F15Rules

15 minutes ago, Saganite said:

Stacking barlows is apparently a common and well known practice, and there is a fair amount of discussion on CN for a start. I cannot begin to suggest the mathematics involved, but your suggestion Dave that it is a product of the two barlows, if I understand you correctly, ie 1.6 x 2.25 = 3.6x 99= 356x seems to be in agreement with what I have read.

Thanks Steve, that was my train of thought. Optically the combination works well, although at c355x I was getting bad floaters and so found the 222x view cleaner. I confess I get frustrated by finding the performance of my previously good right eye deteriorating as I get older.

I'm training my left eye (which is quite a lot better than my right these days) to be my main cyclops viewing eye, and am increasingly finding binoviewers more comfortable on the Moon and, I hope later this year, the planets.

Using barlows, singly or stacked, helps preserve eye relief which again I find more comfortable than using 3.5-5mm eyepieces.

Dave

24 minutes ago, Timebandit said:

 

 

Stacking Barlows on top of each other 😵. That's a new one on me ,and I thought I try different things. Your Tak FS128 deserves better.  Stop being so tight and get some proper high power eyepieces😀

 

 

Thanks, thats really helpful.

11 minutes ago, John said:

The Baader 2.25x gives 1.3x amplification when the optical element is threaded directly into an eyepiece barrel.

 

Hi John,

The baader barlow 2.25x I have is made up of 3 parts, the lenses being in the bottom two parts, the top section having a T2 thread I believe. The bottom of the two bottom parts won't unscrew from the "middle" part of the three, (it was like that when I bought it on SGL from another member): the top of the middle part is threaded and is the part that screws into the eyepiece barrel. Hope that makes sense? So, are you saying that without the T2 top component the bottom two sections only deliver 1.3x magnification?

Thanks,

Dave

Hi all,

I'd like to tap into your  wisdom regarding ep and barlow combinations please..

My scope focal length is 1040mm. Using a 10.5mm eyepiece on it's own gives me 1040/10.5= 99x, right?

So, adding in a Baader 2.25x barlow lens threaded in to the bottom of the 10.5mm gives me 99 x 2.25 = 222x (approx), right?

Finally, (and this is the bit I'm not sure of), if I thread in a x1.6 barlow nosepiece into the bottom of the 2.25x barlow (so there are then two barlows "stacked" in the bottom of the 10.5mm eyepiece, does that then give me 222x1.6 = 355x magnification in total? Or am I missing something that I should take account of in the calculations with two barlows being used stacked one on top of the other?

The images and their scaleI see seem to suggest I am about right, but it would be good to get some independent confirmation or correction from the more mathematically able among you! 😊

Many thanks,

Dave

20 hours ago, johninderby said:

80mm f/10 now ordered. 🙂

Look forward to your first light report John, congratulations 👍.

Dave

8 hours ago, GazOC said:

They certainly look stunning, I know telescopes are "for looking through, not looking at" but I much prefer a bit of colour over the plain white that most scopes seem to sport

I respectfully disagree.

I agree that these scopes do look stunning. But I think it's the red hardware that really catches the eye. And there seem to me to be just as many, or more,  non-white refractors sold these days as white ones.

I will always prefer a white tube myself, not only aesthetically, but because in use the white tube shows up more easily in the dark, and because they don't show lots of fingermarks like shiny black ones do.

I think FLO are to be applauded for bringing an ED apo doublet at F10 to the market, and it would be great if this could be extended to a 100mm F10 in the future. 

I wish FLO every success with this very interesting new range.

Dave

I bought a pair of these almost 2 years ago now and have been/am delighted with them.

Great build, sharp out to 75% or more (VERY sharp in central third), great colour and contrast.

A pleasure to use and hold.

Highly Recommended

Dave

3 hours ago, FLO said:

We are a UK retailer so our information comes from Vixen-UK

I understand that Opticron (Vixen's UK distributor for some years) are losing the franchise in the UK to Bresser GMBH. If correct, that sounds to me like a retrograde step, unless they plan to do some serious marketing in the UK for once.

I am a big fan of Vixen products, but they don't appear to do half the advertising that OVL/Skywatcher do?

57 minutes ago, paulastro said:

Many congratulations to both yourself and your daughter Dave, you must feel rightly proud.  Good to see the pictures too, just a shame they are  being kept in a museum and not put to good use on the night sky.

Many thanks Paul. Yes, my wife and I are very proud of both our daughters who got Firsts in their degrees, and our youngest who got a Distinction in her Master's on Friday. And of our son, who like me, hated academia and never went to Uni, but rather went into grocery retail and is now a deputy manager of a large superstore turning over £50m a year.. Horses for Courses, as they say😊.

It is a shame these scopes aren't currently in use, but they did get quite a bit of attention so perhaps being on display to thousands of students has a value in itself?

Dave

24 minutes ago, John said:

Superb - thanks for snapping and posting the photos

They remind me of some of the refractors that are at the Norman Lockyer Observatory at Sidmouth.

 

Thanks John, just got to love those old long fracs! Would be great to put one up against a modern scope, just to see...😊

Dave

On 24/01/2020 at 20:15, dweller25 said:

Not F15 ?? 
Scandalous 😂😂

Now, now, David..

I'm nothing if not inclusive!😁😁

Thanks Steve, we had a wonderful day and the weather was kind to us as well.

Yes, that mount is a beast. I'd have liked more time to look at it. These were clearly University class instruments, I can only guess what they must have cost when new! I don't know the focal lengths, but I'd guess between F12  and F14 or so..as such they should be pretty well corrected..

Dave

We were up at York University today for the graduation of my youngest daughter in her Master's👏😎..

The gathering venue before the ceremony was the main Physics building, and while we were waiting for her to get "Gowned and Mortar Boarded" up, I had a little wander and noticed a couple of very nice old brass refractors both mounted side by side on a very substantial looking solid iron pillar type equatorial/altaz mount.

I asked if I could pop into the room they were in to take a couple of pictures, and this was readily agreed.

I also snapped a short info piece which I attach below and which gives a little more info on these fine old scopes dating from 1859 (just expand the pic to read the details).

Thought fellow refractors fans might like to see them too😊..

Dave

For a while I've fancied a smaller aperture pair of bins for daytime ultra portable use, especially casual birdwatching both in the garden and on local country walks (we are lucky enough to be just 150 metres from open fields. For night use I have an excellent pair of Opticron SR-GA 8.5x50s (made in Japan), so although I would like to use the smaller pair on the night sky now and then, the primary use would be in the daytime.

I had a nice old pair of Zomz 8x30s which gave nice sharp views, albeit with a slightly yellow cast. I also wanted closer focusing capability and better fine focusing mechanics for comfy watching of birds in the garden. So I gave the Zomz to my daughter and hubby, who also wanted to get a taste of binoculars, and began a search for some more modern ones.

Having a limited budget of c £60-£70 or so, I felt that a used pair might be the best bet. I started the search on that well known auction site, expecting to be looking for quite a while: however, I had a "saved search" set up for Vixen products, being a big fan of most things Vixen, and within one day of setting the search up, this pair of dinky Vixen Apex Pros came up. Never heard of them. 

I soon put that right by doing a bit of online research, but there wasn't a great deal of info on these particular binoculars: I did however find the same bins marketed under the Ace Avian brand. Here are the key specs at a glance;

- Magnesium Alloy Construction

- Water Repellent Lens Coatings

- Close Focus to under 2 metres

- Fog Proof & Nitrogen Filled

- Twist-up Eyecups with click stops

- Aspherical lenses & Flat Field Coatings

These are, I believe, identical to the Vixen's, and must therefore have been contract manufactured by Vixen for Ace Optics.

I liked the online description of the Vixen's as being little used and in great condition, so I made a cheeky offer and was delighted to secure them at quite close to my budget - not bad considering the only retail price for these that I could find was c £300.

I was taking a bit of a risk as the seller was new to online selling and had virtually no feedback: however, the seller communicated well and seemed to answer my questions promptly and genuinely, so I went ahead and bought them.

They arrived safely, well packed, and upon opening them it was clear that these bins are almost as new, and very rarely used. I was both pleased and relieved.

Below are some photos of the bins.. I'll post up my thoughts on their performance in part 2..

Thanks for reading😊

Dave

1 hour ago, DaveS said:

And I'm 64 in just over a month

Vintage '56 twins!!👍

12 minutes ago, Telescope40 said:

Hello. 
+1 for the Pentax 12x 50’s as bought from Dave @F15Rules

I still have them.  Nice binos !! 

John 

Thanks John..👍

..and they have a nice 4.3mm exit pupil for us oldies (I'm 64 in 3 weeks !!😱)

Dave

I second Ade's very sound advice. For me, Pentax can do little wrong, and the 10x50 and 12x50s by them that I had were great, albeit with a fairly narrow fov (c.4.5 - 5.0 degrees as I recall, but pretty typical for 10x50 porros). Very sharp across most of the field, with great contrast.

I also owned the Opticron Adventurer MK1 and the later version (10x50s), and both were very good for the price.

I now have a pair of Opticron SR-GA 8.5x50s (made in Japan) which are excellent, though sadly now  discontinued.

Looking at the FLO site, I think the new version Pentax SP 10x50 WP with Nitrogen purging, waterproofing and the latest lens coatings would be great for you. With your voucher you could buy these for just £49 plus p&p, and these would give you wonderful views day and night.

Good luck with your final decision!😊

Dave

26 minutes ago, mikeDnight said:

One TV spokesman commented that its down to "marketing"

If that is true then what price the concept of "meeting customer needs / preferences"? - a concept that drove the marketing strategy of all of the major companies I worked for in my sales & marketing career - and the same for my competitors!

I'm not in the game of knocking Tele Vue..they make excellent products and have been very innovative over many years. But eyepieces undercuts and their refusal to get rid of them are (along with sky high prices), the reason that I haven't owned a TV eyepiece for c 10 years. I just vote with my feet.

I should also say that I don't like Explore Scientific tapered barrels either, although not as aggravating as the undercuts.

Can't we just get back to nice smooth barrels,? No undercuts mean one less manufacturing step needed, so maybe even a small cost saving to the customer?.. now that WOULD be innovative!😁

Dave

I hate undercuts. Period.

Dave😃

Lovely, uplifting report..thanks!

After what seems like almost 5 months now of endless rain, cloud and dampness, it was great to be reminded of a black, clear sky overhead.

I hope you get many more of them..😊👍

Dave

There are a couple of RACI illuminated finders on UK ABS.

One is an Option USA 40mm but the brightness difference vs a 50mm will be hardly noticeable.

The Stellarvue is a nice finder.

HTH,

Dave

https://www.astrobuysell.com/uk/propview.php?view=157384

https://www.astrobuysell.com/uk/propview.php?view=157478

5 hours ago, John said:

I also started to find that I was concentrating so much on finding subtle differences between products that I was not enjoying observing as much. That was what prompted me to change tack somewhat.

 

Very much how I felt/feel John. Over the past decade I have bought and sold dozens and dozens of eyepieces. I confess that during that time I sold many really good eyepieces simply because I had read glowing reviews of different ones and therefore had thought "they must be better than mine" - as they had lots of good reviews/likes/appreciative comments. 

In fact, more often than not, the ones I replaced with the "sexy" ones were actually as good as, or sometimes even better than, the raved about eyepieces- this meant that I had sold some perfectly good, effective eyepieces and replaced them, often at a higher cost, with units that to my eyes were no better in UK field conditions.

When I took early retirement 6 months back, I had to sell a lot of nice eyepieces to cut my cloth for my new circumstances. In truth, of all the eps I sold, the only ones I really miss are three: Morpheus 17.5mm, Vixen LVW 22mm and a Vixen HR 3.4mm. I'd like to replace all three eventually. For now, my vintage set of 1980s/90s Japanese Carton 10.5mm, Carton zoom 7-21mm and 28mm (and Hyperion zoom Barlow 2.25x) give me everything I need , and are good enough to show pretty much all my ageing eyes can discern.

Sure, they don't have the latest coatings available today, but they give uber sharp, contrasty and low scatter views which are right up there with my previous Pentax eyepieces, but with a little less wide field. And they are all comfortable to use - and the more comfortable I am when observing, the longer I want to observe for, and the longer I observe for, the more I see.

Simples!😊👍

Dave

On 03/01/2020 at 22:14, mikeDnight said:

Hi Jaydee. Another option would be to get just one really good eyepiece and a barlow this year rather than two mediocre ones. If you were to buy a 17.5mm Baader Morpheus you'd have a spectacular eyepiece for deep sky. At 17.5mm it would give you a power of ~ 69X, and if you were to use a 2X barlow you'd get 137X. Not at all bad for great lunar views! 

I think Mike's logic is sound here, especially if you buy used pieces..over 90% of the eyepieces I've ever bought were used  (a lot of eyepieces!), and the vast majority performed like new ones. The Morpheus are a big step up from the Hyperions.

You might also consider a used Vixen LVW 22mm - a wonderful, now discontinued 65 degree widefield which I believe is superior to the Pentax 20mm XW. It also barlows very well.

Good luck with your choice 👍😊

Dave

I had the pleasure of owning a Vixen HR 3.4mm for a short time. It was a lovely eyepiece and I only wished the planets had been placed in the UK so I could have checked out Jupiter etc with it in my FS128.

I do hope to get another at some point when circumstances allow. I did get to try it on some doubles and had my best ever view of the double double with it - low light scattering, great contrast and very tight airy disks. 

The 3.4mm is the only one of practical use to me in my Tak (Focal length 1040mm)..it would be great if they made a couple of longer focal lengths, perhaps a 4.5-5mm and a 6mmwould do nicely!👍

Dave

On 20/12/2019 at 13:28, Sunshine said:

I have spent much time imagining how incredible it would be to witness Betelgeuse finally blow up... I can't wait, please let it happen in my lifetime. How lucky we would all be.

...unless we were inhabitants of Betelgeuse 3...

...or 4,5,6,7,8,9 etc etc ☺

Dave