John

24 minutes ago, Spile said:

I suspect the “missing” screws are the Allen key bolts that are recessed so you can’t see them.

My thoughts as well. There are also 3 threaded holes on the rim of the base which would hold a mirror cover in place if it was the 200P F/5 model. Skywatcher don't fit these plates on the F/6 dobsonian version but the screw holes are still there.

This is how it looks (for the benefit of the original poster): C = collimation screw, L = recessed hex / allen locking bolt, X = empty threaded hole as mentioned above

These are the sources that "Clear Outside" uses:

Maybe FLO can answer that ?

They developed "Clear Outside" and still support it as far as I'm aware.

A group of us SGL members were beta testers for the facility when it was being developed.

The UK Met Office is one of the sources of data for CO.

Great scope - congratulations !

2 inch eyepieces are only useful for low power / wide angle views. In due course you may want one but for now the 1.25 inch fitting eyepieces will be fine. You don't loose any light by using 1.25 inch fitting eyepieces by the way, they just can't show as wide a field of view as a 2 inch eyepiece.

Unless the mirror is filthy, leave it be for now. A little dust will not make any difference to the views.

Take a photo of the back end of your scope and post it on here so we are not "shooting blind" with regards to screws that may or may not be missing

On the 200P dobsonian scope there are 3 small screw holes that are empty, 3 large collimation screws and 3 inset grub screws which are locking screws. It would be good to see a photo to confirm what you have.

I tend to use tight, uneven brightness double stars to see how well a scope is doing. Theta Aurigae is quite a good candidate at the moment. The separation is around 4 arc seconds and the component stars are magnitude 2.6 and 7.2 respectively. The star is quite high in the sky later in the evening as well.

The 127 mak-cassegrain (which I think has a working aperture of 120mm) will be capturing nearly 2.8x as much light as the 72mm refractor does. That will make more of an impact on the views of DSO's than the larger exit pupil does I think.

The seeing has to be pretty good for me to get sub-arc second splits here. Tegmine is a good test.

52 and 32 Orionis are another couple that stretch the scope and seeing (and observer !). 32 is 1.3 arc second split and (usually) doable. 53 is fractionally under an arc second and can be very tough. Both nicely on show in the top half of Orion's "torso" currently.

I was quite impressed by the Aero ED 40mm clone that I had for a while. It was relatively lightweight for it's size, well corrected across the field of view even in my 12 inch F/5.3 dobsonian (although the exit pupil with that scope would not be the most efficient) and seemed to provide an AFoV which was the equivalent of the Pentax XW's (70 degrees).

13 minutes ago, Mr Spock said:

No, 72° 

It is also physically measured at 72°, it's just not 42mm... See the images for comparison - all taken with the same iPhone. You see how much larger the fov is over the 22mm 65° LVW.

I've seen some with 65 degrees marked on them. Maybe Vixen aren't sure themselves !

2 minutes ago, Mr Spock said:

I made a post about these issues earlier.

https://stargazerslounge.com/topic/378099-a-few-eyepiece-tests/

You can see from the 42mm LVW it's field of view is 72°, but due to distortion it only covers 65° actual. Overall it's not actually 42mm, it's only that in the centre.

Doesn't the 42mm LVW have 65 degrees marked on the barrel ?

6 minutes ago, Orange Smartie said:

Looking good! If someone could also get round to inventing a right-angled Rigel or Telrad as well, I'd be happy.

Tele Vue did something like that - at a price !!!:

https://www.televue.com/engine/TV3b_page.asp?id=40

There used to be a right angled mirror adapter for the Telrad as well but I'm not sure that it is still available

Very annoying

Excellent finders - I use those on my 12 inch dob and 8 inch newtonian

58 minutes ago, cajen2 said:

Now saying 19th January......and counting....😄

I wonder who is doing the beta testing ?

19 minutes ago, John said:

Yikes - dodging showers now !!!

The things we do to catch some starlight

In between the clouds / light rain flurries the stars look lovely and very tempting (of course !).

 

 

Can't go on much longer like this but the clear patches of sky are pretty nice - just not enough of them.

Have managed to see an Owl, a Cats Eye and an Eskimo though, nebulae that is

Beta Monocerotis will always put a smile on my face - what a gorgeous triple star

7 minutes ago, John said:

Miraculously, after a very rainy day, the skies have just cleared for a while so I've popped the ED120 refractor out. I doubt it will last long but you never know !

 

Yikes - dodging showers now !!!

The things we do to catch some starlight

In between the clouds / light rain flurries the stars look lovely and very tempting (of course !).

4 minutes ago, mikeDnight said:

Hi John,

I've used the Calocloth along with solvent free Calo spray for quite a few years for cleaning my FC lens and eyepieces.  I find them both excellent. I bought mine from my local optician, but they aren't only for spectacles, as on the info they are mainly used for expensive camera lenses etc. I spray onto the cloth, not the lens so as not to get the fluid spray between the elements.

Thanks Mike.

The "spray on the cloth" method is the one I use as well, for the same reason.

Miraculously, after a very rainy day, the skies have just cleared for a while so I've popped the ED120 refractor out. I doubt it will last long but you never know !

A long time ago (a decade ?) I bought the Baader Microfibre cloth with their Wonder Fluid.

The cloth has done excellent service for me and has been washed (carefully) quite a few times now and I'm thinking that a replacement might be due.

I see that FLO stock the Calotherm micro fibre cloths in 3 sizes now as well as still carrying the Baader one. They describe the Calotherm as probably the best microfibre cloth available.

Does anyone know how these two cloths compare in practical use ?

I'd happily buy a new Baader cloth to replace the old one but wonder if the Calotherm (which is new to me) might be an even better option.

Thanks

The Ladybird books series used excellent artists. I used to have the Astronomy one plus 4 different ones on birds and even one on fishing !

At one point some of them were getting quite collectable.

One of my early astronomy books ( borrowed from the local library ) was the 1st edition of the "Challenge of the Stars" by Sir Patrick Moore and illustrated by David A Hardy. I have the 2nd edition currently. Illustrations like this stay with you when you are young and imaginative

Some fantastic reports coming in of the past couple of nights observing

They make great reading today as the raindrops are sliding down the windows again

Great going Nik

I forgot to try Dubhe when I had my 12 inch scope out the night before last

3 hours ago, SuburbanMak said:

Thank you - Sirius is an odd one, when I've split most doubles there's been a definite "Aha!" moment, this is much more intermittent & uncertain. I have looked at it for hours and am starting to see some consistency in the "hints" of a pale dot, last night at around the 3 o'clock point, relative to the line of 9th/10th mag stars to the immediate W (which last night were certainly the crispest I've seen them).  The Mak is great for doubles on the whole but has a slight messiness to the diffraction rings compared to my Towa 339 f15 which is why I'm not "claiming" this as a definite. May well be that this is as good as it gets on this one

This was the view that I got with my ED120 refractor in Feb 2021 which should correlate with the view through your Mak-Cassegrain. You are quite right that splitting Sirius is quite unlike other double star observing. The challenge is not the "gap" (11 arc seconds currently) but spotting a faint point of light amongst the glare / light halo from Sirius A which can easily have a radius of 20 arc seconds.

Personally I would try and go for something that has a 95%+ pass and quite a narrow pass width. I have the Astronomik H-B myself but bought that before the TV v2 Bandmates came out (also made by Astronomik as mentioned above).

The targets for H-B filters are challenging so I tend to think that every little bit of help you can get is worth having

A "fat" band width plus a sub-90% max pass seems unlikely to me to be a really effective line filter.

53 minutes ago, Nicola Fletcher said:

.... if only my 4" refractor was up to the challenge...!

I think it has been done with a 4 inch refractor, when everything else comes together

(not by me though !)