Buying a new OTA HELP!

04Stefan07 (Stefan) · #1 09-01-2016, 11:49 PM

Currently I have an Astrograph after coming from a MAK. I have only used it twice but quickly realised that an Astrograph isn't the scope for me.

All I want is an OTA that can be used for both visual and astrophotography. When I purchased the Astrograph I actually didn't realise that this type of design is purely just for astrophotography. It has a great sized aperture and focal length but is more designed for deep sky stuff and for people who only want to image.

This is what I need in an OTA:
- Ability to use it for both visual and astrophotography
- Be used for planetary/moon and deep sky imagery
- Be suitable for an HEQ5 Pro mount
- Can be used with an Orion 50mm Mini Guidescope
- Budget of no more than how much the Astrograph is worth ($500).

Any recommendations or advice would be appreciated.

Cheers,
Stefan.

Atmos (Colin) · #2 10-01-2016, 01:20 AM

I'd say an 8" newt either F/4 or F/5. Great for visual because of the small secondary and astrophotography, will need a coma corrector for larger sensors though but you'll need a corrector for most telescopes anyway.

raymo · #3 10-01-2016, 01:37 AM

Got to agree with Colin, but I would go with the f/5, easier to focus, more
tolerant of miscollimation, falls within your budget, and an HEQ5 handles it o.k.
raymo

04Stefan07 (Stefan) · #4 10-01-2016, 08:19 AM

I have been eyeing the ones mentioned below.

http://www.bintel.com.au/Telescopes/...oductview.aspx

I would have thought it was pushing it for weight though?

04Stefan07 (Stefan) · #5 10-01-2016, 08:54 AM

My thoughts.

- SCT/MAK (would love to go down this path but to get an OTA that has a decent aperture is way out of my budget!)
- Reflector (this seems to be the way to go by many people)
- Refractor (again like the SCT/MAK it becomes very expensive to get one with a good aperture but the optics are fantastic).

Still very undecided, need a bit more help and suggestions.

glend (Glen) · #6 10-01-2016, 10:19 AM

If your going to be imaging then you have to work the imaging capacity of the HEQ5, which really is probably around 12kg max. The manufacturers listed capacity sometimes is broken down into suggested imaging and visual limits. The published figures for the HEQ5 at 15kg is the visual capacity.
The GSO (aka Bintel) 8" f5 weight is listed as 12.2kg. Once you add in the camera, a guide scope, adaptors, etc your going to push up the weight by probably another 1 kg for all of that. So it looks like the that scope will be a possible imaging match for the HEQ5 but keep the attachment/accessories weight down for best performance.

04Stefan07 (Stefan) · #7 10-01-2016, 11:41 AM

Good point mate.

Would like to keep the weight down though so I don't need to compromise my accessories.

Quote:

Originally Posted by glend

If your going to be imaging then you have to work the imaging capacity of the HEQ5, which really is probably around 12kg max. The manufacturers listed capacity sometimes is broken down into suggested imaging and visual limits. The published figures for the HEQ5 at 15kg is the visual capacity.
The GSO (aka Bintel) 8" f5 weight is listed as 12.2kg. Once you add in the camera, a guide scope, adaptors, etc your going to push up the weight by probably another 1 kg for all of that. So it looks like the that scope will be a possible imaging match for the HEQ5 but keep the attachment/accessories weight down for best performance.

04Stefan07 (Stefan) · #8 10-01-2016, 11:59 AM

Any suggestions on the below?

- Celestron Omni 150 OTA (150mm x 750mm Newtonian reflector)
- SkyWatcher Black Diamond 120/1000

glend (Glen) · #9 10-01-2016, 12:30 PM

Aperture is king, I would not go smaller if you can get an 8" within the weight limit. Teleskop-Express reworks GSO 8" imaging newts in carbon fibre tubes. The ota weight is just over 7kg inclufing the rings. However, as with all things carbon fibre it is more expensive than locally sourced steel tube standard versions, like twice as much or more.

04Stefan07 (Stefan) · #10 10-01-2016, 01:21 PM

That would be a nice tube to get but Carbon Fibre would be way too expensive!

rmuhlack (Richard) · #11 10-01-2016, 01:39 PM

My suggestion would be a 5 inch or 6 inch f5 newtonian. This would keep you within both your price constraints and the weight limits of the HEQ5. These are two options, both with 2 inch focusers which would be mandatory for imaging:

5 inch skywatcher newt: http://myastroshop.com.au/products/d...sp?id=MAS-069A
6 inch skywatcher newt: http://myastroshop.com.au/products/d...p?id=MAS-069A2

I have previously used a 5inch newt for DSLR imaging on a HEQ5, with very good results - see astrobin link here

04Stefan07 (Stefan) · #12 10-01-2016, 02:06 PM

Would you know how much these tubes weigh?

Quote:

Originally Posted by rmuhlack

My suggestion would be a 5 inch or 6 inch f5 newtonian. This would keep you within both your price constraints and the weight limits of the HEQ5. These are two options, both with 2 inch focusers which would be mandatory for imaging:

5 inch skywatcher newt: http://myastroshop.com.au/products/d...sp?id=MAS-069A
6 inch skywatcher newt: http://myastroshop.com.au/products/d...p?id=MAS-069A2

I have previously used a 5inch newt for DSLR imaging on a HEQ5, with very good results - see astrobin link here

raymo · #13 10-01-2016, 02:15 PM

My Skywatcher 8" f/5 weighs in at 9.9kgs complete with tube rings, dovetail, 9x50mm finder, electric focuser, open end cover, and dewshield.
My HEQ5 happily carries that plus my 80mm achro and a DSLR with lens, and a 12.5mm illuminated reticle EP.
You can remove the dust cover on the rear end if you want, it weighs
300gr, half the weight of a DSLR.
I agree with Glen, why go with a 5 or 6" when the HEQ5 will carry the SW 8" plus accessories easily?
Hope this helped.
raymo

04Stefan07 (Stefan) · #14 10-01-2016, 02:56 PM

Looks like a Newtonian design telescope is the way to go.

Out of curiosity with the refractors other than aperture are there any good points about them?

rmuhlack (Richard) · #15 10-01-2016, 03:08 PM

Quote:

Originally Posted by raymo

I agree with Glen, why go with a 5 or 6" when the HEQ5 will carry the SW 8" plus accessories easily?

Well Stefan has stated he wants to keep the weight down and have an OTA for less than $500. Anyway, I found a 5 inch f5 newt to be a perfect match for the HEQ5. The setup I used, with OTA, 2 x losmandy dovetail bars, guide lens & cam and cooled DSLR (all shown here) was about 10kg. Great FOV, a well matched image scale (ie focal length to pixel size) and reliable tracking.

For reference, the 150mm without finder or rings is 6 kg (see here) while the 130mm without finder or rings is 3.7kg (see here)

Tropo-Bob (Bob) · #16 10-01-2016, 03:22 PM

+1 for 150mm.
Keep it to something that the mount can handle with ease.

raymo · #17 10-01-2016, 03:35 PM

For the imaging I can go along with you Richard, but Stefan wants visual as well, and the 5 just can't compete with the 8, especially for resolution
when viewing the moon or planets.
I've had all the popular scope types, but am biased toward Newts and
Maks, so I will let the refractor buffs sing their praises for you.
raymo

raymo · #18 10-01-2016, 03:44 PM

The HEQ5 easily carries the 8" f/5 with all it's accessories Bob.
If you look around this forum and elsewhere, I think you'll find that this scope/mount combo is arguably the most popular budget level rig.
raymo

04Stefan07 (Stefan) · #19 10-01-2016, 03:46 PM

Mhmm hard choice here!

The main feature I am after is to have a good visual experience but at the same time to pop a camera whether it is a CCD or DSLR and take a few photos of planets/moon/deep sky.

I have used all types of telescopes and they all have their advantages and disadvantages. I know one type will be better at imaging then visual and vice versa.

Still not sure...

DarkArts · #20 10-01-2016, 03:53 PM

Within the weight limits of an HEQ5/AZ-EQ5-GT, your choices are limited.

You want visual and DSO photography and planetary and to guide with a finderguider all on an HEQ5-class mount. That's tough. I think you'll have to compromise on something. My pick would be an 8-inch SCT. The SCT is an all-rounder. You might just be able to guide it (when you have a, say, 0.63 focal reducer fitted) with a finderguider, but I'd go for a camera with big pixels or binning or a better guide method.

You ought to be able to find a Celestron C8 second hand but it might be a tad over $500 ...e.g., 'casstony' recently sold a C8 OTA for under $800.

Here are a couple of packages including C8s (you might be able to convince the seller to split the package):
http://www.iceinspace.com.au/forum/s...d.php?t=141549
http://www.iceinspace.com.au/forum/s...d.php?t=141525

Or, if you're really, really strict about the budget, here's an ad for a C6, which will be well within your weight limit and easier to guide:
http://www.iceinspace.com.au/forum/s...d.php?t=140957

Hope that helps.