MalcolmM

1 minute ago, F15Rules said:

..and of course Tak eyepieces binoview very well!😈😂..

Dave

I have a pair of Tak Erfles which give a pretty decent wide view and when I win the lottery I'll double up on the others No more temptation please

49 minutes ago, wookie1965 said:

Just a quick one would binos work in my refractors and would I get any benefit please. 

Others more experienced than me can give you the pros and cons and possibilities. All I can tell you is the WO Binoviewers work great in my Tak FS100DC but I had to use a Baader diagonal and a glass path corrector in order to achieve focus. Doing a search on the forum will give you lots of advice on what works/does not work. I'm afraid I don't feel qualified to give you a good answer!

13 minutes ago, F15Rules said:

I hope my opening comments didn't sound critical..I think it'd just be a shame if you missed out on the great views (for selected targets) that binoviewers can deliver versus cyclops views.. 

Hi Dave, not critical at all. I'm just getting started in this hobby after a very long hiatus and I think advice like this is invaluable, albeit too late for me having already bought a bunch of Tak eyepieces But like I said, I have been bitten by the Tak bug

Malcolm

2 hours ago, F15Rules said:

Why be "afraid to concede.."?? -why not just celebrate the fact that you have found a way to improve even further on already excellent views?

Hi Dave, I should probably have put a smiley face on that sentence as it was really just to poke fun at myself and my blind devotion to Tak equipment I enjoy the WO Binoviewers very much but also like the look of the Max Brights. I hope you do not have to wait too long for them to become available so you can treat yourself and then tempt me with an excellent review

5 hours ago, Louis D said:

I've discussed binoviewers with some CN folks who have used several different high end binoviewers, and the main differences are in clear aperture size, mechanical construction, and accessories.  Image quality doesn't vary much, so entry level BVs are just fine for planetary viewing.

That's very interesting and also quite reassuring, the jump from WO level Binoviewers to the next level up seems to be quite a jump in cost!

3 hours ago, mikeDnight said:

I've been using the same old Revelation binoviewer since 2008 and think its an amazing piece of kit. I feel it is arguably the single most impressive game changer, as far as lunar and planetary observing is concerned, of anything I've ever bought, and worth every penny of the £99 I paid for it. I have used other binoviewers alongside my own but have not really noticed much of a difference between them. I've not yet had chance to observe with a Takahashi binoviewer, which I imagine you're referring to when you say "fully Tak light path!"? I think its the 45° angled bino head that put me off buying one.

My fully Tak light path is Tak scope, Tak prism and Tak eyepiece. I wanted it to provide a better view than the (non Tak) Binoviewer and Baader eyepiece but had to concede this time the non Tak combination was better I hope your Revelation Binoviewers bring you many more years of service!

I've bounced between Binoviewers and Cyclops for a few months now and never really have found one better than the other. I really love setting up a purely Takahashi optical path (bit of a Tak fanatic), but today I spent an hour and a half observing the sun in white light jumping between all combinations of eyepieces and Binoviewer. I'm afraid I was disappointed to concede that WO Binoviewers plus 1.6 GPC and 10mm Baader classic Ortho was both easier to view and provided better views than my fully Tak light path!

6 hours ago, bond19 said:

Spot-on. That was indeed the problem. Along with the centre bolt not being long enough to secure the Scopetech Zero.  

Very glad you got it sorted. I'd be interested in hearing how you get on with it. I was very tempted with one but went for the giro ercole instead which I like very much but sometimes miss the slow motion controls. 

Fantastic observation! 

I really enjoyed your video too.

That is a very impressive setup you have.

I may be wrong but it looks like the top threads on the offending screw are stripped? I wonder can you get replacement parts?

The Manfrotto website has a spares section https://www.manfrottospares.com/475b-parts.html

I couldn't see the bit you need for your tripod but I may have been looking at the wrong model.

You might need a whole center column  

I had a startravel on an alt/az mount. I tried some very basic photography with a DSLR attached. I found bright stars were always surrounded by a bright blue halo! So I would second the sentiments of good for wide field visual but not good for AP.

1 hour ago, wimvb said:

Have you seen the "no eq" dso challenge in this forum?

 

Perfect, that's exactly what I was looking for!

Thanks very much. I hadn't seen that thread.

Malcolm

Hi,

I am constantly blown away by the many fabulous pictures posted on this forum. I am a visual observer but occasionally like to slot a DSLR into the eyepiece holder just to record what I have seen.

I would be very interested if anyone else does something similar and would post pictures of what you can expect with minimal effort.

Here's two of mine.

M81 and M82 was taken with 10 sub second exposures on a manual alt/az mount through a SW 102 Star Travel, no darks or flats, ISO12800 and processed in Sequator. I think I can just make out some spiral structure in M81 and you can see the 'exploding' center of M82.

M45 really surprised me in that I captured the blue nebulosity. I had photographed this before but never captured the nebulosity. This is 20 x 10 second exposures at ISO 1600. It was using a Tak FS60CB on a driven alt/az mount. Again it was processed in Sequator and then some very small tweaks and cropping in gimp.

Malcolm

M81M82_seq_light.tif

Hi, I think it's a little unfair to compare an 80mm with a 250mm! That being said, I'm a 'refractor man' but your descriptions of the views through your Dob sound fabulous! I could be sorely tempted!

11 hours ago, qisback said:

I had a really good discussion with esure; initially they were confused about what I wanted but eventually they covered it as additional bespoke items to the insurance.

I had the criteria of something like:

1) "I'd like to put all my kit in the garden and run 2 cables to it, leaving it unattended and operate it remotely"

1) "I'd like to go to the middle of no where, setup my kit, run a cable into a caravan, set a session going; get drunk; fall asleep and I want all the kit covering on insurance"

They had be specifically declare items over £1k (so the scopes, cameras etc) but every other item if it was purchasable separately was covered old for new.

They did ask questions about; could I put it in the car when it was unattended, how often it would happen, and I was transferred to another department, etc. I simply stated that I didn't want to supervise the kit and most of this would happen in the 4-5 months over winter; in the end after a hour phone call it cost me £60 extra to cover it all. Both in the garden and out and about.

 

Hope that helps.

Love your description of the caravan AP session Thinking it would make for a fantastic Bob Newhart sketch, if anyone is old enough to remember him!

1 hour ago, Don Pensack said:

So the GPC 1.6x became 2.0x in the forward position.

Yip, that seems to be the case. Does that seem fair enough to you? Is that what you would expect?

Hi @Don Pensack, @globular, @Louis D

I hope you don't mind me tagging you all.

I did a wee experiment - hopefully following your instructions.

I measured the FOV (using a ruler) for (a) diagonal + eyepiece (b) diagonal + WO Binoviewers with the WO 1.6x nosepiece barlow between the diagonal and the scope and (c) as for (b) with the addition of the WO 2x nosepiece barlow attached to the Binoviewers (accepted that that may not be advisable!). 

The same eyepiece was used throughout.

I've attached a drawing which hopefully explains better than words!

Anyway, if we call magnification in (a) as x1, then (b) is ~ x2 and (c) is ~ x4

So that would seem (I think) to tie up with what everyone is saying; the x1.6 + binoviewer is actually giving x2

As an aside, I cannot achieve focus with any other combination of the above.

Many Thanks for all your replies,

Malcolm

Fabulous! Quite inspiring what you can achieve with a single frame unguided (I'm assuming!). I can see I'm gonna have to head to Wicklow!

On 01/10/2021 at 11:52, JeremyS said:

Good to see your sketches Malcolm. 
After I got the Extender Q, I’ve pretty much left it in FS60Q configuration all the time.

Hi @JeremyS, am I right in thinking you also have an FOA60? How does it compare with the 60Q?

Malcolm

Hi,

I can attach my DSLR to the end of my scope and get lovely wide field shots.

If I were to buy the Takahashi x2 barlow and put it between the scope and the camera would I still be able to achieve focus without having to use extensions etc?

Just for context, this is just to get quick shots, not serious AP. I tend to take 10 - 20 shots on a driven alt/az mount, no darks or flats and use Sequator for stacking (I have yet to get better results using DSS and Gimp!)

Many Thanks,

Malcolm

Fabulous photo and particularly interesting for me as I have been trying to find all these clusters visually in a 4" refractor from the suburbs. My notes say of NGC654, "Need averted vision, something there, you're just not sure what!"

I might print your photo (if that's allowed) and use it for a reference.

An indulgent update! Got a quick chance to view the moon again this morning and configured the Tak as a 60Q for comparison. I couldn't use the 4mm TOE this morning; too much power in the bright low contrast sky. The Nagler zoom at 6mm gave the best views and this configuration definitely gave more detail than the 60CB mode with the 4mm TOE. Focus is also easier to achieve in this mode due to the shallower angle of the light rays I think with the increased focal length?

I have attached a pic of comparison sketches! I now have huge respect for those of you who post lovely sketches. It is incredibly difficult. The more you look, the more you see, the more you want to get down on paper and you simply can't, there is too much detail. As a mark of my ignorance you can see from the first sketch I thought I was looking at the Mare Crisium! A real crisis of seeing

Malcolm

2 hours ago, Don Pensack said:

A Barlow only magnifies by the set amount at one position back from its lens.  Increasing that distance increases the magnification, decreasing that distance decreases the magnification.

Since focal planes in eyepieces are not all at the shoulder, the magnification of a particular barlow will vary according to which eyepiece is in it.

Complicating that even more is the fact that not all barlows have their rated power exactly at the end of the eyepiece tube.  

Eek.

 

So there is a very easy way to tell the magnification of a barlow with a particular eyepiece:

--time the passage of a star on the celestial equator across the field with the eyepiece alone.  Convert that time to digital minutes (i.e. 2min.12sec. is 2.2min.)

--time the passage of the star from edge to edge with the barlow or GPC in place.  Convert that to digital minutes.

--divide #1 by #2.  Voilà! the magnification of that Barlow or GPC with that eyepiece (or whatever else happens to be in the focuser), regardless of where the GPC is placed.

 

Some Good news: the 2" PowerMate 2X only changes magnification by 0.1x over 4 inches of travel away from the lens!

So, to all intents an purposes, just assume it is 2X (remember that timing might yield 2.02 or something like that).

The Glass Path Corrector (OCA) in the binoviewer has a set magnification when used with the binoviewer.  But it is designed to be used attached directly to the binoviewer, not in front of the star diagonal.

When used in front of the star diagonal, it magnifies by more, just like a Barlow.  You will have to do the star timing trick to discover exactly by how much more.

If you have 2 GPCs (and I would not advise it), one by the binoviewer and one a few inches farther away, then the magnification facor may be somewhat unpredictable since the internal light path of diagonals are NOT all the same in a given size of diagonal.

Whatever that magnification is, just multiply it by 2 when used in a PowerMate, whether the PowerMate is used in front of a diagonal or in front of the binoviewer.

 

The star timing trick doesn't even have to be a star on the celestial equator, but the star moves across the field fastest at that location, meaning you'll spend less time timing the passage.

Thanks very much for your reply, that's a lot of information and I think it is in agreement with what globular is saying. I have a couple of questions if I may:

Is the star transit timing experiment (which I will attempt when the rain and clouds disappear!) saying that the magnification is proportional to the field of view? This will be a little tricky for me as without the 1.6x in front of the diagonal I cannot achieve focus. But hopefully I'll get a close enough result. I can then compare that with globular's formula.

Second question: when you say the light paths through the diagonal are different, does this mean focus will not be consistent across the field of view? So I would be better using shorter focal length eyepieces than 2 GPC's to get higher power?

If I attach the 1.6x direct to my binoviewers I cannot achieve focus. Another member in another post suggested I could remove part of the telescope to shorten the light path but I'm not sure I want to go that far on the basis of if it ain't broke, don't fix it!

Many thanks,

Malcolm

8 minutes ago, callisto said:

I was going to get one of these earlier in the year but I never... wish I did now 😪

It's never too late! I'm sure FLO would be delighted to help

I also am very confused by this and have done a fair bit of searching on-line for explanations. I have not really found a consistent answer. I feel there ought to be a relatively simple formula but I have not been able to find one. In my own experience, with a 740mm FL scope, 1.6 x GPC before the diagonal and WO binoviewers with say 20mm eyepieces, I feel I get much more magnification than 740 x 1.6 / 20. But maybe this is an illusion due to different Fields of View? And then it is complicated even further if I put another GPC between the diagonal and the binoviewers!

If there are any Physicists out there who could give a simple explanation with a ray diagram please chip in