Stu

Just now, JeremyS said:

I’m sure you’ve forgotten a few Stu 🤔

You may well be right!! 🤪

Apart from the first three, these are in no particular order. Plenty of repeats in there, and a couple of scopes I have re-bought again after selling them and regretting it. It’s an illness, clearly 🤪

Celestron C150HD

Orion Optics OMC200

Astrotech 106mm f6.5

William Optics ZS SD66

Televue 76

Televue 85

Televue Genesis

Televue Genesis

120ED

120ED

120ED

Orion Optics VX12L

Orion Optics VX12L

Orion Optics VX12 f6

Orion Optics VX10L

(To be honest, it may have been two 10” and two 12”, I can’t remember!)

Burgess Optics 90mm

Stellarvue 80ED

Vixen 80mm f11.3

Vixen 80mm f11.3

Tak FS-60C

Tak FC-76DC

Tak Sky 90

TAL 100r

TAL 100RS

Sumerian Canopus 16”

Sumerian Alkaid 14”

TS 72mm f5.9

PST 40

Vixen 150mm f9

ST80

Carton 60mm f16.7

Tak Mewlon 210

Orion Optics 6” f11

Celestron C8 Edge

Celestron C925

Zeiss Telementor

Vixen FL102S

Heritage 130p

Heritage 150p

APM LZOS 130 f6

Orion Optics OMC140

Orion Optics OMC140

Intes 7” Mak

ST150

Celestron C65

2 hours ago, GeezerGazer said:

Stu, in re-reading your reply, I think I’m getting that the aperture should be cut off-center so that the vanes and the secondary are outside the aperture opening. Correct?

Yes, correct. Position the hole so it is inbetween the vanes and avoids the secondary, that will reduce any diffraction effects.

As Geoff says, don’t put anything over the film such as a clear cover as this will reduce the optical quality.

Providing you are using decent and safe film such as Baader AstroSolar ND5.0, and the filter is firmly held onto the scope then there is no danger to optics from using the full 12”. The issues are mainly around seeing conditions in that larger apertures for solar are often affected badly by poor seeing. Somewhere around 100mm to 120mm is often the optimum giving good resolution and cutting through poor seeing. If you can fit a 100 or 120mm aperture between your secondary support vanes that would be ideal.

On 14/03/2024 at 15:46, Don Pensack said:

Whatever exit pupil that results in is the exit pupil it happens to be.  I would never look at exit pupil to decide what eyepiece to use.  I wonder if anyone does.

I think the only time I do is when using narrowband filters in smaller scopes. It just helps make sure you don't end up with a dim view whilst wondering why.

Other than that it’s normally about picking the right high mag for planets or doubles etc, or at the mid/low end choosing an eyepiece which frames the object. I find exit pupil useful to explain what effects you see, but I agree it’s not something I generally use in choosing the eyepiece to use.

Just now, wookie1965 said:

I was thinking that worth a try I dont know how the person marked it up, I would have put the arrows pointing together but someone else could have done just what you said point them the same way.

Give it a go Paul, nothing to lose.

1 hour ago, wookie1965 said:

Well that's it folks I am done selling up no point doing this hobby I am down £342 so selling up make my money back thanks for all your help and good luck to you all in the future.

Without volunteering his services….. could you ask @Peter Drew to have a look at it for you Paul? If still interested I’ll check the 120 and we can talk then.

9 hours ago, Marki said:

I think I'd keep my Skylight 10mm f13 achro

Gosh that’s tiny, pocket sized in fact, ideal for travel 😉

I’ll answer genuinely and without being accused of going on about my scope…. I would keep my FC100DC for many of the reasons given already; airline portability, grab and go at home, great Solar, Lunar, Planetary and doubles performance, quick cooling and good widefield deep sky results too. It’s the one scope which has kept me going through periods of poor weather and busy personal/work life when there have been only brief opportunities to observe.

3 hours ago, paulastro said:

Not necessarily, users of other makes and apertures of scope just don't feel the need to go on about them all the time. 

Personally, I'd prefer to have something with more aperture that was more useful for deep sky as well as planets and double stars 😊.

 

 

 

 

Please stop this Paul. A question was asked and genuine answers were given. Owners of Starfield, Vixen, AP, Skywatcher, StellaMira, Celestron, Askar, TAL, APM, LZOS etc etc refractor scopes and of course any other type of scope are welcome to post. I’ve asked repeatedly not to perpetuate this brand antagonism so please let it go.

I’m quite happy with what I’ve got 🤪, but I too fancy an AP at some point, possibly a 130GTX which is travel friendly, or even a Traveller but they are unobtainium now.

Outside that, either a 180 or 210 Mewlon and perhaps replace my current dob with an 18” Obsession with a decent mirror in it.

18 hours ago, DirkSteele said:

So much for not contributing to this thread again in 2024! Have been thinking about a nice pair of binoculars for a while and pulled the trigger as a self gifted birthday present. Looking forward to putting them through their paces….

 

 

Already know I will be posting here again soon as I need to buy some adaptors so I can fit nebula filters to the objectives.

Nice, sure you will love them. I re bought a used pair a while back as I missed the ones I sold. They do work well with filters; I use one OIII and one UHC and it shows the North America Nebula beautifully. I also bought some screw-in solar filters which are great for a quick peek.

2 hours ago, gp102m said:

Just four for me:

• Vixen 102M
• Fullerscopes 8.5" Newtonian
• ST80
• 200P Dob

 Nice set there. Out of interest, how does the 200p compare with the 8.5”?

Amusingly enough, I was reading the side effects on a medication I am taking, and one of them is listed as ‘compulsive shopping’, so I have a medical excuse for my excessive scope collection! 🤪

I think you can observe quite successfully without knowing anything about exit pupil, however understanding it can just help you know why certain combinations work better than others, and why you see certain effects.

For instance, observing Planets in a 100mm refractor at x200 is likely to show floaters if you have them. Understanding that they start to become prominent at an exit pupil of 1mm or less starts to explain why. In this instance it would be 0.5mm, so you options then become using binoviewers or, say, moving to a 200mm scope which would give you a 1mm exit pupil at the same mag.

At the other end of the spectrum, if, say, you were using a 55mm Plossl in an 8” dob, you would notice that the background sky is washed out if observing under any form of light polluted skies, plus it feels like looking down a straw. Knowing about exit pupils and apparent fields of view might take you down an expensive path to a 21mm Ethos which gives nearly as large a field of view but with a 3.5mm exit pupil rather than 8mm. Much darker sky background and more satisfying image.

If viewing through a narrowband filter, using too small an exit pupil makes the image much too dim. This help understand that you CAN use these filers in small scopes but you need to keep the magnification low to keep the exit pupil large. Similarly in unfiltered views, if you use too high a mag, you will end up with an image which is too dark; x200 on the Ring nebula gives a nice big image scale but if you exit pupil is 0.5mm you will hardly see the target. Options are again, drop the mag or increase your aperture. That’s why big dobs are used to hunt down small faint galaxies; you can use high powers whilst still maintaining sufficient image brightness to see the target.

So you see it does matter what exit pupil you are using, and knowing that helps you understand what your best options are in terms of kit combinations.

10 hours ago, Cjg said:

Show your Mum @Stu’s post. 🤣 He’s definitely ‘taken one’ for the forum / astro community in general, being on the way to having a different scope for each day of the month🤣

The trouble is, with our weather, it’s more like a scope for every clear night a year!! 😩

Perhaps this should be in a different thread, but has anyone used both 180 and 210 Mewlons? Any views on the relative merits? I’m tempted at some point (when I’ve sold a few scopes and have some money 🤪) to buy another having had a 210 before. Cooling was always a challenge on the 210, not sure I ever got it right, and there is something that might make me prefer the lighter, faster cooling 180. 6 smaller diffraction spikes may be nicer too?

1 hour ago, Nicola Fletcher said:

This is a great post @Stu for demonstrating to my family that my five scopes could get a whole lot worse. Thank you! 😂

PS. That really is an amazing collection.

🤣🤣

I am well aware that it is ludicrously unjustifiable, and that I do not need them all. I do just enjoy owning them, some are fairly rare but excellent examples which would be hard to replace such as the Genesis and Vixen FL102S. The TAL Alkor is a lovely little thing. I don’t use it much but it’s not worth much either (about the price of a used Ortho!) so I keep it 👍

I should probably just plead the fifth here…..

Currently it sits at 16, with two additional projects yet to be completed.

EDIT Forgot my Omni 120mm so that’s 17 😬

Most used are the FC-76DCU, FC100DC, FS-128, 8” f8, 16” and the two PST mods. I should really move a few on, but there are some comparisons I want to make between the ST and LT 80mm, some are kept for sentimental type reasons (Telementor and Alkor) and some like the Genesis and FL102S I just need to use more! Clouds!!! 🤬

Zeiss Telementor

TAL Alkor

77mm f11.8 Hilkin

ST80

LT80AZ

FS-60Q

FC-76DCU

FC-100DC

Genesis

FL102S

Vixen 102mm PST Mod

Celestron Omni 120mm XLT

FS-128

AstroSystems 150mm f6

150mm f10 PST Mod

Orion Optics 8” f8

16” f4.2 Truss Dob

150mm f10 Project

12” f6 (Nichol Mirror set) Truss dob

1 hour ago, Ratlet said:

There does seem to be a trend now of scopes being optimised for binoviewing, with removable sections.  Either that or I'm noticing them because I'm interested in binoviewing.

Must say, this one went under the radar till you posted.

To be fair, TS have been doing it for a while but it’s good to see these sorts of features in other vendors products. I know it adds a bit to the cost, but removeable sections solve so many problems and are a benefit for travel too, so I wish more scopes had them.

Back in the days when I knew nothing about anything really, including fields of view and object sizes, I tried observing M31 with my OMC200. This was an 8” f20 Mak, so had a 4000mm focal length! Even with a 31mm Nag it gave x129 and a 0.63 degree field of view, likely vignetted a fair amount.

Needless to say I didn’t see much! Just the bright fuzzy glow of the core filling most of the field of view. Even M32 was out of view. Took me a while to work all this out; it was before the time I was active on here so had few sources of information. Once I got my 106mm triplet I understood!

13 minutes ago, vlaiv said:

Something like this:

https://www.firstlightoptics.com/stellamira-telescopes/stellamira-110mm-ed-f6-refractor-telescope.html

(that's my "hope to have M31 and other wide field stuff" scope)

That would do it 👍

I used to have a 106mm f6.5 triplet apo which framed the Veil beautifully with a 31mm Nagler. I basically copied John’s Vixen 102 f6.5 setup after reading of his observations 👍

I’m with Piero and others that actually M31 looks fab in a widefield; for me that means my old Genesis with a 31mm Nagler in it giving a very flat five degree field. From a dark site with proper dark adaptation, you really start to see the full extent of the galaxy and its satellites set in context with the surroundings.

Dobs are great tools, but you won’t fit all of it in, certainly not enough to see the outer edges because it will be largely filling the field of view. Again, as said, with a proper big dob and dark skies you can hunt down globs surrounding it which is crazy, never had the chance myself but would love to give it a go.

19 minutes ago, bosun21 said:

Does anyone else appear to have this streak?

Quite a few of us around! 👍🤣

My like was for the second picture 🤣

Looks like a really well though out scope Paul, great optics and flexibility too. Out of interest, how much does it weigh, with rings?

Planning any trips abroad? Could be good!!👍