Kevin Kretsch

THIS! Especially with the eyepiece port open like that, seeing that must dirt and dust on the outside, the internal dust must be correctly dealt with. A small amount of dust on the front glass is relatively easily dealt, and even possibly ignorable, but the internal mirror surfaces are easily permanently damaged if something goes wrong. I would recommend giving it to someone who knows how to do this. In fact, I think Clay Sherrod is still offering his cleaning and tune-up service... http://arksky.org/aso/supercharge No better man for the job. Assuming there is nothing other than cleaning to do, and assuming the motor drives and gear are workable you will have a VERY cool telescope. The learning curve can be a little steep but you'll get there. Also, I think that's an ETX-90. It looks like my one, and IIRC the 105 came with a bigger field tripod and a right-angled finder.

I have a 15mm, 20mm, and 26mm 4000 Super Plossl and I really like them. They are better than my 17mm Celestron plossl (a 1990's "Halloween" model) and my 32mm Orion Sirius plossl.

I feel like magnifying the blurryness makes my brain unhappy. It "wants" to see the details at a certain scale. Getting too far away from that doesn't help. For me, I'd vote image no 2 or 3. 1 is nice but too small to see the details, and 4 is too big, just looks blurry even though it has the same amount of detail. Throw in the loss of brightness and I'll vote for number 2. FWIW, I've never successfully used more than ~40x per inch with Jupiter in my ETX-90. And I don't recall a tight double within Rayleigh criterion that I couldn't split at 25x per inch.

My ETX-90 has a 1250mm focal length so it doesn't take short focal length eyepieces to get magnification/seeing limits. My highest magnifcation is with a 15mm + barlow to get 166X but that usually too high to be useful.

First off, the Meade series 4000 Plossls are actually really good. Yeah, people gripe about where they're made or not made, and wax lyrical about the mythical early Japanese made ones that were polished with magical unicorn fur, but they are all good, some even say better than most other plossls apart maybe from Tele Vue. Forget about the ETX-80 for planetary. It's great for wide field star clusters and such but too short a focal length for high magnifications. The ETX-90 is fine for planetary, due to it's long long focal length (which also means cheaper eyepieces perform better) but small aperture limits detail. Example - shadow transits and Great Red Spot on Jupiter appear as fuzzy darker patches, rather than clean edged circles that we see in good photos. But they are there and always exciting (to me anyway). If you go for a different type of eyepiece, all that won't change much, if at all. Yeah, maybe with nice orthoscopics or more expensive plossls you'll get a little more contrast but that's about all you'll gain. As an example: With my own ETX-90 I have Meade 4000 plossls in 26mm, 20mm, 15mm with a Meade #126 short tube barlow lens. The 15mm + barlow gives 166X which is too much magnification for most nights because atmospheric seeing rarely allows it. But the 20mm + barlow gives me 125X. Yeah, the image is small but you can count multiple cloud bands on Jupiter, see shadow transits (as a fuzzy dark patch) and the GRS, make out planet and ring shadows on Saturn, you'll get nice views of larger mars details Mars in the coming months coming up to its opposition. Also you'll easily split close double stars down to 2 arcsec, and of course have spectacular views of the moon. I'm happy with that and I have no plans to upgrade those eyepieces for now.

Nice shot! There is something really nice about the range of shades here, I mean, yeah, it's a little dark but it's gorgeous dark!

Welcome, Jeremiah! My ETX-90 is 22 years old. It's had a few repairs and fixes along the way but it still works and optically it is as good as it ever was.

Weclome, Saif!

Thanks Pebo. Helpful hint from one noob to another - nebula, white dwarf, sub dwarf, and brown dwarf are not user names. I was getting terribly confused, that was why.

Some eyepiece lines are parfocal amongst themselves, and some are not, and some change over time, and some eyepieces of different brands are parfocal with each other and some are not. Is there a list what's parfocal with what? Is it plausible/possible to do one? FYI, my 1998 Meade Series 4000 26mm Plossl is not parfocal with my new Chinese Meade series 4000 Plossls 20 mm and 15 mm (which had I known would have definitely influenced my purchase decision). But the new Meade Plossls *are* parfocal (or very close to ) with my 1990's Celestron Plossl and the Orion Sirius 32mm Plossl.

Can I suggest slightly different approaches? 1) Tin foil very gently pierced with a small sewing needle. You can literally make them in seconds, with practice you can get very good at making tiny holes. Fold the tin foil over the front of the LED torch and hold in place with tape or rubber bands. Yes, it's a bit DIY and fragile not a lovely robust thing you can pull out of a case and go (although with a little ingenuity you could make it so). 2) A ball bearing. The reflection of a light source in the surface of a convex mirror always appears reduced in size. A 1cm diameter ball bearing produces a tiny reflection image. Makes a great artificial star when illuminated by a small flash light a short distance away. Again, with a little creativity you could make a fixed setup that could easily be mounted to a photo tripod.

Wow! What lovely welcome! Thank you everyone! I like this place already!

Hello everyone, My name is Kevin. I'm 47 years young, an Irish and American citizen who grew up in Ireland, just north of Dublin, ans currently living in Paris, France. I have family all over the US but Buffalo, NY, is also somewhere I call home. I had been stargazing with my dad since I was a kid but started "real" astronomy back in 1995 with my first pair of 10x50s followed by an ETX-90EC in 1998. I moved to Paris in 2000, though the ETX stayed in Ireland and got very little use. With Coronavirus lockdown I had a good opportunity to get my old ETX up and running again. Even though I live in the center of a heavily light polluted city, I have a 20th floor balcony, which helps! And so here I am, hoping to share my enthusiasm and love for astronomy. With a small, slow Mak I have learned to particularly love planets, double stars, and star clusters. That will serve me well in Bortle 8-9 skies! By day I'm a guitar teacher, guitar tech, and house husband. I'm an ex-physicist (PhD 1999 in photophysics) and an ex-gigging rock'n'roll musician (~1200 concerts since 2001). I'm a 7+ year moderator on a guitar forum so I truly appreciate the mods' time and attention. (Yes, I have already read the code of conduct). I did recently sign up to another astronomy forum, but while perfectly nice and knowledgeable, it seemed like a bunch of old men and not enormously welcoming. I really want to be part of a community and preferably, a more inclusive one. Just like my beloved guitars, astronomy is for everyone but it can seem unfriendly to anyone who is not male. It's hugely important to me that we overcome that. And so SGL was recommended to me on twitter by one of your awesome moderators and here I am. I'm looking forward to be a part of the SGL community!