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4.7mm EP 82' too much for my 6se?

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#1 Summit sky

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Posted 24 December 2013 - 05:19 PM

Wondering if that EP would be too powerful. The EP calculator says it would be 319x power and 26' FOV

#2 hamdul

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Posted 24 December 2013 - 05:32 PM

My 2 cents worth says YES. I believe the scope specs says Max Mag. 354X I think whoever came up with that figure was high on drugs. I believe that a more reasonable Max Mag would be 300X and if you ever got that much it would be on very, very rare nights of perfect seeing. I would think that on most nights of good seeing 250X could be expected.

Fred

#3 hopskipson

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Posted 24 December 2013 - 05:52 PM

You would be pushing the limits of your scope. I have used it on occasion in my C8 but it gives a very mushy view.

#4 CelestronDaddy

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Posted 24 December 2013 - 07:26 PM

My thought is no it's not too much but with a caveat :grin: I've read that it (magnification over 50x aperture inch) might actually benefit you on very tight double stars and some types of nebula, in particular ... planetary nebula. On planets it may be a little too much and you might loose some resolution. I plan on getting one for my 150mm SCT but it would be used primarily for difficult for aperture (150mm) doubles stars and PN. I'd suggest that you borrow one if you can and evaluate it to be sure. I have read on CN that you can push the rule of thumb limit on some objects as mentioned ... maybe azure1961p will chime in....

#5 Sorny

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Posted 24 December 2013 - 09:58 PM

I don't use anything under 8mm on my 5se...

It depends greatly upon seeing, but I'd say that is just too much for the scope.

#6 TonyDralle

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Posted 25 December 2013 - 07:13 AM

The "maximum magnification" is just a guideline. On most nights of average seeing, I find 250x (8mm eyepiece) is about the limit for a sharp view. Occasionally, I have used a 6.4mm (about 312x).

On the other hand, the very high magnification provided by the 4.7mm might work for resolving close double stars, as Tony (the other Tony!) says. But it would almost always simply show two very close fuzzy blobs rather than a nice sharp image, except on that maybe once a year night of exceptionally steady seeing.

- Tony (near Pittsburgh)

#7 Midnight Dan

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Posted 25 December 2013 - 09:59 AM

Technically, no it's not too much. But practically, yes it is. On most nights, the seeing (atmospheric stability) will limit your magnification to far less than what the scope is capable of. You may be able to use it on rare nights of perfect seeing but those will be ... well, rare!

I have a 5mm Hyperion and almost never use it in the 8SE. If you need any other eyepieces in your lineup, I'd say go for them first. You'll get much more use out of them.

-Dan

#8 BigC

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Posted 25 December 2013 - 01:25 PM

The 4.7mm will be good on rare nights of excellent seeing;a 6mm will be useful many more nights;and some nights either the 10mm or the TV and easy chair are better.

#9 CelestronDaddy

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Posted 25 December 2013 - 03:11 PM

I use a 6mm abbe ortho with the 6SE and it's a good combo and the views are very good. The 4.7mm would be good for tight doubles and PN but a bit much for planetary work. Sky conditions need to be good for the higher powers...

#10 Summit sky

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Posted 25 December 2013 - 04:31 PM

Cool thanks. Hoping to go outside this evening and try the new Xmas gift out. So to ask then a follow up ? How do you know if you have the "once in a year nights"?

#11 CelestronDaddy

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Posted 25 December 2013 - 05:42 PM

Look at the Little Dipper and see how many of its main stars you can count with your naked eyes. If you can see all or most of them then you have a good night. Not sure if this is exactly correct but it's close. :grin:

#12 Midnight Dan

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Posted 25 December 2013 - 09:53 PM

Counting the stars in the little dipper will give you an indication of how much light pollution there is, or how the transparency of the sky is for the night. It won't tell you anything about the seeing condition, which is the stability of the atmosphere.

To check seeing, use one of your highest power EPs, and look at a moderately bright star like Polaris. Use this web site and match up what you see to gauge seeing:
http://www.damianpea...m/pickering.htm

-Dan

#13 CelestronDaddy

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Posted 25 December 2013 - 10:35 PM

Dan - I've never seen that website before! Thanks for posting it. There are several ways to determine seeing conditions and I'll keep that site handy :grin:

#14 Summit sky

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Posted 26 December 2013 - 12:38 AM

Thanks again. I'm -3' outside. Set up the scope and bootloader error. *BLEEP*. Classic. Guess I gotta find an adaptor to get running. Total *BLEEP*!!! Kids aren't happy either.






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