Binoviewer Performance Questions

[Thewalkingastronomer]

Hi John,

Just a quick point from me on the contrast and dimming aspects of binoviewing,  I have easily observed both (brighter) parts of the veil nebula in a 3" apo with UHC filter and had one of the best views I've ever had of the Andromeda  and Sculptor galaxies with the same set up (hints of dust lanes on m31). This was with maxbrights and 19mm panoptics though was also from the pristine skies of La Palma. I guess the point being in my experience even the view of dim and low contrast objects can be enhanced by using two eyes.

Adam

[Timebandit]

42 minutes ago, Thewalkingastronomer said:

Hi John,

Just a quick point from me on the contrast and dimming aspects of binoviewing,  I have easily observed both (brighter) parts of the veil nebula in a 3" apo with UHC filter and had one of the best views I've ever had of the Andromeda  and Sculptor galaxies with the same set up (hints of dust lanes on m31). This was with maxbrights and 19mm panoptics though was also from the pristine skies of La Palma. I guess the point being in my experience even the view of dim and low contrast objects can be enhanced by using two eyes.

Adam

 

I should imagine being in and having the pristine skies of La Palma did help the binoviewing experience considerably ?

[Thewalkingastronomer]

Yes I would agree .

I have however still manged to observe the veil from my house on the south coast  with the same set up and found the view more pleasing than in mono

[John]

Even more excellent feedback - thanks very much !

One quick further question, are twist ring compression ring fittings preferrable to set screw ones such as the William Optics BV uses, if I'm given a choice ?

Thanks !

 

[spaceboy]

I read twist rings are recommended to avoid any offset. Similar to the same recommendations for self centring adapters on newts. No point having perfect collimation if a thumbscrew is pushing the eyepiece off centre.

[Stu]

John, I've not read all the replies so apologies for any duplication.

I do think binoviewing is a very personal experience, and much depends on your eyes as to how you like it.

I've said a number of times on the forum that I've tried quite a few different makes, some I have got on with, and others not.

I think my eyes are very sensitive to miscollimation, and they are also different in the views they give. It's hard to explain, but my right eye gives brighter, more colourful images that look quite grainy, whilst my left eye shows much more detailed views which are not so bright and less colourful.

I struggled with the William Optics and Baader Maxbrights because they seem to have too much adjustment in the eyepiece holders and I found it too much hassle to adjust them, particularly when changing eyepieces. The TS binoviewers have self centering holders which worked very well and the collimation seemed good to me. I had some Denkmeiers which were good, and now use Baader Zeiss Mark IVs which I really like.

These do not have self centering holders, just having single set screws, but the holders have very tight tolerances so the collimation is very good.

I have found that I enjoy using the binoviewers for Solar and lunar observing. The contrast and detail are wonderful, and there is a definite reduction in floaters. I use high powers, up to around x200 on the sun, equivalent to around 3.7mm focal length eyepieces. I achieve this using Barlows with Zeiss 25mm Ortho eyepieces.

I do still struggle using them on planets though. Weirdly I see more colour using the binoviewers with my Tak, but the image seems to have the detail smoothed out. I definitely see more detail using a single eyepiece but don't enjoy having to look around the floaters.

I think if I were going to start out again, I would grab a pair of TS binoviewers with any GPCs required, some 25mm Plossls and see how you get on. The Taks seem to have a fair amount of infocus available which makes life easier, though I'm unsure about the DLs.

Hope that helps.

Stu

[niallk]

6 hours ago, Mak the Night said:

I wouldn't underestimate the 25mm Sky-Watcher MA's for an inexpensive bino pair.

+1

I use a pair of these 25's, and also have a pair of 15mm TV plossls.  The cheap 25mm's deliver enjoyable views!

[spaceboy]

42 minutes ago, Stu said:

I think my eyes are very sensitive to miscollimation, and they are also different in the views they give. It's hard to explain, but my right eye gives brighter, more colourful images that look quite grainy, whilst my left eye shows much more detailed views which are not so bright and less colourful.

I had a very similar experience to this Stu. I don't think it is due to a miscollimation though. If I recall correctly when I looked inside the WO BV's one side had an extra element. In my mind I put this down to needing equalizing the focal length between the left and right side after being split through the prism. I shall see if I can find a picture of a disassembled BV on the internet to point it out.  

[spaceboy]

Sorry it wasn't an extra element but a totally different one on one side to the other.

[John]

It's funny but I would have thought a binoviewer would have the same optical layout on both sides with the beam split occurring very early in the system. Obviously they don't work like that from the photo above.

Thanks for posting that.

 

[John]

1 hour ago, Stu said:

....I think if I were going to start out again, I would grab a pair of TS binoviewers with any GPCs required, some 25mm Plossls and see how you get on....

Hope that helps.

Stu

Thanks Stu - your post does help.

I think the approach you set out is how I'm going to tackle this.

[Dixie]

Spot on that binoviewing is a personal experience.  It's difficult to quantify whether you see more or less - the brain does some pretty impressive image processing without or without them. For what it's worth if you like spotting faint fuzzies you'll lose out - on solar system and brighter DSO different story.  Here's a pair of Denk standards on my scope - the view of the moon I had recently blew my socks off again 10 years after buying them.  Couple of 25mm TV plossls in there - they are really nice.

Rich

[spaceboy]

10 hours ago, John said:

It's funny but I would have thought a binoviewer would have the same optical layout on both sides with the beam split occurring very early in the system. Obviously they don't work like that from the photo above.

Thanks for posting that.

 

It is probably identical more so in the case in actual binoculars where you have 2 lens supplying the image to both eyes but with a single "lens" source such as in bino-viewers being split in to two I guess it makes sense although as you say one would at first think it to be identical. Had it not been for a small amount of dust in the WO BV's needing a quick blow out I'd have been none the wiser myself. TBH I would not have given it a second thought if Stu's comment hadn't reminded me. Although saying that I did only experience this phenomenon on the sun in WL. 

[Timebandit]

12 hours ago, John said:

Thanks Stu - your post does help.

I think the approach you set out is how I'm going to tackle this.

 

Hi John. I think this would be a good way to get into binoviewing. The TS IMO are well worth purchasing. They will not break the bank to purchase, the quality of build IMO is good , they are relatively easy to set up and use. And the views they give are also good in my opinion. I dont think you will regret getting some TS to get you back into binoviewing. With regards to eyepieces some second hand SW 25mm wa were the first paired eyepieces i had for binoviewing and again gave very nice views in the TS IMO. I have tried to pair up a few of my existing plossl and Ortho since, to give that little bit extra performance in which my opinion to my eye's they do seem to give you that little bit extra . But I think this is a nice way to get some quantity Binos at sensible money. I did do a little bit of a review on these in the members equipment section and some photos to give  an idea of my set up .  

I hope you enjoy binoviewing ☺

[Moonshane]

I cannot recall John, are you at SGL12? If you are then you'd be welcome to borrow mine for a bit

[Peter Drew]

Although you adjust your IPD with a binoviewer the same as you do with a binocular, only one side of a binoviewer moves relative to the full body. I think the optical item in the lower half of the strip down image is a rhomboid prism, this would prevent image rotation during IPD adjustment.

[Timebandit]

Hi John . Ditto, if you are in the Hereford area at the SGL party at the end of the month then give me a shout and will pop the TS Binoviewers off to you to try out. I will even trust you with my televues plossl pairs and the 18mm BGO's if want to try those also ?

[Moonshane]

If you have a pair of TV 25s I wouldn't mind comparing them to my cheapie Antares which I should have by then if you don't mind?

[Timebandit]

4 minutes ago, Moonshane said:

If you have a pair of TV 25s I wouldn't mind comparing them to my cheapie Antares which I should have by then if you don't mind?

 

Hi Shane, sorry buddy i have only got the 25mm in the SW ,and therefore did not think it was worth the expense of replicating in televues (the 25mm SW were pretty good IMO) . 

[Moonshane]

To be honest I was hoping that I'd have the 'there's no difference' revelation when I compared 

[John]

Thanks very much again folks

Unfortunately I won't be at SGL12 but I appreciate the offers to try some BV's out.

I've managed to source a reasonable pair of BV's with a 2x barlow nosepiece if needed and a pair of the older "silver top" 25mm Skywatcher plossls so I should be able to experiment with this kit to see what it can do for me. 

I'll report back once I've had a chance to try it out

The response to this thead has been really excellent - what a great forum SGL is !

[spaceboy]

On ‎19‎/‎10‎/‎2016 at 14:40, Moonshane said:

Just to be clear, I am not proposing chopping anything off with a saw, rather getting an engineer to cut off a section with a lathe and make a connecting adapter to allow it to be returned to standard if required.

I'm not sure how much scopes have to be shortened to make them completely barlow / gpc free with BV's, or at least allow them to focus trouble free, but I wonder how the final baffle in the OTA will effect the mod as these tend to be pretty close to the focuser ?? It may appear to be a redundant baffle given the long throw on refractor draw tubes but it is there an no doubt put there for a reason.

 

[mikeDnight]

17 hours ago, John said:

Thanks very much again folks

Unfortunately I won't be at SGL12 but I appreciate the offers to try some BV's out.

I've managed to source a reasonable pair of BV's with a 2x barlow nosepiece if needed and a pair of the older "silver top" 25mm Skywatcher plossls so I should be able to experiment with this kit to see what it can do for me. 

I'll report back once I've had a chance to try it out

The response to this thead has been really excellent - what a great forum SGL is !

I love the silver tops John, but you'll probably find 25mm a bit on the low side for lunar and planetary. 18mm may be better! Using my bino viewer with X2 Barlow attached and 16.8mm ortho's in my Tak with a 1.6X extender Q attached giving F11.8 and goodness knows what rediculous power, the view just got better. I really felt like i was about to fall over the edge of those lunar mountain ranges which just towered from the lunar floor. It made my stomach roll!  Very Nasmyth in 3D!

Mike

[Moonshane]

2 hours ago, spaceboy said:

I'm not sure how much scopes have to be shortened to make them completely barlow / gpc free with BV's, or at least allow them to focus trouble free, but I wonder how the final baffle in the OTA will effect the mod as these tend to be pretty close to the focuser ?? It may appear to be a redundant baffle given the long throw on refractor draw tubes but it is there an no doubt put there for a reason.

 

Me neither!

[YKSE]

On ‎2016‎-‎10‎-‎21 at 08:04, spaceboy said:

I'm not sure how much scopes have to be shortened to make them completely barlow / gpc free with BV's, or at least allow them to focus trouble free, but I wonder how the final baffle in the OTA will effect the mod as these tend to be pretty close to the focuser ?? It may appear to be a redundant baffle given the long throw on refractor draw tubes but it is there an no doubt put there for a reason.

 

If we only consider the focuser travel needed for using a binoviewer or without:

For only using the EPs in the market, there's about 40mm focus travel difference. A binoviewer needs  another 110mm+, so a somewhat safe number is that 160mm focus travel is needed to accomodate using binoviewer and cylops. A focuser with this long focus travel is just impractical and/or uncessary expensive for most cases. A split tube in some refractors is a much more convenient solution.