Binoviewers - taking the plunge...

Discuss telescope eyepieces.
User avatar
davesellars
Pluto Ambassador
Articles: 0
Offline
Posts: 465
Joined: Fri May 31, 2019 1:02 pm
4
Location: UK
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Binoviewers - taking the plunge...

#1

Post by davesellars »


OK, so I have been thinking for some time how best to get higher power with comfort for lunar and planetary observations - mulling over a barlow or a 3mm eyepiece etc etc and it seems to be that binoviewers are very recommended for this type of observation which then cancels out floaters and additional comfort using both eyes as well as obtaining more detail. Seems to make sense... :)

So, today from a random search on flea-bay I came across some generic (OVL / Skywatcher / other...) binoviewers that were stated as never used. Comes with the 2x barlow to obtain focus and case. After making an offer and accepted I made the purchase so I'm looking forward now to the arrival of these and most likely with accompanying clouds... :p

For eyepieces, for the moment I only have two which are the same (25mm Skywatcher 52 degree Plossls) which came with a couple of scopes. Unfortunately the 10mm plossls are slightly different (one is 52 deg and the other a standard 50...) Still, with the 25mm eyepieces I figure that will give me 12.5mm effective focal length to start and be able to make a judgement about the binoviewer quality against single EP use and see if I get on with the bins anyway (some people seem not to be able to get a single image...). If all goes well with the 25mm eyepieces then I'll think about a couple of eyepieces to get me down to an effective EP focal length of around 3.5mm to 4mm.

Also, this setup will be great for my kids to look through for lunar or DSOs Using the 25mm plossls and a binoviewer with any of the refractors will much easier for them than a single EP where they struggle a bit still getting used to looking through one eye.
SW Flextube 12" Dobsonian.
Starfield ED102 f/7; SW ED80; SW 120ST
EQ5 and AZ4 mounts
Eyepieces: TV Delos 17.3 & 10; Pentax XW 7 & 5; BCO 32,18,10; Fuyiyama Ortho 12.5; Vixen SLV 25.
User avatar
Bigzmey United States of America
Moderator
Moderator
Articles: 8
Offline
Posts: 7548
Joined: Sat May 11, 2019 7:55 pm
4
Location: San Diego, CA USA
Status:
Offline

TSS Awards Badges

Re: Binoviewers - taking the plunge...

#2

Post by Bigzmey »


Congrats Dave! If collimation is good those basic prism BVs are good performers. I have also started with a pair of 25mm Plossls, really liked the results and after some consideration purchased second set of BCOs.

With very similar setup to yours SV 102ED F7 +1.9x Burgess OCA (which came with my Orion's BVs) BCO/BCPs pairs of 32mm, 18mm and 10mm work nicely. 6mm was taking it too far, I could not marge the images with them.
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
User avatar
davesellars
Pluto Ambassador
Articles: 0
Offline
Posts: 465
Joined: Fri May 31, 2019 1:02 pm
4
Location: UK
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Binoviewers - taking the plunge...

#3

Post by davesellars »


That's good to know many thanks Andrey. I was thinking the 18mm BCOs would probably be perfect (also relatively cheap!) with them and I already have a single 10mm BCO so would pick up another one. If I could boost the amplication from 2x to more like 3x then I would get effectively 6mm and 3.3mm which should work well.
SW Flextube 12" Dobsonian.
Starfield ED102 f/7; SW ED80; SW 120ST
EQ5 and AZ4 mounts
Eyepieces: TV Delos 17.3 & 10; Pentax XW 7 & 5; BCO 32,18,10; Fuyiyama Ortho 12.5; Vixen SLV 25.
User avatar
Bigzmey United States of America
Moderator
Moderator
Articles: 8
Offline
Posts: 7548
Joined: Sat May 11, 2019 7:55 pm
4
Location: San Diego, CA USA
Status:
Offline

TSS Awards Badges

Re: Binoviewers - taking the plunge...

#4

Post by Bigzmey »


If you use OCA designed for binoviewers you will get the advertised factor. I.e. 2x OCA screwed into the nose of BV would give 2x power (i.e. 10mm EP will work as 5mm).

However, if you take a nosepiece from a standard 2x barlow (like Celestron barlow below) and screw on the BV, it will actually give you ~3x factor, i.e your 10mm EP will work as 3.3mm.

https://agenaastro.com/celestron-1-25-2 ... -lens.html
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
User avatar
davesellars
Pluto Ambassador
Articles: 0
Offline
Posts: 465
Joined: Fri May 31, 2019 1:02 pm
4
Location: UK
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Binoviewers - taking the plunge...

#5

Post by davesellars »


Bigzmey wrote: Fri Apr 01, 2022 11:15 pm
However, if you take a nosepiece from a standard 2x barlow (like Celestron barlow below) and screw on the BV, it will actually give you ~3x factor, i.e your 10mm EP will work as 3.3mm.

https://agenaastro.com/celestron-1-25-2 ... -lens.html
Many thanks for the confirmation. I assume you use a 1.25" diagonal? Did you have an issue to reach focus otherwise (since it's the same setup...)
SW Flextube 12" Dobsonian.
Starfield ED102 f/7; SW ED80; SW 120ST
EQ5 and AZ4 mounts
Eyepieces: TV Delos 17.3 & 10; Pentax XW 7 & 5; BCO 32,18,10; Fuyiyama Ortho 12.5; Vixen SLV 25.
User avatar
Bigzmey United States of America
Moderator
Moderator
Articles: 8
Offline
Posts: 7548
Joined: Sat May 11, 2019 7:55 pm
4
Location: San Diego, CA USA
Status:
Offline

TSS Awards Badges

Re: Binoviewers - taking the plunge...

#6

Post by Bigzmey »


davesellars wrote: Sat Apr 02, 2022 8:37 am
Bigzmey wrote: Fri Apr 01, 2022 11:15 pm
However, if you take a nosepiece from a standard 2x barlow (like Celestron barlow below) and screw on the BV, it will actually give you ~3x factor, i.e your 10mm EP will work as 3.3mm.

https://agenaastro.com/celestron-1-25-2 ... -lens.html
Many thanks for the confirmation. I assume you use a 1.25" diagonal? Did you have an issue to reach focus otherwise (since it's the same setup...)
I am using Baader T2 prism diagonal, which is slightly bigger than 1.25". Most of BV users use prism T2 or 1.25" diagonals. Prisms have shorter light path and also have less light scatter on bright targets (Moon, planets, stars) compared to mirrors.

I can't reach focus with BVs and diagonal, but when I add 1.9x OCA or lens from 2x barlow the setup reaches focus no problem. This is a common thing with refractors (unless they are designed for BVs). Fracs don' have enough inward focus for added
light path, so one needs to use OCAs to compensate.
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
User avatar
davesellars
Pluto Ambassador
Articles: 0
Offline
Posts: 465
Joined: Fri May 31, 2019 1:02 pm
4
Location: UK
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Binoviewers - taking the plunge...

#7

Post by davesellars »


Bigzmey wrote: Sat Apr 02, 2022 5:39 pm I am using Baader T2 prism diagonal, which is slightly bigger than 1.25". Most of BV users use prism T2 or 1.25" diagonals. Prisms have shorter light path and also have less light scatter on bright targets (Moon, planets, stars) compared to mirrors.

I can't reach focus with BVs and diagonal, but when I add 1.9x OCA or lens from 2x barlow the setup reaches focus no problem. This is a common thing with refractors (unless they are designed for BVs). Fracs don' have enough inward focus for added
light path, so one needs to use OCAs to compensate.
OK, so the binoviewers arrived... seems to be in great condition.
bins1.jpg
bins2.jpg
So I tried them out briefly looking at some trees about 500 metres away (that's as far as I can see from here) and it's too cloudy to see anything else at the moment.

First slight minor issue is that rather oddly, the nose of the binoviewers won't enter a 1.25" diagonal that has compression fitting or indeed any 2" to 1.25" adapter that I have that has compression fitting on it. You can see that the diameter of the bins nose is slightly more than the barlow/OCA 2x nose it's attached to here:
bins3.jpg
It's not a massive problem but means you lose about 12mm inward focus and the barlow itself is rather more slippy and easier to rotate in the diagonal... It did just come to focus though - it may not however at infinity.

I do however have a 1.25" 45 degree Skywatcher prism diagonal that came with the 120ST... the nose of the bins fits this fine and it's rather more snug. This diagonal is just a standard fitting with single screw to tighten... not the most secure but ok to test. Like this, I have a bit more inward focus to play with.

As far as I can tell, they were in collimation to look a the a roof-top and and some trees using the 25mm eyepieces but the extended eye relief (from the barlow effect?) made it a touch difficult with these eyepieces although I think there's probably extra effect from daytime viewing / brightness from this perhaps.

So I think the next purchase once I've ensured that at least the bins are in collimation with the eyepieces I have (realised afterward that one is a Celeston 25mm and the other a SW 25mm (both identical though aas far as I can make out!) is perhaps a 1.25" barlow for the nosepiece to give me 3x amplification - I am assuming that this will also send the focal point quite a bit back giving me more room for focus... Then I can re-evaluate the fitting with the diagonal.
SW Flextube 12" Dobsonian.
Starfield ED102 f/7; SW ED80; SW 120ST
EQ5 and AZ4 mounts
Eyepieces: TV Delos 17.3 & 10; Pentax XW 7 & 5; BCO 32,18,10; Fuyiyama Ortho 12.5; Vixen SLV 25.
User avatar
Bigzmey United States of America
Moderator
Moderator
Articles: 8
Offline
Posts: 7548
Joined: Sat May 11, 2019 7:55 pm
4
Location: San Diego, CA USA
Status:
Offline

TSS Awards Badges

Re: Binoviewers - taking the plunge...

#8

Post by Bigzmey »


The BVs and case look very similar to my Orion BV, except that you seems to have collar locks on them (my have compression rings with screws). Great that they are collimated.

The slightly bigger barrel is an odd thing. It should be a standard 1.25" EP barrel, in fact you should be able to unscrew it and replace with a barrel from an EP you don't use.
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
User avatar
davesellars
Pluto Ambassador
Articles: 0
Offline
Posts: 465
Joined: Fri May 31, 2019 1:02 pm
4
Location: UK
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Binoviewers - taking the plunge...

#9

Post by davesellars »


Bigzmey wrote: Tue Apr 05, 2022 8:54 pm The slightly bigger barrel is an odd thing. It should be a standard 1.25" EP barrel, in fact you should be able to unscrew it and replace with a barrel from an EP you don't use.
The 1.25" nose fitting to the binoviewer I can see is not a typical 1.25" fitting... it is somewhat narrower.
bins4.jpg
The nose of the bins itself is a standard 1.25" inside diameter and threading... ensured it is with a 1.25" filter!
SW Flextube 12" Dobsonian.
Starfield ED102 f/7; SW ED80; SW 120ST
EQ5 and AZ4 mounts
Eyepieces: TV Delos 17.3 & 10; Pentax XW 7 & 5; BCO 32,18,10; Fuyiyama Ortho 12.5; Vixen SLV 25.
User avatar
Bigzmey United States of America
Moderator
Moderator
Articles: 8
Offline
Posts: 7548
Joined: Sat May 11, 2019 7:55 pm
4
Location: San Diego, CA USA
Status:
Offline

TSS Awards Badges

Re: Binoviewers - taking the plunge...

#10

Post by Bigzmey »


davesellars wrote: Tue Apr 05, 2022 9:13 pm
Bigzmey wrote: Tue Apr 05, 2022 8:54 pm The slightly bigger barrel is an odd thing. It should be a standard 1.25" EP barrel, in fact you should be able to unscrew it and replace with a barrel from an EP you don't use.
The 1.25" nose fitting to the binoviewer I can see is not a typical 1.25" fitting... it is somewhat narrower.

Image

The nose of the bins itself is a standard 1.25" inside diameter and threading... ensured it is with a 1.25" filter!
Bummer! Then the simplest would be to use old style no compression ring diagonal like your 1.25" 45 degree Skywatcher prism. I agree, not the most secure option, but still more secure than holding BVs just by the OCA/Barlow glass element.
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
User avatar
davesellars
Pluto Ambassador
Articles: 0
Offline
Posts: 465
Joined: Fri May 31, 2019 1:02 pm
4
Location: UK
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Binoviewers - taking the plunge...

#11

Post by davesellars »


OK, so I managed to get the nose off and checking the thread and diameter is slightly different from nose I've taken of the SW prism diagonal (to compare).

Really oddly though the binoviewer nosepiece fits going the opposite way into a compression fit diagonal... Going the correct way though, that kerf at the rim you can see seems to be slightly wider or something which stops it from fitting...
bins5.jpg
What an odd design..... :p
SW Flextube 12" Dobsonian.
Starfield ED102 f/7; SW ED80; SW 120ST
EQ5 and AZ4 mounts
Eyepieces: TV Delos 17.3 & 10; Pentax XW 7 & 5; BCO 32,18,10; Fuyiyama Ortho 12.5; Vixen SLV 25.
User avatar
davesellars
Pluto Ambassador
Articles: 0
Offline
Posts: 465
Joined: Fri May 31, 2019 1:02 pm
4
Location: UK
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Binoviewers - taking the plunge...

#12

Post by davesellars »


I forgot I have two Televue 2" to 1.25" adapters adapters with compression fittings... Strangely, the bins nose piece fits both of these (snugly). Not that that helps massively apart from determine that some 1.25" compression fittings are tighter than others...

For now I've fitted a 2" to 1.25" in-travel televue adapter to the nosepiece of the 45 degree prism diagonal which gains me a little more as the fitting is narrow compared to a standard 2" to 1.25" adapter. Should gain me enough at least to get focus at infinity for now without changing anything else until I've tested the bins on the Moon with the EPs I have...

I shall most likely end up getting the Baader T2 prism in the future... At least that gives me an option to change the eyepiece holder for a more standard type if necessary.
SW Flextube 12" Dobsonian.
Starfield ED102 f/7; SW ED80; SW 120ST
EQ5 and AZ4 mounts
Eyepieces: TV Delos 17.3 & 10; Pentax XW 7 & 5; BCO 32,18,10; Fuyiyama Ortho 12.5; Vixen SLV 25.
User avatar
davesellars
Pluto Ambassador
Articles: 0
Offline
Posts: 465
Joined: Fri May 31, 2019 1:02 pm
4
Location: UK
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Binoviewers - taking the plunge...

#13

Post by davesellars »


So I managed to get out for a little while looking at the Moon with the bins with the 4" refractor. The seeing was horrendous but the bins provided a nice comfortable view with the 25mm eyepieces (57x). It took me a while to find the perfect adjustment for the eyes and get used to using them. No double images at least and the lunar features looked nice and sharp despites the bad level of seeing.

I tried 10mm eyepieces (although one is a 52 degree FOV and the other is a standard 50 degree), so not matched however i was able to judge the contrast, brightness and detail to say that with effectively a 5mm (143x) is about perfect for use with this scope.
SW Flextube 12" Dobsonian.
Starfield ED102 f/7; SW ED80; SW 120ST
EQ5 and AZ4 mounts
Eyepieces: TV Delos 17.3 & 10; Pentax XW 7 & 5; BCO 32,18,10; Fuyiyama Ortho 12.5; Vixen SLV 25.
User avatar
Bigzmey United States of America
Moderator
Moderator
Articles: 8
Offline
Posts: 7548
Joined: Sat May 11, 2019 7:55 pm
4
Location: San Diego, CA USA
Status:
Offline

TSS Awards Badges

Re: Binoviewers - taking the plunge...

#14

Post by Bigzmey »


Congrats on the first light Dave!

It seems that for most people ability to merge images comfortably breaks somewhere around 7-9mm. I believe it has to do with the field stops getting too small. In my experience with BV and SV102ED, the lowest comfortable FL was 9mm. At that time I was using the nosepiece from 2x barlow, so the effective FL was about 3mm, which produced ~238x and 0.4mm exit pupil.
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
User avatar
davesellars
Pluto Ambassador
Articles: 0
Offline
Posts: 465
Joined: Fri May 31, 2019 1:02 pm
4
Location: UK
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Binoviewers - taking the plunge...

#15

Post by davesellars »


Bigzmey wrote: Fri Apr 08, 2022 12:03 am At that time I was using the nosepiece from 2x barlow, so the effective FL was about 3mm, which produced ~238x and 0.4mm exit pupil.
Thanks Andrey!

I'm still mulling my options as this is having to be done on quite a tight budget... :p Trying to avoid unecessary purchases and do this bit by bit.

I like the idea of the 18mm BCOs... this kills two birds with one stone as I'd like to have one of these for use anyway with the refractor a lightweight setup. These will have to be a future purchase though and stick for the time being with the 25mm EPs for the moment.

I'm wondering how much more length will be added by use of a shorty barlow - enough to avoid having to get another diagonal and be able to then use a 2" diagonal? There's a GSO 2.5x (seems to be actually more like 2.1x but anyway...) triplet lens in 1.25" which is pretty cheap here (£40), and may have found one used for half that if it hasn't gone already... I'm figuring that the entire barlow attached to the binoviewers (as long as the nosepiece fits...) will be approximately more like 4x in this way... so that would give an effective FL of 4.5mm more or less... which would be great for lunar observation.
SW Flextube 12" Dobsonian.
Starfield ED102 f/7; SW ED80; SW 120ST
EQ5 and AZ4 mounts
Eyepieces: TV Delos 17.3 & 10; Pentax XW 7 & 5; BCO 32,18,10; Fuyiyama Ortho 12.5; Vixen SLV 25.
User avatar
davesellars
Pluto Ambassador
Articles: 0
Offline
Posts: 465
Joined: Fri May 31, 2019 1:02 pm
4
Location: UK
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Binoviewers - taking the plunge...

#16

Post by davesellars »


Purchased the barlow for the sum of £20 which is a great price. As a bonus, this will work well with the 7mm Pentax XW which will work out somewhere between 3.1 and 3.3mm FL. Will have to see if the binoviewers nosepiece fits into the barlow though.
SW Flextube 12" Dobsonian.
Starfield ED102 f/7; SW ED80; SW 120ST
EQ5 and AZ4 mounts
Eyepieces: TV Delos 17.3 & 10; Pentax XW 7 & 5; BCO 32,18,10; Fuyiyama Ortho 12.5; Vixen SLV 25.
User avatar
Bigzmey United States of America
Moderator
Moderator
Articles: 8
Offline
Posts: 7548
Joined: Sat May 11, 2019 7:55 pm
4
Location: San Diego, CA USA
Status:
Offline

TSS Awards Badges

Re: Binoviewers - taking the plunge...

#17

Post by Bigzmey »


davesellars wrote: Fri Apr 08, 2022 5:17 pm Purchased the barlow for the sum of £20 which is a great price. As a bonus, this will work well with the 7mm Pentax XW which will work out somewhere between 3.1 and 3.3mm FL. Will have to see if the binoviewers nosepiece fits into the barlow though.
I never tired to insert the BVs nosepiece into a 2x barlow, I unscrewed the 2x barlow glass element and screwed it on the BV nosepiece the same way as you do with OCA. Give it a shot and see what happens.

I don't believe you will reach focus with 2" diagonal or 2" zoom but if you already have those you may try as well.
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
User avatar
davesellars
Pluto Ambassador
Articles: 0
Offline
Posts: 465
Joined: Fri May 31, 2019 1:02 pm
4
Location: UK
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Binoviewers - taking the plunge...

#18

Post by davesellars »


Bigzmey wrote: Fri Apr 08, 2022 5:44 pm
I don't believe you will reach focus with 2" diagonal or 2" zoom but if you already have those you may try as well.
I think you're correct regarding the 2" diagonal as it would extend to much the path before reaching the barlow lens.

I read some others having used a shorty barlow on the binoviewers which gives extra amplication. If the bins nosepiece fits the barlow however I can use the 1.25" diagonal without any issue at least come to think of it. Worth trying though as I've got this barlow for use in mono mode anyway even if it doesn't work with the binoviewer!
SW Flextube 12" Dobsonian.
Starfield ED102 f/7; SW ED80; SW 120ST
EQ5 and AZ4 mounts
Eyepieces: TV Delos 17.3 & 10; Pentax XW 7 & 5; BCO 32,18,10; Fuyiyama Ortho 12.5; Vixen SLV 25.
User avatar
davesellars
Pluto Ambassador
Articles: 0
Offline
Posts: 465
Joined: Fri May 31, 2019 1:02 pm
4
Location: UK
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Binoviewers - taking the plunge...

#19

Post by davesellars »


Ok.. So another update in the great binoviewer experiment... :)

Received today a Celestron Omni 2x barlow.. which obviously came with a healthy supply of clouds for first time in weeks... :p Actually, the break from the intense heat is a bit of a relief!

Anyway, lens screws off the barlow and although the threads seemed a little tighter it successfully screwed on to the binoviewer nosepiece. Slotting all this into a 1.25" to 2" adapter made a really secure connection to a TV 2" mirror diagonal. I figured the further focal length now required would approximately make up for the length in the 2" diagonal. So... a short break in the clouds (sort of) allowed me to test it out on the Sun with the 25mm eyepieces. Fortunately.. success! I was able to reach focus using the SW 80ED which I have a Baader clicklock attached to it - so the assembly is completely secure even with the extra weight of the binoviewer and 2" diagonal. Momentarily I was able to get a nice view of a few sun spots and take the opportunity to change over an eyepiece to a 15mm plossl and also the 10mm BCO, however drifting high clouds somewhat scuppered this a bit. the 15mm produced a really nice image but by the time I'd got to the 10mm the conditions had got worse... tested the magnification factor by comparing the 25mm in the binoviewers to the 10mm BCO (both 52 degrees) and could see that the 25mm was still producing a slightly larger image - I'd approximate equivalent of around 8 - 9mm so that seemed to confirm the approx 3x power that the 2x barlow lens cell was giving with the BV.

Unfortunately, it looks unlikely I'm going to be able to test it out tonight on the Moon baring a miraculous turn of weather... I'm thinking around 15mm area may give me a good general power and then another 10mm BCO for when seeing allows...
Last edited by davesellars on Mon Aug 15, 2022 5:39 pm, edited 1 time in total.
SW Flextube 12" Dobsonian.
Starfield ED102 f/7; SW ED80; SW 120ST
EQ5 and AZ4 mounts
Eyepieces: TV Delos 17.3 & 10; Pentax XW 7 & 5; BCO 32,18,10; Fuyiyama Ortho 12.5; Vixen SLV 25.
User avatar
Bigzmey United States of America
Moderator
Moderator
Articles: 8
Offline
Posts: 7548
Joined: Sat May 11, 2019 7:55 pm
4
Location: San Diego, CA USA
Status:
Offline

TSS Awards Badges

Re: Binoviewers - taking the plunge...

#20

Post by Bigzmey »


That's great! Now you can use your BV with a good quality diagonal. Having 25mm, 15mm and 10mm pairs should cover your BV needs nicely.
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
Post Reply

Create an account or sign in to join the discussion

You need to be a member in order to post a reply

Create an account

Not a member? register to join our community
Members can start their own topics & subscribe to topics
It’s free and only takes a minute

Register

Sign in

Return to “Eyepieces”