John

I have recently acquired an 8 inch Skywatcher dob (solid tube) and needed to make similar improvements to the azimuth motion.

After a few experiments I found adding a single "milk carton" washer between the stock teflon washer and the bottom board worked quite well. It takes some of the weight of the scope off the teflon pads but is still stable. Some folks find that they need more than one such washer but in my case, one worked just fine.

I cut the washer from this type of milk carton. Another tip is to remove the milk before cutting the washer 😁

Lots of cloud around here but the forecast is better later on. I expect it will be a "grab the tak" session again !

2 hours ago, globular said:

Great idea - but do you think the BCO has enough eye relief to take it?

8mm of ER, according to Baader.

23 minutes ago, Higgs_Bozon said:

The issue still persists. Exactly the same event with the mirror diagonal.

But no extension tube ?

It is beginning to seem as if there is something amiss with the objective lens of the telescope. Maybe it has been taken apart for cleaning and one of the lens elements put back in the wrong way around ?

I did go for nearly a decade without a scope when my children were born. I maintained my interest in astronomy via binoculars, the Sky at Night programme and astro magazines. 

No web forums back then to tempt me but there were some visits to Telescope House and a couple of other equipment dealers now and then to whet the appetite for when I could get a scope again.

I've always referred to myself as a "sky tourist" so I'm quite comfortable with casual astronomy 🙂

I also like @Alan White's concept of being an "equipment curator" 👍

1 hour ago, doublevodka said:

I've had and got a few, see my sig, but I don't have one that can do all. I like the contrast from the refractors, but then you have CA, the reach of the Mak, but then it's not much good for the dimmer stuff......

 

That's it in a nutshell - if you are going to have just one scope, where do you compromise  Probably my most capable "all rounder" is a Skywatcher 200P F/6 dob that I picked up for a crazily low price a few months ago. While it doesn't have anywhere near the cachet of my refractors it does do a wide range of night time observing tasks really well....... 

I have been thinking along similar lines lately. It's probably just the weather that's fuelling it 🙄

I suppose a more positive justification would be to get as much out of a single instrument as possible through extensive use on a wide range of targets.

Not sure that I'm convincing myself as yet though 🤔

7 minutes ago, Asoor said:

I think they look okay, right?

It is a little difficult to tell from those photos but on balance they look OK.

The inside of the tube seems to have been carefully flocked to reduce light scattering, which is another plus for this scope having been the property of a careful and thoughtful owner.

I completely forgot about this event 🙄

Good to see that some managed to catch it though 🙂

It's pretty cloudy / rainy here this morning so I suspect I would not have been able to see much of it.

15 hours ago, Stu said:

I suspect your 120ED is a particularly good example John..... 

I have come to that conclusion. It is the only ED120 that I have used so I can only share my experience with this one example. I have seen excellent optical reports of a number of other examples, published by Herr Rohr. 

Similarly with my Tak, Vixen and TMB/LZOS - they are the only examples of these types that I've used. All the rest out there might be rubbish 😁

2 hours ago, Asoor said:

I'll ask them for pictures of the internals, the telescope has no eyepieces included unfortunately. My main concern is that I live in an apartment and would need to take the telescope to a nearby park or something like that. Would that be feasible with such a heavy mount?

The telescope tube will probably just lift off of the wooden mount so that you can carry them separately. From the pictures it is designed this way and most dobsonian mounts (the wooden mount is in the dobsonian style) do this.

Incidentally, in the photos the telescope tube is the wrong way round on the mount. Maybe the seller does not know much about the scope ?

I would pronounce it "Bor-tul" but spell it as @Floater suggests. 

I was surprised to learn that the scale has only been around since 2001 when John E Bortle published it in Sky & Telescope. Here is that article re-published by Sky & Telescope in 2008:

Light Pollution and Astronomy: How Dark Are Your Night Skies? - Sky & Telescope (skyandtelescope.org)

7 minutes ago, Fedele said:

I had  the same 120 ED golden version and the FC100 DL. I sold the 120 ED with no dubt, but FC100Dl have clour intra ed extra. 
I buyed the TSA120 and i sold with no esitation the FC100DL

Sounds like you had different experiences with both your ED120 and your FC100-DL to mine then. 

My FC100-DL performs very much like a smaller aperture version of my TMB/LZOS 130mm F/9.2 triplet. No false colour visible (to me) in either scope.

1 hour ago, Asoor said:

I'm thinking about getting a 114/900 because of the weight difference but I'm worried that I wouldn't see anything well with one

If you find the Celestron Omni 150 too heavy in it's mounting, the telescope tube can be removed from the wooden mount and mounted on a lighter mount such as the Skywatcher AZ4.

The Omni 150 is a much more capable scope than the 114mm / 900. The 150mm gathers 73% more light than the 114mm.

7 hours ago, Franklin said:

I thought you were visual only?😁

Darn - you got me there ! 

My worst nightmare 😬

1 hour ago, Asoor said:

Is it a better bet than the other 150mm?

The Celestron Omni 150's are made by the same company that makes the Skywatcher scopes. The mirrors in them are good and the primary mirror will be parabolic.

I don't know anything about the other 150mm you linked to but the 3-vaned secondary support does not look as good as the Celestron Omni's is, the finder is worse than the Omni's and the focuser looks to be plastic. 

It would be good if you could ask the seller to send you some photos of the Celestron Omni's mirrors to check their condition.

20 minutes ago, Asoor said:

I also found this one

https://www.kleinanzeigen.de/s-anzeige/teleskop-celestron-omni-xlt-150-dia-150mm-fl-750mm-gebraucht/2575443916-242-2048?utm_source=sharesheet&utm_medium=social&utm_campaign=socialbuttons&utm_content=app_android

it's celestron so that might be something 

It is a decent Celestron Omni 150mm F/5 newtonian that has been mounted in a somewhat oversize but probably stable home build dobsonian mount.

Quite a good place to start visual observing but entirely manually driven so you will have to find targets for yourself. You will need to buy some eyepieces for the scope - I don't think it comes with any.

Not a bad deal for 150 Euros as long as the optics (the mirrors) are in good shape. It is probably quite heavy judging by how it looks.

1 hour ago, globular said:

Thanks Neil.

 It sounds like it's doing it's job. I think I'll ask Santa for one 🎅

I get the impression from some other posters, about filters in general not specifically a swan filter, that there is an unreasonable expectation that filters should work miracles. Your description of it making a slight but noticeable difference to contrast, allowing you to see a bit more of it a bit more easily, is what I'd expect. 

That's fair point.

The one that gets closest to being a "magic bullet" is a good O-III filter used on a receptive target such as the Veil Nebula. That can be quite a transformative experience 🙂

When I've observed NGC 604 I have tried UHC and O-III filters but, in my case, I thought they were not making much, if any, difference plus of course they dimmed out M33 altogether. I first spotted NGC 604 with my 12 inch dob. As with many targets, once you have done it, it becomes a little easier to see subsequently, or at least realise that the conditions / scope are not showing it !

I agree that M110 is a good test for sky transparency. On the very best nights here I have seen M33 with 7x35 binoculars. I've never seen it as a naked eye object, though, even under the darkest skies.

8 minutes ago, globular said:

@Littleguy80 How are you finding the Baader SWAN filter? 

I saw your post tonight regarding Comet C/2023 H2 Lemmon. You said you were using your Tak FC100DF and APM 30mm UFF - so an exit pupil of 4mm or so?  Is a large exit pupil key in activating the SWAN?  

I was just thinking the same when I read Neil's report. 

3 hours ago, John said:

Saturn looks good just now 🙂

Even at 300x (ED120 refractor).

Well it did look good ...... for about 30 minutes 

There is an Intes 6 inch F/12 mak-cassegrain in the classifieds for your budget. Nice double star scope I would think 👍

(I've nothing to do with the sale I ought to add)

Interesting that the one surface that was damaged by the damp was on the flint element. There have been rumours for years that the fluorite element was the more fragile.

Looks like the work in the damaged surface has been successful 👍

Saturn looks good just now 🙂

Even at 300x (ED120 refractor).

Well it's good to know which nights are likely to be cloudy over the coming 3 months ! 😁