Help with scope choice...

[rocketandroll]

Hi all

After talking about it for over 14 years I finally went ahead and joined my local astronomy society this week and am hoping to finally go and get myself a telescope.

Now, I know full well the following statement is on a par with a newbie angler turning up on a fishing forum and stating "I'd like some advice on getting in to shark fishing" but...

My real interest is in trying to get into deep sky object imaging.

I don't have an enormous budget for now, and feel it'd be silly to leap into buying thousands of pounds worth of equipment without starting out smaller.

So...

If I want to have a first stab at imaging galaxies and nebulae (and my expectectations are suitably low, anything recognisable as not just being a blured star would be a start) so... what equipment advice would you give?

I have an Eos 20D which I'm happy to use, or I'm happy to invest in a CCD and some frame-combining software if that's a better method. I need something relatively portable as I need to drive to dark sites and regularly attend outdoor/capmping events at dark/rural sites. I want something forgiving to the novice user... and something I can get set up and get started (inc any adapters/imaging equipment) for under £1000.

I know it's really all about diameter and accuracy of the drive system on long exposures... but can anyone give me actual product recomendations?

Thanks!!

Ben

[nightfisher]

first of all, welcome to sgl, and well done for stating just what you want to achieve.

Im not qualified to really advise you but the minimum mount is gonna be an EQ5 with motor drive, and scope wise an 80 or 100mm ED refractor with short focal length

[rowan46]

Welcome to sgl, Can I suggest that you get and read this book first it may be the best £20 you spend on imaging Books - Making Every Photon Count - Steve Richards I bought this and decided that imaging on my budget was impossible it saved me a packet as I would have gone out and tried to make do. This lists the basics you will need for astrophotography a reliable and repeatable process for taking photo's and help with processing it will also give you time to get your posts up so that you can access the for sale board . because with that budget you will need to go 2nd user route

[rowan46]

I am sorry perhaps i wasn't as helpful as I should have been The first priority is the mount this needs to be rock solid, able to track accurately suitable for guiding. this is considered the minimum mount Skywatcher - Skywatcher HEQ5 PRO Synscan

[rocketandroll]

...many thanks for the help so far, have ordered the book as it does indeed look like being a very useful read.

Thanks also for the mount advice... it's only really just dawning on me how critical the mount is, almost over and above the sheer size of the scope you put on it. Have been trying to get reviews of a lot of the mid range 5" and 6" 'go-to' type reflectors and it always seems to be the mount they come on that lets them down when it comes to astro-photography.

£700+ just for a mount is pushing my £1K budget a bit, but maybe the second hand route is the best one. What's the post count at which the for-sale forum is accessible then?

Oh... and I've had conflicting advice... lots of people have said that for DSO imaging you are best off with a big diameter reflector, others (as above) have said a refractor... so which is right?

Thanks again!

Ben

[smoggy]

I believe its 50 but don't quote me on that, I'm not up to those dizzy heights yet!

[nightfisher]

yes the post count is 50 for the for sale section.

have a really good look in the deep sky imaging section and what set up a lot of people are using

another source of second hand is a site called uk astro buy and sell

[rowan46]

apparture is required for visual its not nearly as critical for dso imaging, as the camera does the imaging rather than the eye. prime requisite and heart of any imaging system is the mount it seems after that most people get a fast refactor usually around 80-100mm range as it puts less strain on the mount.

[rocketandroll]

...thanks again to those who have replied so far... there you go, I was about to go out and spend a load on a reflector and it seems that's not what I need at all!

So, a refractor with a short focal length? Being somewhat experienced in such things in photography, but not astronomy... what counts as a 'short focal length' in these kind of scopes?

Are there any specific stats I should be looking out for that would denote what would make a better scope for this kind of work? All the blurb on the retail sites for these kind of scopes seem to focus on their suitability for planetary work, which worries me a little ;-)

If anyone has some specific scopes I might want to look at, that'd be great... seems £400 - £600 seems about right for a 4" or so reflector WITH a mount... does anywhere sell these sort of scopes seperately if I'm buying 'HEQ5 PRO' to mount it on?

Cheers again all, and thanks for your patience with me and all the rest of the newbies which I'm sure this forum has been innundated with in the last fortnight ;-)

Ben

[Photosbykev]

the 80-100mm referred to above is the tube diameter/aperture of the telescope they are suggesting rather than focal length. It took me a while to work that out after coming from a photographic background. Typical focal lengths are something like 400mm and above. The site sponsor FLO sell a good range of refractors which are suitable for mounting on the HEQ5

[nightfisher]

probably the best choice would be a 100 or 102 mm ED refractor with a focal ratio about f5, this would give superb dso and good planetary imaging with your dslr hooked up to it, mounted on the HEQ5 will be a stable versatile set up, think there is a 102 ed on uk astro buy site for about £250, about right money for good secondhand

[rowan46]

plenty of astro shops sell scopes without mounts they are usually found on the page marked ota (optical tube assembly)

[rocketandroll]

Cheers all, and thanks Kev... I did work out the 80-100 was the tube dia... just needed some figures for focal length as I had no frame of reference for telescopes :-)

I'm off to have a look around and see what's out there now I have a better idea what I'm after!

Ben

[malc-c]

Ben,

To a degree I'm going through the same process - looking for a scope that can show me where things are and allow me to do astronomy from the comfort of my living room if I so wish. The guys on here have pointed me towards an Explorer 150PDS on a EQ5 pro mount

Googling around this retails for around £680. This would leave you £320 of your £1000 budget to get extras, such as the CCD camera and possible some software to control the scope.

My other choice was a Celestron C6-SGT, which is a couple of hundred more than the 150PDS, but the guys suggest that the drives are noisy and no where near as good a quality as those on the EQ5 pro mount.

You see this is the same problem I have... you find something and then someone else throws a spanner in the works

[rocketandroll]

Cheers Malc!

That looks a pretty good scope... I was actually just looking at the Explorer 200P on the same mount which Telescope House have for £760 or so.

I've just been looking at refractors around the 100, 102mm mark and can only really find ones that are about f8 or f9... if there are any around the F5 mark as suggested, I'd love to know what they are and get some more details?

Still somewhat confused.... !!!

Ben

[rowan46]

I am not an imager but if I put this up for you someone will put you straight William Optics - William Optics Megrez 72 Original Model

[E621Keith]

Larger aperture apo are more difficult to correct, so the lower cost ones are generally f9. There are 4" apo around f6, but they are well above your budget even second hand. e.g. TMB105, FLT98, TV101 ...

The 150p and C6 are both fine scope. I heard the CG5 GT has better bearings and stronger tripod than EQ5.

Larger telescope with bigger aperture will be better at capturing light and smaller DSO. However, they place a lot of demand on the mount, so EQ6 is often the minimum requirement for any scope between than 200 - 250 mm. Beyond that, the mount cost sky rocket to £5-15k.

[nightfisher]

Unfortunately imaging DSO`S seems to be the more demanding and expensive side of astronomy, an 80mm f5/6 scope would be the best, however if you get a scope say f9, it will just take longer to capture the image, and if you went for a 200p you would need a heavier mount, you could go a different route and get a maksutov like a skymax 127 or 150, i have seen images done with these type of scopes and they can be superb, but harder to produce as being f11 or higher so exposure times will be even longer and guiding will be more demanding. i think you could do dso imaging with a big lens fitted to your dslr and mount camera on top of scope to make use of the mount for the guiding

[rocketandroll]

ok... getting closer to a plan I think :-)

I'm veering towards the Evostar 80ED DS-Pro... but need some further help on the mount...

Which version of the HEQ5 should I be looking at as there seem to be a few...

There's the HEQ5, the HEQ5 Syntrek and the HEQ5 Pro GOTO.

Do I need the GOTO?

Are they mechanically the same? Does the GOTO (as the name suggests) just have a GO-TO function that the cheaper versions don't have? I know that'd be useful for a beginner but is it critical? I am happy to find the object I want the 'old fashioned way' if necessary :-)

Again, I don't want to skimp on the mount and regret it.... but I also don't want to spend more than I have to and find there are loads of extras that push the cost up and up.

It's been suggested that the HEQ5 has some mechanical problems and parts that should be replaced as standard? That doesn't sound great :-)

Is that really the best mount for a scope of that size with a DSLR hanging off it?

Thanks again folks, and I appreciate your time!

Ben

[Woody]

Hello mate, I am pretty much in the same boat as you, wanting to do DSO photography. I have just ordered some kit so I have no practical experience with all this but through my reasearch I went down the HEQ5 Syntrek route. I figure if I am going to be doing long exposures than I also need a guidescope with a guide camera. So the guide camera will be hooked up to a laptop and by using Stellarium or a similar program I can use that to do the "GOTO" part of the operation, if needed.

Clear as mud? Hope it helps some.

Cheers

[rowan46]

you will probably find that once you have it you would like the go to the heq5 syntrek can be upgraded by getting the handset but as you can see that adds £200 on the cost so its cheaper to buy it straight. There is something called eq mod which if I understand correctly is a free way of making it goto using your laptop. google eq mod for more info

[malc-c]

Ben,

When I googled that mount there was some posts / sites that mentioned some metal pins bend easy and when slewing the drives chatter... Which is causing me some concern as I too am looking at getting a scope (150PSD) on this mount with the goto function.

Can't comment on the differences, but my guess is that you can get it in the undriven mode (no motors), driven (either both or just RA) and then goto which has the skyscan unit that plugs into the motors and gives the computer control. So basically the same mechanics but different drive options

[rowan46]

in answer is it the best ' the answer is no its not. it is however the cheapest the eq6 would be better as next cheapest after that you are talking about £4000 for the next mount

[rowan46]

malc-c you will be pushing it imaging with a 150 on this mount remember you still have to put a guide scope guide camera etc on it and the recommeded limit for astrophotography is %50 of the mounts rated load limit my mistake i've just realised i've answered someone else post it will be fine for visual work with that setup

[nightfisher]

have a look here

U.K. Astronomy Buy & Sell