John

The double cluster (sometimes known as the "Sword Handle") is a really splendid target even in small apertures and binoculars. I can just about see them with the naked eye here on a decent night but some magnification is what brings out their true nature and beauty.

One of my favorites for showing at outreach events - always gets a few gasps

The 8mm BST Starguider is a good eyepiece and should be very sharp, especially in the central area of the field of view.

I have compared the 8mm Starguider with my 8mm Tele Vue Ethos in my 12 inch dobsonian at a star party a few years back and I was surprised just how good the much less expensive BST actually did.

With the screw up and down eye cup section, the positioning is usually up for non-glasses wearers and down for those who do wear glasses when observing.

In your scope the 8mm is giving you 81x magnification which is really just a "medium" magnification with the scope.

Might be worth checking the collimation ?

I often use the visiblity, or otherwise, of the 4th star in Sigma as an indicator of whether the E & F Trapezium stars might be visible.

Here is another approach. Here the scope position has been moved using a simple wooden adapter. This moves the centre of gravity of the scope tube downwards to match the centre of the altitude axis:

http://www.homebuiltastronomy.com/stool/EasyAltAzMountModification.htm

As you can see, you are not the only person to be affected by this sort of issue with this type of mount !

1 hour ago, wibblefish said:

...Someone else has mentioned pushing the telescope further forward on the rings also so I might see if that would help.

That does help a bit.

In this article a spring is used to a similar job to the counter weight on the AZ-3 mount:

https://astromart.com/reviews-and-articles/reviews/mounts/alt-azimuth/show/virtual-counterweight-for-az3-mounts

Maybe even some stout elastic or a bungee would help if you can find a suitable place to connect each end ?

Fascinating stuff !

That last fact in particular is rather mind bending

34 minutes ago, Stardaze said:

Wow, all in a year? I think you raise a very valid point though in that it can be costly going through the incremental upgrade path. I like to future proof too, having a core set is certainly the eventual goal that will work well in anything, but I’m not far away really. Probably won’t quite attain your perfect collection but do fancy the E6 and E13.

It's a fair point but it's also difficult to explain to someone new to the hobby why they should spend £3K on an eyepiece set for the £1K scope that they have just bought

Sometimes a journey is the way .....

Sounds like the same sort of issues that you get with the AZ-3 mount.

I think they are caused by the centre of gravity of the scope being above that of the altitude axis.

With the AZ-3 folks would add a counter weight on a bar to counteract the tendency of the scope to tip backwards when pointing upwards. The AZ-3 modification is detailed here:

https://stargazerslounge.com/topic/275499-finally-finished-my-az3-modification/

Maybe you could adapt it for the AZ Pronto ?

15 minutes ago, Louis D said:

Those look more like Synta diagonals, such as the WOs that have the nasty constriction ring in the bottom you noted:

GSO diagonals look like these:

GSO 1.25" 90-deg 99% Dielectric Mirror Diagonal with Compression Ring:

GSO 2" 90-deg 99% Dielectric Mirror Diagonal for Refractors:

Notice also the 2" to 1.25" adapter.  This is a hallmark of many GSO 2" products.

I agree Louis.

I'll withdraw my recommendation on the 1.25" Stellamira diagonal on that basis. The 2 inch one is OK though.

I've owned diagonals in the style that you post above and they are pretty good, especially the 2 inch GSO type. You can get those under a number of different brands, usually, although stock levels are very scarce just now, like many astro items.

1 hour ago, MrFreeze said:

The Svbony one is excellent - https://www.aliexpress.com/item/32881221402.html . Supposedly a dielectric mirror, metal body, with a compression ring to avoid marking your eyepiece barrels. At £20.50 (+VAT) it's a bargain, and they give excellent service  (normally about 8 days delivery time - beware it's Chinese new year this weekend, so deliveries may be delayed a week or two ! )

David

I can't see dielectric in that specification

Usually dielectric coatings give a reflectivity of 97%-99%. That one claims 90% so I would suspect standard coatings.

For the price though the spec is fine.

The GSO diagonals that I've used have combined good build quality and good optical performance with a reasonable price eg: ones like this:

https://www.firstlightoptics.com/diagonals/stellamira-1-25-90-di-electric-diagonal.html

https://www.firstlightoptics.com/diagonals/stellamira-2-90-di-electric-diagonal.html

18 minutes ago, Dantooine said:

John’s won his bet 👍

he just knew.. a manual reflector and 100 degrees.. no contest. 

Nope - I lost it

1 hour ago, Kon said:

@jetstreamI have not heard back from Astronomik but i had a very frustrating night last night on nebulas, so i want to buy a filter soon.

 

Would you go for the:

https://www.firstlightoptics.com/televue-filters/tele-vue-bandmate-oiii-filter.html

or

https://www.firstlightoptics.com/uhc-oiii-visual-filters/astronomik-oiii-filter.html

(unless there is another OIII from these companies i missed)

The price difference is marginal so happy for either you think it is better; you seemed very happy with your earlier post on TV but @Johnwas happy with his Astronomik.

I would go for the Tele Vue. The Astronomik is very good but for that small price difference I would go the Tele Vue. Apart from Gerry, I have read great reports on the Mk II Tele Vue Bandmate filters from a number of other sources as well.

The Mk I Bandmates were very mediocre though - I'm not surprised that they moved to a different manufacturer.

Nice report on a lovely target Baz

32 minutes ago, JeremyS said:

Last evening it was minus 6 deg C, but the seeing was generally very stable. It got the Tak TSA 120 out before dusk and got on with variable star work in the observatory until 21.30. Turning Tessa towards Rigel, I noticed how stable the seeing was, with a huge split of the secondary and with text diffraction rings.
 

Surely this had to be the night for Sirius and the Pup? I’ve tried for decades without success, but only a few times this season with the TSA (which I got last Spring).

 

Well seeing wasn’t quite so good down at the altitude of Sirius. Using the Vixen HR 3.4 (x265), I could see the Pup about 2/3 of the time right on the edge of the primary’s “skirts” (I think John used that expression and it’s perfect!). Switching to the  Vixen HR 2.4 (x 375) helped a bit. 
 

I looked at some other objects for a while and came back to Sirius at 22.30. With the HR 2.4 the Pup was visible most of the time.

 

Excellent result Jeremy

I'll have a go with my ED120 when we get the next clear night - I've still not managed it with that scope, or the FC100-DL.

I know that there has been some skepticism expressed in some quarters (not SGL) on reported sightings of Sirius B with relatively small aperture instruments so I hope that is being overcome with these reports 

9 minutes ago, mikeDnight said:

I'm not sure its the amount of glass or the thickness of the lens that causes the problem, but rather the cell in which the lens is secured.  I had a beautiful NP101 IS ( a quad) that just didn't like the cold. It easily took an hour before it gave good star images on a night of -5°C. I have observed with it when the temperature had dropped to -15°C, at which point it just didn't want to play at all.  None of my Takahashi refractors ever had issues with accliatisation, not even the 152mm fluorite doublet, and I'd regularly use them while they were caked in ice. With the Tak's, the lenses are mounted in a cell that is mounted in a cell, so the lens doesn't get stressed by the outer cells contraction to the same degree as some other scopes on sub zero nights.  The FS152 for example was at full power after 15 to 20 min's no matter what the temperature drop. Granted, I can't ever remember observing at -25° C though. 

I agree that objective cell design does have an influence on cooling times.

Great report Mark !

I think my mistake last night was to concentrate on things other than galaxies initially, waiting for Leo and Ursa Major to rise to a more favourable altitude. By the time that had happened, my transparency was getting worse so even simple stuff like M51 was far from it's best

Glad you got some good results

I was a little concerned about cool down times when I was considering my 130mm F/9.2 triplet. I had read mixed reports. I don't get it too cold here, 5 below is a really cold night here, but the scope does live in a centrally heated room. So far, (I've owned the scope since Summer 2016) I have not noticed any particular issues with cool down times. The scope needs a bit longer than my ED120 but 30-40 minutes at most and it's delivering excellent high power images. 

My triplet is an air spaced LZOS. Maybe the F/9.2 focal ratio means that the glass thickness of the elements is a little less than the faster versions ?

11 hours ago, John said:

...Sirius B was showing relatively easily at 198x and up so I've been having a go at Proxima B which is even harder - the B star is just 4.5 arc seconds away from the Proxima A and the brightness difference is massive again - 10,000x difference !

Didn't get a sniff of it even at 600x but I'm not surprised really 😉

 

Did anyone spot my deliberate mistake here ?

What I should have said was Procyon B of course. Proxima B is Proxima Centauri B which I have to leave to our southern hemisphere friends to spot

Must warm my brain up a bit more before posting .....

4 hours ago, Voyager 3 said:

With these small , bright PNs , increasing the mag helps nicely in bringing out the shells and central star as they have high surface brightness .

Yep - I was using 338x to observe the Eskimo last night with my 12 inch dob.

I don't know how it is for you tonight Mark but I'm finding the transparency none to good here.

Even the easy galaxies are looking far from their best with my 12 inch dob. I've concentrated on other, brighter targets tonight because of this. The seeing is quite steady though.

Hope you have it better for galaxies in Thornbury !

Nice one !

I was looking at that one with my 12 inch dob earlier. The central star is clearly visible. With some averted vision you can see a sort of 2 layered appearance to the nebula with the central star in the brighter core surrounded by a fainter "halo" which I think is supposed to be the hood of the Eskimo's parka !

Using a filter such as an O-III or UHC slightly enhances the 2-layer look but makes the central star harder to see.

It is a nice planetary nebula

Tonight is not so blowy but a bit colder.

Transparency is not that good tonight but the seeing is steady.

Sirius B was showing relatively easily at 198x and up so I've been having a go at Proxima B which is even harder - the B star is just 4.5 arc seconds away from the Proxima A and the brightness difference is massive again - 10,000x difference !

Didn't get a sniff of it even at 600x but I'm not surprised really 😉

Nice views of various other brightish stuff but I have the feeling that it's not a great night for dim galaxies

The views of Sirius and and the Pup star were some of the best I've had though

12 minutes ago, Beardy30 said:

Glad to see the bresser Mak 127 OTA is not effected , I agree with John these will now be more popular 

Not yet, anyway:

30 minutes ago, garryblueboy said:

 

The TMB 130ss lens was a Japan lens then moved and made in Taiwan Thomas said this before he died but wouldn’t say who made it due to the competition in the market place 

The link I posted earlier in this thread were Thomas posting on CN and thats what he said.

Do you think it's going to be clear Mark ?

The forecast is OK but there seems currently to be quite a lot of large chunks of cloud around.