F15Rules

1 hour ago, JeremyS said:

If ever I have to self-isolate, can I do it in the FLO warehouse? 

In the Takahashi section?

At night?

😬

Knowing my luck, if I tried to do that, I'd end up in the section where all the boxes of "May Contain Clouds" stickers are stored...

Dave

What a rollercoaster!

Glad it all seems to have worked out for you now though.

Vixen make fine scopes and I'm sure  now you've fettled it, it will meet or exceed your expectations 👍😊.

Dave

22 minutes ago, AdeKing said:

Here is my new to me and first Vixen mount, a Vixen GP fitted here to an old TAL wooden tripod which has been modified with an EQ5 top plate.

 

A great mount Ade..often copied, but never bettered for what it is IMHO. And available used for the price of a single decent modern eyepiece!👍

Dave

That Astro Systems part has clearly Focused your thinking, John!

Maybe you could do a Turn with it at Kelling??

There again, maybe you shouldn't Pinion your hopes on it catching on..

I'll leave now before I get put to the Rack! 

Dave 

Well, I don't have Amazon so sadly I can't watch it anytime soon:-(.

It would be good if it could be on BBC, or Sky, or YouTube...could anyone er, "Make it So"? 🙃😁

Dave

5 hours ago, JOC said:

@johninderby Ooo.....is that what you've been funding recently 😄

So I got the 4.5mm one of these - thanks @johninderby.  So now you all know what I'm waiting for 2nd hand, BUT whomever has it for sale please don't offer it up for a few months before I've saved up again.  Don't they look nice?  Not quite in the same league as a box of green and black, but I still think they are nice.

 

NB.  I refer to this as my 'posh box'  I keep all the others in a different box and they are handy if I have visitors round or do some STEM work with the telescope.

Looks like you are saving the est (17.5mm) til last! - an amazing eyepiece.

I'd be interested to hear what you think after a comparison of the Pentax XW5 and the Morpheus 4.5mm?

Dave

Or this one?

https://www.amazon.co.uk/Sunmns-Comfortable-Neoprene-Binoculars-Strap/dp/B07GWN98JD/ref=asc_df_B07GWN98JD/?tag=googshopuk-21&linkCode=df0&hvadid=309904628344&hvpos=&hvnetw=g&hvrand=7874414855090856118&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9044874&hvtargid=pla-652638144627&psc=1

Dave

You beat me to it Steve!

A truly wonderful scope.

Dave

15 minutes ago, Raph-in-the-sky said:

Quick question: What are the advantages of this kind of scope? Is it better than a 10'' dob at anything besides transportability?

 

- Looks great

- Tighter Stars/sharper images- important for example on tight doubles' separation

- no diffraction spikes

- Better contrast

- Easier to mount on a tracking mount (less important on an AZ mount)

- permanently collimated, very unlikely to ever need adjustment

- easier to look through (I know that is subjective, but I honestly believe that)😊

- Looks great (did I say that before?)🙃😁

Dave

On 13/02/2020 at 14:12, Saganite said:

A Moonlite stepper motor for the Moonlite focuser on my 5" f15 refractor. With such a long tube it is not possible to focus without the image dancing around, and on high powers is annoying to say the least, so this I hope will vastly improve if not eliminate the problem. 

A thing of total beauty Steve...

..and the stepper motor looks ok too!🙃😊

Dave

On 21/01/2020 at 23:15, geoflewis said:

Just found this thread, what a cracking read - all of it, but especially the OP by @Ships and Stars

+1 for that, a real "log burner/fireside" read..(even though I was actually on the loo at the time!)😱😁😁.

Seriously, thanks for the time and detail in that report 👍.

Dave

8 minutes ago, John said:

Uneven brightness between components of a binary system makes them harder to split even if the separation between is relatively unchallenging. Sirius A and B being the most extreme example.

John, you posted just before me! Well put!👍😊

Dave

34 minutes ago, Geoff Barnes said:

Come down here for a holiday folks, you'll all see E & F easy peasy! 😀

How are you fixed next July Geoff??😁😎

13 minutes ago, Marvin Jenkins said:

Just wanted to ask an open question to all of the above. As yet I have not got past A to D. Halfway through this thread I notice that #chiltonstar said that a good night exposes the F star an excellent night the E star.

This seems to be echoed by further posts. Don’t want to sound obvious but why is the alphabetical E star harder to see than F? Surely someone looked through a telescope back in the day and said “look a fifth star in the trapezium” the E star!!!

Why are they out of order to the views recorded on this forum? Surely if it is A B C D star then the next easiest is E followed by F not the other way round.

Marvin

 

It's a fair point Marvin.

I've always thought the received wisdom is that E is easier than F..however, E is somewhat fainter than F (see below), so you would think F would be easier to see?

I think though that the seeing is the key factor, although transparency is also important: when I can see both E and F, the F star can seem to be slightly fainter than E.. but now and again, if the transparency is good, but the seeing is not great, I can see F but not E..                                                                                                            Here, it gets a bit confusing, as the A star is NOT the brightest of the A-B-C -D Trapezium four: actually, the C component is about a magnitude brighter than A: now, since the F star is close to the brightest C star and E is close to the fainter A star, then F can get lost in the glare of the bright C star  ( rather as The Pup companion of Sirius can easily be list in the glare of Sirius itself), when the atmosphere is more unsteady or turbulent, whereas E, being close to the fainter A component can more often be glimpsed when F cannot.                                                                        I found this on the net, which may help..  (credit: Astropix com, my italics and bold type ref seeing, optical quality and skill) -                                                      

"The four brightest stars in the Trapezium (A, B, C and D) are easily visible in a four-inch telescope with decent optical quality under good seeing conditions. They range in brightness from about magnitude 5 to magnitude 8. All are hot class O and B stars.

With more magnification and good seeing conditions, two fainter stars, E (mag 11.1) and F (mag 10.12) can also easily be seen in moderately sized amateur instruments. These stars are part of the Trapezium's multiple-star system. Because of their proximity to the much brighter stars in the Trapezium, their visibility in a telescope is more dependent on good seeing, optical quality, and observer skill.

Three other faint stars, G, H and I are also part of the system, but are too faint to be seen except in very large amateur instruments. Other fainter stars are also involved in the system.

Many of these stars are themselves binary and multiple star systems.

θ Orionis - The Trapezium Multiple Star System Star Magnitude Notes A 6.72 - 7.65 Eclipsing Binary in 3-star system B 7.9 - 8.65 Eclipsing Binary in 5-star system C 5.13 Spectroscopic binary star D 6.71 Double star E 11.1 Spectroscopic binary star F 10.12 Binary star

I hope that makes sense🙃😊.

Dave

I too got an hour outside tonight from 8.20 ish til c9.30pm. Using my Tak FS128 with Revelation Binoviewers (with which I am very pleased), and in very good seeing (although quite windy), I got a lovely view of the A-D stars - but no E or F Stars seen..very comfortable viewing at c x100 to x170 though.

A little later, switching to cyclops mode, both E and F were very obvious at c 150x with a Carton 10.5mm UWA fitted with a x1.6mm Barlow nosepiece. I also saw both E&F using the Carton Zoom at 7mm (giving c148x).

So my take on tonight is that binoviewers lose around half a magnitude or more versus cyclops viewing, and this tonight made the difference in spotting these two tiny, faint dots..

Perseverance is vital!😁👍

Good luck with your 130p!

Dave

If you aren't stuck on brand new, you could advertise for a used Vixen ED 103s F 7.7 Apo doublet. A better brand and of known excellent optical quality. 

I've owned 2 of these and if I hadn't been lucky enough to get a 5" Tak I would still have one.

An ED114s (the bigger brother of the above) went recently within your budget.

A fair price for a used ED103s in vgc is £600-750, with rings and 50mm finder - a bargain when you consider that the new price now is around £1700. They really are very close to Tak quality, whatever glass is used.

Good luck with your search 👍

Dave

Fascinating read, and full respect to you for having the skills and pluck to do this!

I owned 2 M603's and a Lomo Astele Mak 150mm a few years ago and was very impressed with them all optically. They always seemed built like tanks and very industrial, but optically superb, especially on Lunar, Planets and Doubles.

I'm sure that, once you have worked your magic on it, yours will perform like a champion!

Thanks for sharing 👍😊

Dave

25 minutes ago, Mark at Beaufort said:

I bought the Apollo binos because of the filter option. I am not aware of any other make that provides this option. However, you could send a message to Steve Tonkin - 'binocularsky' because his knowledge is second to none on this subject.

Yep, Steve is "The Man", no question about it. I was just dipping into his book again recently and his knowledge is mind boggling!

Dave

An interesting thread👍.

I've not owned BA8 quality 70mm bins (ie Helios quality), although I have owned the 50mm equivalent, and they too were MUCH heavier, too heavy to handhold comfortably for more than 10 minutes or so, I found. 

I'd just offer two suggestions for a fair comparison?..

1. All BA8 quality binos are relatively heavy and can only really perform to their best when mounted on a tripod or monopod. And I think the same applies to most "lower quality" larger binoculars as well: a proper, detailed assessment of image quality, field of view, colour rendition etc can only be really done on a static or almost static view, which means a tripod or other mount.

2. For the past week or so, the moon has dominated the night sky, being at or very close to Full.

I think this makes a true comparison test very difficult, especially on fainter objects which might be right as the limit of the binos' reach. Often, I have found that the very faintest stars my 50mms can detect (and which are present in large numbers), just "pop into view" under a dark, moonless sky when held very still or supported. I think the same applies to teasing out fainter details.

You mentioned a short comparison on M42 the other night? I actually found, looking through my 5" scope at M42, that I could barely see any of the nebula at all, such was the glare from the moon - I could just make out the faintest D star of the Trapezium. So I'm not surprised that it was difficult to tell any difference with your pairs of bins.

I'm sure that when you get the chance for a moonless night comparison, using a mount of some sort, that the Helios will stretch ahead of the Cometrons (as so they should, given the price difference!). But the Cometrons can still give pleasant views and will have a case for keeping them handy as Mark  and Alan say, for very quick views, being much lighter to hold for a few minutes.

Indeed , I recently bought a nice small pair of Vixen 8x32s just to have handy for birdwatching or  short night time views when on holiday or short of time..horses for courses and all that😊.

I look forward to your full review when time permits and I'm sure you will enjoy both pairs enormously, albeit in different ways.

Dave

Thanks Louis.

I've actually owned a couple of that very Barlow in the past. I liked it, but used it only for Cyclops viewing at the time as a full Barlow and didn't try it just as a nosepiece only.

They do come up for sale over here quite cheaply, so I may keep my eye open for one.

Dave

Well, I did get out last night from about 9.15pm til 10.30pm.

I used a combination of cyclops and binoviewing, and was just delighted with the quality of the seeing here last night. It was a little misty, no wind whatsoever, and a few degrees above freezing.

The 85% illuminated moon was my sole target apart from one very quick look at M42 in Orion - the nebula was all but invisible due to the brightness of the moon, and of course no sign of E and F stars, but the Trapezium main four were pin sharp and really nicely defined.

On the Moon..first off was the Carton 7-21mm zoom. The 7mm setting gave a nice 60 degree field at 148x. I could immediately see, 100%, the "A" craterlet in Plato. And, unlike a few nights ago, when I saw it as a tiny, light coloured smudge, this time it was a sharply defined tiny circular pit.

I felt I might be able to see more as my night vision improved, so I put in an 18mm Tak mc@ ortho of known excellence, with the Baader 2.25x zoom, giving 130x. This time I had a very distinct impression of intermittently seeing other objects, and the overall vista was jaw droppingly sharp: this is where I felt my Tak EM2 equatorial mount came into its own - it has a simple, single axis RA drive, but it just holds the object right there in the centre of the field for half an hour or more with just a simple visual polar alignment. I slotted in the Carton 10.5mm 65degree SWA -this is the ep that I kept at the expense of my trusty Pentax XL10.5- and I put in the baader barlow, giving me  223x. This did the trick and I definitely saw 3 craterlets, all defined, tiny pits.

I decide it was time to try the binoviewer now. I only have two pairs of fairly cheap plossls for binoviewing, one at 30mm and one pair at 15mm. The latter, used without a Barlow, just come to focus with about 3mm to spare (I managed this by using several baader components all using up a bit less precious in-focus than most adapters).

The 15 mm pair only give 69x with no Barlow, but to my astonishment I got the best view of the evening! At just 69x I could glimpse 3 perfect, sharp tiny dot craterlets! I also suspected at least two other features right at edge of my vision..and the view was so much more comfortable than just using one eye: I was able to just sit there, fascinated, taking in the view for a good 10 minutes.

The whole outline of the massive crater was almost etched, with virtually no shimmering at all from the atmosphere.

It was now that I did something really stupid..I wanted to try the barlow 1.6x nosepiece, thinking that, based on other comments in this thread, I would get about 3x the native ep power, in this case that would have been 3x69, ie 207x. I was so excited to see how that view would look, having seen what I had seen at just 69x, so I put in the nosepiece and.... nothing! Just a vague blur. Try as I might I could not get focus...

By now I was quite cold, but still elated, so I called it a night and determined to figure it out inside in front of the log burner!

Of course, what I had done was screw in the nosepiece in the wrong place! Instead of screwing it into the binoviewer nosepiece, and then putting that into the Baader prism diagonal, I had stupidly screwed it into the prism diagonal nosepiece, adding the whole light path of the diagonal into the mix! So, of course, I wouldn't have got focus without a very sizeable extension tube in the optical chain - and goodness know what magnification factor that would have been?

Of course, the above is rather embarrassing, but I offer it a) so you can have a laugh at my expense, b) as a salutary warning against getting over excited and rushing things, and c) for those of you who are debating whether to take the plunge and try binoviewing, I would encourage you to try it for yourself!

I don't know how a cheap pair of unbranded plossls can deliver such a wonderful view, ahead of a cyclops view from a really good quality eyepiece, but I know what I saw, and I can verify what MikeDnight has said for a while..2 cheap eyepieces can be better than one! It must just be something to do with how the brain processes two images? Whatever it is, I'm delighted with what I saw last night 👍😎!

Thanks for reading.

Dave

Hi Mike,

Yes, I too have a pair of Revelation binoviewers, the later model with compression ring/helical focusing eyepiece holders (I sold my wonderful Celestron/Baader 45 degree angled bv's last year as part of my slimming down exercise).

I really like the Revelations, although I've had very limited use so far due to the lousy weather. I have cheap pairs of 15mm and 30mm plossls and in daylight the other day I tried using a pair of 1.6x nosepieces (attached to the filter thread of each ep) just to see if the magnification increase works ok when using the pair.

Using our nearby church tower as a target (about 80-100m away), I could get focus ok, with c 4 or 5mm in-focus to spare. Interestingly, the point of sharp focus seemed hardly different whether using the eps natively, or with the 1.6x nosepieces in place..?? 

Whether I can get sharp focus natively at infinity, ie on the night sky, I hope to find out tonight. I will also try the 1.6x nosepiece threaded into the nosepiece of the binoviewer, which I think will give 3 or 4 times native magnification (is that right?)..that would be the equivalent of c 3.75mm eyepieces, or c 277x - that's about my limit when viewing in Cyclops mode, so will be interesting to see if my floaters are less severe in that situation.

Thanks for all the very useful and interesting feedback, I hope to iron this all out before long now!😁

Dave

Hi Alan

The original Celestron Ultima and Parks Gold Ps Masuyamas did come with folded eyecups. I'm not sure about all the other versions, I suspect the Baader Eudiascopics do/did too.

See photo below of what they look like.. (not my set, sadly!😱😁).

They really do work well too, in my experience.

HTH,

Dave

1 hour ago, Timebandit said:

 

 

 Sorry Dave you did not find my banter helpful😉. Obviously a different sense of humour. 

But if I had a top quality frac like the Tak FS 128 , then I would not be stacking Barlows. I personally would have a set of Pentax XW 3.5 to the 10XW , for normal high power viewing, and a set of Vixen HR for the nights of exceptional viewing conditions (when we are lucky enough in the UK) . I think a scope like yours deserves top quality eyepieces to get the best out of it. As a scope is only as good as the weakest link in the optical chain. 

 

 

 

Hi Timebandit,

Don't worry about it..😊

I like to think I have a good sense of humour, but last night I was looking for actual feedback and advice on the subject in hand as I had just been trying out the various Barlow permutations available to me.

I fully agree that my FS128 "deserves top quality eyepieces". Indeed, before I retired 6 months ago it was fed with a mixed diet of Pentax, Morpheus and Vixen HR eyepieces. But enforced retirement brought about a change in my circumstances and I had to let a lot of nice things go to supplement my income in the (hopefully) short term.

I make no complaints about that as I have been able to keep the Tak (my most prized astro possession), and, in place of the more modern wider angle eyepieces I have built a small collection of extremely good but older Japanese eyepieces. These include a Tak ortho, a Nihon Seiko (NS) volcano top ortho, and three Carton Japan units with fov from 55-65 degrees in 1.25" barrels..believe me, these deliver views on axis every bit as sharp as any XW or Morpheus I have ever used.

My real problem more recently is eye relief..very short eps are quite uncomfortable for me these days and hence my interest in Barlow experimentation as these help give high magnifications but maintain the longer eye relief you get with longer focal length eyepieces. And on all too rare really good night's, the FS128 will take ridiculously high levels of power-indeed, the scope manual encourages owners to go up to or beyond x100 per inch of aperture..that's 500x or more for my scope! sadly, my floaters will kick in long before that level!

The Vixen HR 3.4mm was a notable exception, having good eye relief and was very comfortable, I found. When circumstances allow, that will be one of the first "hi end" eyepieces I aim to re-acquire!👍😊.

Dave

5 hours ago, Louis D said:

Multiplying barlow magnifications together might not work precisely if the barlows won't seat all the way into each other, as would be the case with older, long barlows.  You might not be able to reach focus in that case, either.

I had a quick go last night before the clouds rolled in, for around 40 minutes.

The baader 2.25x Barlow bottom two sections (the top two shown in the photo below), which contain the optical elements threaded into my eyepieces fully with no problems.

The 1.6x WO nosepiece Barlow then threaded into the bottom of the baader Barlow, again fully and with no problems, so I am fairly confident that the magnification multipliers referred to above are accurate.

Accurate or not, the views put up in each of the eyepieces I tried them in were truly wonderful. The seeing last night for a short time was the best I have had here for many months.

Although I'm not the biggest Lunar fan, I was just rivetted by the lunar landscape and just how sharp it was, however much magnification I threw at it! Based on the stacked Barlow in my Carton zoom at its highest power 7mm setting I was getting c 355x with no image breakdown: however, at that magnification the floaters in both my eyes were quite distracting, so I dialled the zoom back a bit to an estimated 270x which gave me a cleaner view.

I do believe I spotted 2 or 3 craterlets in Plato last night, visible as lighter "spots" on the crater floor, so I was well chuffed with that😊👍.

In my excitement I forgot to try for the craterlets with my binoviewer, I have read that they can be easier to see with bv vision. If it clears later I might try for that tonight.

Dave