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electric focuser Vs Microfocuser

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#1 Benjamin B

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Posted 15 October 2005 - 02:11 PM

I have the C11 OTA and I´m going to buy me a new focuser. I´m used to the Takahashi and I want that feeling with the C11 too. What would you recommend buying? electric focuser or microfocuser.

#2 Rusty

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Posted 15 October 2005 - 07:55 PM

You'll have two choices - either a knob that operates the scope's stock mirror-moving focuser, or an outboard focuser like the JMI or WO.

Here's what I settled on after trying the JMI Moto-Focus, which replaces the stock Celectron knob. I didn't like it; it was prone to overrun - not JMI's fault, just the design.

I then tried the WO Crayford manual, which was great, but at high powers, touching it caused the scope to vibrate.

So I now have the JMI NGF-S (since superceded), and it's just right; it's especially useful for imaging. Rough focus is handled by the stock focuser with a large rubber doughnut on it; fine focus belongs to the JMI.

#3 Eddy

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Posted 16 October 2005 - 04:52 AM

Hi Benjamin,
I opted last year for the NGF-C from JMI. It works very smooth and I don't have any mirror shift anymore. Since I recently started with astrophotography and because there were some vibrations when touching the focuser at high power, I upgrade the NGF-C with the motofocus system. It is a real improvement as well. One of the advantages of the JMI focusers, in my opinion, is that you can upgrade the system when budget allows.
Cheers,
Eddy

#4 Benjamin B

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Posted 16 October 2005 - 05:03 AM

How is the JMI focus when you dont have motofocus? I have my Takahashi and the focus is a dream. How about JMI?

#5 Tim13

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Posted 16 October 2005 - 09:47 AM

I recently bought the JMI NGF-C for my LX200 8inch classic. I wanted a focuser that had a low profile, and that would eliminate mirror shift while focusing. The JMI was the answer for me. It is very smooth, and allows for sharp focusing. Not only that, but you can use a standard diagonal with it, instead of getting a dedicated SCT diagonal.

The JMI is like a snow blower for me. It's one of those things that I didn't realise how much easier it makes life, until you have one. I would recommend it without reservations.

As a side note, WO is apparently going to release a 2 speed version of their focuser at a fairly low introductory price point. If you're in no hurry, you may want to wait for this to come out.

Here is the link to my mini review of the NGF-C: JMI mini review

#6 Benjamin B

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Posted 16 October 2005 - 10:55 AM

Yes I know about the WO two speed. But you lose the motor upgrade.

#7 Chris Schroeder

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Posted 16 October 2005 - 03:43 PM

How is the JMI focus when you dont have motofocus? I have my Takahashi and the focus is a dream. How about JMI?


Very smooth, I was out imaging Friday night and the allen screw on the gear loosened, I couldn't find the allen wrench for it at the time so I just focused manually. With a very gental touch, I was able to achive focus without jarring the image on the screen.

#8 Eddy

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Posted 17 October 2005 - 02:49 AM

Focusing is very sharp and easy. Also, like Tim mentioned, you can use a normal diagonal and don't need the special SCT one. I don't think that, for visual use, you need a dual speed focuser. I use the original SCT focuser for rough focus and do the fine-tuning with the JMI. Also the motofocus is handy for imaging. You can look to the laptop screen while focusing with the electric focuser. For visual obs, I still use the manual "way". It is much faster than with the motofocus system.
Cheers,

#9 Benjamin B

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Posted 17 October 2005 - 03:10 AM

Now the question is. WO focuser or JMI.

#10 Chris Schroeder

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Posted 17 October 2005 - 10:14 AM

For visual either, although the JMI is more compact but with a more limited focusing range. For imaging, the JMI with motorfocus.

#11 Eddy

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Posted 17 October 2005 - 12:03 PM

For visual either, although the JMI is more compact but with a more limited focusing range. For imaging, the JMI with motorfocus.

I fully agree. It all depends what you want to do. The advantage with the JMI is that you can upgrade the focuser later if you intend to do astrophotography. On the other hand, if you just intend to observe visually a two speed might be handy as well (not a must though). I think WO is bringing a 2-speed on the market for their refractors, but I am not sure for the SCT's.
Cheers,

#12 Benjamin B

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Posted 17 October 2005 - 12:55 PM

WO will have a two speed focuser this month. And its very interesting. It will be the same that are out on the market now, but with two speed. The big question now is witch one will be the best focuser?

#13 Tim13

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Posted 17 October 2005 - 11:45 PM

"The big question now is witch one will be the best focuser?"

Get both, and do a shoot out article. ;) :question: :shocked: :lol:

Tim

#14 Eddy

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Posted 18 October 2005 - 03:15 AM

Ha the stressful :smirk: life of buying new things...

Good luck with your choice,

#15 Benjamin B

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Posted 18 October 2005 - 05:18 AM

yea, funny . But, how is the "original" WO focuser? :smirk:

#16 Benjamin B

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Posted 26 October 2005 - 10:00 AM

Have anyone heard any bad things about the WO focuser? Know when a "new" is coming out. Or maybe JMI will come out with a new focuser. Any news and experience are welcome.


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