Advice on new telescope/accessories

[kkara4 (Krishan)]

Originally Posted by Amaranthus

You can do PEC + AG if you use pulse guiding. Then AG is only correcting for the stochasticity, leaving PEC to deal with the determinism

If you are working at a long FL you'll ideally want an off-axis guide port and sensitive CCD guidecam. If shorter FL (widefield), then a guidescope and CMOS guidecam are fine (this is what I currently use, even for my C8 @f/6.3)

Thanks Barry. What would I need exactly for the AG part in your first paragraph?

For your second paragraph, what do you use for the guidescope and guidecam?

[Amaranthus (Barry)]

A sensitive guider that uses a CCD for an OAG setup. Lodestar or similar.

I use a NexImage 5 planetary cam or Orion SS G3 as my guider (the latter is my basic mono CDD imager, I use it as a good AG when imaging with my DSLR). Guidescope is either my ED80T CF (when imaging with the C8), or my SW120 achro (when imaging with the ED80T). But most people go for a dedicated 80 mm achro guidescope.

[kkara4 (Krishan)]

Originally Posted by Amaranthus

A sensitive guider that uses a CCD for an OAG setup. Lodestar or similar.

I use a NexImage 5 planetary cam or Orion SS G3 as my guider (the latter is my basic mono CDD imager, I use it as a good AG when imaging with my DSLR). Guidescope is either my ED80T CF (when imaging with the C8), or my SW120 achro (when imaging with the ED80T). But most people go for a dedicated 80 mm achro guidescope.

Thanks Barry

I think What I will do is stick to un guided at first, purely from a cost perspective, and if I find I end up desiring an autoguided setup I can always invest in a dedicated guidescope then . Because sounds like we are talking $2K plus to autoguide, way blowing the budget (which ive already blown lol).

I think with 1 minute of unguided accuracy I should be fine, and I dont think planets will be an issue because frames which drift could simply be discarded anyway.

[Amaranthus (Barry)]

Not necessarily You can get a basic but robust AG package for under $600:
http://www.bintel.com.au/Astrophotog...oductview.aspx

[kkara4 (Krishan)]

Originally Posted by Amaranthus

Not necessarily You can get a basic but robust AG package for under $600:
http://www.bintel.com.au/Astrophotog...oductview.aspx

Thanks Barry that looks awesome! i thought i was pretty much looking at a proper 80mm refractor and all the trimmings to get a decent guiding setup!

[kkara4 (Krishan)]

well I now own a 9.25 Edge HD Should arrive next week, as well as the G11

now to have fun buying all the other bits!

Assuming the G11 comes stock as it would directly from Losmandy, do I require a dovetail plate or anything like that to mount the scope?

Also are these good quality? http://www.deepspaceproducts.com/d-s...4234_8985.html

am thinking of widefield rig on one side (300mm lens/camera) and the edge on the other

[astro744]

Originally Posted by kkara4

well I now own a 9.25 Edge HD Should arrive next week, as well as the G11

now to have fun buying all the other bits!

Assuming the G11 comes stock as it would directly from Losmandy, do I require a dovetail plate or anything like that to mount the scope?

Also are these good quality? http://www.deepspaceproducts.com/d-s...4234_8985.html

am thinking of widefield rig on one side (300mm lens/camera) and the edge on the other

Bintel sell the genuine Losmandy one. See http://www.bintel.com.au/Accessories...1/catmenu.aspx

There is also an Orion model at Bintel for a bit less although I'm not sure if it is an exact copy. What you want to look for is what holes are pre-drilled and tapped in each plate to make sure it suits your needs. Also look at how the tightening knobs feel to turn and how well the clamps release. I've only ever gone with the genuine saddles not wanting to try the others just in case and the price of the genuine has always been reasonable.

I think you will have balance issues at certain angles with one heavy SCT on one saddle and a much lighter camera and lens on the other. You may be better off piggy backing the camera on top of the SCT.

[kkara4 (Krishan)]

Originally Posted by astro744

Bintel sell the genuine Losmandy one. See http://www.bintel.com.au/Accessories...1/catmenu.aspx

There is also an Orion model at Bintel for a bit less although I'm not sure if it is an exact copy. What you want to look for is what holes are pre-drilled and tapped in each plate to make sure it suits your needs. Also look at how the tightening knobs feel to turn and how well the clamps release. I've only ever gone with the genuine saddles not wanting to try the others just in case and the price of the genuine has always been reasonable.

I think you will have balance issues at certain angles with one heavy SCT on one saddle and a much lighter camera and lens on the other. You may be better off piggy backing the camera on top of the SCT.

Awesome Astro thanks a lot for the link and advice! The balance issue makes perfect sense now that I think of it. I will wait till my Edge arrives so I can measure the holes in its dovetail to ensure I buy the right version

[Amaranthus (Barry)]

You must be soooooo excited.

I've always bought genuine Losmandy saddles/mounting plates. I figure that these are 'buy once in your lifetime' items, so may was well get the best.

[kkara4 (Krishan)]

Originally Posted by Amaranthus

You must be soooooo excited.

I've always bought genuine Losmandy saddles/mounting plates. I figure that these are 'buy once in your lifetime' items, so may was well get the best.

I am indeed keen as!

I also share your mantra Barry, I have no intention of getting other than a Losmandy plate at the moment!

It would have been nice to buy a Nagler 31mm eyepiece as well, but alas that will stretch my budget beyond what I am willing to stretch beyond what I already have .

Looking forward to the learning curve as well, i think its fun playing with new toys (albeit a very expensive toy!)!

[Amaranthus (Barry)]

A Panoptic 24 mm could be a good cheaper widefield eyepiece to secure in the interim. I also plan to eventually buy a Nagler 31 -- once I get to dark skies (which will be in a few months when I move to rural Tasmania). It gets spoilt by the wash-out effect of light pollution where I currently live.

[kkara4 (Krishan)]

Originally Posted by Amaranthus

A Panoptic 24 mm could be a good cheaper widefield eyepiece to secure in the interim. I also plan to eventually buy a Nagler 31 -- once I get to dark skies (which will be in a few months when I move to rural Tasmania). It gets spoilt by the wash-out effect of light pollution where I currently live.

I will check out the Panoptic thanks Barry. Id rather just use the included EdgeHD one till I save up enough money again for the Nagler though

[el_draco (Rom)]

Originally Posted by kkara4

well I now own a 9.25 Edge HD Should arrive next week, as well as the G11

now to have fun buying all the other bits!

Assuming the G11 comes stock as it would directly from Losmandy, do I require a dovetail plate or anything like that to mount the scope?

Also are these good quality? http://www.deepspaceproducts.com/d-s...4234_8985.html

am thinking of widefield rig on one side (300mm lens/camera) and the edge on the other

I would be a little careful going SBS. It adds a degree in complexity when it comes to balance that I dont think is justified. You will also need to have a counter weight system to balance the scopes, despite the ability to slide the SBS on the mount head.
(eg) http://www.bintel.com.au/Accessories...oductview.aspx

You may find it easier/ cheaper to go for top and bottom D plates with radius blocks designed to fit your scope. Losmandy stocks all you'll need and you can get it through Bintel.

(eg) http://www.bintel.com.au/Accessories...oductview.aspx

Losmandy also have various camera platforms you can use to mount the camera
(eg) http://www.bintel.com.au/Astrophotog...oductview.aspx

Use the KISS principle as much as possible.

Rom

[kkara4 (Krishan)]

Originally Posted by el_draco

I would be a little careful going SBS. It adds a degree in complexity when it comes to balance that I dont think is justified. You will also need to have a counter weight system to balance the scopes, despite the ability to slide the SBS on the mount head.
(eg) http://www.bintel.com.au/Accessories...oductview.aspx

You may find it easier/ cheaper to go for top and bottom D plates with radius blocks designed to fit your scope. Losmandy stocks all you'll need and you can get it through Bintel.

(eg) http://www.bintel.com.au/Accessories...oductview.aspx

Losmandy also have various camera platforms you can use to mount the camera
(eg) http://www.bintel.com.au/Astrophotog...oductview.aspx

Use the KISS principle as much as possible.

Rom

Thanks for the reply Rom, the Edge HD i believe requires the DC925N dovetail, which is good because it is $30 cheaper than the one linked! I will double check when the scope arrives though

I will stick to the piggyback method then - with those radius blocks provided, do you just undo screws in the existing OTA housing and mount the blocks to them?

[el_draco (Rom)]

Originally Posted by kkara4

I will stick to the piggyback method then - with those radius blocks provided, do you just undo screws in the existing OTA housing and mount the blocks to them?

The holes in the radius blocks match those in the OTA. Get rid of the orange bit of junk on the edge, flimsy and dumb. Couple of losmandy plates look good and are very rigid. The build is beautiful. When changing the plates over, go gently and undo from below. Any flakes of paint that come loose will come out the hole. when screws go back in, do this VERY gently, the threads are identical and there should be no binding.

Rom

[kkara4 (Krishan)]

Originally Posted by el_draco

The holes in the radius blocks match those in the OTA. Get rid of the orange bit of junk on the edge, flimsy and dumb. Couple of losmandy plates look good and are very rigid. The build is beautiful. When changing the plates over, go gently and undo from below. Any flakes of paint that come loose will come out the hole. when screws go back in, do this VERY gently, the threads are identical and there should be no binding.

Rom

Thanks Rom, sounds good. Not sure what you mean by the orange part but sounds like ill see it once I have the scope in my hands!

[Camelopardalis (Dunk)]

Originally Posted by Amaranthus

A Panoptic 24 mm could be a good cheaper widefield eyepiece to secure in the interim. I also plan to eventually buy a Nagler 31 -- once I get to dark skies (which will be in a few months when I move to rural Tasmania). It gets spoilt by the wash-out effect of light pollution where I currently live.

Barry and I disagree on this but a 24mm Panoptic is not a wide field eyepiece in a long focal length scope

Stick with the Axiom/Luminos that it comes with...it'll have a wider field stop and show you more sky and really, they're not as bad as they sound. Sure, it's no Nagler in a fast Newtonian, but it's well suited to a f/10 SCT.

[kkara4 (Krishan)]

Originally Posted by Camelopardalis

Barry and I disagree on this but a 24mm Panoptic is not a wide field eyepiece in a long focal length scope

Stick with the Axiom/Luminos that it comes with...it'll have a wider field stop and show you more sky and really, they're not as bad as they sound. Sure, it's no Nagler in a fast Newtonian, but it's well suited to a f/10 SCT.

Thanks Dunk, Ill wack in the included one and see how things look! What makes an eyepiece "suited" to a particular telescope?

[Camelopardalis (Dunk)]

Optical design...telescopes inherently have field curvature and it depends on design, focal length, etc as to how much. This can cause the image to be out of focus at the edges while in focus in the centre, i.e. the focal plane is not flat.

From what I understand (not much!) - and there are experts here that know way more about this than I - eyepieces can also exhibit field curvature and the combination of that from the scope and the eyepiece can either cancel each other out or make it worse, depending on design parameters. SCTs typically have a fair bit of field curvature so it's speculated that the eyepieces Celestron supply have taken that into consideration by design.

Needless to say, this is probably further complicated - or maybe not - for the Edge HD scopes, which have the correcting lenses in the baffle tube to help give them a flatter field i.e. the focal plane is less strongly curved so that the edges and centre are closer to or are at focus at the same point.

I've oversimplified here and I'm sure there are other factors too...

[Amaranthus (Barry)]

If you observe with the f/6.3 FR/flattener fitted, then you get a nice wide, flat field. It is great for visual in addition to AP. Then take it out for high power (if you want) or planetary, where the FC is irrelevant anyway.