Louis D

If you're not getting any interest, try putting OBO in the ad somewhere for "Or Best Offer". Sometimes, someone (or someones) will make an offer, even a low ball one, that might indicate some interest in your item. I searched CN classifieds for the following from your ad and got the following ranges of asking prices that sold (no way to know if for that price): Celestron 23mm Axiom: $125-$150 Lumicon 1.25" OIII filter: $60-$80 Atik EFW2: Impossible to search since you don't specify number of filter positions or size. The range seems to be from $200 to $425. Orion solar filter for 10" SCT: $140+ So, your asking prices in GBP would probably be 70% of those prices given the current exchange rate for USD to GBP. Of course, the second hand British astro market may be more of a buyers or sellers market than the US market affecting asking prices.

At f/10 they will all probably work well out to about 5% or 10% from the field stop. I'm not sure why you'd want to buy 30mm, 42mm, and 56mm eyepieces, though. Would it be to cover a range of exit pupils (3.0mm, 4.2mm, and 5.6mm) for nebula filter usage? I'd recommend getting the 35mm Aero ED if you can find one in stock (TS-Optics sells as the UFL 69° as well). It, along with the rest of the line (30mm and 40mm) tend to perform better than the GSO Superviews even at f/10. That, and you'll nearly maximize your true field of view (TFOV) with the 35mm Aero ED's 44.4mm field stop diameter.

Is the surface smooth or pebbly against which the Teflon glides? If perfectly smooth, it will have too much static stiction to overcome when it comes time to start it moving. Make sure you're using virgin Teflon and not mechanical Teflon. This web page does a good job describing how to modify your bearings. This material might also make a decent bearing surface for the azimuth motion. I've seen similar used in some Dobs. Just make sure the pebbly surface is glossy and not matte.

Both of my Dobs use large Teflon pads riding on Ebony Star Formica (which is discontinued, I believe). Any pebbly, glossy laminate will work well to provide just the right amount of stiction. Lazy susans accumulate crud over time, ruining the motion.

As far as non-telescope related items, I'd recommend downloading Stellarium and learn how to use it to know what is up each night as well as when and where to look.

I'm assuming it's a Dob. As such, there is no automated tracking. If you really want to get into solar system imaging, I'd recommend buying or building an equatorial mount for it. There are lots of plans for them out there on the web if you're handy. Those collimating tools will work fine. The cheshire is more universal in that it can be used for aligning pretty much everything. The Alilne is handy to keep the focuser hole plugged and to do a quick check of the primary alignment each time you take it out to observe. The secondary generally stays put once set, so the cheshire will get used less. With that Barlow, all you need is a T-ring to mount your camera since that Barlow has a T-thread on top. I would err toward the lower profile versions to avoid running out of back focus. You didn't say if you have any eyepieces beyond the beginner 25mm and 10mm eyepieces that come with it. The 25mm is considered decent, but the 10mm is universally panned. I'd probably budget for 8mm and 12mm or 15mm BST Starguider eyepieces for medium to medium high powers. Since you have a 2" focuser, I'd recommend a 35mm Aero ED eyepiece (if you can locate one in stock) to maximize your field of view for finding and centering objects and viewing large open clusters like the Pleiades.

Calling @vlaiv. He can probably best answer your imaging question vis-a-vis pixel resolution when adding a Barlow.

And when used in a diagonal, the long moment arm of a 2" Barlow or PM with a large eyepiece like the 17mm ES-92 can make the entire telescope turn turtle on an alt-az mount unless a large mass on a long moment arm is hung below it.

The moon is about the same reflectivity as asphalt. Do you ever get eye damage staring at asphalt at noon? Here's an actual video of the moon transiting in front of the Earth. It's not very bright compared to the earth, is it?

Siebert Optics will put together a bespoke 4x Barlow or Telecentric magnifier for you on this webpage. Just search for 4x repeatedly and try to make sense of his webpage to find them.

The first 10 9mm ES-120 eyepieces were sold without defined field stops, so they actually show as a ~140 degrees apparent field of view. It's been reported by their owners that the true field of view is roughly equivalent to the 13mm Ethos's TFOV. Since it has a 22.3mm field stop, this means that the original 9mm ES-120 eyepieces display roughly the same TFOV as a 26mm Plossl. So, not quite the same as a 40mm Plossl with a 27mm field stop, but getting close and at a much higher power. So yes, it can and has been done.

The active regions on the sun do change over the course of days. When they are visible is also due to the sun's rotation rate of about 25 to 35 days. It varies by latitude. Fastest at the equator, slowest at the poles.

I may bring out my box fan that I use at night to blow away biting bugs. I set it up to blow perpendicular to the scope's axis and across my body, so I don't disturb the column of air I'm observing through.

On such a short, light tube, I would recommend mounting the finder directly opposite (or slightly forward or back of, depending the RACI's CoG) the altitude bearing so as not to upset balance at any angle.

I wonder about late-spring in Texas. I just picked up a Hercules 1.25" for my 90mm APO, and there doesn't appear to be any heating of the rear ceramic even around noon. Of course, 90mm is a lot less than 152mm. I was breaking into a full on sweat, though, making it miserable to observe. And it's not even summer yet!

If you'd have used a hinge instead of an angle bracket, it could have folded up flat for storage. The rubber feet would keep it from closing during use.

It seems a bit overpriced for what it is. If you want to go down the ~50 degree route for premium money, there's also the 25mm Vixen SLV. However, since you have a 2" focuser, I would recommend the 22mm Omegon Redline SW, Technosky Superwide HD, TS-Optics Expanse WA, etc. I have the discontinued Astro Tech AF70 version and prefer it to the 24mm APM UFF for about the same true field of view when I have a 2" focuser available. The stiff eye cup screws completely off and can be replaced with the Morpheus one if you want a more pliable eye cup. I only retired it after acquiring a 22mm Nagler T4.

Well, if you like longer eye relief, the 24mm APM UFF and its equivalents (Orion USA, Celestron, Meade, Altair Astro all have their own) is very good. If you're willing to move up to 2" eyepieces, the 30mm APM UFF is just about pure perfection. There are just too many variables to be able to make a recommendation without a hard upper limit on price. Here's my comparison image of all the BST Starguiders (Paradigms) stacked up against the Meade HD-60s (discontinued) and a table of measured dimensions. If you click on the through the eyepiece image and enlarge it, you can get some idea of the edge falloff in sharpness of each eyepiece.

That's a pity they didn't think to include that nifty feature on the 150p. That leaves the user with either using the dovetail rail in a clamp head of some sort: or remounting the entire base on a wide tripod top:

Doesn't it have a 3/8" threaded hole in the bottom of the azimuth axis? If so, you can just thread it onto a 3/8" photo tripod stud or adapt a different type of tripod to 3/8".

The 25mm BST performance is well below that of the 8mm and 15mm version. However, anything that performs better at 60 degrees around 24mm to 25mm is much more expensive.

I sometimes use my GSO 2" ED Barlow with a TV PBI to eliminate exit pupil issues and hard vignetting for the whole night just to change things up. It allows me to use my 2" eyepieces like the 40mm Meade 5000 SWA, 40mm Pentax XW, 30mm APM UFF, 30mm ES-82, 26mm Meade MWA, 22mm Nagler T4, and 12mm & 17mm ES-92 eyepieces at higher powers. They provide a different experience compared to my normal 1.25" eyepieces in the 6mm to 20mm range. Longer eye relief, wider apparent field of view, etc. Otherwise, I rarely use any Barlow, 2" or 1.25", except to reach focus with my binoviewer.

I just use a plastic, stacking patio chair for most of my observing. It's convenient because it's already out on the back patio, so one less thing to haul out. When my back gets tired, I can lean back, unlike most dedicated observing chairs.

I've got a SVBONY 20mm 68° on the way. I'll give it my usual testing and observing runs as time allows. I'll see how it stacks up against my other 18mm to 22mm eyepieces. I'm hoping it might work as a pair in my binoviewer if it isn't that great monovision-wise.

Next time, try tapping on the edge of the sun on your phone's screen to get it to focus on the sun rather than on the eyepiece.