Looking for right mount

[cresskh]

Hi all,

I'm planning to upgrade my mount, currently I'm using EQ-1 which sucks.
My friends all recommend me to go for iOptron ZEQ25, and I looked it up. It looks great and all, but it's over my budget and I can't find 2nd hand selling near my region.
Then I saw someone selling EQ3-2 at a cheap price, and I wonder if I should take it.
My primary concern is the mount might not support when I plan to upgrade my scope in about 1-2 years time. My target scope is GSO RC 6" or GSO Newtonian 8" f/4 or anything in the category for DSO.

So I'm asking for advise on a relatively cheap mount (<$500) which can support 6"-8" scope for DSO. Not necessarily GOTO mount.
Any advise on a scope to match with the mount is also welcomed.

Thanks!

[michael.h.f.wilkinson]

If you can find a second-hand Vixen Great Polaris, that would be great. The EQ5 is a clone, which could be an alternative. The Great Polaris has better fit and finish, however. The EQ3-2 might be a touch light for an 8" F/4.

[billyharris72]

Hi there. It depends what you want to do. The EQ3 is very much a visual observing mount for light to medium scopes, though it could probably support a small scope (e.g. an ST80) for astrophotography exposures of 30 seconds or so. It definitely would not take an 8" reflector (6" is the absolute max, and you would not be able to use it for photography at all with a tube that size). I'm assuming you're aiming for AP since your other target scope is an RC, which is basically a pure imaging scope and really not well designed for visual observing - again, this would be way too big for that mount.

I'd recommend, if you want short exposure (30 sec or so) astrophotography, to go for an EQ5. That would handle a 6 inch reflector for (short exposure) AP or an 8" for visual - with this mount I don't think an RC would be a sensible choice of scope. For that you would need an HEQ5 or EQ 6 as an absolute minimum.

With this in mind, and bearing in mind your budget, I'd recommend someing along the following lines:

For visual only

An 8 inch Dob or a 6" reflector on an EQ3.

For (limited) imaging and (limited) visual

An EQ5 and a short tube refractor, or a camera and telephoto lens mounted direct.

 

[cresskh]

35 minutes ago, billyharris72 said:

Hi there. It depends what you want to do. The EQ3 is very much a visual observing mount for light to medium scopes, though it could probably support a small scope (e.g. an ST80) for astrophotography exposures of 30 seconds or so. It definitely would not take an 8" reflector (6" is the absolute max, and you would not be able to use it for photography at all with a tube that size). I'm assuming you're aiming for AP since your other target scope is an RC, which is basically a pure imaging scope and really not well designed for visual observing - again, this would be way too big for that mount.

I'd recommend, if you want short exposure (30 sec or so) astrophotography, to go for an EQ5. That would handle a 6 inch reflector for (short exposure) AP or an 8" for visual - with this mount I don't think an RC would be a sensible choice of scope. For that you would need an HEQ5 or EQ 6 as an absolute minimum.

With this in mind, and bearing in mind your budget, I'd recommend someing along the following lines:

For visual only

An 8 inch Dob or a 6" reflector on an EQ3.

For (limited) imaging and (limited) visual

An EQ5 and a short tube refractor, or a camera and telephoto lens mounted direct.

 

Yes, I am aiming to go into AP slowly due to budget constraint. Which is the reason why I am upgrading my equipments slowly, mount first scope later.
Why EQ5 doesn't suit for imaging with RC? The payload should be fine right?
I think as starters, I will try short exposure AP first for brighter DSO before going into the real faint DSO.
So maybe for now, a moderate mount might be sufficient for me?

[cresskh]

1 hour ago, michael.h.f.wilkinson said:

If you can find a second-hand Vixen Great Polaris, that would be great. The EQ5 is a clone, which could be an alternative. The Great Polaris has better fit and finish, however. The EQ3-2 might be a touch light for an 8" F/4.

Unfortunately I couldn't find 2nd hand Vixen GP around my region. Vixen is not really popular here due to the price tag.

[brantuk]

If it has to be an EQ3-2 then it's best to look for one with the steel tube legs rather than the square alloy legs. It'll be much more stable but you will still have to calculate the load and stay well within limits. This site gives most popular mount loadings for imaging and observing (in the dimensions section):

https://focusscientific.com/index.php/cPath/49_56

Hth

[wuthton]

46 minutes ago, cresskh said:

Why EQ5 doesn't suit for imaging with RC? The payload should be fine right?

It's not just payload but you've also got the focal length to consider and a 6"RC is well out of the EQ5's comfort zone for imaging purposes. 

I imaged with an EQ5 Pro for a few years and would never consider anything over 500mm and even then for reasonable results it needs to be small and light, ie a refractor. 

[billyharris72]

2 hours ago, cresskh said:

Why EQ5 doesn't suit for imaging with RC? The payload should be fine right?

You're right in terms of weight; the EQ5 could definitely support it. My reasons for thinking it's not a good choice for that tube are:

1) Partly focal length. At 1,350mm you need something very stable, and so need to go less than the rated payload (which is for visual). The typical guidance I have seen on here suggests that, for a reasonably short focal length, half the stated load, but cut more for a longer focal length.

2) For the 200mm Newt, bulk is as much an issue as weight. It's a great big sail crossed with a great big lever and is not conducive to stability. I use one for visual on an EQ5 and it's okay, but right on the limit.

3) The EQ5 is a good visual mount (it's what I use and I like it a lot). But it is not designed for AP. For example, the gearing on the drive is not as smooth or precise as the HEQ5 or EQ6 mounts, and it suffers from periodic error (all mounts do, but this more than the more high-end ones). You can use it for AP, but it will be at its best with a smaller scope, or for shorter exposures. I've seen good pics on here with a 150mm scope and an EQ5, but it would be really hard work since it pushes the mount so hard.

4) Taking 2 into account, a RC to me says long exposure, serious atrophotography and / or astrometry. It's not built for anything else (it suffers from a large central obstruction, poor contrast and severe off-axis astigmatism in exchange for getting rid of coma). It's a fantastic scope for the specialised purpose it is designed for (basically measuring stuff), but is outperformed by Newtonian, SCT or refractor scopes for a mixture of visual and AP, or for "typical" amateur astrophotography.

I think if you went with an EQ5, had lots of patience and subbed the RC6 with a 6 inch SCT and focal reducer you would have something more usable, but a small (80mm) refractor would be even better. You really don't need a lot of magnification for good DSO photographs, stability is much more important.

Billy.

[Owmuchonomy]

I fear you will be eternally disappointed in DSO imaging outcomes with anything less than an HEQ5 especially at focal lengths over 750 mm.

[billyharris72]

2 hours ago, Owmuchonomy said:

I fear you will be eternally disappointed in DSO imaging outcomes with anything less than an HEQ5 especially at focal lengths over 750 mm.

There is a lot of truth in this, but I would say it depends to a large extent on your motivation. I use an EQ5 and an ST80 (if I'm going to have a shaky mount I might as well have some CA as well). My attempts at astrophotography are, frankly, awful. And frustrating. But also enjoyable. I'm learning about what works and what doesn't, and when I manage an even vaguely half-decent effort it's an image I took -  it serves as an observing record of something I saw. I also sketch (equally badly!) at the eyepiece, and feel I benefit just as much from this.

What it comes down to is that I am primarily a visual observer, and see photography as a way of recording what I have seen, or possibly bringing out a touch more detail by using longer (but still short) exposures. That, plus the challenge of learning a genuinely difficult skill, is fun and enriches my enjoyment of the hobby. If I want awesome images I've got the internet and astronomy mags, but these are not things I aspire to produce. I'd like to, but I don't have the budget.

I think the disappointment would be if someone went for an EQ5 and a scope too big for it, hoping to take beautiful, long-exposure images of faint DSOs. That would be a recipe for frustration of an altogether less enjoyable kind. But so long as the expectations are realistic I'd say go for it. Bearing in mind what is achievable even with a barn-door mount, I'd hate to put someone off for lack of budget.

[jambouk]

In deep sky [long exposure] astrophotography, the mount is just, if not more, important than the scope. Scopes are relatively cheap. I'd say you need to reassess how important the imaging is to you, and if you really want to be doing long exposures (more than 15-30 seconds) then I think you need to re-think the proportion of money you propose to spend on the mount.

for the scopes described, I'd say an HEQ5 would be the minimum and I fear even then an 8" newtonian will be too much for it, so I think an NEQ6 or AZEQ6 which are probably 2x-3x your current mount budget.

james

 

[cresskh]

Thanks guys! Really appreciate all the advises.

I'm not really getting a RC6, but it looks great and I am tempted.
But I have no idea which scope is best suited for my purpose. Hell, I'm not even sure what's my main aim.
I mean I'd like to go DSO, but it seems like my budget constraint really puts a limit there.
At the same time, I'd like to casually do lunar/solar/planetary too.
Maybe I'll end up buying 2 sets of mounts/scopes for different purpose...

[jambouk]

It's not uncommon for newbies to want to look at, and image solar system targets and DSOs. So there needs to be a compromise, as no one scope allows this easily. 

If the interest is more towards the solar system imaging then the mount is less important, but if you go for a latger aperture scope you'll need a more chunky mount.

I'd say get a decent mount and that keeps all options open to you.

Astro kit holds its price reasonably well so if you buy good quality stuff second hand, look after it, you'd be able to sell it on in a year or two and not be greatly out of pocket. 

You have to remember all the added costs of other things such as dew control, motor focuser, field flatteners, focal reducers, barlows or power mates, batteries, planetary camera and filters, DSO camera and filters, licenses for software, usb leads, usb hubs, vibration pads, velcro... It's a never ending money pit. Any budget you identify for astro will not be enough and you'll need to double it. 

James

[ollypenrice]

On 23/3/2016 at 14:53, cresskh said:

Yes, I am aiming to go into AP slowly due to budget constraint. Which is the reason why I am upgrading my equipments slowly, mount first scope later.
Why EQ5 doesn't suit for imaging with RC? The payload should be fine right?
I think as starters, I will try short exposure AP first for brighter DSO before going into the real faint DSO.
So maybe for now, a moderate mount might be sufficient for me?

For some reason payload seems like a fixation on astronomy forums. It does need to be respected but it is much less than half the story. The bulk of the story is about accuracy. A small RC with typical DSLR might be imaging at 0.7 arcseconds per pixel. This means you want to be achieving a tracking accuracy, under guiding, of around half that, say 0.4 arcseconds. This level of accuracy is very hard to obtain. It is perfectly possible on premium mounts (6000 USD and upwards) and can sometimes be achieved on budget ones like the HEQ5/NEQ6. But even when the mount can do it, will the stability of the sky (the seeing) allow it? Quite possibly not.

There really is no point in buying an inadequate mount. If it cannot track to the accuracy dictated by your pixel scale (focal length is a shorthand way of saying the same thing) then you would get the same real resolution plus a wider field of view by using a shorter focal length.

It really is 'mount, mount, mount.' If you have the most accurate rifle in the world but the sights are rattling loose you won't hit your target. No way round this.

Olly

[Neil27]

I think Olly brings some valid points to the discussion.

However the OP did mention getting into this hobby slowly, with AP on brighter objects first then fainter ones later and as skill, equipment improves.

I think anyone looking for an up to $500 mount will not expect text book results but with a modest small refractor or a smaller RC and a lot of patience it can be achieved, just not as readily as a set up costing many times that and under very favourable skies.

Often the end goal is thwarted by many things, budget being one of them. 

[jambouk]

There any many types of "imager" - Olly is one of a handful at the far end of the continuum who only settles for perfection, while the rest of us just sit opened mouthed at the results and the hours and hours it has taken to capture and process the data. 

On that continuum are those who like to hold their smart phone to the eye piece of a Dob mounted relfector, those with kit classically totally inpractical for astrophotography, those who are happy with rough and ready unguided images (myself included here) and those who guide and aspire to be nearer to Olly on that scale.

If you are happy with rough and ready inages you'll be able to get these with whatever scope / motorised mount combination, but as Olly suggests the less matched up the scope and camera [and mount] the more rough (and less ready) your images will be

I would still suggest an HEQ5 mount or equivilant should be the minimum you should go for if you are "serious" about wanting to do some astrophotography. Plenty of people guide these mounts and get very nice results, but not paired with a scope with a 2m focal length I suspect. There are always exceptions to the rule and somone probably has imaged with 2m focal length on a very low quality mount, but you'll be throwing away lots of subs and limited to very short exposures. 

The other thing I can't see mentioned if your sky - what is the light pollution like there?

James

[cresskh]

4 hours ago, Neil27 said:

I think Olly brings some valid points to the discussion.

However the OP did mention getting into this hobby slowly, with AP on brighter objects first then fainter ones later and as skill, equipment improves.

I think anyone looking for an up to $500 mount will not expect text book results but with a modest small refractor or a smaller RC and a lot of patience it can be achieved, just not as readily as a set up costing many times that and under very favourable skies.

Often the end goal is thwarted by many things, budget being one of them. 

Thanks Neil for speaking up my mind.

I still haven't decide which direction in AP that I want to go into. Of course from all the website and magazine, DSO seems to attract me the most, but I also do understand from my local astronomy club that DSO is at the far end of spectrum and it will suck you (and your money) in forever. There's no turning back.

I'm still a beginner with limited budget, and am happy to be on a slow learning curve to that I can acquire and master each and every skills and knowledge. It's a hobby, not a race to the top. I enjoy the process of learning and interactions with amateur astronomers from all walks of life.

[cresskh]

3 hours ago, jambouk said:

There any many types of "imager" - Olly is one of a handful at the far end of the continuum who only settles for perfection, while the rest of us just sit opened mouthed at the results and the hours and hours it has taken to capture and process the data. 

On that continuum are those who like to hold their smart phone to the eye piece of a Dob mounted relfector, those with kit classically totally inpractical for astrophotography, those who are happy with rough and ready unguided images (myself included here) and those who guide and aspire to be nearer to Olly on that scale.

If you are happy with rough and ready inages you'll be able to get these with whatever scope / motorised mount combination, but as Olly suggests the less matched up the scope and camera [and mount] the more rough (and less ready) your images will be

I would still suggest an HEQ5 mount or equivilant should be the minimum you should go for if you are "serious" about wanting to do some astrophotography. Plenty of people guide these mounts and get very nice results, but not paired with a scope with a 2m focal length I suspect. There are always exceptions to the rule and somone probably has imaged with 2m focal length on a very low quality mount, but you'll be throwing away lots of subs and limited to very short exposures. 

The other thing I can't see mentioned if your sky - what is the light pollution like there?

James

I'm staying in Kuala Lumpur, the capital and light pollution is very bad here. There's no regulations to control that. But one to two hours drive away is not a problem for me to get a dark sky. The main problem here is the cloud with average rainfall of 2500mm. We can only pray for that.

[ollypenrice]

If you don't go for a high performance mount do go for a short focal length. I think that what matters from my previous post is that long focal length imaging is only worthwhile if you have a mount that can deliver the necessary accuracy. If you put a 6 inch RC on an EQ3 you will probably obtain no more detail than you would with a 300mm camera lens and you will have a fraction of the field of view. It would be pointless. This has nothing to do with perfectionism, just reality.

If you are fighting LP then narrowband imaging with a mono CCD is the best way - but expensive.

Olly

[DanWebster]

I have an EQ5 mount, and with ST80 and a QHY5ii for guiding, my Equinox66 and Canon 1100D can get good 5 minutes subs.

I specifically chose the Equinox66 because it only weighs 2KG and the focal length is just 400mm.

Here's a random 5 minute sub of M81 and M82 

I've not been able to try for longer subs, as I've only just got it up and running a couple of weeks ago, but I'm hopeful that there's more in the setup.

My back garden is quite sheltered too, so it gets very little wind, which no doubt helps.

 

None of that stops me wanting a bigger mount though... an AzEq5 GT would be nice... and a CCD... and a permanent setup while I'm at it... 

Until then the EQ5 is doing ok, especially now that it's not struggling with the huge 200p.

[kens]

Assuming you have a DSLR, you may do well to simply put it on your mount with say, a 200mm or 300mm lens. There are numerous DSO targets suitable for those focal lengths and it is a great way to learn astrophotography.

BTW, since you are located near the equator you want to be sure whatever mount you get can work at low latitudes without, say, the counterweights striking the tripod  legs

[jambouk]

If you have bad light pollution, you won't get away with lots of 15 second subs on  a colour DSLR sensor. You will either need much longer subs with a strong LP filter or as Olly says, a mono sensor and narrowband. Either way you'll need to be prepared to guide. Therefore again you need at least an HEQ5 or equivalent. 

james

[cresskh]

Yes, LP is bad here but I probably won't try DSO in where I stay. Local astronomy club here always organizes trips to dark places for imaging, sometimes for few nights.

I guess I'll have to see what kind of mounts are up for sale in my region, and decide based on my budget. I'm interested to get an RC but you guys are right, if my mount can't support the FL, no point in getting that. Perhaps just a refractor and I'll start off with planetary and maybe some brighter DSOs. I'll be more than happy as a beginner.

[cresskh]

Btw, what's your opinion on some mid range mounts like iOptron? Seems to be a popular choice here in my place...