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#1 ponz

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Posted 27 January 2013 - 11:53 AM

..to actually taking a picture.

I've been familiarizing myself with my new equipment - SkyWatcher Pro 80ED, Atlas, miniguider package, etc.....Actually I am stilll clueless regarding the the guider, software, etc.....but at least I know the scope and mount a little.

I picked up an Explore Scientific 11mm eyepiece, a TeleView Powermate 2.5x, and a camera ring adapter for the TeleView Powermate. I feel between those pieces and the 5mm and 20mm that came with the scope, I can SQUEAK as much visusl capability from this scope that is possible.

Back to imaging:

1)When I attach my camera directly to the scope, I can achieve a decent focus (down the street anyway)

2)When I attach the camera to the diagonal I can't achieve focus at all

3)Scope to Powermate to camera = no focus at all

4) Scope to diagonal to Powermate to camera = focus

Shooting full frame the vignetting on my exposures is quite circular. If I choose APS-C size capture the exposure fills the frame.

In the view finder when composing, I see a circular shadow, which makes focusing quite difficult. I'm also not tickled pink with the overall sharpness of any of these expoures.

Before I study up on the miniguiding system and imaging software, I'd like to take a few basic shots unguided with my Sony a900 (full frame).

So, for now, here's my question. Which configuration would YOU choose to get your first shots of the moon, or maybe Jupiter (if there's enough magnification)?

Please don't give up on me now guys.

Ponz

#2 zerro1

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Posted 27 January 2013 - 12:55 PM

Get a bahtinov mask for focus precision on stars. Image the moon first but expect it to be a little disappointing on clarity. Atmospherics cause it to seem off focus, that's why people video image the moon and planets.

#3 CounterWeight

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Posted 27 January 2013 - 05:36 PM

Just as an aside - the miniguider setup during the day to start (to get initial focus) is a good idea as well.

I'd use the imaging configuration without Barlow or Diagonal, less to go wrong or cause issues in general. Just keep it as simple as possible until you start getting images. On the good side, once you know where to start looking for best focus (as in position of focuser tube in/out) it shouldn't change. Is there a distance scale screened onto the focuser tube? if not bring something to get an accurate measure of where you want to be. (for one of mine I stuck a piece of painters tape until I could get the measure) If you get luna pretty close, you should be pretty close for getting stars.

#4 ponz

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Posted 27 January 2013 - 07:23 PM

Just as an aside - the miniguider setup during the day to start (to get initial focus) is a good idea as well.

I'd use the imaging configuration without Barlow or Diagonal, less to go wrong or cause issues in general. Just keep it as simple as possible until you start getting images. On the good side, once you know where to start looking for best focus (as in position of focuser tube in/out) it shouldn't change. Is there a distance scale screened onto the focuser tube? if not bring something to get an accurate measure of where you want to be. (for one of mine I stuck a piece of painters tape until I could get the measure) If you get luna pretty close, you should be pretty close for getting stars.


Time to study up and break out the laptop to use the miniguider, huh? Focus on what. Just a distant object?

No distance scale. Wouldn't that mark change if/when I use the diagonal and/or barlow? "to get an accurate measure" Like a permanent marker on the slider?

One more thing Jim. There's one spot on my focus tube, if you will, that hangs up and I have to help it gently pass that spot. I'm wondering if it's an issue or if I should attempt taking it apart and re-greasing it. Youe additional thoughts please.

I will also buy or make that B-Mask.

Thanks
Ponz

#5 CounterWeight

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Posted 27 January 2013 - 08:51 PM

Unsure about the rough spot, there's a lot of those scopes out there so hopefully some with first had experience can help out there. You could aslo post the question on the dediacted refractor forum and may get some good play there as well.

Mini guider - yep that's the ticket! Not a bad idea to also get it roughed in on scope center. also will allow you to get a chance to goof with the expose and contrast controlls for the miniguider, you'll want to be familiar with were to change numbers and all that in the PHD autoguider software. It all gets much easier as you go.

Everything changes as to position depending on what you add into the focal path, but again I'd wait to try barlowing until you get all the rest down to a routine. That's just me though. You can experiment during day with a barlow but it will dim the image somewhat depending on how sunny a day it is can make a big diiference in minimum exposure settings. A Barlow will be important for planetary imaging, a field flattener for wide angle deep space.

I would avoid using a diagonal entirely for imaging, it's not required (if needing to add distance I'd opt for threaded spacer tubes instead) and can cause issues with flateness also called 'orthogonality', or just 'ortho problem'.

They sure handy at times and nice for visual. I'm always seated for visual and don't use unless I really need to.

#6 proteus5

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Posted 29 January 2013 - 09:43 AM

One more thing Jim. There's one spot on my focus tube, if you will, that hangs up and I have to help it gently pass that spot. I'm wondering if it's an issue or if I should attempt taking it apart and re-greasing it. Youe additional thoughts please.

Ponz


Ponz,

I had a tight spot on the focuser on mine also. What I found was that the knob had been put on the shaft at a slight angle. If you turn the scope over and rotate the focus knob you'll see an allen set screw through a small hole. All I did was loosen that set screw "very Slightly" and reposition the focus knob straight, then re-tighten the set screw . Now it focuses very smoothly.

If this is your rough spot issue. It was an easy fix.

There is no grease in the focus assembly so don't add any or you may induce a slipping problem.

Attached Files



#7 proteus5

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Posted 29 January 2013 - 09:48 AM

Oh and if you should have a slipping problem here is a post on how to deal with that. I'm not sure if you have to register to read it or not, but if you do it's free.

I haven't done this, so if you do, proceed at your own risk. Sounds like there are some small parts in there.

How to fix Skywatcher ED80 slipping focuser

#8 CJK

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Posted 29 January 2013 - 09:57 AM

That's a great link, Robert. I had the same problem with the stock focuser on my daughter's ED80: the draw tube slid back the first time I put in one of the larger Nagler EPs I'd bought to go with her scope.

I solved the problem by replacing the stock focuser altogether. It's an expensive way to go, but what a difference.

-- Chris

#9 ponz

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Posted 29 January 2013 - 09:58 AM

Thanks Robert. Tight spot or slipping. That is the question.

My issue is, when turning the knob, the scope will sometimes no longer move. I'd have to lend a helping hand. So...would that be considered a tight spot or slipping?

I'll check out 'both' of your advices..

Thanks
Ponz

#10 proteus5

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Posted 29 January 2013 - 10:21 AM

I don't have the slipping issue, so I can't address that. What I had was the focus knob was on at a "very slight" angle. When you turned it, it would go fine for 3/4 of a turn, then you could feel a slight bind for a 1/4 turn. At first I thought the shaft was bent. I figured I'd see if I could adjust it before I returned it, and that's all it took. Hope yours is the same easy fix.

#11 ponz

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Posted 29 January 2013 - 06:46 PM

Oh and if you should have a slipping problem here is a post on how to deal with that. I'm not sure if you have to register to read it or not, but if you do it's free.

I haven't done this, so if you do, proceed at your own risk. Sounds like there are some small parts in there.

How to fix Skywatcher ED80 slipping focuser


Robert - The info at that link worked perfectly! Like the author, I can now hold my scope from the focusing tube, jiggle it and it still holds tight!

I highly recommend that tutorial to ANYONE having a slipping or binding issue with this type of focuser.

It was a piece of cake!

Thanks again,
Ponz

#12 proteus5

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Posted 29 January 2013 - 06:56 PM

Ponz,

Glad it worked out for you. Mine seems to be OK, but it's good to know that it works if I have to do it some day.






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