John

My skies are Bortle 5 as well. The Skyliner 200P that I have recently acquired performs very well now that I've made a couple of minor tweaks to it. Optically it's very good indeed. I owned one about 10 years ago and have forgotten how good they are.

The focuser seems to have been a weak link in quite a few brands / models that I can think of over the years 🙄

That sounds quite logical 👍

Nope. You know what happens when there is a screw, bolt or knob labelled "do NOT touch" though 😈

This is true. The instructions for the Feathertouch micro pinion unit mention this and describe testing the pinion shaft to check it is straight. There are some useful photos in on the first page of this which show how the Tak FC pinion is held in place. Might be useful even if not fitting an FT: Microsoft Word - MPA-TAK Instructions.doc (starlightinstruments.com)

Yes it is very similar. I use this guide for my Vixen focuser: Vixen Focuser Adjustments (miltonhill.us)

This guidance was posted by @mikeDnight on the CN forum. It refers to the FC100-DC that he had at that time: The stiff focuser problem is easily resolvable! I noticed in a side by side comparison with a FL102 that my DC focuser was really quite stiff, so after giving it some consideration, I eventually plucked up the courage to try and rectify the problem. Now the focuser is buttery smooth and easy to move. First remove the pinion by unscrewing the top cover and then the two screws on the brass plate underneath. It's a simple process and you can do no harm. Next, remove the locking nut on top of the focuser. Now there are three small grub screws also on top of the focuser. The holes for these grub screws may be filled with glue to prevent tampering. The glue however is quite soft and a fine Allen key can be pushed through it. Unwind each of the three grub screws equally until the drawtube slides freely by hand. Then gently retighten each grubscrew evenly and a fraction at a time, until the drawtube feels firm but still easily moveable. Uneven tightening will result in image shift! Trial and error may be necessary to get it just how you want it. Next, reattach the pinion by screwing the two screws holding the brass plate back on focuser. Don't overtighten these screws! Then reattach the pinion cover. Mike

I found the same with the Skywatcher focuser, all though not as extreme as in the above photo. I now use a shorter eyepiece extension tube - 35mm whereas the original 1.25 and 2 inch adapters are around 50mm. This change means that the focuser is racked out a little further to get eyepieces to focus so the end of it does not intrude into the light path, or at least not as much. I can't say that I've noticed a difference in the views though, to be honest. It is also worth bearing in mind that not all eyepieces come to focus at the same point. There can be as much as 15mm difference depending on the brand / model of eyepiece. So that can affect the degree to which the focuser extends into the light path as well.

The focuser on my FC100-DL was rather stuff when it was new. I found that I could adjust the focuser to make it good to use. The process is documented somewhere online - I'll see if I can find a link. I then found the DL focuser fine to use for a few years but I came across a Feathertouch micro pinion upgrade at a reasonable cost so added that and now the focuser feels just the same as the full FT on my TMB/LZOS 130mm. I've not tried either the Tak or the Moreblue upgrades.

It's closer to the HEQ5 than the EQ5 I thought. Of the ones I mentioned above it actually did the best job with the 130mm F/9.2 triplet. I didn't use the GOTO system so I can't comment on that. My 130mm F/9.2 triplet has similar mounting needs to a 150mm F/8 doublet in terms of weight and length. In the end I ditched EQ mounts and found a superb T-Rex alt-azimuth mount, which did the job far, far better than any of the EQ mounts.

Another thing very noticeable tonight is the apparent size difference in the eyepiece between Ganymede and Europa. These two are on the same side of Jupiter tonight and not too far apart. The physical size difference between them (illustrated below) is clear from the eyepiece view. Their apparent diameters (according to Stellarium) are 1.78 arc seconds for Ganymede and 1.06 arc seconds for Europa.

I've just popped out with my 100mm refractor because I noticed that a patch of clearer sky had appeared with Jupiter and the moon in the middle of it. I got some very nice views of Jupiter with the GRS just past mid-transit. The NEB is showing lots of interesting details currently. In particular there is what looks to be a noticeable pale "bay" on the southern edge of the NEB to the NW of the GRS's position. Both the NEB and the SEB seem to have twists or knots in them and variations in the darker colouration. Far from the plain bands that sometimes show. The GRS seems a stronger salmon-pink tone that last time I saw it as well. 150x - 180x seems to be delivering the strongest contrast variations in the jovian features this evening. Glad I bothered to get out 🙂

Baffled by baffles 😁 My Vixen has quite few in the focuser drawtube as well plus 4 in the main tube.

Quite thick cloud here as well as a bright moon so no real chance of aurora sightings I suspect. If the cloud thins a bit I might take a look at Jupiter later. Apart from that plus the moon, nothing else showing through the murk currently.

I tried a Celestron AVX, an HEQ5 and a Vixen GP-DX while I was searching for a mount for my 130mm F/9.2 refractor. The AVX was GOTO but I just skipped through the setup and used the handset to control the motor drives. The HEQ5 and GP-DX were non-GOTO, just driven in RA and DEC.

If it is better here tonight than it was last night, I won't have enough magnification to do it justice 🙂

That does seem to be a strong theme from last night - the seeing was poor for some and yet excellent for others. Sometimes not all that much distance between them either. There seems to be more to seeing than just the jetstream position. Maybe more localised factors come into play as well 🤔 Last night I found 225x and even 257x very good for observing Jupiter with my ED120 refractor. More often 150x-180x are better on the giant planet with those higher magnifications being employed on Saturn and the moon. Sometimes even lower (eg: 130x) is the best for Jupiter. Last night I found even "silly" magnification over 300x and as much as 450x (as high as I can go) was still delivering crisp lunar and double star views. More nights like that would be excellent while the planets are well placed 👍

Just finished my session with a lovely view of the Trapezium stars including E & F. The nebula is rather washed out by moonlight but the stars of Theta 1 Orionis (to give it the full title) were very crisp with the 2 fainter components being visible with direct observation. Brrr - it is cold though. Winter observing is here, but hopefully with the promise of some more clear nights 😃

That raises another interesting topic - cost v performance. With so much optical equipment there is a marked difference when you move from the basic to the next level (eg: from stock eyepieces to, say, the Starguiders. The performance differences between those and the next step up are quite a lot less and when we start to consider the very top end stuff, the performance differences are subtle at most and sometimes only discernible under good to excellent conditions. I'm not even sure what "4x better" would look like even if it were there 🤔

Many thanks for reminding me of Epsilon Arietis, close to Uranus. A lovely tight pair of stars that I have not observed for a long time. My seeing seems to be still good with this pair cleanly split from 225x upwards. Thanks again 👍

I've noticed a couple of features within the structure of the NEB that looked a bit like twists in the belt. That is not a scientific explanation of course but that is what they put me in mind of. I saw a pale elongated feature that ran diagonally across the NEB a few nights back. I described it as a "pale slash" then but that does not seem to be on show tonight. I did notice a couple of festoons coming from the S edge of the NEB. There is a lot going on in and around the NEB that is for sure ! I'm just going to find Uranus myself now to complete my gas giant "set" this evening 🙂

Sorry for those for whom the seeing is poor tonight but it's first class here. On the moon I've had glimpses of the Doppelmayer Rilles in the Mare Humorum which are normally quite a challenge in the 120mm aperture. The concentric ring crater Hesiodus A is showing well in the Mare Nubium. These are very sharp at 300x tonight. The floor of Gassendi is a riot of rilles, peaks and rough terrain. So much to see.

The clouds are staying away and the seeing seems to be really pretty good here now 🙂 With supper out of the way I can concentrate on the moon and Jupiter for a while 👍 I seem to be under a more benign part of the jetstream tonight.

I've moved on to Neptune now. Tiny little disk (2.3 arc seconds) but clearly not a star at 150x and upwards. I could not spot Triton with the 120mm tonight but the moon is not far away so that might have drowned the mag 12 moon out. Some annoying clouds floating around currently. Hope they shove off rather than build up ! If it stays mostly clear I'd like to observe all 4 of the gas giants this evening 🙂

I forgot about this ! I've missed this evenings chance I think. I'll try and get it over the weekend. If I do it will be my 2nd toolbag - I saw the one they lost from the shuttle Endeavour back in 2008 😁