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deeppurple247
member


Reged: 06/04/07
Posts: 62
Loc: 51° 24'N 1° 16'W
Going past the maximum useable magnification
      #2616519 - 09/01/08 09:57 AM

Hello,

I was thinking of getting an 8mm Hyperion eyepiece for my 4" mak which will put the magnification to 163x. If I get the fine tuning ring for the eyepiece it will put the eyepiece apperture to 6mm and therefore the magnification to 217x, and the maximum useful magnification for my scope is around 200x. How bad will the 217x be for this scope?

Thanks

Alex


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panhard
Carpal Tunnel
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Reged: 01/20/08
Posts: 2574
Loc: Markham Ont.
Re: Going past the maximum useable magnification new [Re: deeppurple247]
      #2616553 - 09/01/08 10:18 AM

If you go past the max the view will get and fuzzy and if I remember correctly dimmer. I did that with a 3x barlow to see what happens. I have an 8 mm hyperion on a good night it is good. but on poorer nights I can't use it. Last night was real good here I tried using the smaller of the 2 rings it worked out ok. I hope this helps you out.

--------------------
Orion xt10i
8 & 17mm Hyperion eye pieces
koning 32mm 25mm skywatcher eyepieces
lumicon 0111 & antares variable polarizing filters
12x50 binos
A love for this hobby
"What goes around comes around."
"She who must be obeyed."
Herb c
cloudy nights my # 1 site
43.53°n 79.17°w


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Midnight Dan
professor emeritus


Reged: 01/23/08
Posts: 619
Loc: Brockport, NY
Re: Going past the maximum useable magnification new [Re: panhard]
      #2616652 - 09/01/08 11:03 AM

Don't do it! If you exceed the maximum allowable magnification, your scope will explode!

Just kidding! The maximum limit is not hard-and-fast. You probably wouldn't notice the difference between 200x and 217x.

However, even at 200x you may not have great views. This is usually limited by the seeing conditions. On nights with very stable skies, you can probably get there. But most of the time that's not the case.

I have a Hyperion 5mm which puts me at 406x and the limit of my scope is 400x. I haven't put that eyepiece in the scope for months. The 8mm (250x) is about as far as I go and even then the image is starting to get soft. Once you look through an EP and see that the image is soft, enlarging it with a more powerful EP will just make it softer so there's no point.

On the other hand, the fine tuning rings are cheap so it's not a big deal to try it out. But I think the vast majority of the time you'll be much happier with the native 163x of the EP by itself. The EP I use the most is my 13mm Hyperion which gives me about 150x.

I don't have any experience with the fine tuning rings, but I think I've read that when you put them in, you're opening up the lower end of the EP and you have to be very careful about not introducing any dirt or dust into the system. So its probably not something you want to put on and off very often like you might with a barlow or a filter.

-Dan

--------------------
Scopes: Celestron NexStar 8, Orion EON 72mm ED/APO on Astroview mount (EQ3)
Eyepieces: Celestron 40mm, 25mm, Baader Hyperion 13mm, 8mm, 5mm
Other: Telrad, 2x Barlow, 0.63x Focal Reducer, Dew-not strips, DewBuster controller


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Nick Lloyd
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Reged: 10/24/06
Posts: 1641
Loc: cincinnati
Re: Going past the maximum useable magnification new [Re: Midnight Dan]
      #2616908 - 09/01/08 01:07 PM

On very very good nights you can push the magnification past 300x. Of course, this is for bright stuff like luna, planets, double stars, and a few planetary nebula.

217x for a 4" telescope is not unheard of.

--------------------
"The best scope is the one you use." -rcg




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dgs©Moderator
Postmaster
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Reged: 03/29/04
Posts: 13911
Loc: West Monroe, Louisiana
Re: Going past the maximum useable magnification new [Re: Nick Lloyd]
      #2617169 - 09/01/08 03:04 PM

The moon is plenty bright enough to pull it off, IF the seeing doesn't go too swimmy. I've tried what is sometimes referred to as 'stupid magnification' of 666x on the moon. It was dimmer and a little soft around the edges of everything, but way bigger.

I wouldn't even bother to try it on even the planets. I can seldom get to 333x on Jupiter... more often 250x for Jupiter just because of atmospheric turbulence. Saturn is a little better about taking magnification for some reason. I can more often get that one at 333x, but sometimes have to back down to 250x. 'Stupid magnification' is reserved for the moon on nights I'm in a frivolous mood. I don't think I'd spend much money for something that would only do that. I do it with the 333x eyepiece and a 2x barlow, each of which can do more 'normal' duty.

--------------------
- david
8"Ø Newtonian on SVP, Moonlite CR2, Telrad
PST Oberwerk Ultra 15x70 Orion Ultraview 10×50
Hand-me-down Sears Refractor (Discoverer) 60mm×900mm



"What we have done for ourselves alone dies with us; what we have done for others and the world, remains and is immortal." --Albert Pike


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smasraum
sage


Reged: 01/13/08
Posts: 492
Re: Going past the maximum useable magnification new [Re: dgs©]
      #2617230 - 09/01/08 03:34 PM

Putting the tuning rings in is not a big deal. You can easily put them in when you're out. I wouldn't do it in the middle of a dirt field on a windy night, but under normal circumstances, it's not a big deal.

As has been stated, the guideline is 50-60x per inch which would put you at 200-240x as max. Of course, in a refractor 4" means 4", but in a reflector, you loose the area from the central obstruction. I'd guess that most of the time 150 will be best for you, but it doesn't hurt to push it from time to time. It won't hurt anything.

--------------------
Steve
Houston (Friendswood), TX
Space Center Houston
8" Zhumell Dob - Woo Hoo!!
Celestron C102 f/5 - Thanks Tim!
21mm, 13mm Hyperion
2.5x TV Powermate
Canon Rebel XT
Nikon 7x35
Bushnell 10x50


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mosheriffic
super member


Reged: 03/31/08
Posts: 159
Loc: Marysville, Wa.USA
Re: Going past the maximum useable magnification new [Re: smasraum]
      #2617392 - 09/01/08 04:47 PM Attachment (3 downloads)

Heres a shot of "stupid magnification"!
Crater Copernicus @ 609X. Shot with Orion SSSI II through NexStar 8SE.

Edited by mosheriffic (09/01/08 05:06 PM)


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Lee Jay
sage
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Reged: 02/27/08
Posts: 419
Loc: Westminster, CO
Re: Going past the maximum useable magnification new [Re: deeppurple247]
      #2617408 - 09/01/08 04:53 PM

I've gone to 633x on my 5" Mak at times. On double stars, it doesn't harm anything, you just get to see the Airy disk more clearly. On high-contrast targets like doubles and the Moon, I go to 250x-317x all the time.

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