mountainsean
super member
Reged: 11/27/06
Posts: 182
Loc: Colorado
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I'm considering dipping my toe in the waters of binoviewing with a entry-level viewer like the WO or SV3. As I understand things, Nighthawk NG is "bino-ready" in so far as I can unscrew the extension tube and avoid needing an OCA. Due to BV light losses, it would seem prudent to use the binos with the NHNG on bright objects like planets and the moon at 100-150x or so. For the NHNG's focal length of 560mm, that means EP's in the 4-5mm range. I've read comments about small FL ep's being "difficult" to use with binos. Is it really the EP focal length, or is it more the degree to which you push the magnification per inch of aperture? Does it really make sense to use binos with such a small scope at these mags? I assume so since SV makes a big deal out of the NHNG being bino-ready, but low-power, wide-field views of DSO's doesn't really seem to be taking advantage of the strengths of binoviewing.
Thanks,
Sean
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Zhumell 9.75" f/5.1 Dob
Orion 127mm Mak
Stellarvue NHNG
William Optics EZTouch
4mm TMB/Burgess Planetary
11mm Nagler T6
14 mm Meade 5000 UWA
18 mm Meade 5000 UWA
2x Televue barlow 1.25"
3x Antares barlow 1.25"
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David E
Post Laureate
Reged: 05/25/06
Posts: 4177
Loc: North Carolina
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Sean, I think everyone goes through a bit of a learning curve as individual experiences can vary somewhat with binoviewing. After a year and a half of binoviewing, I have settled down to these two basic strategies:
For deep space and general purpose, I use my SV102ABV in bino mode so I can get the lowest possible power and brightest image out of my eyepieces.
For lunar/planetary work, I put the extension in and use, in my case, the 2x BVA for my Stellarvue binoviewers. I discovered that using a pair of 10mm eyepieces with the 2x BVA was easier than using a pair of 5mm eyepieces with the scope in bino mode. But I have an older pair of SV binos with the single set screw in the eyepiece holder. People with the current model BV3 with self-centering diopters may find short focal length eyepieces easier to work with than I do. This may also be the case with users of the premium brands like the standard Denks and Televue.
Now, my 3" class refractors are not binoready, so I have to use the 2x BVA with them. For this reason I don't do much dso work with binos in my 3" scopes.
As far as light loss, binoviewers give you about 1/2 magnitude light loss, more or less depending on brand and individual differences. So IMO dso work through binos with a 3" scope can still be rewarding if your skies are dark enough (and you modify your target list).
David E
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mountainsean
super member
Reged: 11/27/06
Posts: 182
Loc: Colorado
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Thanks David. I'm still a bit on the fence w/the whole idea (especially the thought of having to double up on EP's), but I might try to find a used set of BV's on Amart. One more question if you don't mind - can I use a regular barlow with the SV3's? i.e. put the barlow in the diagonal and put the BV's in the barlow. If so, what does that do to the mag?
Thanks,
Sean
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Zhumell 9.75" f/5.1 Dob
Orion 127mm Mak
Stellarvue NHNG
William Optics EZTouch
4mm TMB/Burgess Planetary
11mm Nagler T6
14 mm Meade 5000 UWA
18 mm Meade 5000 UWA
2x Televue barlow 1.25"
3x Antares barlow 1.25"
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David E
Post Laureate
Reged: 05/25/06
Posts: 4177
Loc: North Carolina
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You're welcome Sean. Yes you can use a standard 2x barlow between the binos and the diagonal if you are using a refractor. I think that gives you about 3.5x. EdZ is more of an expert here and I'm sure he'll help out with that question. With that kind of magnification you want to start with a low power pair, some inexpensive 25mm plossls would work very well. You probably already have one to mate with. With the Stellarvue BV3 for example, you can go with their 2x BVA or something like Siebert Optics OCA. The BVA is less expensive but you only get one power, so you end up buying more eyepieces than you would with the Siebert system. Either way, you will end up spending some money. 
David E
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David E
The funniest thing about this message is that by the time you realize it doesn't say anything, its too late for you to stop reading it.
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Douglas
Vendor - Night Vision Astronomy
Reged: 05/21/07
Posts: 343
Loc: Pound Ridge, NY
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I just put an order in for the Denk II binoviewers with the Power X Switching system. While I will use them primarily in my 12.5" Obsession, I wanted to also use them in my Stellervue NHNG and had the very same concerns about the short focal length, low magnification, eyepiece dilemma. The suggestion to use a 2x barlow seems like a fix, I have a 2x powermate that I could use but my question is this ... could an extended dovetail be enough to balance the weight of the bino, two eyepieces and a heavy 2" 2x Powermate? I use the extended dovetail plate with my 2" 17mm Nagler and still have to crank down on my MicroStar mount to keep it from drifting ...
If I could balance the setup the 2x powermate would solve the magnification/eyepiece problem. Any thoughts or suggestions anyone??
- Doug
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Night Vision Astronomy
Stepping Stone Observatory
BIPH Image Intensified Binoviewer
Obsession 12.5" AN/SC
Tak FSQ-106 EDX2 & EM-200 Temma II
QSI 532wsg CCD & SX Lodestar Guide Camera
MallinCam Hyper Plus Color
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b1gred
Enginerd
Reged: 04/01/04
Posts: 16902
Loc: Castle Rock, CO 6677' MSL
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Call Russ at Denkmeier and get his advice. He'll help you figure out what you need to make it work.
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"Dark Skies & Great Viewing"
RandyR / W0RDR
GPS 9.25 XLT/Sky Align /FeatherTouch
TV85 w/FeatherTouch
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David E
Post Laureate
Reged: 05/25/06
Posts: 4177
Loc: North Carolina
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Quote:
I just put an order in for the Denk II binoviewers with the Power X Switching system. While I will use them primarily in my 12.5" Obsession, I wanted to also use them in my Stellervue NHNG and had the very same concerns about the short focal length, low magnification, eyepiece dilemma. The suggestion to use a 2x barlow seems like a fix, I have a 2x powermate that I could use but my question is this ... could an extended dovetail be enough to balance the weight of the bino, two eyepieces and a heavy 2" 2x Powermate? I use the extended dovetail plate with my 2" 17mm Nagler and still have to crank down on my MicroStar mount to keep it from drifting ...
If I could balance the setup the 2x powermate would solve the magnification/eyepiece problem. Any thoughts or suggestions anyone??
- Doug
You should be able to use the Denk II with the PowerXswitch with the NHNG in "mono" mode. With the extension removed, you can use the Denk II (or any other brand of binoviewer) without the PxS. This will give you 1x, or no additional magnification out of your eyepiece pair. Stellarvue now sells a balance dovetail rail and I would recommend it, but I would first try things out and see how they work. There's a chance, depending on your mount and setup, that you can get things to work the way you want them to without it.
David E
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David E
The funniest thing about this message is that by the time you realize it doesn't say anything, its too late for you to stop reading it.
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bginaz
sage
Reged: 12/15/04
Posts: 309
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In BV mode I built a bracket and attached it to the mount so I could use 3D counter weights. It put the scope/Denks in perfect balance.
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Brian G
Carlsbad NM
JC Penny 7x35
Pentax 10x50
Miyauchi 20/26/37x100
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David E
Post Laureate
Reged: 05/25/06
Posts: 4177
Loc: North Carolina
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That's a good idea Brian. I can't tell from your photo, does the weight slide back and forth on your bracket? 
David E
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Douglas
Vendor - Night Vision Astronomy
Reged: 05/21/07
Posts: 343
Loc: Pound Ridge, NY
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Brian: That is a great solution. The extended Dovetail rail I have now definitely couldn't handle the balancing with a powermate on top of the bino system.
Dave: I think I can use the Power X Switching by not removing the SV extension and using a 2" OCS. I have an email in to Russ right now to confirm. I want the advantage of the Power X Switching because I need higher magnification with the short focal length of the NHNG.
I went with the D21 eyepieces which will be great for my reflector (1590 focal length), hoping to catch some DSO's with the binos! For high power planetary work with the NHNG, I was also hoping for high magnification without having to deal with high power EPs and the problems that come into play there. I am hoping I can use the 2.5 power X switching setting to bring it upto 66x power and with a 2x Powermate on top I could get 133x power.
What do you think?
- Doug
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Night Vision Astronomy
Stepping Stone Observatory
BIPH Image Intensified Binoviewer
Obsession 12.5" AN/SC
Tak FSQ-106 EDX2 & EM-200 Temma II
QSI 532wsg CCD & SX Lodestar Guide Camera
MallinCam Hyper Plus Color
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David E
Post Laureate
Reged: 05/25/06
Posts: 4177
Loc: North Carolina
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Quote:
Dave: I think I can use the Power X Switching by not removing the SV extension and using a 2" OCS. I have an email in to Russ right now to confirm. I want the advantage of the Power X Switching because I need higher magnification with the short focal length of the NHNG.
I went with the D21 eyepieces which will be great for my reflector (1590 focal length), hoping to catch some DSO's with the binos! For high power planetary work with the NHNG, I was also hoping for high magnification without having to deal with high power EPs and the problems that come into play there. I am hoping I can use the 2.5 power X switching setting to bring it upto 66x power and with a 2x Powermate on top I could get 133x power.
What do you think?
- Doug
Doug, please let us know what Russ says as I am thinking the same thing. Regarding the Powermate, I'm not entirely sure that arrangement would work, but it makes sense that it would because Powermates are generally parfocal with the eyepiece they are used with. Of course, if it didn't work you could always buy more eyepieces. 
David E
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David E
The funniest thing about this message is that by the time you realize it doesn't say anything, its too late for you to stop reading it.
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bginaz
sage
Reged: 12/15/04
Posts: 309
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Hi Dave
No the weights are fixed and the scope is slide in the clam shell for fine adjustment. To adjust the other axis, I spin the weights up or down.
With this setup, the scope is in perfect balance from 10 to 90 degrees. It stays right where I put it with the Dec nob completely released. It's made tracking a breeze
Brian
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Brian G
Carlsbad NM
JC Penny 7x35
Pentax 10x50
Miyauchi 20/26/37x100
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Douglas
Vendor - Night Vision Astronomy
Reged: 05/21/07
Posts: 343
Loc: Pound Ridge, NY
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Dave, since you have the same setup (NHNG with Denk IIs) what do you recommend for high power EPs? Looks like you had a set of Naglers in the pic.
I got a quick reply from Russ saying that he was busy assembling and would respond later but that he didn't recommend using a Powermate for high magnification.
I'll get more details when he frees up.
- Doug
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Night Vision Astronomy
Stepping Stone Observatory
BIPH Image Intensified Binoviewer
Obsession 12.5" AN/SC
Tak FSQ-106 EDX2 & EM-200 Temma II
QSI 532wsg CCD & SX Lodestar Guide Camera
MallinCam Hyper Plus Color
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Douglas
Vendor - Night Vision Astronomy
Reged: 05/21/07
Posts: 343
Loc: Pound Ridge, NY
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I meant Brian, sorry Dave!
- Doug
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Night Vision Astronomy
Stepping Stone Observatory
BIPH Image Intensified Binoviewer
Obsession 12.5" AN/SC
Tak FSQ-106 EDX2 & EM-200 Temma II
QSI 532wsg CCD & SX Lodestar Guide Camera
MallinCam Hyper Plus Color
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Douglas
Vendor - Night Vision Astronomy
Reged: 05/21/07
Posts: 343
Loc: Pound Ridge, NY
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I have read posts indicating you can use barlows and powermates with binos. Also read that it is better to magnify the image before it goes through the prism (with a barlow or powermate) as opposed to after, as would be the case with high power EPs.
Folks have mentioned that while barlows increase their magnification yields when paired with binos, that powermates maintain their proper magnification.
I'll mention it to Russ when we do get to speak and see what he says.
- Doug
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Night Vision Astronomy
Stepping Stone Observatory
BIPH Image Intensified Binoviewer
Obsession 12.5" AN/SC
Tak FSQ-106 EDX2 & EM-200 Temma II
QSI 532wsg CCD & SX Lodestar Guide Camera
MallinCam Hyper Plus Color
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bginaz
sage
Reged: 12/15/04
Posts: 309
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Hi Doug
Those are 19 Pans in the photo. They are great EPs but a lot of elements for an 80mm to pull light through. After reading many fine posts from people like EdZ, I decided to switch to TV 32mm Plossls. The difference in light gathering is amazing.
As for high power, like you, that is my next step. I have the Denk 2X multiplier that I can screw into the front of the diagonal when the scope is in standard mode. This yields app. 2.25X bringing the 32s to app. 14mm. Pleasing views but still a tad small on planets. I've also tried the 4mm TMB planetary EPs but way to much for this scope.
I think the "sweet" spot for high power BVing in this scope is somewhere between 6 and 10mm. I'm hoping for input from other NHNG owners to help me decide.
Sorry I'm not more help.
Brian
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Brian G
Carlsbad NM
JC Penny 7x35
Pentax 10x50
Miyauchi 20/26/37x100
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 18806
Loc: Cumberland, R I , USA42N71.4W
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Quote:
I've read comments about small FL ep's being "difficult" to use with binos. Is it really the EP focal length, or is it more the degree to which you push the magnification per inch of aperture? Does it really make sense to use binos with such a small scope at these mags?
I use my 5" scope at BV magnifications tops about 125x-135x.
I use my 80mm scope at BV magnifications about max 85x. For wide field views of open clusters at about 50x-60x, I see a lot deeper into the faint cluster stars without the binoviewer. My Megrez 80 with a 10mm Radian at 50x mono far surpasses the view I can get with any binoviewer in the same 80mm scope at 50x. So, if you want lower power wide-field views, I would recommend go mono mode.
Keep in mind, when you put a binoviewer in an 80mm scope, you turn it into a pair of 56mm binoculars. Even a 4" scope with binoviewer is equivalent to only a 72mm binocular. It just gets used at higher than normal binoculars powers.
Quote:
One more question if you don't mind - can I use a regular barlow with the SV3's? i.e. put the barlow in the diagonal and put the BV's in the barlow.
I've used a barlow in front of the BV. Using a stock 2x barlow, as David mentioned, boosts magnification up to about 3.5x. If you can unscrew the front piece of the barlow and screw it directly on to your BV, then the magnification factor will be about 2.8x. These values for a Celestron standard barlow.
Quote:
I have read posts indicating you can use barlows and powermates with binos. Also read that it is better to magnify the image before it goes through the prism (with a barlow or powermate) as opposed to after, as would be the case with high power EPs.
This would be the case with any scope in bino or mono mode. Putting a barlow (a light cone modifier) in front of the unit, effectively changes the f# of the light cone. This reduces some aberrations that may be present in the incoming light cone. Using high powered eyepieces to accomplish a similar magnification behind the focal point would simply magnify the aberrations present in a faster light cone image. You can find some very good information written by BV vendors that states, binoviewers are best used with eyepieces between 24mm and 14mm.
I use eyepieces from 32mm to 12.5mm, although in my SVB3, I use from 25mm to 12.5 and more often reach for my 14mm Radians than the 12.5 Ultimas.
No matter what binoviewer I'm using, SVB3 or Denk Big Easy, I found for instance that using the BV to observe faint objects, such as the moons of Saturn, put me at a deficit. The faintest moons always disappear from view in the binoviewer. Whereas I can sometimes see 5 moons without the binoviewer, at the same magnification thru the binoviewer I can usually see only 3 and sometimes struggle to see 4.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
Edited by EdZ (07/20/07 10:07 AM)
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Douglas
Vendor - Night Vision Astronomy
Reged: 05/21/07
Posts: 343
Loc: Pound Ridge, NY
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Thanks EdZ. I spoke to Russ at Denkmeier today. He said that he has heard that TV doesn't recommend using Powermates with Televue Binos, although we don't know why. That is a question best suited for Al Nagler since he was responsible for the design.
Russ is field testing his own designs and equiplment to provide the best options for various magnifications when using his Binoviewers. I have a lot of respect for Russ, and their dedication to producing equipment specifically designed for use in his binoviewing equipment. This is one reason I went with his D21s as opposed to other EPs. I feel he has optimized his equipment for use in his binoviewers and they produce the best combination.
Russ is going to send me a 3.2x multiplier cell which I can play around with (positions) on the NHNG to increase magnification. It will help me avoid another set of EPs and can be used on my Dob as well.
He had offered to custom design a power x switching system for use with my refractor and newt, a hybrid, but I chose to go with the multiplier cell because I felt the magnification would be too high in my Newt with any hybrid arrangement.
One thing is for sure, Russ is the man!
He even offered to send me the multiplier cell to use for free to see if I like it and if I decide to keep it I can pay him then.
I'm sure many folks have found that binoviewing can bring into play many complicated issues since everyone's scope focuses differently and has different tube length specs, etc. I am glad I ordered my binos through Russ, great customer service, expert advice, and a willingness to customize for special needs. Now I know why there are so many good things posted about his binos and his company on CN!
- Doug
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Night Vision Astronomy
Stepping Stone Observatory
BIPH Image Intensified Binoviewer
Obsession 12.5" AN/SC
Tak FSQ-106 EDX2 & EM-200 Temma II
QSI 532wsg CCD & SX Lodestar Guide Camera
MallinCam Hyper Plus Color
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