Louis D

Wouldn't one of the imaging forums be a much better place for your question? Unless you're doing manual guiding with an eyepiece in the OAG, I don't see how eyepieces even figure into this.

I put together some existing images I have to show how a couple of budget 20mm/23mm eyepieces compare. The 20mm is the SVBONY UWA with a 67° AFOV and the 23mm (closer to 23.5mm) is the Aspheric with a 63° to 64° AFOV. Neither is great at f/6, but both improve dramatically at f/12. When shopping for eyepieces to use in a slow scope, budget eyepieces become a much more viable option. Both also work great at f/18 in my binoviewers with a 3x (effective) Barlow element to reach focus.

Adding a baffle ring at the bottom of an eyepiece with an inner diameter no smaller than the field lens can greatly reduce some forms of stray light. The Vixen HR eyepieces did this: They even extolled their careful attention to stray light control: I've also read of folks disassembling their eyepieces to blacken lens edges and spacer rings as well as to add flocking to reduce stray light.

When you start finding objects with the goto, make sure to look up to the sky using whatever unit power finder you settle on. This way, you'll quickly learn the sky and eventually you'll find you don't need the goto anymore for the showpiece objects. I love going to public star parties and putting a floundering newbie's scope on a DSO using dead reckoning on the sky and sighting along the scope. It never fails to astound them. Sometimes, I shoot from the hip and don't even sight along the tube and just go by judging alt-az angles looking at the tube orientation. You too can get there with practice. Personally, I would recommend the Rigel QuikFinder over the Telrad for the 127 Mak due to size. Even a cheap RDF can work well enough starting out. A 50mm RACI would be money well spent just for the wide angle views to put objects into context on the sky.

Try putting vibration suppression pads under the tripod feet. I bought a pair of new old stock, 1990s pure Sorbothane insoles off of ebay and cut them into squares to put under each tripod foot. Problem solved. Vibration dampening went from 3 seconds to 1/2 second. You can also purchase new Sorbothane pads off ebay. This won't solve your instability problems if you're on spongy turf, though. Weight is indeed your best option then to compress the turf. You could also work each foot down through the turf to help somewhat. Here's what the full Sorbothane insoles used to look like: I don't think they're sold like that anymore due to cost. Now, Sorbothane is used in just the heel and ball parts of the insole. I've never tried the commercially available vibration suppression pads, but if they're using urethane, they won't be as effective as Sorbothane. When I tap the telescope, vibrations just go "thud", so to speak. It's really quite amazing.

You're right, I can't recall seeing poor light control documented pictorially anywhere for eyepieces. I guess it's one of those "I know it when I see it" sorts of things. Ghosting: Pretty obvious with planets. If you move the planet around the field of view and a dimmer image, generally on the opposite side of the FOV, dances with it, that's ghosting. Only on axis will the two images merge. If the alignment isn't perfect, contrast is greatly diminished and you're better off moving the image off-axis. Light scatter: An overall term applied to light not going where it's supposed to go. It can be narrow angle or wider angle. Glare: Generally seen as a glow or spiking around bright objects on-axis obscuring fine details or close, dim companions. Professional telescopes resort to using an occluding disk of some sort along with precise baffles. Amateur scopes and eyepieces rely on fine glass polish, smooth reflective surfaces, and smooth coatings to minimize light scatter. I believe this form of stray light is referred to as narrow angle light scatter. Flare: Generally associated with bright objects off axis or even outside the FOV introducing stray light into the FOV. Again, moving a bright object in and out of the FOV and around the FOV will show light streamers pointing back to the source. It can be handy for recentering a bright object once it strays outside the field of view. Telescope and eyepiece design minimize this effect with light baffles, light traps, flocking, blackening, etc. Internal reflections: Yes, these often lead to flare and can contribute to glare. If your scope and/or eyepiece are poorly baffled and mechanical/optical bits are not properly blackened, you will see an overall glare or even flare in the worst cases in the FOV. There is also stray light in systems such as catadioptrics where unfocused light from the front aperture bypasses the mirrors and goes straight into the eyepiece due to poor baffle tube design leading to glare and/or flare. Sorry I can't help with any photographs. When I take cell phone camera FOV images indoors, I have to have all lights turned off near the telescope, and I have to shield the top of the eyepiece from reflecting even dim stray light into the camera lens with my free hand, so I have dealt with photographic stray light extensively doing this. Sounds like a project for you to document photographically. 😉

It's not surprising why Tele Vue is so popular here when the other options are so expensive.

I'm thinking of using some Protostar flocking material to line the rear baffle tube of my 127 Mak. I just haven't had the time to work on that project.

Have you tried the US? They're in stock at Agena Astro, Eyepieces Etc, and High Point Scientific to name a few reputable dealers. They are $299 before VAT here, so figure $359 with VAT but before import tariffs and shipping, so figure about 290 GBP minimum imported. How badly do you want one?

I much prefer the APM Hi-FW 12.5mm to the 12mm NT4. It has much less SAEP exit pupil finickiness, much less EOFB (which extends to the center of the NT4), better eye relief, and it's sharper to the edge at f/6. Of course, I prefer the 12mm ES-92 to either, but it's much bigger and 2"-only. Some folks prefer the 12.5mm Morpheus to either the APM or NT4, but I've never looked through one to comment on it. Then there's the Docter/Noblex 12.5mm that's supposed to be terrific except for price and the presence of AMD.

Absolutely go with single vision in the base plastic lens. That way, the entire field is in focus at once, you can look up to the sky as needed, dispersion is at a minimum off axis, and cost is low enough that you don't feel bad about having a dedicated pair for astronomy. Check online retailers. I've bought a pair of Brodie frames for $9 and a pair of Bennet frames for $19 from EyeBuyDirect and have been perfectly satisfied with their quality. To avoid coatings on the lenses, on the lens selection page go into clear->customize->1.5 index lens included and there's no additional charge for the lens. Imagine paying under $20 for a pair of quality single vision eyeglasses. I took a leap of faith, and haven't been disappointed. I've got readers and computer glasses from them as well. Just ask your optometrist for the appropriate prescription for each usage. I don't know if they sell worldwide, but I would hope there are similar online retailers in other parts of the world.

Same here, they're called property taxes. However, sales taxes (VAT equivalent) allow for a second source of local income to reduce the tax load on property owners. Sounds like that's not the case in Europe. It just seems really strange to not keep sales taxes local having grown up with that taxing scheme. It's why (until recently) interstate sales tax free internet sales have been extremely detrimental to local governments in particular.

That's really rough. I'm hoping my eyes never start doing that. My astigmatism amount and angle have remained relatively constant after presbyopia set in and stabilized a decade ago.

Ah, so you were comparing 2009 130P prices from memory to 2022 150P prices from a web search.

Apologies to the mods and everyone who finds this annoying, going way off topic, but I can't find an answer online, and I have always been curious, so here goes: How does a local government get a share of the VAT money collected back from HMRC? Does HMRC keep track of local sales receipts and automatically remit a proportionate amount back to them? Do local governments have to submit grant proposals (as in the US) with supporting documentation? Is money automatically sent based on the population of the governed area? Does the national government simply keep all the VAT revenue for national expenses such as defense? I literally can't find a simple answer to this online. All the answers pertain to how to collect and remit VAT, but not how local governments receive their share of VAT revenues. This is not an issue in the US because all sales tax money collected remains local to the state and county/municipal level (each tacks on a percentage). As such, we try to shop locally to keep our tax dollars working locally to maintain local infrastructure and services. There are programs in place to redirect state level sales tax revenues to sales poor areas from sales rich areas, so it's not completely lopsided in favor of wealthy areas.

If you hunt around the following websites, you might be able to identify which company makes it based on mechanical similarities: Kunming United Optics Sharpstar Jinghua Optics Long Perng

Fewer than you have in your sig. 😉

Perhaps you got a hit on a Skywatcher 150 Mak, Skywatcher 150PDS, or Skywatcher 150 EvoStar? 🤔 Simply post a link to whatever you got a hit on at 3 times the price of the SW 130P Heritage Flextube which would be about 3*£175 = £525 to clear up this misunderstanding on pricing.

Not using them much?

The 150 is only $35 more than the 130 here in the US. Unless the size difference is an issue, I'd go for the 150p.

Yes. I've measured the eye lens recession to be 7mm! It would have around 19mm to 20mm of usable eye relief if it was brought up to be nearly flush with the top.

Given the weight and length of the OTA, it sure seems massively undermounted on that EQ mount; or am I missing something here?

How do you get on with the TS ED 35mm in your sig? I find its 14mm of usable eye relief a bit tight with eyeglasses. Otherwise, it's a decent, near-maxfield, lightweight eyepiece. If the eye lens wasn't recessed, it would be great with eyeglasses.

Let us know how you get on with it once you receive it and have a chance to look through it.

It's 331.93 € excluding VAT (which is roughly $350) for us Americans. You have to compare apples to apples because US list prices don't include sales tax since it varies state by state, county by county, and city by city. Sales tax is an important source of local revenue to help keep down local property taxes. I have no idea how local governments in Europe get VAT money if they can't directly charge it on sales. In the US, once the federal (national) government gets its money, states and municipalities have to apply for federal grants for specific projects, not day to day governmental expenses, and hope for the best.