HEQ5

[LouisJB]

Hi,

Ok so I need a new tube. I'm going around in circles between a 150 or 200 Newtonian as a 'budget' upgrade and have already posted a bit on here about it. I settle on the 200 then think it will be too big to work well except for visual on an HEQ5 (with ST80 guider). I can take the finders off when imaging, I think the total weight will be around 12KGs or thereabouts. If I go 200mm it will be 200PDS or the similar (but maybe nicer) GSO 200 F5

Then I see a lot of people using this setup and saying it works ok on an HEQ5.

I can't really justify some really expensive carbon tube 8" newtonian, then I might as well put the money to something in a better design like an RC. I could just wait and get something like the 8" RC carbon, or I could wait again and upgrade to NEQ6 and then have choice of the 190MN or similar - but in totally that's considerably more expensive overall.

Really trying to avoid wasting $$$ on stuff that doesn't get along a sensible long term path. 

What I'd like is something I can get decent results with for now, for the next say 6months until I know where I'm heading and what I need. So either spending the minimum now on something that works, or waiting and completely starting again from an NEQ6 upwards. I guess that probably means a 150 would suffice, but it's very little more for a decent 200

Any opinions on this dilemma, it seems really hard to know which way to go without trying things out. The advantages of the 150PDS for example would mean maybe I'd keep it even when getting a longer focal length tube (say the 1600mm Focal length RC), and the RC weight wise would be totally OK on the HEQ5 pro. Then again the 200 would be that much better visually and somewhere in between. However there's no point me getting the 200 size OTA if when I attach the camera etc my imaging is basically thwarted by insurmountable tracking accuracy and balance issues. Then there's the ED80. Arrrgh!

Probably I should get the 150PDS and coma corrector and see what I can get out of it, forgetting that a very little more $ can get a fancier 200mm OTA, should I?

What do I want to image? Everything! But galaxies would be my main goal, and planetary nebula. Bit's of nebula also, I realise I won't be able to satisfy both ends of the spectrum and would be ok only imaging details of parts of big nebula so that galaxies etc are more detailed and close-up.

Please help  

[rowan46]

you may struggle with the pds on a heq5 its a bit longer than the 200p which it can just about cope with and the extra torque generated by the extra length may introduce inaccuracies. Having said that its only what I have read so take it with a pinch of salt till a real imager comes along.

[leelee970]

Always a dilemma.

Myself the mount is the important thing to get right. Save your pounds that little longer and get something better.

But saying that I've an Orion  8" sitting on a Heq5 Pro and I have no problems (even with a second scope attached). But you must get the balance right.

[LouisJB]

But saying that I've an Orion  8" sitting on a Heq5 Pro and I have no problems (even with a second scope attached). But you must get the balance right.

Interesting, do you do any imaging with that setup?

[leelee970]

Yes, I do imaging - planets and DSO

[LouisJB]

ok, well that sounds encouraging did you manage to balance with 2 x 5kg weights? I presume you can do >5min subs with guiding and not get tracking issues show up due to the weight then.

That's all I'm after really, whatever I get is not going to be the final word. But if the 200mm tube with guiding would work reasonably for now on an HEQ5 pro then I can always put that setup on an NEQ6 later when I might by then be thinking to move an even better tube. Sort of stepping-stones between OTA and mount upgrading, incrementally. But if the 200 fails to work I'd be left with a useless setup. So from what you say it sounds plausible...

6-million dollar question, would you go as far as to 'recommend it' or would you take a 150PDS or similar for the primary purpose of imaging on that mount?

[red dwalf]

i`ve recently upgraded myself having had a lovely HEQ5 pro for many years, but when your imaging although the gear doesn`t look too heavy it soon mounts up, with two scopes duel mount bar and two cameras attached it weighed in at just under 10 kg, almost on the limit so no room for any flexabilty, guide scope was a st80 aswell so hardy any weight there, so if you want a mount that your not going to have to change for a long time then i would go for the neq6, new prices only £200 more than a heq5. 

[red dwalf]

scopes wise i would surgest two, a ed80 for imaging, why ? price is not too bad for a good quality ed80 and are versitile little scopes which work well with lots of different cameras be it a dlsr or a smaller ccd chiped camera,

secondly a SCT, again great versitile scopes, can be used for deep sky imaging with reducers although alot of people will disagree, but i`ve had good results, and secondly a great scope for planetary imaging with the long focal length these scopes have and grerat focus travel too.

i have an 8" sct and would only get rid of it for a nice 9.25 version

[malc-c]

A 200P combo with camera and guide scope is right on the limit for the HEQ5, but it works

However, if you are looking at imaging, then the 200PDS with it's larger mirror is more advisable.  SW in my opinion have poor manufacturing processes when it comes to their secondary mirrors,which results in a fifth diffraction spike in most bright star images. I resolved mine by spending £100 on an better secondary from a 3rd party company and now the scope performs really well.

[LouisJB]

Thanks. if I get a skywatcher it will be a PDS for sure, I assume weights are about the same.

For the 200mm sizeI'm actually considering the GSO equivalent which seems to have improvements addressing the issues you mention - slightly better focuser, better mirror cell, small cooling fan also. 

In the 150 size, probably it would be the SW 150PDS as there is no obvious better alternative at that price point.

ED80 comes up a lot. I'm not even sure which one exactly would be used. An ED80 pro, they are around £500 ish?

Interestingly in the local shop the guy said, if you continue in astrophotography you'll end up with one of these -> pointing to a ED 120 pro apo (I think that's the right model) - at around £1500-ish. If that's where I would end up (and ironically that's ok on an HEQ5 pro apparently) then maybe anything else should be as cheap as keeps me going. It's just the 150PDS and 200 GSO are separated by £50 and yet the GSO is much more OTA for the £!

As for SCTs, that's a whole other ball game that I know little about, although I read about mirror flop and that really long focal lengths are probably not what I want. For planets I could get a small compound later for special purpose planets and moon, but I don't think it would be the best DSO tube for me at this stage (but happy to be convinced otherwise).

In terms of that sort of compound my main contender was the 1600mm RC carbon, which again is on on an HEQ5 pro! (about £1000).

Quite a lot of options...  

If I can make the GSO 200 work well enough for imaging until the next upgrade, I'd rather get it over the 150pds due to  the fact it's going to be massively better when used visually and the slightly longer 1000mm focal length would be better for DSOs like galaxies etc yet still not too long to make guiding extremely sensitive to inaccuracies anywhere in the chain from mount to camera.

[rowan46]

The ds will be fine just about I was getting mixed up with the pl which of course isn't made for the 200. So if you are going to image with it the 200pds is the one you want

[JAS]

I have been using the 200pds with st80 guide scope on a heq5 for imaging with a dslr for a couple of years. I was regularly achieving 10 min subs. I have now purchased a mono CCD camera and want to double or triple the exposure time. I am having a lot of problems pushing it past 10 minutes despite the reduction in weight by using and off axis guider. I have now decided to change to an ed80 pro for the weight saving, the heq5 is capable if it isn't overloaded.

If you are considering serious imaging without spending loads on upgrades (leaves more cash for the camera, filters ect) then I would consider the small refractor.

Jason.

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[leelee970]

Sorry for delay getting back to you LouisJB - work got in the way.

 

I added an exercise weight (from Tesco). I also made sure the scope was placed on mount with camera towards mount (hope that makes sense).

[LouisJB]

Sorry for delay getting back to you LouisJB - work got in the way.

 

I added an exercise weight (from Tesco). I also made sure the scope was placed on mount with camera towards mount (hope that makes sense).

No worries! So how many weights, 1 5kg + one exercise weight, or 2 x 5Kg + one exercise weight?

I have 2 x 5Kg weights already, hope that would suffice without extension bars since the centre of the OTA is closer to the pivot point than the weights and that is were most of the weight is (ST80 is pretty light).

[LouisJB]

I have been using the 200pds with st80 guide scope on a heq5 for imaging with a dslr for a couple of years. I was regularly achieving 10 min subs. I have now purchased a mono CCD camera and want to double or triple the exposure time. I am having a lot of problems pushing it past 10 minutes despite the reduction in weight by using and off axis guider. I have now decided to change to an ed80 pro for the weight saving, the heq5 is capable if it isn't overloaded.

If you are considering serious imaging without spending loads on upgrades (leaves more cash for the camera, filters ect) then I would consider the small refractor.

Jason.

Sent from my GT-I9505 using Tapatalk 2

Interesting. I guess (really is a guess) that really long guiding will be impacted by more than weight alone. What sort of things require such long exposure vs. more subs of a shorter length (i.e. 3 x 10mins stacked rather than 1 x 30 mins).

The thing is a small decent refractor is 1/2 the cost of the 8" RC and I would imagine the latter is significantly better for DSOs (speed, once reduced and still retaining a longer focal length), whereas the smaller 150PDS or 200GSO are fast F5 and yet relatively a small bit of pocket change by comparison (probably the cost of OAG setup).

Well if I have that right, the APO ED 80 or similar is >£500, the 150PDS is £229 only. Ok so there are correctors to consider, the Newtonian requires a coma corrector, the refractor will also require some sort of corrector or reducer?

There is the second hand market of course. I saw one 8" RC got for just over £500, that's starting to seem quite a good deal (I could keep the HEQ5 pro indefinitely) or maybe I can get an ED80 or similar second hand. the 150PDS and 200 GSO seem to come up infrequently second hand be comparison, so I've seen so far anyway.

In terms of refractors, can anyone say exactly which model (of the ED80 style OTAs) is the right one for imaging and what reducers etc would be needed - any links to the right models?

[LouisJB]

lets say I'm crazy do join others putting a 200mm OTA on an HEQ5 pro with ST80 on top for guiding.

What length dovetail would be best, the longer 32cm ones or the standard 21cm ones would be equally as good? I guess again this should require a losmandy saddle upgrade, but one step at a time I'm not there just yet...

[rowan46]

Have you read making every photon count 

http://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html

the reason the ed80 is cited as a good companion for the heq5 is the combination is of its speed, simplicity, focal length and weight. the heq5 isn't the best imaging mount its just the minimum required for consistant good photo's but it has to be helped. If you start putting big scopes or very long focal lengths on it then your percentage of subs is going to come down. Yes you can put a 200pds on it and it will work but its not its best combination and if you start putting big and long focal length scopes on it is going to struggle. The best scope for a heq5 is a small short focal length scope put one of these on it and you have a system that will produce quality the refractor is easiest because of its focus, sharpness and its ability to plug and play.

http://www.firstlightoptics.com/pro-series/skywatcher-evostar-80ed-ds-pro-ota.html

http://www.firstlightoptics.com/reducersflatteners/skywatcher-focal-reducers.html

[JAS]

You can get the ED80 (ota only) for £350 here http://www.firstlightoptics.com/pro-series/skywatcher-evostar-80ed-ds-pro-ota.html

You will also need a flattener/ reducer, that is shown at the bottom of the page.

The longer exposures are to pull out the really faint details in nebula ect, and are most commonly used with narrow band filters, that's what I am trying to do anyway!

I don't recall the size, but I just used the standard skywatcher dove tail that came with the scope and added a matching one to the top of the scope rings to mount the guide scope.

Jason.

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[LouisJB]

Ok great. For the ED80, I don't have a 2" diagonal or reducer. I guess the reducer is equivalent to the coma corrector for a newt for about the same price, so I can ignore that. But a diagonal will add some cost about the OTA and corrector/reducer. Still an interesting proposition. In which case I could possibly justify a 100ED - but I'm not totally sure. I can justify more expenditure on something I might keep long-term, but as this stage it's almost impossible to know what I'd really use ultimately. 

In terms of dovetails, ok so standard length is probably good enough by the sounds of it or you would have changed them.

I'm going to read-up and consider the refractor possibilities. Certainly makes the mount issue easier. That or the smaller 150PDS does simplify my HEQ5 situation and get me going for now.

[JAS]

I have not found any reason to change the standard dovetails to be honest.

Jason.

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[frugal]

. In which case I could possibly justify a 100ED - but I'm not totally sure. I can justify more expenditure on something I might keep long-term, but as this stage it's almost impossible to know what I'd really use ultimately. 

If you want to do imaging, check the focal ratios of the scopes. The 80 and 120 are both f7.5, but the 100 is f9, which is a lot slower for imaging.