amaury

You get more mag, at almost the same TFOV, with noticeable more eye relief. Diminishing returns is something very common in the hobby to be honest. Whether the price difference is justifiable is totally your call. For most people it would be hard to justify.

I have the same telescope, and as Louis D said, it is doable to record planets with a dob, but it's not by any means the right tool for the job.

I find myself in a similar position nowadays. I started studying at night two weeks ago. I work during the day. That means I only really have time to stay up late on weekends. The moon, and doubles are my main targets. I got to say I was never a big fan of doubles. A zoom makes it much more satisfying.

I just got a planisphere this morning. Thanks a lot @Richard_B This is a really nice-to-have item for visual observation and not messing my dark adaption using the phone app.

Thanks Richard, I don't necessarily need one, it's a nice-to-have sort of thing really. I think the stars move very slowly over decades but for the most part, the sky it's mostly the same as it was 20 years ago I think. For planets it's different story I guess. I also use a couple of apps that are quite handy, they mess with your dark adaption, however.

This is my first upgrade for my 8" f6 Dob after quite a bit of research and insight from you guys. A rebranded Explore Scientific 82 24mm from Opticstar (first class dealers as John said, highly recommended).

Hi Baz, It's good to hear from you. The click-lock systems is lovely yes. The one you point at is the extension bit only. I want to change the 2" focuser fitting/adapter as well (the M54 connection) I might get this one plus the extender you mention. https://www.firstlightoptics.com/adapters/astro-essentials-2-inch-compression-ring-adapter-for-sky-watcher-newtonians-and-72ed-refractor-m54.html Going fully click-lock makes the fitting plus the 37mm extension 10mm too long, I am not sure if I'll need those 10mm of in-travel focus.

Sorry to revive this thread but I am about to do something very similar with the Baader Click-lock system. I have a SW Skyliner 200p, same focuser fitting and adapters. (11mm and 47mm respectively of optical length) That is an effective optical length of 58mm for any adapter. I am planning to change the fitting with the baader click-lock, the one below. https://www.firstlightoptics.com/adapters/baader-2-clicklock-m54-clamp.html That alone has a 30mm of optical length, I am guessing that is too short to the "stock" optical length. I'll be missing 27mm of back-travel in my 2" eyepieces. Baader also sells a 2" 37mm extension https://www.firstlightoptics.com/adapters/baader-2-clicklock-clamp-37mm-extension.html Somewhat close to this. That brings the total optical length to 67mm for my 2" EPs, that means I'll be missing around 9mm of in-travel. Is this ok? or should I disregard the click-lock system completely? I only do visual. Thanks in advance

potentially another re-branded ES 2X 2" focal extender? @johninderby @KP82 @Stu1smartcookie even cheaper. https://www.altairastro.com/altair-lightwave-2x-2-inch-flat-field-apo-tele-extender-barlow-2833-p.asp

I had been saving globular cluster for clearer nights. Last night was probably the clearest night I've had in the last month or so. I had never attempted one before. Literally last night was my first time ever with globular clusters. I drive my 8" Dob half for 30min to get to a Bortle 4 area, just for context. I am a total beginner too. I took my time. I started NW with the double clusters near Cassiopeia. I love that one. Moved W to Auriga, M36, M37, M38, very beginners friendly and a lovely sight. Spent a good time in M35 in Gemini (although the waxing moon was too close). I always go to the Beehive too, easy to find, and still a lovely view. M67 always gives me some trouble, I find it tricky to find, I did eventually find it. That was my last stop in SW before jumping to Arcturus in the east. This is going to sound very silly but my heart was pumping like crazy. My expectations were mixed. M3 is apparently one of the brightest globular clusters in the night sky (top 3 I read somewhere), however, Turn Left at Orion warned me: "M3 is as faint as a sixth-magnitude star". Anyway, I thought it was going to be easy to find. How wrong I was. I don't know how many times I scanned the Arcturus-Cor Caroli, and the Muphrid-Cor Caroli sections expecting to come across a "super bright/compact/ grainy" ball of light. As posted in that simulated view by @mdstuart, and going back to the topic of this thread, M3 looks rather dim, I could see a lot of graininess for sure. That's how I would describe "how does M3 look like?" from a beginners perspective that the only thing I had seen before was the moon and open clusters.

I can tell you this regarding your comment. I contacted several companies, some in Europe too (they seem to have better stock), and the guys from Opticstar were the most responsive ones by a long shot. Just ordered the XL 82 24mm with them.

Thanks John, just wanted to make sure, it just seemed too good to be true. ES are already good value EP in terms of performance per dollar, and on top of that you can get a cheaper re-branded version with the same performance. Plus this, price is pre-rise. Made it a no-brainer for me considering the current circumstances with price and availability.

I reckoned I better digress here instead of creating a new whole discussion. Is it just literally an Explore Scientific re-brand? or is there a catch? Browsing around I noticed that Opticstar also has a re-branded ES82 lineup that is 40quid cheaper than the actual Explore Scientific one, and they actually have stock. http://www.opticstar.com/Run/Astronomy/Astro-Accessories-Telescopes-Opticstar.asp?p=0_10_5_1_8_322 Is it just literally a name change? I reckon if the eyepiece is made in the same factory in China, there will be zero optical perfomance difference and the is no "catch" other than a "name". Is it something like the ES/Maxvision case?

@Louis D, Do you think the same can be achieved with an ES82 24mm? the specs say it has 17.5mm of eye relief, in practice Don mentioned it has more like 14mm of effective eye relief. Haven't read any comments about folding the eyecups in the ES82 eyepieces.

Thanks Steve. Very useful information as usual. That chart from televue is handy. Another reason for me to maybe stay around the 4mm exit pupil or maybe observe with my right eye which doesn't have any cylinder correction (I tend to observe with me left eye for some reason, the one with -0.5 Cyl) I've read good things about that Omegon (and re-brands), I'll keep it in mind. The APM Ultra Flat Field 30mm have been reported to be eyeglasses-friendly when the eyecup is folded down. Still not anywhere near the 22mm of eye relief they state in the specs.

Where did you buy from @Deadlake? Astrograph?

Expectations are high on this one. I'll be patient instead of buying the Morpheus line up from 12.5mm down.

That is appreciated Stu. I am learning a lot from you guys. Wow!! that is a beast of a telescope! I'd be happier with darker skies with my 8" f6. It's that "perceived contrast" that have made mid/hig power with ultra mega wide field of views (20mm/100afov for example) very appealing.

Thanks @Stu, as @johninderby said, using exit pupil alone or any variable alone is an over simplification of a very complex subject such as the visibility of a given astronomical object. It's a never ending balancing act of many variables. I guess that explains why people have many eyepieces 😅 The general consensus seems to be that the 20mm is more useful in most instances. Something tells me I'll buy both 😆 You guys have any insight about the ES82 24mm? it seems to be a happy middle, a quick search tells me it's apparently the weakest of the ES82 family.

Yes and no. For extended objects, contrast is independent of exit pupil. Magnification can make you see more detail due to the increased resolution so it seems that contrast improved, it is actually still the same contrast (for extended objects). That's is the real benefit of observing the same TFOV but with a higher magnification. There is this good article that explains it better than I do. https://medium.com/@phpdevster/how-telescope-aperture-affects-your-view-24507147d7fc What you are really giving up with the 20mm/100deg EP is eye relief. I believe there isn't a single 20mm/100deg eyepiece that is eyeglasses-friendly. On the other hand, the APM UFF 30mm has superb eye relief.

I'll do my homework with this. It helps yes. The thing is that with my scope (8" 1200mm f/6 Dob), the APM 20 gives me 1.67deg TFOV, that makes the APM 30 UFF redundant as it almost overlaps in terms of TFOV (1.75 TFOV for the UFF). The one thing I would be giving up with the 20/100 is eye relief (15mm). I only have very small corrections (-0.5 Sph and -0.5 Cyl) so I think I can do visual observing without glasses. Maybe I am wrong here and I am being too optimistic. I totally understand that usefulness now. I just never considered ~20mm / 100 degree eyepieces because of the massive price premium of those specs. I was aiming more towards 24mm/82 deg or 30mm/70 because they have an equivalent TFOV in my scope, better eye relief, and better prices, at the expense of more exit pupil (which wouldn't be an issue in truly dark skies, but it doesn't get better than bortle 4 for me).

I'll pay the premium for usefulness. Thanks Louis.

Thanks Stu, looks a like a bargain compared to a 21mm ethos or a ES100. I reckon I have to consider import fees when buying from Europe now. Is it any different than importing something from the US? I can get a similar TFOV with an ES82 24mm, a bit better eye relief and a tad cheaper than the APM 20mm

I have read many good things about the APM too, that it punches above its weight, but never thought it would be better than a Pentax XW. Those are premium EPs as far as I know. The Baader Morpheus will be the 12.5mm (aiming for the "sweet spot" of 2mm exit pupil) Thank you all for your insight. It is appreciated indeed.

Thanks Rob. (that was a funny pun tho'). I certainly understand there will be better contrast with the 21mm EP in bortle 4/5 skies. The thing is the balancing act between price/TFOV/Exit Pupil etc. Those 21mm with 100 AFOV EPs have a really steep price, as much as I would love to have one of those, I don't want to spend 80% of my budget on a single piece. I'll keep them in mind for a future investment for sure.