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Focuser dilemma !

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#1 bouffetout

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Posted 20 January 2013 - 05:58 PM

I'm still looking for buying a refractor in June but since I read about it ,I found out that focusers seems to be a problem on refractors when doing astrophoto . A lot of people seems to change the stock one for a FeatherTouch ...
Is there a less expensive option for a sturdy focuser that would work fine for astrophoto ???
One other thing, would you go with a Orion ED80 600mm with another focuser...Or with a SkyWatcher ED80 600mm with another focuser ???
Since both of them are not triplets ,are they up for the task for astrophoto or I should wait and get a triplet ???
Problem is even with triplets ,most of them need a better focuser and that brings the price up a lot ???
Thank you !
Maxx

#2 fmhill

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Posted 20 January 2013 - 06:06 PM

It is my opinion that you want an APO triplet for astroimaging.

If you purchase a Explore Scientific ES series APO, they come with an excellent two speed focuser from the factory, you do not need to change to a different focuser...

I have the ES127 ED/APO and am very happy with it, I get great images with it using a Canon 60Da camera...

#3 microstar

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Posted 20 January 2013 - 06:32 PM

I had the same question about triplet versus doublet when I started imaging with my Megrez 72FD doublet - would I be disappointed with the results. Having tried it a bit I'd have to say I'm pleasantly surprised with the astrophotography potential of small doublets. With a field flattener (which you will need regardless) I'm only really seeing color separation near the edge of field and corners, and I've looked at images from triplets and even they show some color separation in the corners; stars closer to the centre of the field didn't look much different. If I was buying new and had the money I'd go with a triplet, but I have the Megrez and think I'll stick with it for a while yet rather than spend the cash to upgrade condidering the small difference in image quality. As your objective size gets larger the triplet design becomes more important I think, but at the 72mm - 80mm range I don't see a huge difference.

Re focusers, I have a Moonlite on my other scope and have been happy with that.
...Keith

#4 bouffetout

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Posted 20 January 2013 - 07:00 PM

Thank you Mitch !

#5 bouffetout

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Posted 20 January 2013 - 07:11 PM

Thank you Keith ! I went to the Moonlite site and the price is quite good for a quality focuser...I love it .
Maxx

#6 RogerRZ

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Posted 21 January 2013 - 06:16 AM

I would say that most stock two speed focusers are adequate for a DSLR camera, as long as they provide enough infocus.

If you still feel need to replace the stock unit, Moonlite provides, in my opinion, an outstanding value, along with very good customer service.

#7 bouffetout

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Posted 21 January 2013 - 06:31 AM

If I buy a focuser ,it will defenitely be a Moonlite .
Thank you Roger !

#8 Jon Isaacs

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Posted 21 January 2013 - 08:06 AM

It is my opinion that you want an APO triplet for astroimaging.



I don't think one can generalize about doublets versus triplets, there are too many variables to be considered. Aperture and focal ratio is important as well as glass choice and overall design quality. There have been many, many wonderful deep sky images take with the ED-80 FPL-53 Doublet. It's F/7.5 focal ratio is help in terms of color correction.

I don't think it's clear how the comparison between the ED-80 F/7.5 FPL-53 doublet would compare to the ES 80mm F/6 FCD1 triplet. Too many variables.

As far as the focuser... rack and pinion is the best for heavy loads. Asian refractors with good quality, two speed rack and pinion focuser are becoming available in increasing numbers.

Jon

#9 bouffetout

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Posted 21 January 2013 - 08:26 AM

Thank you Jon ! It's really not easy making a wise choice for a small refractor for astrophoto ! I called my local dealers and the choices I had made first are not in stock and the waiting is long.... :confused:

#10 oo_void

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Posted 21 January 2013 - 10:29 AM

Both of the scopes you mentioned are essentially the same ... Orion is the USA model and Skywatcher is the international version. Both are made by Synta. That said, both usually have exceptional optics and make a great, beginning, astrophotography scope. Of the two, I believe that the Orion is a single speed focuser, while the Skywatcher has a dual speed focuser. Skywatchers are also better accessorized with case, diagonal, and a couple of Plossl eyepieces, but also cost a bit more.

I've never had the Orion model, but I started with the Skywatcher. That said, the Skywatcher focuser is it's weak point. It can hold a smaller DSL, but if you already have the upgrade bug, it could definitely be better. There are numerous upgrade options available since the scope is so ubiquitous. William Optics makes one (what I ended up buying for mine), as does Baader, along with Moonlite and Feather Touch. Personally, if I were to go through that cycle again, I'd get a Moonlite; Cheaper than a FeatherTouch and while providing a better resale value than the WO or Baader should you plan on upgrading later (you'd sell the scope and focuser separately to realize the greatest return). Since this is such a common upgrade for this scope, you may be able to find one used for a good price if you're patient.

#11 bouffetout

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Posted 21 January 2013 - 10:40 AM

Thank you OO_void ! The SkyWatcher Black diamond 80mm with a Moonlite would make a good scope ! And like you say easy to sell it if I want further upgrade !
Maxx

#12 Jon Isaacs

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Posted 21 January 2013 - 12:19 PM

Thank you OO_void ! The SkyWatcher Black diamond 80mm with a Moonlite would make a good scope ! And like you say easy to sell it if I want further upgrade !
Maxx


How much is that going to cost you? The Skywatcher is around $700, the focuser is around $350... You are going to have more than a $1000 invested.

That would buy you a StellarVue 80mm F/6 FPL-53 Triplet with a rack and pinion two speed.

Jon

#13 oo_void

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Posted 21 January 2013 - 12:44 PM

There are actually two StellarVue's for sale on in the classified section.

http://www.cloudynig...ct=72776&sor...

http://www.cloudynig...ct=72619&sor...

... along with an Orion 80mm triplet ...

http://www.cloudynig...ct=72161&sor...

#14 bouffetout

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Posted 21 January 2013 - 01:03 PM

When I write to dealers in Canada ,they don't have it in stock and so far ,three of them I could order them but the waiting is long...The StellarVue is one of my first choice !
So is the AT90EDT ...
And nobody can tell me if the WO GTF81 is worth it ! And often I have read people having problems with their WO scopes!
There is the Orion 80mm carbon fiber triplet ,but I don't want carbon fiber ...
There is Explore Scientific 80mm triplet ,there again I coudL'nt find much about it other than it doesn't have FPL-53 glass.
:question: :question: :question:
Maxx
P.S. I don't want used.

#15 bouffetout

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Posted 21 January 2013 - 01:06 PM

Thank you oo_void for all the links but I feel uneasy about buying used scopes. At first it was a possibility but it's not anymore !
Thanks again man !
Maxx

#16 oo_void

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Posted 21 January 2013 - 01:22 PM

First, I'd recommend moving over to the refractor forum if you're still up in the air about scopes. Like I mentioned previously, those Synta 80mm's are highly regarded and probably the best bang for your buck when it comes to astrophotography. Doublet vs. Triplet ... you'll find many a debate over there (and BTW, I upgraded the focuser on my fancy ES127 also ;) )

As for used gear, about half of my stuff is used ... the ES127CF, my Meade SN-6, and one of my Moonlites being the big items. I've also been on the other end, selling a SkyWatcher 80mm, a CG-5, and a 102mm doublet. I've sold and purchased both off CN and "the other site" and have had no problems. I even purchased a CCD once that had some electronics issues and the buyer totally stepped up and refunded my money. Just do a bit of easy homework though. On CN, you can see the user's profile including previous posts and comments on past sales, etc. I'd stay away from people who've created an account just to post an ad, but you can almost always trust an active member of the site.

#17 bouffetout

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Posted 21 January 2013 - 02:22 PM


About the skywatcher ED80mm 600mm F.L. they changed the focuser for a double speed and it seems fairly good.
Do you think it could be good enough to hold a DSLR and stay focused ??
Thank you again !
Maxx
P.S. The more pictures i see taken with that scope ,the more I think it's for me !

#18 oo_void

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Posted 22 January 2013 - 12:46 PM

On my sample of the SkyWatcher 80mm ED, the focuser (shown in the picture) slipped, when pointing at zenith, with a Nikon D90 attached. Additionally, the focus lock would cause so much movement when engaged, I'd lose critical focus.

Posted Image

I had to replace it with a WO, shown here ...

Posted Image

#19 bouffetout

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Posted 22 January 2013 - 01:43 PM

Very nice kit you Have there my friend !
Do you like the William Optics focuser ? Is it the digital one ? When you lock it does it make the focus shift ?
I don't know how much they cost ,but I might buy a moonlite because a lot a people recomended it .
Thank you for helping me !
Maxx

#20 oo_void

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Posted 22 January 2013 - 08:56 PM

It "was" just a simple WO drop in replacement; literally took less than 5 minutes to install. It too shifted when the lock was engaged, but I was able to increase the tension to the point where locking wasn't needed. Remember, a traditional crayford lock just applies pressure to the tube via the lock screw, so shifting is pretty common to the design.

I learned my lesson with that rig, one of them I mentioned before. If I were to upgrade a focuser again I'd go with a Moonlite. It's worth the extra money and if you go non-motorized, they've solved the lock shift issue with their design.

#21 bouffetout

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Posted 22 January 2013 - 09:11 PM

Thank you for sharing your experience with me ,that will prevent me from making the same mistake...I will try to help debutant amateur like you helped me ! That's cool ! :)
Maxx






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