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Old 15-07-2019, 05:02 PM
LewisM
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Extender, Barlow or Ortho?

Want to use the FSQ-106N a little for visual - at f/5, it needs some magnification to show any detail

Trying to decide between the Tak Extender Q1.6, a decent 2x barlow (Tak, TV or Vixen) or just get a quality Ortho, like the Tak Abbe's or Fujiyama in say 2 or 4mm.

The Ext-Q is exxy and hard to find some times, Barlows vary and do go IN to the drawtube which can be problematic contacting the rear Petzval element of the FSQ, and short FL Orthos can be "fun"

Opinions?
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Old 15-07-2019, 06:05 PM
N1 (Mirko)
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Lewis, I'd be the first to say ortho, but at 4mm their eye relief is extremely short, and below that you are pretty much limited to non Abbe designs like the Nagler Zoom, Vixen HR or the hard to get Pentax XO. The latter two I have, and they work extremely well in my fracs, but they are pricey. A good extender might be a better choice, since it can also be used in your imaging if you are after more power there.

Edit: extender as in Powermate or the ES version of it
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Old 15-07-2019, 06:09 PM
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MortonH
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If you're worried about Barlows in the drawtube does that mean you won't be using a diagonal?

The FS-78 I owned for a while came with an extender but it was annoying to screw it in when needed. It also seemed a bit darker than my TV Barlow at the same amplification. The image quality through the TV also seemed a bit better. Ended up selling the extender and using TV 2x and 3x Barlows.
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Old 15-07-2019, 06:37 PM
Tropo-Bob (Bob)
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An Ortho EP works better on slower scopes. I think F5 is too fast for it to perform well.
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Old 15-07-2019, 07:08 PM
LewisM
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Quote:
Originally Posted by MortonH View Post
If you're worried about Barlows in the drawtube does that mean you won't be using a diagonal?

The FS-78 I owned for a while came with an extender but it was annoying to screw it in when needed. It also seemed a bit darker than my TV Barlow at the same amplification. The image quality through the TV also seemed a bit better. Ended up selling the extender and using TV 2x and 3x Barlows.
Morton, the issue is MOST barlows except the Shorty versions have LONG nosepieces - a real issue with rear lens contact in Petzval designs. I have yet to see a quality shorty - the Meade one is carp. I wanted to try the newer ED element barlows, but they too have long insertion tubes.

I MIGHT try a Tak ED extender (2") in the FSQ, but it's an expensive experiment unless I can find a loaner... the Tak charts and recommendation table on their site says only the Q1.6 for the N version I have.
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Old 15-07-2019, 07:10 PM
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Atmos (Colin)
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I have a 4&6mm Fujiyama and although the eye relief is short I really done mind it as it just feels like looking through a pin hole but without the blackouts because it is a distinct hole.

From what I’ve read they’re not the best in faster scopes but the fastest I’ve used mine in is F/9.
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Old 15-07-2019, 07:13 PM
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MortonH
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Snap up the 3mm and 4mm DeLites in the classifieds!
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Old 15-07-2019, 07:24 PM
LewisM
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Gawd, I dunno Morton - even say the 5mm only gives me 106X

Might just buy the FOA60 after all with the Q module. Tax return due any day now
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Old 15-07-2019, 07:32 PM
Wilso (Darren)
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I’ve the 1.5x extender that I use on my Fsq/tsa is parfocal with my eyepieces where as the Tak 2xbarlow 2 element requires inward focus but is a cheaper option.
The older shorty Barlow’s parks gs, celestron ultima, and Orion shorty plus are reportably as good as the new powermates and are a three element Barlow made in Japan.
I enjoy using both but I don’t think you can beat using an eyepiece by its own.

Last edited by Wilso; 18-07-2019 at 12:17 AM. Reason: Add
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Old 15-07-2019, 07:35 PM
LewisM
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Darren, I have been thinking about the 2X Tak barlow - it is relatively short. Claude sells it for a bit over $200 - which is more than a TV barlow, but again, the brevity of it's design is a major plus. By the time I use the FSQ-106 M72 to 2" adaptor, then put in a 2" to 1.25" adaptor, the Tak barlow will only protude in to about the bottom of the CAA.

This one also is relatively short, but it is optically an unknown entity unless someone knows otherwise: https://www.bintel.com.au/product/bi...v=6cc98ba2045f
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Old 15-07-2019, 07:43 PM
Wilso (Darren)
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Yes the Tak is good, I picked one off Steve earlier in the year.
You can also detach the Barlow and screw it directly on the eyepiece giving you a different magnification increase. (Use straight through or a 2”Diagonal only)

Last edited by Wilso; 16-07-2019 at 06:12 PM.
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