Breaking the piggy bank

[FrenchyArnaud]

Hi all, 

After quite some time using a alt/az goto 114mm and a 150mm on eq3+RA motor, the GF and I have decided to break the piggy bank and step things up. Like, step things UP, WAY UP. 

Specifically, we are thinking 250 or 300 mm on HEQ5 PRO or even 6. We also would like a 2" focuser. The main is visual (we have a thing for M objects + Jupiter and Saturn... Don't ask) but beginning some decent AP is also on the table. (We have all it takes for that... Except OTA+mount!)

Budget is £1500, stretchable but not too much ! Of course we have a few ideas already, but if you have in mind "the" combination ota+mount for us, i'd be happy to hear about it... ;-)

[John]

For visual I'd go for a dobsonian at those apertures. A 10" or 12" equatorialy mounted newtonian is a really massive instrument and more beneficial if permanently mounted (ie: observatory / roll off shed). For the 12" I think the EQ6 is definitely required as well.

A 10" dob is pretty portable and easy to set up and use and even a 12" is still quite manageable.

If AP is a strong aspiration then I'm not sure the HEQ5 would be enough for either optical tube and even the EQ6 might be pushed.

See what others suggest though - thats the joy of this forum - you will get lots of feedback pretty quickly

[nightfisher]

For mainly visual a big newtonian really wants to be on a dob base, it just makes so much sense. Why not look out for a decent used 10 or 12 dob and look for a used HEQ5 to suit the imaging with a smaller scope

[Chris]

I'd say two setups, so working on £1500 ish budget:

1) 10" Dob for visual - https://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-250px-dobsonian.html 

2) Advanced VX mount and 130pds plus coma corrector for imaging:

https://www.firstlightoptics.com/celestron-mounts/celestron-advanced-vx-mount.html

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-130p-ds-ota.html

https://www.firstlightoptics.com/coma-correctors/baader-mpcc.html

 

[FrenchyArnaud]

The paradox we encountered is the following : 

- the 114 alt/az goto is pretty good at tracking but does not have the pure light power for AP. Magnification is great but resolution is low. AP is possible but rotation occurs even at 20s expositions...

- the 150 has much more light gathering power but its mirror is beyond [censored]. (Big boss seben) And the eq3/ra is too flimsy for any AP other than planetary. (Allowing ultra short exposures)

So we want something that would solve those issues and give the better of both : aperture, stability, resolution, Goto. 

Now, I understand why you both say "dobsonian" but it still is fundamentally an altaz (field rotation)... And in any case, I don't think I can gather the budget (or the space in the car) for a 10/12dob goto + a 8/10 eq5. 

If anything, I'd rather limit the aperture to 8/10 on the same budget but have a rock solid goto eq mount and a first class set of mirrors. I was watching the skywatcher 250 pds + heq5 pro (£1500 new), but I am not clear on the quality of its primary ? 

[FrenchyArnaud]

The VX mount is a lead to explore, I need to figure out how it compares to the heq5 pro (similar price)

A dobsonian non goto...I din't know, I haven't really thought of it. My first reaction is, it would have to be a "foldable" one if we really are to load two of those beasts in the car...

[FrenchyArnaud]

After a few extra nights punching holes in what grey matter I have left, I decided it's not gonna be dob, it's gonna be heq5pro (or eq6 if good 2nd hand deal). We'll change the car for a big estate anyways. 

I am still uncertain though as for the OTA, i am really considering the sw explorer 200pds (or maybe 250), but is there something obviously "better" in the same kind of aperture+price? 

[John]

If your remaining budget would run to it, the Orion Optics newtonians are lighter than chinese equivilents and have very good optics. They do cost quite a bit more though. An Orion Optics F/4.8 10" newtonian optical tube, bought new, would cost around £970 including the premium quality mirrors option and a 9x50 right angled finder. The HEQ5 mount would carry such a scope well for visual and maybe even for some astro photography ?

 

[FrenchyArnaud]

I was unable to locate this ota+coating options, do you have a link by any chance? 

[John]

Here is a link to the Orion Optics page for their 10" VX optical tubes:

http://www.orionoptics.co.uk/VX/vx10-10l.html

Remember that the listed prices do not include VAT - that is added on at the end.

[ronin]

If the intention is AP then you will need bigger then an HEQ5, they would just about handle visual but you would need an EQ6 at least and if you went to 300 then I would say an EQ8 minimum, fairly sure you will find the EQ6 inadaquate for a 300. Talking recently to someone who is finding their EQ6 is really inadaquate for AP and are looking for a bigger option.

If the chance occurs go look at the mounts, preferably in use. They are a bigger item then many suspect and if they are too much then they do not get used and you do no observing or AP.

[DRT]

I think your objectives need a big aperture Dob for visual and a big mount and good quality smaller aperture scope for AP. You do not need a massive scope to take good images, but you do need a good mount. A massive scope helps for visual.

You need two set-ups unless you are prepared to compromise on both

 

[Chris]

Definitely two setups if you want to do AP and visual. Under dark skies a lot of aperture is a good thing for visual, but I'm still unclear why you think you need a lot of aperture for AP? for planetary imaging with very short stacked exposures yes for the resolution, but for seep sky it's all about f/ratio, quality of optics, and a short enough focal length that the mount can cope and track the object for long enough to take multiple long exposures without the photons smearing across the sensor. 

Google the ED80 and 130pds, or look at the images people have take on here, and see what kit they have used   Not many people use massive Newts for deep sky AP unless you have something like a 4k Mesu mount, or an EQ8 minimum permanently setup in an observatory. For DSO AP on the go you honestly want an HEQ5 or AVX plus something like an ED80 or 130PDS. 

I'm looking at the below as my next imaging plus grab and go scope, it's tiny. Quality not aperture for DSO AP

https://www.firstlightoptics.com/william-optics/william-optics-zenithstar-61-apo.html

 

 

[MartinFransson]

I have the HEQ5 and a 150-PDS. I would NOT put a 250 or 300 on it! A 200 might work but it will not be rock solid for AP as you wanted. Don't think the AVX is any different. For AP I would go for a used 130-PDS, they are so cheap and if you take a look in the thread "imaging with the 130-PDS" you will see that it is capable of wonderful stuff in the right hands. 

[FrenchyArnaud]

Considering your answers, and the fact that I already have a 114-f9 and a 150-f5, I came to the conclusion that first and foremost, what I really need is the max-payload mount I can find.

So the hunt for neq6 begins then, after a few months, I'll figure if a 10" f4 is of interest for me and would be confortable atop the mount. I will in any case try to find a modern 100 or 130mm with a DS focuser. 

[FrenchyArnaud]

Well, the hunt was short 

It seems that, thx to a member of the forum, I'll have a neq6 within a couple of weeks. 

 

[nightfisher]

22 hours ago, FrenchyArnaud said:

Considering your answers, and the fact that I already have a 114-f9 and a 150-f5, I came to the conclusion that first and foremost, what I really need is the max-payload mount I can find.

So the hunt for neq6 begins then, after a few months, I'll figure if a 10" f4 is of interest for me and would be confortable atop the mount. I will in any case try to find a modern 100 or 130mm with a DS focuser. 

If you put a 10" newt on an EQ mount for imaging you will hate it, the largest newt i would consider is the GSO 8" f4 but even that would be a pain in the rump

[DRT]

10 minutes ago, nightfisher said:

If you put a 10" newt on an EQ mount for imaging you will hate it, the largest newt i would consider is the GSO 8" f4 but even that would be a pain in the rump

I agree with that. There is a very good reason why Newts built specifically for imaging tend to be small. 

@FrenchyArnaud - if you want a big aperture imaging scope you should consider a large SCT (a C9.25 being a popular choice) rather than a Newt. The Newt will simply be too unstable at the size you are considering. 

[FrenchyArnaud]

Yes, I am considering CST's too, but at the moment tbh 1) I am not clear with the perfs (2000mm+ of focal length? I am scratching my head. F10? For AP... Not sure about that) and 2) the 9.25 would be a financial stretch which I am "uncomfortable" with now. 

Having looked at the question under every possible angle, it seems that in any case, whatever the ota, the mount will always be the weak link at the end of the day. 15kg or 40kg, it actually changes nothing : I am not walking with it to my usual spot, it will have to be by car, so it makes sense to go oversized (as much as my finances allow). 

Once I have a real "feel" of what those xxl mount really give, then I will be much more in the clear to what I really need for a bit of hobbyist AP. It might be the case that a 130pds is just fine, or I turn to refractors or to CSTs... I am open minded. I'll first spend some time playing with the 114+dslr+neq6 and then... then, in a few months, I'll consider the rest ;-) If I really think a massive ota investment is useful, I'll do it. I'll stay with my 6" max in the meantime. I've waited 40years to be able to get into the hobby, I can wait 2/3 months for the next upgrade ;-)

[DRT]

52 minutes ago, FrenchyArnaud said:

Yes, I am considering CST's too, but at the moment tbh 1) I am not clear with the perfs (2000mm+ of focal length? I am scratching my head. F10? For AP... Not sure about that) and 2) the 9.25 would be a financial stretch which I am "uncomfortable" with now. 

1) that is what focal reducers are for

2) a second hand C9.25 would be a good option. 

 

 

[spillage]

I think if you are going for dso imaging and expensive refractors are not an option then a 130 or 150 pds is a great option. I think you will need to add a coma corrector to get the best out of it and the dark art of collimation is a must (Its not as bad as some say and I enjoy this).

Is there any reason that you cannot image from home? This option make the whole affair a lot easier to begin with. I still find that even using my home gear I can sometimes forget basic things. I find there is allot of planning needed for remote ap but then again allot of people do. Maybe for me its the time issue and when I get more spare time I will start to do more away from hq.

[FrenchyArnaud]

4 hours ago, spillage said:

Is there any reason that you cannot image from home?

Yes. I have a very small garden in the middle of a suburb, so very little line of sight (and nothing below 25°alt) and it's submitted to city light and neighbour's windows lights 24/7.