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8" Orion f/5 vs 6" Explore Sci Mak-Newt f/4.8 OTA?

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#1 spongebob@55

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Posted 01 May 2013 - 08:37 PM

Well now I'm going for my wide field OTA. I live and would be observing in a white zone with this scope, mainly brighter DSO, doubles and planets. Since I don't like twisting a newt for a proper position, I'll be using the Orion Atlas Pro AZ/EQ-G GoTo Mount in the AZ mode for either one I pick. I also like to sit as much as possible with my back/hip issues.
The 8" would have greater light gathering, and would cool faster, but would need a better 2 speed focuser,$250 ish, rings, $60, and a SV finder $249. Probably not as good for higher magnification than the ES, or? 29% obstruction. $300 OTA + $560= $860
The ES is more expensive at first,$999, but has the rings, finder and focuser. 32% obstruction. Carbon tube instead of seamed aluminum. Harder to collimate and probably more often.
Now the big question: quality of views ergo optics? What do you think? Quality views/optics would be very important.
Your input is appreciated. Any other ideas for scopes on this mount?
Thanks
S.Bob

#2 Darren Drake

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Posted 02 May 2013 - 07:37 AM

If the optics in the 8 inch are of typical quality that scope should easily outperform the 6 inch with a big obstruction. Everything will look better.

#3 Jon Isaacs

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Posted 02 May 2013 - 09:36 AM

I own a Synta manufactured 8 inch f/5. It's a good scope but I don't use it a lot. A few thoughts:

- I don't understand the finder scope. You plan to use it on a goto mount, a red dot should be fine. In any event both need the same finder to be comparable.

- coma is an issue. I use a Paracorr with mine. I also use a stock Crayford single speed.

- To my eye, lower power wide field viewing is refractor territory from a white zone. The stuff is there to be seen in a larger scope but the sky is washed out and not particularly attractive. A 5 inch refractor will have the throughput of the 6 inch Mak newt but probably better light control.

Jon

#4 spongebob@55

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Posted 02 May 2013 - 10:35 AM

[quote name="Jon Isaacs"]I own a Synta manufactured 8 inch f/5. It's a good scope but I don't use it a lot. A few thoughts:

- I don't understand the finder scope. You plan to use it on a goto mount, a red dot should be fine. In any event both need the same finder to be comparable.
---- You're absolutely right. Duh. When I use my 102mm on my GoTo mount now, I use a red dot and that's only for lining up the collimation stars. Then, never gets used again.

...coma is an issue. I use a Paracorr with mine.
----Dag, didn't think I'd have to use a Paracorr, so thanks....

I also use a stock Crayford single speed.
---... really, the one that comes on it?....hmmmm...I see lots of comments on line about the focuser is bad, but perhaps thats for AP, not visual.

- To my eye, lower power wide field viewing is refractor territory from a white zone. The stuff is there to be seen in a larger scope but the sky is washed out and not particularly attractive. A 5 inch refractor will have the throughput of the 6 inch Mak newt but probably better light control.
---Jon, so you mean a 5" fast refractor? I've given up on refractors b/c the CA bothers me way too much for the ones I've had and looked through. But I welcome your continued input on that....

I thought the mak-newt would be able to be used more effectively b/c of its 'marketed' ability to be pushed to higher powers vs a faster newt.

Thanks
Bob

#5 Jon Isaacs

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Posted 02 May 2013 - 12:13 PM

---Jon, so you mean a 5" fast refractor? I've given up on refractors b/c the CA bothers me way too much for the ones I've had and looked through. But I welcome your continued input on that....

I thought the mak-newt would be able to be used more effectively b/c of its 'marketed' ability to be pushed to higher powers vs a faster newt.

Thanks
Bob



Bob:

I am thinking apo or ED refractor.

As far as the Mak-Newt and high magnifications... Generally people are discussing premium quality Mak-Newts with small central obstructions. Like Darren, I see the 8 inch F/5 Newtonian being capable of higher magnifications. For one thing, it won't be running of light so soon.

Jon

#6 spongebob@55

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Posted 02 May 2013 - 01:24 PM

---Jon, so you mean a 5" fast refractor? I've given up on refractors b/c the CA bothers me way too much for the ones I've had and looked through. But I welcome your continued input on that....

I thought the mak-newt would be able to be used more effectively b/c of its 'marketed' ability to be pushed to higher powers vs a faster newt.

Thanks
Bob



Bob:

I am thinking apo or ED refractor.

As far as the Mak-Newt and high magnifications... Generally people are discussing premium quality Mak-Newts with small central obstructions. Like Darren, I see the 8 inch F/5 Newtonian being capable of higher magnifications. For one thing, it won't be running of light so soon.

Jon


Thanks Jon,
Your comments give rise to some other questions. What are other premiun Mak-Newts I should investigate?
Perhaps I should look into a slower, premium newt, like a Teeter STS 8" f/5.9, (19% central obstruction) along with others makers (like who?)
Regards,
S. Bob

#7 spongebob@55

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Posted 02 May 2013 - 01:25 PM

also, I'm done with 5"/6" ED/APOs.

#8 Pinbout

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Posted 02 May 2013 - 01:50 PM

Would you ever consider putting one together? spend the money where it counts on the mirrors and focuser and put it in a tube. the rings you can always get. astro sytems spider. astogoods cell. get a discovery optics mirror set, not gso. its really very simple.

#9 spongebob@55

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Posted 02 May 2013 - 01:59 PM

Would you ever consider putting one together? spend the money where it counts on the mirrors and focuser and put it in a tube. the rings you can always get. astro sytems spider. astogoods cell. get a discovery optics mirror set, not gso. its really very simple.



Hi Danny:
going to Wawayanda on Friday or Saturday? I'd like to go to Shiholo in PA and try there.....ever been there?

Anyway, back to the post:
sure, but its never 'easy' the first time and that's what I'd be. I have NO idea where to start.....good book?
Bob

#10 Pinbout

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Posted 02 May 2013 - 03:08 PM

Would you ever consider putting one together? spend the money where it counts on the mirrors and focuser and put it in a tube. the rings you can always get. astro sytems spider. astogoods cell. get a discovery optics mirror set, not gso. its really very simple.



Hi Danny:
going to Wawayanda on Friday or Saturday? I'd like to go to Shiholo in PA and try there.....ever been there?

Anyway, back to the post:
sure, but its never 'easy' the first time and that's what I'd be. I have NO idea where to start.....good book?
Bob


most likely sat. maybe tomorrow also, maybe.


never been to Shiholo in PA. give me a couple days warning and I can see if I can go.

If you need a book, I can lend you one, but it is very easy. the hardest part is getting up the nerve to do it.

All you need is a drill, hole saw, and a hacksaw to make the ota. I even have a nice tube for ya if you want. its what I made this with...

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#11 NewMoonTelescope

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Posted 02 May 2013 - 06:12 PM

+1 on building one if you have access to a few basic tools.

+1 also on the 8"F5 outperforming the 6 inch mak. I believe it would hold higher mags more consistently, and as long as the 120° edge support points are in light contact with the mirror, collimation may not be as frequent as you may think. My eye doesn't require a paracor until about F4.2, but this is very subjective. Everyone has a different tolerance as it pertains to coma. You can always find used dual speed focusers in the $150 range, and about the same for a very decent finder (used).

#12 Pinbout

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Posted 02 May 2013 - 06:48 PM

hey bob, I know some guy who quoted me $40 to waterjet this out of baltic or 1/4 alum. he said the wood stains a little but since it would be painted black I wouldn't think its bad.

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I would imagine rings wouldn't be that much different in $$$ ... :grin:

#13 Pinbout

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Posted 02 May 2013 - 09:59 PM

If you make it you could make a dedicated scope for native binoviewing, or at least have two positions you can attach the cell so you can view native binos (no barlows) or regular mono style

Could be pretty cool.






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