Rangefinder10

On 06/12/2020 at 12:37, RobertI said:

Absolutely! Amazing price. I have the same binoviewer and have been enjoying some great views of Mars.

I'd be interested to know what magnification your barlow ends up giving you. I ended up using a 1.3x barlow which actually turned into a 5x barlow when used with the binoviewers (due to the increased barlow to eyepiece distance in the binoviewer I believe), giving me 175x in my 100ED refractor which was just perfect for Mars. 

Hi Rob

How do you do that calculation?

John

On 06/12/2020 at 00:28, Space Hopper said:

I should have realised the same, but didn't. Although i'm not that familiar with the WO bino.

But glad you got it sorted.

And please post your impressions with this setup : we'd love to hear them 🙂

 

 

Will do, as soon as the clouds pass, whenever that will be!

Problem solved😀

And it was in my possession all of the time, but I hadn't thought to use it.

The little 1.6 W.O. barlow, sitting in my binoviewer box, screwed into the end of the bino!!

I'd tried various extension tubes but all obviously too long.

I had in mind that I needed much more focus draw than actually required.

Thanks to everyone for your help. The forum is a great source of knowledge and assistance.

cheers

John

3 minutes ago, Space Hopper said:

Hi.

If its any help the 3 Baader GPCs will 'buy you back' the following lightpath in mm's

1.25x gpc     20mm

1.7x gpc       35mm

2.6x gpc      65mm

 

I'm not sure how compatible they are with the William Optics bino though, or where you even put them ?

If you go down the Baader prism diagonal route, the 2.6 gpc screws into that (rather than the bino in the case of Baader binoviewers)

 

Another option would be to try a 2" Barlow and see if it focuses with that first.......?

 

Thanks Rob

I think that Ihave  a 2” Barlow tucked away somewhere.

I’ll see if that works

cheers

John

I’ll put in a question to Williams in the USA to try and obtain more info

John

Stu

nothing in focus at all in any position, completely blurred

John

Here are some pics

I tried different focus lengths but to no avail.

I will try the GPC route to see if That is my solution

many thanks for all the helpful suggestions

John

Thanks Stu

I’ll try and post some later

cheers

John

1 minute ago, Rangefinder10 said:

I have the W.O. Version ,  cost me £50, and at that price I thought “ nothing to lose”

John

I just simply assumed that it would be ok with my Megrez 72 but didn’t seem to work

25 minutes ago, Stu said:

This is the one I have:

https://www.teleskop-express.de/shop/product_info.php/info/p609_Baader---ZEISS-90--diagonal-prism---T2-thread-on-both-sides.html
 

There is a cheaper non Zeiss Baader one which would still be very  good. The T2 format is very good and has a short optical path. Depending on which binoviewer you have, you may be able to make a direct connection to the prism to keep the path length short. That’s what I did here when using my little Telementor. The short extension just allows space for a GPC so it doesn’t hit the prism; that is one thing you do have to be careful about. Some eyepieces have long barrels and can hit and damage the prism surface, as I found out once to my cost. Some GPCs screw directly into the binoviewer so the extension may not be needed.

I have the W.O. Version ,  cost me £50, and at that price I thought “ nothing to lose”

John

8 minutes ago, vlaiv said:

Just to add to answer already provided by Stu, prism diagonals are better suited to slow scopes.

When used with fast scopes, due to angles involved there is possibility of introducing chromatic aberration.

For this reason, mirrors are preferred for faster scopes and prism diagonals for slower scopes. For fast scopes, there are options like this:

https://www.teleskop-express.de/shop/product_info.php/info/p9870_TS-Optics-T2-90--Star-Diagonal-Prism-with-28-mm-free-aperture-for-Observation-and-Photography.html

which you can equip with low profile adapters to shorten optical path.

Thanks Vlaiv

I'm soaking these details up as fast as I can.

John

I'm not totally hung up on the matter of binoviewers. It's just that a bought a pair out of interest from Ian King when he was shutting up shop last year, because I wanted to experience the difference in use,  but not yet been able to make them function, and was curious about the critical factors to take regard of when choosing my next scope.

17 minutes ago, Stu said:

A dielectric generally means a mirror diagonal ie the reflective surface is a first surface mirror and a prism is a glass prism where the reflection happens via total internal reflection off the diagonal side of the prism.

Plenty of info here:

https://www.cloudynights.com/articles/cat/articles/mirror-vs-dielectric-vs-prism-diagonal-comparison-r2877

Very helpful, thanks, I will have a more detailed review

John

9 minutes ago, Stu said:

Which mount will you be using John?

I have a Skytee 2 and an AZ5.

My concern about weight is more to do with lifting capability.

Whilst manageable now, I'm trying to look ahead a year or two where I may not be so capable of lifting heavier weights.

5 hours ago, Stu said:

Some very good advice already John. All I would add is that some scopes have removable sections in their OTA so as to give more inwards focus to cater for binoviewers. You often uses GPC (Glass Path Corrector) with binoviewers which helps correct for some of the inherent CA from the prisms, but also applies a barlow affect which gains back some optical path length. This obviously also gives higher magnification, which may not be what you want so it is often a compromise somewhere along the line. I use mine almost exclusively for high power observing so use a x1.7 or x2.6 GPC. 

https://www.teleskop-express.de/shop/product_info.php/info/p476_Baader-Glasspathcorrector-1-2-6-for-Baader-Binoviewers-with-T2-Connection.html

This scope for example has a section by the focuser which can be removed to give more inwards focus.

https://www.teleskop-express.de/shop/product_info.php/info/p10133_TS-Optics-Doublet-SD-APO-125mm-f-7-8---FPL-53---Lanthan-objective.html

Stu thanks for your comments. That is indeed one of the scopes that I've been looking at, but I felt was perhaps a little too heavy.

Ideally I would like to try and keep the OTA weight down to no more than 5 kilos if possible.

".......and preferably prism over dialectric" for my education what is the difference?

John

Thanks for the comments to Vlaiv and John

Thanks Vlaiv

So is it then just a matter of asking the question at the point of scope selection, are they bino friendly or not?

John

I have spent many hours reading through some very entertaining, interesting and very informative topics throughout the forum over the past few months. This novice has learned an awful lot from this. I love the banter between some obviously good friends.

I am aiming some time soon to acquire a 4"/5" doublet apo refractor (if there are any actually left in stock) when I finally decide which to go for. One aspect that puzzles me in reading of the benefits of binoviewing is that some refractor descriptions describe them as being bino ready/friendly.

What makes some more readily bino friendly than others? Is it the size of the focuser, availability of focus extensions? or am I misunderstanding something.

Are all refractors capable of being used with binos as well as eyepieces?

I would welcome your advice

John

Thanks to all for the great welcome

cheers

John

Hi SGL

I've recently joined the Lounge although I've been soaking up knowledge by reading through many topics and postings  for some time.

I've also been admiring the many fabulous setups that are on show throughout the forums.

I'm a new old boy (late 70's) to this hobby, although I've been generally interested in looking at the sky for many years.

I bought a new WO Megrez 72 some 10 years ago, together with a WO zoom eyepiece and a 3mm SPL, which I used on a Manfrotto tripod for both terrestrial and the night sky viewing.

I'm purely visual with zero interest in computer imaging.

I decided earlier this year, start of lockdown, to devote more time to this hobby, and invested in some new additional equipment, I must say with some mixed results.

I bought a new SW SkyMax 150, a set of Hyperion eyepieces, and a SkyTee2 (manual altaz preferred). I didn't get the results that I expected from the SkyMax probably due to my local seeing conditions, and returned it.

Kept the eyepieces, as a wearer of specs and a long time camera user, the long eye relief 20mm is a critical factor for me. It doesn't matter how good the eyepieces are if you can't see through them properly!  I thought that they would be a decent standard of eyepiece for whatever I chose to replace the Mak.

The SkyTee is now back with FLO for repair/replacment under warranty after a few weeks use, poor agricultural quality. I think that I might to uprate this sooner rather than later

After my foray into new territory with the Mak, I've decided that my preference is to stay with a frac ( I'm a fan of sit down viewing), so I am now looking out for a decent 4" frac doublet apo

Simplicity, comfort, enjoyment and ease of use of equipment are most important factors

cheers

John