Louis D

It tends to be an issue until fully dark adapted so your iris can take in the entire exit pupil. I know presbyopia has little to nothing to do with it because eyepieces with SAEP looked the same to me before I got it and after. What I'm trying to figure out is why SAEP is more noticeable in slower f-ratio scopes. Perhaps something to do with the combined exit pupil size between the scope and the eye?

About 8mm in my experience. That yields a 0.6mm exit pupil (assuming an actual 118mm aperture) which is right at my limit with floaters. YMMV

Keep a close watch on your batteries. Once mine corroded inside the Telrad after 12 years, I couldn't get it working again even with a new battery holder soldered in. No such problems with the 20 year old lithium button cell in the Rigel QuikFinder.

And I'll once again advocate for widest field at about 30x and exit pupil of 6.7mm with something like a 40mm SWA. It's a noticeable jump up in true field of view when trying to frame large clusters like the Pleiades or Collinder 70, that is unless you're using a 25mm ES-100 to get a 4.2mm exit pupil, in which case the difference is only 0.25 degrees, so not a big improvement then. On the other hand, a 6.7mm exit pupil is not very useful for hunting faint fuzzies due to the washed out background, but it's hardly noticeable when taking in bright clusters. That TFOV is also handy for centering bright objects when your finders aren't exactly aligned with the main scope.

We get up to softball sized hail (about 4 to 5 inches) on rare occasions in Texas and Oklahoma, though not around here. They tend to fall closer to between the Oklahoma City and Dallas-Fort Worth latitudes.

I have the 10mm Delos and love it. Absolutely no flaws edge to edge even without a coma corrector at f/6 (yes, I've swapped repeatedly and found no difference). By comparison, the 12mm ES-92 really needs a CC. I also have the 9mm Morpheus, and it appears to be very close to Delos quality. The 7mm XW shows a bit of chromatic aberration off axis on bright stars, so a bit of a disappointment for me. Otherwise, it is quite sharp and contrasty. My venerable 5.2mm XL is still an excellent performer at that focal length. Sharp and contrasty edge to edge with no faults that I can detect. The 3.5mm XW is very sharp and lacks any faults that I can see. However, that is one tiny exit pupil it produces, so I rarely use it. I tend to binoview at those exit pupils to keep floaters at bay. I picked it up for $215 during an Amazon flash sale, otherwise I wouldn't own it. All that said, I've thought about picking either or both 6mm and 8mm Delos eyepieces. However, I rarely feel a need to split the difference between the 7mm and 9mm and 7mm and 5.2mm eyepieces. I do have the 5-8mm Speers-Waler zoom if I really feel the need for those focal lengths. However, it's eye relief is lacking for eyeglass wearers despite the LER of Waler meaning long eye relief. I highly recommend the 30mm APM UFF. It's basically flawless edge to edge with high sharpness and contrast.

What's your budget? I recommend getting a deep Pelican style case so eyepieces can be stored upright. That way, you can pack more eyepieces into the case. The cheap, aluminum looking cases out there actually have thin walls made of textured and painted plastic that puncture easily if banged up against a sharp corner. The blow molded Pelican style cases are practically indestructible by comparison, as well as being waterproof. Something like this case on Amazon would be ideal for large eyepieces without breaking the bank. I've found these Chinese made cases are very robust. Certainly not quite as good as my Doskocil case, but a fraction of the cost. Just make sure it is sent with the P&P foam inserts. Apparently, one reviewer got one without any. I'm guessing a resold customer return. Apparently, the actual case is orange based on review images, hence the clearance price.

Do you guys actually get hailstorms like we do in Texas? We never hear about it over here. Our town just got pummeled three weeks ago by baseball sized hail. Luckily, my house was on the edge of it and only got up to about 20mm hailstones that didn't do much damage other than strip a few leaves off trees. Here's some images from folks who got it much worse than me.

I looked through one being run by a beginner at a star party a few years ago, and the image of Jupiter it was showing was much sharper than the views through other 8" SCTs on the field that night. Apparently, the optical corrector in the rear baffle really helps bring out low contrast details. The owner had paired it with Delos eyepieces and was running it with a tablet wirelessly. It all seemed to work seamless together for him as he selected other objects from the tablet to slew to. It made me think about getting one for fun. Highly recommended if you've got the money.

Sadly, nearly the whole company closed up shop.

There's always one in the crowd who has to prove me wrong. Hope you're proud of yourself. 👏 😒 😄

Indeed. Not even Americans use inches for focal length. Aperture, yes, focal length, no.

Focal length of 1295mm for the primary mirror. I'm not sure what the 51.0 refers to. If you measure the physical width of the mirror in millimeters, you could get the f-ratio by dividing it into the focal length.

Having grown up in Iowa and worked in St. Louis for a time, I offer my sympathies to you for living in a state of Misery, I mean the state of Missouri. 😉😁 If you've got the money, go big with an Obsession or Webster Dobsonian telescope.

I've heard VAT is bureaucratic nightmare and paper management expense. This seems to confirm it. With US sales tax, goods just move around tax free until sold to the end consumer. There's literally no tax paperwork to manage for wholesalers. I'm not talking about duty or customs expenses, just VAT/sales tax expenses.

Not at all the right thread or forum to discuss this. I'm no mod, but I'm not going to bite on this anyway. Perhaps Reddit would be a good venue for such discussions with a broader audience?

As far as SCTs and planets, the only SCT I've ever look through that produced a sharp image of Jupiter was an EdgeHD. Traditional SCTs always seem to produce a somewhat blurry view as compared to a Newtonian with a premium mirror of the same aperture. Newtonians with commercial mirrors fall somewhere in between. I think it's down to better figure, lack of astigmatism/coma, flatter field, and smaller central obstruction of the premium Dobs with a Paracorr. The EdgeHD line fixes many of these issues with its corrector lenses in the rear baffle tube making the image significantly sharper at high powers.

As long as demand remains strong and there is no domestic supplier to undercut them, Chinese made scopes will likely stay at inflated prices for the foreseeable future. It's not in their best interest to cut prices if they can sell everything they make at the current prices. They've already driven out or bought out just about every non-premium astro equipment supplier over the last two decades, so they're not likely to be undercut on price by a local producer.

I will say they are sublime, though. My best views of Jupiter were through a Zambuto equipped 12.5" Mag-1 Portaball on an Osypowski equatorial platform some years ago at a star party.

If you clad the whole think in brass plate, it would have a definite steampunk vibe.

As for me, I find the kidney beaning very moderate to unnoticeable in use. Despite having the same size eye lens and AFOV as the other two NT4s, it does have longer eye relief making it easier to use with eyeglasses. Back to back comparisons over multiple sessions led me to oust the Astro Tech AF70 22mm from my A-team case and replace it with the 22mm NT4. It has a bit less eye relief (about 2mm less), but it is significantly sharper at the edges. The centers are roughly equivalent. The wider AFOV of the NT4 sealed the deal to live with the tighter eye relief.

The ES-92s were pretty easy for me to get used to. I never got on with the 17mm or 12mm Nagler T4s very well. It turns out the latter two have strong SAEP. The 22mm NT4 is pretty decent to use. I'm wondering if the 16mm Nirvana has undiagnosed SAEP. It makes the field of view all but impossible to hold once the field stop pops into view.

Now you're just trying to make us jealous. 😉

Sounds like NYC photo retailers. Unless you're buying product, they really don't want to be on the phone with you.

Thanks, I forgot about that. I didn't even mention Obsession who uses OMI and Ostahowski mirrors. I'm sure I'm missing a few others. There are also a bunch of others like Star Splitter and Tectron who, like Starmaster, and closed up shop over the past 25 years. Their used scopes can make for a good deal.