Wednesday, August 01, 2018

20180731 New Eyepiece 30mm ES 82 degree and Saturn

Since I got a 2" focuser for my Ranger, I always wanted to go for a 2" diagonal plus a wide field grenade level eyepiece.  Formerly, I had owned an Antares 2" SCT diagonal and also later a Zhi-tong 2" diagonal, and they served me well, and my eyepiece was a 2" 40mm Pentax SMC XL which I loved so much!  I sold it before I transformed my Ranger into 2".  I always missed the wide field and the observation comfort of the Pentax SMC XL!

Recently, I got my 85ED and it features a 2.5" focuser.  My Tele Vue 1.25" diagonal is aging after twenty years of service.  So, it's time to update myself with a modern 99%+ dielectric diagonal, so why not go for a 2 incher?  It's a ES carbon fibre model which I've written about it shortly before.

After about one week of usage, I'm confident about the brand.  So, I took the plunge to buy a 30mm 82 degree eyepiece of the same brand:


It feels heavier than the Pentax SMC XL, a little bit bigger as well.  It's very well made, despite it's made in China.

First of all, I tested it with my 85ED on terrestrial objects and it's color free.  It is not as comfortable as the Pentax SMC XL but it's close.  The eye-relief is decent, the eye cup is small but effective.  I could see the whole gigantic 82 degrees field of view all at once, the feeling is immersing.  With the Pentax SMC XL, the feeling is huge and wide, and this one, there is more space than you can view all at once.  The higher magnification should be favorable.  Remember, I had sold my Pentax SMC XL and so it is not a side-by-side comparison, but it's a comparison from my highly favorable memory of the Pentax.  So, it could be unfair.

Switching to the sky, stars were pinpoint to about 80% of the whole field and the outer stars require re-focusing to become pinpoints, and thus it's field curvature.  I don't know it's the 85ED or the eyepiece itself.  But anyway, it's good enough for all purpose.

With the 85ED, it's at 17x having a 4.82 degree true field of view!  It's just stunning!


With this eyepiece, re-balancing is a must!  I took the above picture before the test.

I scanned around the little patch of sky from inside my home, and I found a strange "star", I soon realized that it must be Saturn.  Plugging in my 20mm widescan eyepiece confirms that.  Hey, why not take a snapshot of it?


1607 (UT+8), 85ED 5x Powermate, Drizzle 1.5x.

Poor seeing at 5/10, transparency 5/10.  Saturn is a rare target for me, I want to try more this season when it's still in good position from inside my home.

My setup was changed a bit last night, I order two more short monopod extenders for my Nexstar mount, I used them to replace my camping table, which is not very stable after all.


It's now more stable, but I will want to make a wider base for it, to prevent it from tipping over.  I will also want to make a longer cable for my Nexstar controller so that I won't introduce vibration to the setup when I need to touch the keys.


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