus.... what else?


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OK, so I've had my 10 inch dob for a year now, and am really enjoying looking at the skies when the weather allows. I've been surprised on the good nights that despite living in Luton I can still see a fair few things, and have even found a few dark sites not a million miles away to take my scope when I feel like travelling. I also picked up a second-hand 8" Meade which is a goto scope, helping me learn what is where in the sky, but it isn't a 'keeper' so I'll be selling it on soon.

As tends to happen when I get 'into' a hobby, whenever I get some spare income, it goes into said hobby before I have time to think of sensible things to do with it. This time round, I'm hoping to have around £2000 to £2500 coming in, and thought it would be nice to get a mount and scope to try dabbling in some astrophotography. I have plenty of eyepieces, and although it isn't the perfect solution I have a pretty decent Nikon DSLR to kick things off with. Basically what I'm trying to say is that the budget is for a mount and scope to allow me to start taking some pictures of DSOs, and any extra equipment (like a better imaging device etc.) can come another time.

Having done 'the research', I am pretty confident that the NEQ6 is as good a mount as one can expect. Scope-wise, I have read plenty of great things said about the Skywatcher 190MN. So, as far as I can tell, this is what I think I'll be getting. But I thought I should throw this open to you - the experts... because I may have totally ignored other good options.

The only other 'competing' option seems to be a Celestron scope on a CGEM mount. If I went all out, I believe the 9.25 scope on a CGEM mount would just be within budget, but I don't see anyone saying how amazing that mount is (like I have with the NEQ6) and in fact have read a couple of posts elsewhere that suggest there's a small problem with the tracking gears which introduces errors in astrophotography (apologies for not having the link to hand here). 

So what are everyone's thoughts? Am I on the right track? I should say that it would be nice if the scope had good viewing as well as the photo side, so a refractor might not be preferable... but is that a bad assumption?

All your thoughts will be very much appreciated. Thanks to anyone who takes the time to read and respond!

Thanks,

Joe

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I think that's a good starting budget for sure and the NEQ6 is a good starting point. It's the work horse for many in imaging. 

So you are thinking of an MN190...... Here's my thoughts on it. Firstly, If you've not already done so get hold of the book 'Making Every Photon Count' from the book section of FLO> This is something of an imagers bible and will really help with DSO imaging. Read it once, twice and thrice then think about what you want and why ...... now you are in the position to spend as you will know the pros and cons of what you are thinking of and be able to make an informed choice about whether it would suit you.

Have you checked a FOV calculator  - Put in your scope and camera combo with the sorts of targets that you want to image and see if the focal length of the MN190 really is ideal for you.

A refractor is undoubtedly more plug and play - It will require little by way of tinkering, whereas I know of people with MN190's that have had to do a lot of work to get it working well. If you get a good one you'll be fine.... if you don't you'll be busy :)

The refractor that is often banded about is the Skywatcher ED80 - It's a good scope that punches above it's weight and will leave you enough in your budget to get some guiding equipment as well as that really needs to be in your budget as you'll be wanting to get the longest possible exposures that you can. You would also benefit from the reducer / flattener for the scope.

Hope that helps - Just some thoughts on trying to make this very difficult hobby just that little easier :)

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 Basically what I'm trying to say is that the budget is for a mount and scope to allow me to start taking some pictures of DSOs, and any extra equipment (like a better imaging device etc.) can come another time.

Guiding.

You should budget a few hundred and a lot patience to guide your scope. While the software can be got for free, you'll want a small-ish ccd/cmos guiding camera. You can use the finder that comes with the MN190, but it'll need an adapter.

I'm assuming you already have a PC or laptop that you can haul out to control the whole thing with?

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I agree with the comments already made about the MN190 by Sara and Per. It gives excellent views visually and is great value as a fast imaging scope with a good flat field. But there are some buts .....

Do not believe what is sometimes said that collimating a Mak-Newt is just the same as collimating a Newtonian; it is NOT. It is a more complicated process because of the need to align the optical axis with the centre of the corrector lens, in addition to the usual Newtonian collimation steps, and that is not trivial. In my experience, it's not nearly so easy to follow a process that converges reliably towards perfect collimation. Also, the closed tube means you cannot just reach in to the tube to do the things that you would normally do during collimation of an ordinary Newtonian.

If the scope is well collimated out of the box, that's great. If it needs collimating, that's a little more tricky. If you decide at some stage to replace the SW focuser with something better, as several owners have, that will almost certainly mean that re-collimation will be required.

For the above reasons, I would hesitate to recommend the MN190 as a beginner's scope, or if you are not prepared to do some tinkering. The MN190 is also a heavy scope that will need all of your EQ6 to carry it.

Adrian

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I do agree with the above posts as to using a refractor for imaging for a beginner as they are by far the easiest to use & for a beginner making the job easier is always a good thing. I went down the wrong route & started with a Newtonian which on occasions has gotten quite frustrating, but at the time I just didn't have the budget for a refractor so I worked with what I had.

However if you are intent on imaging with a large scope then I have an idea. I see that you already use a 10" Newtonian so in the year of using it you should have a good idea how it works & collimates. If it's an F4.7 like my Skywatcher tube then you can image with that. However that said you would need to upgrade the altitude bolts on the mount as they will almost certainly bend & getting everything balanced & guiding is also tricky plus you would need to get some tube rings & a decent dovetail bar. The only downside with imaging with such a big scope like most Newtonians is that they are susceptible to breeze & even the slightest one can ruin a sub so worth bearing in mind.

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Thanks to everyone for their input. I think I'm going to stick with the MN190, and take note of the difficulties that may face me with collimation of that scope. I'm not the MOST practical, but I feel it is within my capabilities, even if it might be at the edge of them! I think it's the Sky at Night review that keeps it prominent in my mind... although of course their testers will have infinitely more knowledge and experience compared to mine, so I don't kid myself I'll get the best out of it - at least to start with. However, it's a long-term investment, whilst I always knew my 2 current scopes wouldn't necessarily be enough for me if I wanted to get into imaging.

I do have one question though; pete_l mentioned guiding. Is the NEQ6 not a good enough guider by itself, and if not, what extra equipment would I need? My understanding has always been that the scope has pretty good guiding software, especially if you take the time to measure and apply the periodic error correction. If I am mistaken, then does anyone have a link to some suggested added extras?

Once again, thanks everyone for the info, it is very much appreciated.

Cheers,

Joe

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Hi Joe,

Guiding entails having a separate scope\camera piggy backed to the main scope, with output of the camera feeding into some software (I use PHD2 [free]) which then controls the mount such that it keeps pointing at the object you're trying to capture.....

This sounds simple, but can, at times, be very frustrating, especially if you get spurious jumps etc...

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Ah, OK... got you, thanks. So I'm guessing I can get FAIRLY good pictures with the NEQ6's 'guidance' alone, but introducing camera-based guiding equipment will improve things - is that correct? And if so, would the extra £250 be worth it to get the AZEQ6 at THIS stage, which would make it easier to mount two scopes, with a view to buying guiding equipment in the longer run...?

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I don't have direct experience of the MN 190 though it has been on and off my radar at various times. If I *was* going down that route I'd be thinking of an off-axis guider, especially given the FL and the risk of flex.

You won't get a mount that will do unguided imaging (Especially at 1 metre FL) this side of a GM 1000 or ASA 65. Start thinking upwards of £6k for the mount alone. Even a £4.5k Mesu 200 won't do unguided.

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Ah, OK... got you, thanks. So I'm guessing I can get FAIRLY good pictures with the NEQ6's 'guidance' alone, but introducing camera-based guiding equipment will improve things - is that correct? And if so, would the extra £250 be worth it to get the AZEQ6 at THIS stage, which would make it easier to mount two scopes, with a view to buying guiding equipment in the longer run...?

DSO imaging requires long exposures. With a scope of that focal length and even with very careful, polar alignment and balancing  you would be very lucky to get sub lengths anywhere near approaching useful. You'll get something on a camera of course, but ultimately you need to also guide the mount, sooner rather than later  to produce a reasonable picture.  

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If you're going to the trouble of splashing out £2k on an imaging OTA & mount alone, I can say with confidence you will not be satisfied with unguided images at 1 meter focal length on an EQ6, better to plan in your guiding options now. I would back the other opinions on an off axis guider to limit the extra weight on the mount.

Edited by johnrt
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Johnrt - having just looked at the images on your blog, I will happily follow without question every piece of advice you give!

I'll try increase my budget for an off axis guider; from a brief initial look there seem to be some options mentioned by members in other threads in the £300 to £500 category, so unless I've got that too wrong I will investigate those options further!

Thanks again.

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