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is dual encoders needed for imaging?


tony8690

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Hi Guys,

 

In a months time i will be getting this setup (https://www.firstlightoptics.com/reflectors/skywatcher-explorer-150p-eq3-2.html) With GoTo.

My budget is around £600 so this fits perfectly with that, looking at reviews this should do everything i need it to do.

Is there any need for the dual encoders in a mount for AP? if so... would this be a better scope to get? (Orion-StarSeeker-IV-150mm-GoTo)

 

My heart is 99% set on my original option but getting a wider view on things can never be bad.... right?

 

Thanks,

Tony

 

 

 

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No, dual encoders are not required. Dual encoders allow you to move the mount manually, without the controller losing it's position. You might say it's a "nice to have", but not necessary.

Also, if you want to do AP, stick with an EQ mount, the Starseeker is an Alt/Az mount.

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one small suggestion:  go for the 'DS' version of the 150P, (£599) the dual speed focus helps with both visual and imaging..i had one it was great.. :)

Edit:  yes the 130p would be a good bet with the EQ3, imaging on that with the 150pds was always a challenge..!

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4 hours ago, parallaxerr said:

Furthermore, if you're interested in AP, the 130PDS EQ3-2 pro goto combo would be better suited imho. Check out the EQ3 DSO thread :)

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-130p-ds-eq3-pro-goto.html

 

Would I notice much differe between the 130mm and 150mm scope when it comes to photos?

I planned on adding a few extra weights to the mount to make it a bit more sturdy, but when you say keep the weight down are you referring to the mount as a whole or the guidance axles? Would havong more weight from the scope make the scope jolt when tracking?

Not to knowledgeable(spelling?!) When it comes to this kind of thing.

Any advice greatly appreciated :)

Tony 

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If you are not using a sophisticated mount (starting, say, with the HEQ5 or above) then what you need is a short focal length. With a given camera the shorter the focal length, the more tolerant the system will be of tracking errors. If you add both aperture and focal length you won't gain anything unless you improve the tracking.

On an EQ3/2 I suspect that you would get the best results with a fast, short focal length, camera lens. Sure, you'd like to get higher resolution on small targets but, unless you have very accurate tracking, you simply can't.

Olly

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I agree with Olly, and others who advise a shorter focal length. I started out with the 150PDS on the eq3-pro (goto version) with aluminium tripod, and I still don't understand why Skywatchers can market this as an astrophotography setup. The mount is at its load limit with just the scope. So here's my €0.02 worth.

1 replace the tripod with the steel eq5 tripod (or put the mount on a pier).

2 keep the focal length down. 130PDS has 650 mm fl versus 750 mm for the 150PDS. I always got the best results with ordinary lenses rather than a scope.

3 The non-PDS versions of the scopes may not be able to reach focus with a camera.

4 have a look at the eq3 imaging thread in the beginners section.

For better results, Newton reflectors need a coma corrector. This will probably become your first upgrade.

 

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12 hours ago, wimvb said:

I agree with Olly, and others who advise a shorter focal length. I started out with the 150PDS on the eq3-pro (goto version) with aluminium tripod, and I still don't understand why Skywatchers can market this as an astrophotography setup. The mount is at its load limit with just the scope. So here's my €0.02 worth.

1 replace the tripod with the steel eq5 tripod (or put the mount on a pier).

2 keep the focal length down. 130PDS has 650 mm fl versus 750 mm for the 150PDS. I always got the best results with ordinary lenses rather than a scope.

3 The non-PDS versions of the scopes may not be able to reach focus with a camera.

4 have a look at the eq3 imaging thread in the beginners section.

For better results, Newton reflectors need a coma corrector. This will probably become your first upgrade.

 

Would I still get the same image quality as the 150mm with the 130mm? 

Thanks,

Tony

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On 9/16/2017 at 11:59, wimvb said:

With a newtonian, image quality is more determined by accuracy of focus and collimation, than by aperture. The 150PDS and 130PDS are both very capable instruments when set up properly.

Thanks for the Advice Wim

 

would this be a better choice?? 

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-150p-ds-eq-5-pro-goto.html

 

Thanks,

Tony

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Cant find an Edit button so sorry for the Double post :(

 

just looking for some advice.. (again :p )

i was wondering what would be better... should i buy these seperatly

 

https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-heq5-pro-synscan.html

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-150p-ds-ota.html

 

Cost comes to £998

Or should i get:

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-150p-ds-eq-5-pro-goto.htm at £755

 

What would be the main advantages of having the HEQ5 over the EQ5? if i got the EQ5 then thats a saving of almost £250, i know i will need some add ons and a portable power bank? so any recommendations as to what?

 

Thanks,

Tony

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Thanks Wim.

As the EQ5 can take a payload of aroun 11KG, my 150mm P-DS weighs in at around 4/5 KG so it shouldnt have much of a problem.

i wont be getting another scope anytime soon and if i add anything too the scope then the extra weight shouldn't take it over the 11KG?

if i really needed the HEQ5 then i would stretch to that but seeing as other than a bit more stability is the only difference then i think a EQ5 should be ok.

if i need anything else im sure the money i saved should cover some things? can you recommend any good eye pieces? or coma corrector's?

Thanks,

T

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According to the product information on FLO, the eq5 is rated at 9 kg for visual and 6.5 kg for imaging. Imaging payload is always less because requirements are tougher.

Besides the scope you have to calculate in camera plus coma corrector and perhaps filterwheel. Add also guiding scope and camera, and your past the 6.5 kg limit. Otoh, with accurate balance and some tlc, you can probably push the boundaries. The eq3 dso challenge thread is proof of that. (h)eq5 users should be able to give you more accurate advice. As I wrote before, buy the sturdiest mount that your wallet, or financial officer (aka spouse) will allow. You might consider the second hand market.

As for coma corrector, I use the Baader mpcc mk3, which doesn't alter the focal length of the scope. I'm pleased with it. Some people use the skywatcher cc, which shortens the fl somewhat, giving a slightly larger fov.

Other investments you will need are

Bahtinov mask for focusing

Collimation tool. I use a simple collimating cap made from a 32mm drainage pipe end cap, and a laser collimator with the barlow that came with the scope.

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