What scope for an HEQ5 mount?

[Lukeness]

I currently own a SkyWatcher HEQ5 Pro GOTO Mount with a payload capacity of 15kg and a SkyWatcher Black Diamond 10" Collapsible Dobsonian Telescope which weighs 15kg. I've tried putting this on the mount but i'm pretty sure it's too heavy.

So i'm currently looking at buying a smaller telescope to mount on it and was hoping you guys could help me pick one out. I'm looking at something like this http://www.ozscopes.com.au/skywatcher-black-diamond-bd2001p-ota-reflector-telescope.html

So my questions are - Regarding astrophotography, how big of a difference does a smaller telescope make compared to a 10" such as mine? say a 8" and a 6"?

#2 - Whats the difference between a reflector telescope and a refractor, visually and with the use of a SLR camera?

#3 - If the maximum weight on the mount says 15kg, does that mean just the telescopes weight alone or does that include the counter weights as well?

#4 - What telescope (OTA) would you recommend to use with the HEQ5? brand, size etc

#5 - What would be the maximum weight you would want to use with the HEQ5 mount?

#6 - With the link just above where it says 200/1000. What does that mean exactly?

Even if you answer one its greatly appreciated, thanks.

 

[Zuben Elgenubi]

Hi Lukeness, welcome to SGL 

The maximum recommended weight for a mount does not include the counter-weights. However, for imaging, you do not want to be pushing the mount near to its upper limit. Skywatcher give a payload of 11kg for imaging but I'm sure many people would suggest not going over 9-10kg, perhaps even less.

One of the most popular scopes for astrophotography is the small refractor, something like an 80ED:

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

As for the scope in your link, 200/1000 means that it has an aperture of 200mm and a focal length of 1000mm.

[nightfisher]

Again, another vote for an 80mm ED refractor, well regarded for deep sky imaging

[jambouk]

As you've probably come to realise, every telescope has pro's and con's. It's easy for others to highlight these, but the decision needs to be yours.

For imaging: Reflectors have the aperture so light gathering is good, and as there are no lenses, do not generally suffer with chromatic aberration. But... They are generally bigger so potentially pose more of an issue for the mount and may act as a wind sail (though imaging when windy isn't ideal); they suffer with coma so you may need a coma corrector; need collimating; may be trickier to guide than a refractor; sometimes has issues with achieving focus unless you get a low profile focuser; secondary mirror can dew up and people often fit a secondary heater; are bigger to carry around. For observing, the eye piece is generally in a good position but at times is in a very tricky place and may need to get rings which allow you to rotate the tube; large aperture means fainter stuff will be more easily visible.

Refractors [for imaging] are smaller and compact and don't generally need collimating. They can suffer with chromatic aberration depending on which version you buy (less problematic with doublets, and hopefully near gone with triplets (costly)), may suffer with a non-flat field so need to buy a flattener; achieving focus usually less problematic than reflectors, but can usually be solved with spacing rings; front lens can get dewed up so need dew shield/dew bands; relatively easy to guide. For observing, the smaller aperture means harder to see more faint objects, but quality of image may be superior compared to the reflector; eye piece position can be in low positions and may need to use diagonal to make viewing more comfortable.

There will be other pro's and con's, and other may well disagree with what i've put.

There is no one scope for all eventualities. For dso imaging i'd say a small refractor; for observing a big newtonian; for solar system imaging an sct/mak; for solar.... And don't forget a pair of binoculars you can always keep in the car for day time nosing of terrestrial targets and for those times you are driving at night through a dark area and just want to stop and have a nose around the night sky.

James

[laser_jock99]

I currently own a SkyWatcher HEQ5 Pro GOTO Mount with a payload capacity of 15kg and a SkyWatcher Black Diamond 10" Collapsible Dobsonian Telescope which weighs 15kg. I've tried putting this on the mount but i'm pretty sure it's too heavy.

So i'm currently looking at buying a smaller telescope to mount on it and was hoping you guys could help me pick one out. I'm looking at something like this http://www.ozscopes.com.au/skywatcher-black-diamond-bd2001p-ota-reflector-telescope.html

So my questions are - Regarding astrophotography, how big of a difference does a smaller telescope make compared to a 10" such as mine? say a 8" and a 6"?

#2 - Whats the difference between a reflector telescope and a refractor, visually and with the use of a SLR camera?

#3 - If the maximum weight on the mount says 15kg, does that mean just the telescopes weight alone or does that include the counter weights as well?

#4 - What telescope (OTA) would you recommend to use with the HEQ5? brand, size etc

#5 - What would be the maximum weight you would want to use with the HEQ5 mount?

#6 - With the link just above where it says 200/1000. What does that mean exactly?

Even if you answer one its greatly appreciated, thanks.

 

Regarding astrophotography, how big of a difference does a smaller telescope make compared to a 10" such as mine? say a 8" and a 6"?

Bigger is not always better- bigger scopes gather more light but have longer focal lengths- making tracking the stars more difficult. A 6" scope may work well on an EQ5 but even with an 8" scope you might start to struggle.

#2 - Whats the difference between a reflector telescope and a refractor, visually and with the use of a SLR camera?

Reflector pros- large aperture for the money, faster focal ratios (e.g. F4) are possible (more suited to DSLR use), true apochromatic performance.

Reflector cons- large=less portable/bigger mounts required, collimation is required before imaging sessions (not always for visual) and a coma correcting optic is required for imaging (not always for visual), less contrast due to the secondary mirror being in the optical path.

Refractor pros- small portable scopes, no colimation required, more contrast (no obstructions in the optical path), basically 'plug-n-play' scopes.

Refractor cons- optically slow (~F7.5 in many budget ED scopes), for imaging you might still require a field flattener correcting optic, smaller appertue for your dollar!

#3 - If the maximum weight on the mount says 15kg, does that mean just the telescopes weight alone or does that include the counter weights as well?

The payload should not include the counterweights. EQ5 imaging capacity is about 11kg

#4 - What telescope (OTA) would you recommend to use with the HEQ5? brand, size etc

The Skywatcher ED80 refractor is a nice scope for sure, but opticaly a bit slow (like having a camera lens stuck at F8 all the time.....). If I had an EQ5 and wanted to do both imaging and some visual I'd be thinking about a 150mm/6" Newtonian reflector as a compromise all rounder.

A couple of models spring to mind the Skywatcher 150PDS or maybe something similar from the GSO stable like the 6" F5 ?

#5 - What would be the maximum weight you would want to use with the HEQ5 mount?

According to one UK distributer 11Kg for imaging 15kg visual - I never owned an EQ5 but that seems reasonable. As an example the GSO 6" F5 Newtonian OTA mentioned above comes in at 6.9Kg- by the time you add a DSLR camera maybe a guidescope and some other accessories you'll soon get close to the 11Kg.

#6 - With the link just above where it says 200/1000. What does that mean exactly?

It means the apperture of the scope is 200mm (8") and the focal length 1000mm

[MattJenko]

Can't argue or disagree with any of the comments made. I don't think you can go wrong with a 130PDS or 150PDS. I have the refractor, the Skywatcher 80ED for my HEQ5, and think it is great and I am getting some good results (only had it since the summer) and a scope like this makes life a lot easier because imaging is tricky enough anyway, so make it as easy as possible when you start out. Once you know what you are doing a bit more, then you will know what you want and can deal with if you want a change.

[rowan46]

I currently own a SkyWatcher HEQ5 Pro GOTO Mount with a payload capacity of 15kg and a SkyWatcher Black Diamond 10" Collapsible Dobsonian Telescope which weighs 15kg. I've tried putting this on the mount but i'm pretty sure it's too heavy.

So i'm currently looking at buying a smaller telescope to mount on it and was hoping you guys could help me pick one out. I'm looking at something like this http://www.ozscopes.com.au/skywatcher-black-diamond-bd2001p-ota-reflector-telescope.html

So my questions are - Regarding astrophotography, how big of a difference does a smaller telescope make compared to a 10" such as mine? say a 8" and a 6"?

#2 - Whats the difference between a reflector telescope and a refractor, visually and with the use of a SLR camera?

#3 - If the maximum weight on the mount says 15kg, does that mean just the telescopes weight alone or does that include the counter weights as well?

#4 - What telescope (OTA) would you recommend to use with the HEQ5? brand, size etc

#5 - What would be the maximum weight you would want to use with the HEQ5 mount?

#6 - With the link just above where it says 200/1000. What does that mean exactly?

Even if you answer one its greatly appreciated, thanks.

 

1 there is a difference in resolution between a 10" f6 scope and a 80mm f6 scope so theoretically the bigger scope will get finer detail however atmospheric conditions may even the playing field as the seeing may not support the increased appartures resolution.

2 if the reflector and the refractor were equal size  the refractor providing it was apochramtic should give better views as there is no central obstruction. however the cost difference between an apo and a  reflector  makes  the reflector a more cost effective visual scope you get a lot more apparture inches for the same price.   Imaging wise there are trade off which makes the refractor an easier scope to use.  For imaging you don't necessarily need more apparture you an get get more light into a system by leaving the camera shutter open longer so you can have a small scope with good optics and no contrast drop off . This is why many imagers choose a small fast apo as the first  imaging scope

3 counter weights are separate from  payload weight. However if you are imaging you want to stress the mount as little as possible so you should be aiming at aprox 50-66% total payload the nearer 50 you can get it will be best

4 the ed80 with flattener reducer is a proven imagers scope it requires no collimation so its easy to setup. the 130pds and coma corrector is getting good results but its not as easy to use straight out of the tin because of its need for collimation.  If it were my money i may consider getting the 130pds and coma corrector or ed80 and focal reducer if i could afford it and keep the 10" for visual. or if I had to sell the 10" to afford an imaging scope i might consider buying the 130pds and an 8" dob. visual scopes and imaging scopes don't really mix unless you have a shedload of money. If you don't have deep pockets its more cost effective to get 2 scopes that do one thing well rather than 1 scope that does everything well (even should such  a scope exist)

5  as answered between 7.5 and 10kg

6  200 means the apparture  1000 means focal length or  a focal ratio of f5

[lonebod]

Is your collapsible a flex-tube? If so you might struggle to get appropriate tube rings that stay on when the tube is collapsed. If you find them let me know cause I've got the 8" and might think about putting it in an heq5 for visual.

[Lukeness]

Thanks to every one for their answers, i've definately thought about the responses and looked around for something to use especially the 80m ED refractor that you've suggested.

I've put the collapsible tube on mount but i've only put it on the mount when it was extended. The tube rings would get in the way if i were to retract it, so it stays extended. But i'll cease to use this scope on the mount any more.

[Lukeness]

I'm currently trying to decide between what two scopes to buy but im leaning more towards the ED80 as it's been suggested more, but I would also like to use it without my SLR camera, viewing it through a lens with my eye.

The two im looking at are - http://www.ozscopes.com.au/refractor-telescope-skywatcher-black-diamond-ed80.html

http://www.ozscopes.com.au/skywatcher-black-diamond-bd2001p-ota-reflector-telescope.html

the 200/1000 doesn't say how much it weighs though.

So im just asking what you think would be better over all.

[jambouk]

If you hunt around the internet it will say the weight of both scopes.

In my mind these two scopes are polar opposites.

The reflector is a visual scope, the refractor an imaging scope; yes you can do both with both scopes but need to consider all the limitations we have outlined above.

I think you'll be disappointed when looking through the ED80 with an eye piece (a set of lens but referred to as an eye piece). But i worry you may struggle with collimating a reflector. Make sure you watch a you tube video clip on how to collimate a reflector and decide if you want to do this and buy the related kit to achieve this.

If you think collimation is within your grasp, i'd go for the reflector as you can still do basic imaging and have the benefit of greater aperture. You just need to make sure you have a low profile focuser and the relevant adapters to connect your camera to the scope.

Have you been along to a star party and had some hands on the scopes there?

James

[ollypenrice]

I would always have argued in favour of a small apo for deep sky imaging on the grounds of ease in a field which is difficult at the best of times. However, some very remarkable images have been produced recently by two members here using small Newtonians.

http://stargazerslounge.com/topic/229736-heart-and-soul-as-one-10-pane-mosaic-130pds/

http://stargazerslounge.com/topic/229640-trio-using-130pds-with-atik-460-ic-1795-ic-1871-ic-1805/

The 'small' bit is important because if you overload the mount you have no hope of matching this kind of quality. Aperture is not necessarily a virture in DS imaging. An 8 inch scope is not within the comfort zone of an HEQ5, it is right on the limit, which is not somewhere I ever want to be with a mount. Would these guys have done better with a rather larger Newt? No.

DSLRs are not dedicated astro cameras and perform best with fast F ratios. If the F ratio of the optics becomes too fast, however, things like focus, tilt and collimation become very challenging.

But aperture, of itself, is not important.

In 85mm; http://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/i-rNfQT5R/0/X3/M42%20WIDE%202FLsV3-X3.jpg

Olly

[Lukeness]

Ok, I think im going to go with the 80ED. Thanks every one for their input, i've definately learned a lot.

[ollypenrice]

It's a proven path. Have fun.

Olly

[AstroAdam]

Just chiming in, even though you've made your decision

I've got an HEQ5, and I've had various scopes on it in the past for imaging.

1) First attempt was with my 8" f/6 Newtonian.  This DOES work to a degree.  However, it's a heck of a lot harder to balance properly due to the camera being stuck on the side of the tube, as well as acting like the aforementioned 'wind sail' when there's anything other than a light breeze.  You can get results from this, but it's a lot more frustrating and will make you want to give up a lot sooner!

2) 80mm Refractor - Wonderful .  Light, easy to guide with a finder-guider, nice wide field.  Not so good for the smaller objects obviously - especially with a DSLR.  

3) 102ED refractor - See above

4) Celestron C8 with f6.3 reducer (to take it down from a long and 'slow' f10 to f6.3 for imaging. - Good balance between the two.  Light at just over 5kg, not the wind sail that the newt is, but with the same sort of light gathering power.  Harder to guide that the refractors, but worth the effort.  Also doubles (at f/10) as a great planetary imaging scope.

All-in-all Id definitely say avoid biggish Newts on an HEQ5 for imaging unless you have no alternative, or you already have one and want to give it a go.  However, I'd say you'll soon be hankering after a 'frac, so you've made the right decision