Mr Spock

It all depends on seeing conditions and target. In excellent seeing conditions my 12" f5 is sharp at x461 (3.3mm eyepiece) on the moon. On Jupiter, only x190 (8mm).

While you are updating it, can you get rid of all that red. I don't like it

Same here, but Baader T2 prism with 30mm UFF (SL version). No vignetting with the 30mm UFF - it doesn't like the 42mm LVW though, but you don't have one of those.

I'll have a look anyway - I can always report it as not seen.

Altitude makes a huge difference. For a while now Saturn has been mush here, no matter what scope I put on it. My best ever view was with a 140 Mak at x313 many years ago. Saturn was overhead. I'll never forget the sharpness, and inky black background. Along with a sharply defined Cassini, an elusive Encke, and the crepe ring. Eyepiece was a Meade 4000 6.4mm.

That 30mm UFF is amazing on wide fields, it's just so well corrected.

Ah, but when seeing is excellent... With the C9.25 I split 0.7", and 0.5" with the 12". I always like a challenge. At the moment I'm doing a chart for the bottom of UMa surrounding ν and ξ. I note several close doubles, including TDS 8009 at 10.7, 10.7, 0.4". It's worth a try.

One approves of your taste in eyepieces 👍

Lovely image. Reminds me of the fabulous views I get through my SL 12". I have to rely on memory given how much cloud we have these days

Hang from the obsy roof like a bat

Easy peasy for the 12"

List of DS catalogues: http://astro.vaporia.com/start/doublestardesignation.html

For some of the other common catalogues: OΣ = STT OΣΣ = STTA Σ I = STFA β = BU h = HJ Hxxx all follow the same format, so H VI = H 6, H III = H 3

Just remember, in the southern hemisphere the moon is also upside down. Whether or not something is the right way round depends on where you happen to be at the time It's all relative.

3° lower than Rigel, 5° higher than Sirius. Shouldn't be too difficult

From Stelle Doppie name cst SAO coord wds_name last obs pa sep m1 m2 d_mag Grafias Sco 159665 16 04 22 -11 22 23 STF 1998 AB 2019 626 12 1.1 4.84 4.86 0.02

They are all here https://www.stelledoppie.it/index2.php?section=2&azione=cerca_nel_database&cerca=OK&metodo-cat_wds-coord_2000=16&dato-cat_wds-coord_2000=[%2B-] Just type what you want into the search box. Remember, for Σ1177 for example, Type in STF 1177.

Try the same on the moon or Jupiter

The Dawes limit for 100mm is 1.16", and the Rayleigh limit 1.38". I have definitely split 1.2" with the 100mm. At the very best a 1.1" pair looks like an 8.

Should be impossible. At 1.1" the larger airy disks of a 4" will always overlap. You need the smaller airy discs of a 5" and above to separate them.

Thought I'd add my drawing from a few nights ago.

"SVBony 3-8mm, Morpheus 12.5 & 17.mm" You have three really good eyepieces. I'd recommend the 30mm UFF to maintain that quality. It's expensive, but you'll notice a quality drop with anything else. You don't need anything between 30mm and 17mm.

I don't worry about orientation as long as I have the sharpest image and finest detail. I use a 45° erecting prism on my 60mm for birdwatching. Makes sense to have things the right way round.

You can split sub 1" doubles with that, plus colours will come out nicely. Even with small scopes Albireo and Almach are spectacular.

All observations here with the FC100. Seeing was excellent but with my usual heavy light pollution. The 100mm was limited to just below mag 10. All PAs are guesses (hopefully remembering to reverse L+R) I had intended a longer session but I wasted hours trying to collimate the 8" f4... S560 - very wide uneven pair at 10°, x44 Σ1177 - uneven pair, 30°, x185 Σ1186 - a very faint speck at 220°, x247 Σ1224 - uneven, split at x44 but looked great at x247. Φ2 Can - a lovely, bright even pair. Split at x44 but awesome at x247. Tegmine - decided to draw this one. I put the old 120mm achro on to get a proper split of A and B; C was easy and not shown here.