Imaging Scope - £1000 max

[johnb]

So I am an imager and doing quite well to date, current kit is is signature. Every now and then I get to think maybe I should upgrade my scope ?

My interest is strictly DSO's (not interested in Planets etc)

So if you had a £1000 what would you go for ?

John B

[FarSide]

Okay, so you've got a pretty decent mount to start with, which is vital, and actually a 250, though quite large, is also fast. From what i can see on your website your images are really rather good, though they lack some depth that better imaging equipment may lend. Instead of a new scope have you concidered upgrading your imaging gear, such as a CCD etc?

[pete_l]

Well you already have the ability to image at a focal length of 1200mm, so that covers most deep sky targets. If you want to go wider and get more sky around your targets a 100ED refractor will do the job. If you want to go to longer F/Ls and grab some smaller DSOs then a C8 XLT and optional focal reducer is a possibility.

[GlassWalker]

Refractors offer better contrast than reflectors in this application, which can help bring out the faint stuff. If you're doing colour imaging, then get the "best" colour corrected one you can find, at a balance of focal length and ratio. Not sure what's around in that area though.

[Black Knight]

I you are definitely thinking of a new scope, then I think I'd suggest a a nice ED80 together with a focal reducer to get some nice wider-field images. Or like FarSide says, maybe upgrade to a CCD.

[FarSide]

On the other hand, if you have £1000 to play with, you might want to by pass the ED80 altogether and head straight for a decent triplet. The Altair Astro 80ED Triplet, for example, is a darn good choice for widefield images, and with a reducer you'll come away with £300 change.

[Freddie]

Another vote for a CCD here. I think that would give you the biggest/better improvement over a new scope.

[kirkster501]

I was recently in a similar situation to you. I am no expert but may I suggest a used ED80 like I have and was recommended to get? They are wonderful scopes and give you plenty of avenues to learn. Your mount is spot on. All you need then is a camera, i.e. a DSLR or a CCD. As a AP beginner (like me) a used DSLR on ABS should suit you down to the ground. You don't need anywhere near £1000.

Steve

[swag72]

I've had quite a think about this and have a couple of thoughts. Firstly, though a question.

1) Do you feel that there is anything lacking from your present setup? ie: Focal length, field of view

2) What do you want to achieve with this £1000? Where do you want to see the biggest improvement / change?

These are my thoughts. I have recently decided that my 120ED refractor is no good for DSO's as it gives me just too small a field of view with my small chip CCD. So I have decided to use a smaller scope, around the ED80 length. This gives a pleasing field of view for many DSO's although still too small for the larger nebula. So, half of me says that a smaller scope, such as an ED80 is the way forward.

Then I think that instead you could upgrade the camera, and use it on your existing scope. While the benefits of that may not be immediately apparent, a cooled CCD gives you much better processing options when it comes to your images. Less noise for starters.

It's odd, but £1000 sounds like a lot, In reality it's really an inbetween amount. More than enough for a cheaper scope, but if you want to move to the next step up in quality it's not enough.

So I'm undecided. It's a tricky amount to play with and it's also difficult to second guess what improvements you would like to see / anticipate seeing.

Hope that you come back and answer the questions, as I just love spending other people's money!!!

[FarSide]

I've also thought about it, and i've come up with a third alliterative. You COULD buy yourself a cheap ED80; a Sky-Watcher Pro, or something similar for around £400 and then get yourself an OAG, and Autoguider. That way all you have to do is swap the camera and guider from your reflector to your frac when you want to switch between close and widefields.

I also wouldn't guide with the ST80 because the long focal length of the reflector and the short focal length of the frac will clash; you'll have minor guiding problems, and as you know in AP minor becomes major. Also the mirror in the reflector will flex and shift and the frac guider can't compensate for it, hindering guiding. That said, OAGs and Lodestars can come later. Get yourself a CCD camera, and get yourself some CCD time under your belt.

[themos]

Pity that the Altair Astro 115 F7 triplet is a bit over your budget...

[ollypenrice]

You are imaging from London and with a DSLR? Your present images are excellent and most of that is down to the fact that you clearly know what you're doing. But a major factor in your success is the fast F ratio of your scope. No DSLR can, in the end, match a decent CCD but when they get close, as in your case, the common factor is the use of a fast telescope. DSLRs are noisy and usually uncooled so cannot run very long exposures. I would not recommend that you shoot yourself in the foot by dropping to F7 or even F6 when you are currently twice as fast at F4. So, much as I love them, I would not recommend that you go for a small apo. SInce you have mastered the big Newt don't step backwards.

For a wider FOV what I would do is buy a Canon EF200L lens. Peter (Psychobilly) has made the amazing discovery that if you focus on the 1/3 and 2/3 lines of the chip you can run the lens wide open. If you find that you don't quite get away with that you can stop it down, ideally with a simple home-cut aperture mask. I paid £(àà for my own EF200L and use it with a CCD camera where the sampling rate is unfavourable because of the large pixels. Even so it gets results, example to follow.

Alternatively I'd save for a CCD and discover the joys of NB imaging in LP skies.

Olly

[ollypenrice]

PS, sorry, French keyboard. I paid £500 for the lens second hand.

Olly

[themos]

That was with the 200 f/2.8L? What pixel pitch were you using?

[johnb]

Thanks to all for the feedback, I think given all the thoughts that I now need to move to CCD Imaging and take it from there.

Watch out for Noob CCD questions and once again thanks - SGL is a great community.

Regards

John B

[ollypenrice]

That was with the 200 f/2.8L? What pixel pitch were you using?

That's with the Atik 4000s, mono for Ha and OSC for colour with 7.4 micron square pixels. On the big side to say the least but you still get something.

Olly

[FarSide]

Good choice, John. Goodluck with it all.

[LMC]

With a 250mm scope and DSOs as your targets, there's not a lot you'll miss out on until you get to around 16".

As others have suggested, a dedicated CCD is probably your best option.

[Gina]

I've been thinking about where I'm going with my upgrade path too. Not that I have much in the way of funds ATM and seriously thinking of cashing in on some of the things I no longer use. That would also save space.

My "thing" is DSO AP (as most probably know). I'm already branching outwards in FOV by buying old camera lenses to go on my modded and later cooled 1100D. I have a 200mm and a 300mm f3.5 coming (already have a 300mm f5.6 but that's rather slow). Going even wider I have 135mm f2.8 plus 55mm f1.8 and 35mm f3.5 Super Takamar lenses. I have an ED80 with FR giving 510mm FL @ about f6. That works well with my spectrum modded and cooled 1100D DSLR. So I'm thinking I shall be wanting to go narrower FOV but without loosing much light. So I'm thinking in terms of a Skywatcher 190MN Astrograph. That would double my focal length with just slightly more light gathering. And I hear these give excellent images.

I know another option would be to go for an astro CCD camera and that is still something I'm considering. All of this will be some time in the future - probably next year. What I really need - what we really, really want - is some clear skies at night. Without that, this whole discussion is pointless, of course Still, it's nice to dream

[swag72]

Here's a question for you Gina in your upgrade quest .............

1) What are you specifically hoping to image with the MN190?

I ask as if you put a MN190 into a fov calculator using a DSLR and an ED80 in using a small 285 Sony CCD chip (such as the Atik 314L+) your field of view is virtually the same. So my thoughts are that potentially an upgrade path would be better served by a smaller chipp CCD than a 900-1000mm scope.

Also, my other thinking on this is that having used a 900mm scope and a small chip CCD, it was a little bit of a betwix and between focal length. It was generally too narrow for the majority of nebula and really not long enough for the galaxies if you wanted them in nice and close.

I also think that with a CCD you'd get a whole host of other benefits, such as better cooling, better noise control, far more sensitivity for NB and RGB (especially is you went for a mono.

Just my thoughts from reading your post Gina.