josefk

Nice detail and thanks for posting because your top pic 100% validates my visual observation and sketches last night - i'm not imagining things - i'm chuffed to bits. 👍

You've got to move pretty fast @dweller25 in more ways than one. 😉

Thanks and cheap sheepskin gloves! I find them better than even quite technical mountain gloves or mitts for the kind of on-off-on again routine with astro. highly recommended.

i am loving this scope not only for its big strength (flat and wide) but also for its ability to bring me a nice planetary view from a tiny package. Out last night observing the GRS transit on Jupiter at about minus three degrees...

Fabulous session last - a "best yet" Jupiter in the little GnG. Such a shame it was a school-night and i had had early evening plans because in my location it felt like it would have seriously rewarded a long session with bigger kit. Never-mind ~21:00 till 23:30 it was super enjoyable nonetheless both for the astro and for being out on such a lovely crips atmospheric evening. I mainly watched the GRS transit the middle quarter/third over a period of about 90 mins. Great detail for a small scope, seeing felt very steady in deed for quite extended moments. Sketched over here: https://stargazerslounge.com/topic/416550-jupiter-grs-transit-in-the-frost-301123/#comment-4437018

What a fabulous night last night in the frost at minus something or other. Shame it was a "school night" because it felt like conditions were really superb. I spent the best part of 90 minutes in a 2.5hr session observing only Jupiter and it was the best i've seen it in my 85mm scope. Really tantalising and interesting NEB/SEB "detail" while the GRS transited the middle quarter. Wonderful. Here's a rough attempt at capturing the view - 3 sketches in the field and two tidied up this morning. For the starting sketch i made the mistake to try for too long to capture what i could see and so there is quite a bit of rotation error in it i think. I must remember to go much quicker (10-mins per thumbnail) in future. Observation with an 85mm refractor and ortho' eyepieces 5mm, 4mm and 3.3mm. 5mm and 4mm also with the Tak 1.5 extender for magnifications in the x135...169 range. Though NEB and SEB were showing lovely "roughness" or "ropelike" twisting the features were mainly large and darker-on-dark. i didn't see any small barge like features nor any light-on-dark pale ovals except, there was a medium small prominent dark area preceding the GRS seen straightaway and i had the feeling this was more visually prominent after the GRS transited the mid point.

Very nice @SwiMatt - i was working my way over to M36 last night but didn't quite make it - this is compensation enough 😉

I would put a finer focuser on my fine focuser if i could (not joking). I may yet still add a bit of pipe lagging or similar to expand the circumference on my GnG set-up. When my hands get cold i think i pass quite a bit of tremble onto my lightly mounted GnG when trying to get that last bit of sharpness.

Long runs of cloudy sky make me crotchety. Does that count?

@Franklini can get it down to 21” per graduation with a x2 PM in a 2.4m focal length scope but this set-up isn’t preferred and I really would need x5 Barlow in other scopes. Good fun though and educational already in its own way.

That’s another great post to digest!

My problem is I can’t get a magnification high enough to make the marks on the scale measure a meaningfully small number of arc seconds and I don’t fancy buying a x5 Barlow or similar especially to do it. I should say I use the Baader Polaris and it isn’t as finely graduated as the one you showed.

i wouldn't repeat this out loud to anyone really artistic but i have a few (non-astro) "learn to sketch" type books and one of them opens by saying "sketching is a skill not a talent" meaning it can be practised and perfected by anyone 🙂. i live in hope even if so far i may be the exception that proves the rule 😂. ...meanwhile i bet you now you will recall the observations above far better in a few months time from having taken the time to sketch them and i would hazard a guess you probably saw them better at the time from setting out to sketch them and really looking (no offence to anyone not sketching). Cheers

Hi @Sunshine - i found this to be a good read: https://www.handprint.com/ASTRO/bineye1.html#standard Except the anomalous behaviour of the eye/scope combo at "diffraction magnification" (where the visual separation doesn't change even if you magnify it - something i understand in theory but don't know how to apply in practise) it's basically good sound advice to understand your EP FOV in arc minutes then go from there in estimating fractions. With wide angle EPs i'm not too accurate visually dividing the FOV up to estimate a narrow separation but with narrower EPs (e.g.a FOV ~15') you can be surprisingly accurate estimating even at sub arc minute fractions and when i get my eye in even at +/- ~5" (e.g. <5", ~5", 5-10", 10-20", etc.) - especially when you are doing a few doubles in an evening. You sort of get calibrated as it were. I tried an etched reticle (simpler than the one @Franklin shows) and it sharpened up my estimation for position angle (drifting stars from the centre of the EP out of the edge and using the guidelines on the reticle to do this precisely) but i can't get it magnified enough to usefully use the scale for "measuring" separation rather than just being a useful help to more accurate estimations. Cheers

hi @badhex - the camping mat solution doesn't stop me also looking at proper dew shields with built in heaters because the camping mat is flimsy so is semi-consumable. But the big advantage of camping mat material is it is super light. Here's a pic from the spring - this is at the end of an 8hr session. it wasn't super dewey but you can see from my car there was plenty of dew about by this time. I had run the dew heater for 8hrs on a 13,600mAh source and there was still some juice in it...the objective was clear all night though i also realise from this pic that i do extend my dew shield by quite a bit more than i thought with the camping mat (the end of my dew shield is just ahead of where that black elastic band is)...

I also don't have a load of experience with dew bands though i do use one on my bigger refractor. I put mine just behind the dew shield (so probably around the lens cell more or less). So i can run it at the lowest power setting (and so leverage a small energy source for many hours) i put a short section of foil backed camping mat around both it and the dew shield extending the effective dew shield by a few cm by doing so. Seems to work so far. If i fear it is necessary to use it then i use it right from the off - i don't wait for dew to start to form. I despise dew more than any other local impediment to observing. I like IP6x rated bird spotting optics!

How easy or not was Tethys at that proximity @badhex in the 100mm? I had similar proximity of the moons to Saturn one evening last week and could pick out Rhea (with 85mm) but not Tethys (and not Enceladus). There was some glare in the atmosphere but not loads.

This looks fantastic. I've said it before - while i have a technical job and use screens all day at work i don't see myself getting into EAA (i need an analogue hobby as an antidote to work) but in the far future i can definitely see EAA (or more preferably NV if the prices come down) as an alternative to wrestling with a large or very large scope to achieve these views. Not instead of visual but a bit like you do as something to do "as well as". Super.

Uses your phone camera to do this:

There is the “Dark Sky Meter” app for a phone/phone camera. I’m not sure how absolutely correct it is but for your own relative record over time it could be useful. I’ve found it quite educational using it over an extended period of time TBH.

Good luck - feels a bit like committing to a diet in front of friends and family. 😉

What a brilliant night to end the week - a lovely clear night that hadn't been in the forecast. Jupiter was the highlight - i dropped on the Ganymede shadow transit by pure luck - sketched over here: https://stargazerslounge.com/topic/415441-ganymede-shadow-transit-101123/#comment-4430730 After that i spent an hour on the most satisfying "negative observation" i can remember. After trying earlier in the week for NGC 604 (in M33) i tried again last night in a totally systematic way; large, medium, small exit pupils all w/ and w/o UHC and O-III and all given plenty of time at the eye. It felt tantalisingly close at times but still no certain observation unfortunately. Enjoyable in its own way though and satisfying because now i know it's really not going to go in my skies with 85mm of aperture and I do know the star field quite well for next time 🙂. Slightly bizarrely M33 itself looked quite extensive with a medium exit pupil and UHC. I thought it would have been dimmed too much with that filter.

Sounds absolutely awesome Joe. Fantastic

it's probably no consolation but that view of the fells does sound nice in its own right. Slightly jealous here in the Lincs flatlands 🙂

Pure serendipity this one - if i had left the house 30-mins later or spent 30-mins longer on Saturn (i started with Saturn) then i would have missed it. This is Ganymede's shadow transit of Jupiter's southern pole last night. I picked it up about 19:15 a little bit further away from the limb than in this sketch. I felt the shadow touched the limb at 19:27 or just a little after and was undetectable (had cleared the limb) at 19:41 though i appreciate both of these times will be related to the resolution of my 85mm scope, the steadiness of the seeing, and my eyesight. i was surprised at the size of the shadow. Larger than the one other i've seen. Seeing was nice but not fabulous - i couldn't see any real belt detail except a darkening and bulging feature on the NEB in the west. I didn't see any belts or flickers of belts in the southern hemisphere other than the SEB. NTB was intermittent. Faber Pitt Pastel #188 (sanguine) is a good match for the belt colours at the EP 🙂