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Minimum Exit Pupil for Planetary Viewing?

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#26 Sarkikos

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Posted 29 July 2021 - 01:23 PM

Doing so in very good seeing, I find Jupiter is best around 0.6mm to 0.5mm. 

:waytogo:

 

Mike


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#27 Starman1

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Posted 29 July 2021 - 05:15 PM

I have a Meade 8" f10 SCT and am considering getting a better eyepiece for planetary viewing.  I currently use the 7mm Meade orthoscopic eyepiece which gives me a .7 exit pupil and, even at such a low exit pupil Jupiter and Saturn are so bright.  Now granted, seeing is probably the most important factor in planetary views, but we're in that time of year where high pressure and high humidity (and the still air that goes along with it) dominate the weather forecasts here in North Texas.  According to Astropheric and my own views of Jupiter/Saturn/Moon I'm often getting excellent seeing.

 

So how low of an exit pupil can I reasonably go?  I'm considering the Baader Morpheus 6.5mm or 4.5mm eyepiece for planetary.  I wear glasses and the eye relief that the 7mm Meade offers is not enough - I'm having to cram my eyeglasses up against the eyepiece and even then the 5 mm eye relief that the 7mm offers is not enough.

 

Any advice or suggestions would be appreciated, thanks!

It's more a matter of magnification than exit pupil, as long as the exit pupil is, say, 0.4mm or larger.

But you can get wonderful views of Jupiter in the 200-250x range, Saturn at 220-300x, and Mars in the 250-350x range.

Higher powers can be used, but you might not see any more.


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#28 PKDfan

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Posted 29 July 2021 - 08:15 PM

I use a minimum of a .74mm EP (6.5mm Morpheus)* edit, which gives a magnification of 135 in my 4 inch F9 apo.

I am looking to address a slightly higher power of around 160 for slightly easier viewing without dropping colour detail. 

 

So maybe a 5.5mm-6mm solution is best for me, my scope and conditions.

I'm leaning towards a TV product. A Delos or Ethos with extension tube.

 

I have a settlement check that I think I'm going to spend on a luxury eyepiece(s). Just have'nt made up my mind yet on which particular one(s). The Ethos is winning at this point.

 

Clear skies & Good seeing


Edited by PKDfan, 29 July 2021 - 08:17 PM.

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#29 Spikey131

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Posted 29 July 2021 - 08:33 PM

If you want to improve your planetary viewing, I would suggest 2 identical eyepieces and a binoviewer to put them in.  This will enhance your views of the planets more than any single eyepiece.


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#30 Spikey131

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Posted 31 July 2021 - 06:49 PM

Last night we finally got a clear night with decent seeing here in the Northeast.  The 12.5 f/7 Dob was doing a good job showing off the DSOs:  Ring Nebula, Dumbell Nebula, Veil Nebula, Omega Nebula, as well as various clusters and planetaries.

 

So I stayed up late enough for Jupiter and Saturn.  They are still pretty low in the sky, and the seeing around them was a bit shaky.  But when I switched from mono vision with the Ethos 13 to binoviewers, 2x Powermate and a pair of 24 Panoptics, I was amazed.  So much more detail.  The Cassini division and bands on Saturn were crisp.  The GRS bright and colorful, as were at least 7 distinct bands.

 

This once again confirmed for me the value of 2 eyes in binoviewers for solar system observing.


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