Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Binoviewers

Pages: 1 | 2 | 3 | (show all)
REC
Post Laureate
*****

Reged: 10/20/10

Loc: NC
Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: Eddgie]
      #6065830 - 09/06/13 10:21 AM

Ed, yes my scope I'm using the Denks in is a 8" SCT f/10. But, just wondering about your issue withe the Edge HD. My scope is an ACF model which is different from a traditional SCT and has a flat field and no coma at the edge.

Does the use of a different secondary in an ACF have any effect in when using the BV?

Bob


Post Extras: Print Post   Remind Me!   Notify Moderator  
Eddgie
Postmaster
*****

Reged: 02/01/06

Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: REC]
      #6065944 - 09/06/13 11:21 AM

The issue with the EdgeHD 8" is severe aperture loss.

Even the Mark Vs only work at about 7.8" of aperture, and this is with the 10mm SCT to T2 connector (10mm of light path) T2 Prism (38mm of light path) and Mark V (123mm of light path). This is a total light path of about 171mm, and even with this short a path, I am loosing .2" of aperture.

The Binotron has about 127mm of light path with the diopters fully racked in, and if I mate it to the T2 Prism, I add about another 8mm to that for the Quick Connector. The Powerswitch adds 19mm, and we still have 38mm for the diagonal and 10mm for the connector. Total light path is 202mm. That reduces the EdgeHD 8" from 8" of aperture to less than 7.5" of aperture, and that is only in the "both arms out" position.

If you kick in the reducer, the aperture falls to less than 7". The field is wider, sure, but at the expense of a lot of brightness loss.

Remember, as the aperture gets smaller, the secondary shading as a percentage of aperture gets larger.

For a 7" aperture, you only have 38 inch of light collection and you loose 5 square inches because of the obstruction, so now you are at 33 square inches.

By the time you factor in transmission loss, you are looking at a pretty dim image.

Also, in arms out mode with the Binotron, not only is the aperture less than 7.5", but the system the focal length of the scope is 90mm longer than with the Mark V.

If you start with 2300mm of focal length (which is about what you have with the Binotron in the EdgeHD) and you take .63 of that, you are working at 1449mm. This mean D21s give you 68x.

If you use the Mark V with 35mm Ultimas, you get about 63x, and the bigger field stop of the Ultimas means that the field is wider than with the D21s. You are using a bigger field stop at a lower magnifications. The Apparent field is of course bigger in the D21s, but the true field and exit pupil is bigger in the 35s, which helps offset some of the binoviewer imposed dimming.

And you could use 35mms in the Denks, but they vignette notcibly in the low power arm, and as I mentioned previously, I do not like to see any vignetting. In the EdgeHD, the 35mm Ultimas are bright and sharpt to the edge. The same eyepecies in the Denks vignette.

And remember, this is comparing a 7.8" aperture to a 6.9" aperture. Which one do you think gives a brighter image..

I did not like the Binotron in the EdgeHD 8". It is not a good match for the scope.

Even with the Mark V, I am not working at full aperture, but it is close enough to make it difficult to see the difference in brightness.

And remember, I am using the shortest possible light path possible for the Binotron. There is no way to get it as short as the Mark V even If you remove the power switch arm, and if you do, you still have the smaller prisms in the Denks so the outside of the field is not as well illuminated as with the Binotrons using 24mm Hyhperions or 35mm Ultimas.

Again, this is me. I am very sensitive to field illumination..

What works for others is much different than what works for me, and I did not like the result in the EdgeHD 8".


Post Extras: Print Post   Remind Me!   Notify Moderator  
Scott99
Carpal Tunnel
*****

Reged: 05/10/07

Loc: New England
Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: Eddgie]
      #6066101 - 09/06/13 01:04 PM

The little screw on the Baader is somewhat annoying but I've never been close to dropping it either, even with frozen fingers.

I enjoyed using a friends 2-inch BV but I wouldn't want one. I don't really like the way BV"s dim the view of DSO's, so I don't do much low power, wide-field binoviewing. Mostly I use it for planetary, or a quick look around at low power with 25mm Plossl eyepieces.

For higher power the 2 inch system is overkill. I spent the money getting better transmission and clarity with the Mark V.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pingster
member


Reged: 06/27/11

Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: Eddgie]
      #6066607 - 09/06/13 05:55 PM

Eddgie, thats a very informative reply, I have been thinking very hard about the binotron. And the points you raised mirror what I fear.

I love my mrk5s perfect fov in 24pans. Denki, I dislike the way in lower power arm you get vignetting plus you can see uneven brightness around one edge of the fov... caused by the power switch lens getting in the way! Really annoying.

Also I remember when I used precise parts custom part to mate the mrk5 with the PXS, I noticed the optics of the pxs added false colour and was not good over x150mag. I found that a pair of baader zooms gave the same effect as the pxs with more graduations and better optics. Only negative of the zooms is the narrow fov at low mag setting.

The problem with astro gear is that you rarely can have your cake and eat it, theres always compromises.

Edited by Pingster (09/06/13 06:16 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Paul G
Post Laureate
*****

Reged: 05/08/03

Loc: Freedonia
Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: DaveJ]
      #6067648 - 09/07/13 11:37 AM

Quote:

Quote:

"Crashing Bino Syndrome" as it pertains to the Mark V, may be traced back to some not fully tightening the setscrew on the Quick Release adapter. The screw would then loosen further, fall out, and provoke tears.




There's no maybe about it, that's the only thing it could possibly be. Keeping the large easy-to-see, easy-to-grab screw tightened with a gentle twist is all that's required. I've never come close to dropping my Mark Vs. Someone mentioned it being too short. I lengthened mine with an inch of hard rubber fuel hose purchased for a few cents from an auto parts store.




Same here, have used the MkV extensively and never had a problem, but I always double check set screws or clamps on my setup.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Eddgie
Postmaster
*****

Reged: 02/01/06

Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: Pingster]
      #6067707 - 09/07/13 12:09 PM

Quote:

I love my mrk5s perfect fov in 24pans. Denki, I dislike the way in lower power arm you get vignetting plus you can see uneven brightness around one edge of the fov... caused by the power switch lens getting in the way! Really annoying




This is why when I talk about the Binotron or Denks, I always reference the D21s. These eyepecies have the largest field stop that you can use in the Denks without vignetting in low power.

Don't get me wrong, I really like the Binotrons and hope to buy a pair one day. I am bothered by the field illumination falloff, but I still feel like in the Dob, the ability to use all three modes of the powerwsitch make it a far better fit than in a large SCT where it is almost impossible to ever use the high power arm due to excessive magnificaiton.

I think for Dobs and Newts though, the value proposition is much better. The only real tradeoff with the Binotron/D21 is the illumination falloff in low power mode, but this may have something to do with having to have the OCS screwed out some to reachfocus. I was wondering if the probelm would be less if the OCS could be fully retracted on the OCS.

I would rather have a little intrusion of the OCS into the light cone in low power mode than have the light fall off so much. The intrusion at low power doesn't matter, and it is out of the way at medium and high power.

But I stick to what I said earlier. If you made me pick just one, it would be the Mark V because it works best with the EdgeHD 8" and I can get pretty close to the same low power in the Newt with the Mark Vs even with the 1.7x GPC because of the ability to run the Ultimas without meaningful off axis ray interception.

Just because I had not done it before, I checked the Mark V with the 1.7x GPC last night on Vega. I mean in normal focus, it i shard to see that the off axis rays are being affected in Mark V/1.7x combo.

I put in the 35mm Ultimas and defocused about 10 waves, and then slewed the pattern to the edge of the field.

About 70% out from the edge, I could see that there was some very slight slicing of the off axis rays. One edge of the pattern started to slightly flatten and I would estimate that at the edge of the field, the flattening would have accounted for about 15% to 20% of the pattern, and this is why it is hard to see in focus. The brighness (or darkness to be exact) of the edge of the field is not easy to see.

The Binotron though was more like 40% of the pattern being cut, and it is clear to see that the sky darkens considerably well before the field stop even of 20mm ES68s in the low power mode of the Denks.

Under a very dark sky, it might go unnoticed though, and it only seemeed to happen in the low power mode.

Again, I wonder is some of this was not caused by the need to have to extend the OCS so much to reach focus (over half an inch).

Now that I have a lower profile focuser, I would like to re-try. I am guessing I could now reach focus with the OCS fully retracted, which might make a big improvement.

It will only cost me $1250 to find out.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Eddgie
Postmaster
*****

Reged: 02/01/06

Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: Pingster]
      #6067832 - 09/07/13 01:39 PM

The low power arm is not really intended for eyepeices with this big a field stop.

The D21s are the best match for the aperture of the low power arm.

This is why when I write these notes I always say "using the D21s in the Binotron." This is the optimal eyepiece for low power function in the Binotron without vignetting.

If someone does not mind the vignetting then of course they can use lower power eyepieces with bigger field stops.

And if you use the Denk with 26mm Plossl you get about the same magnification in my dob as using the Mark V with the 35mm Ultima.

As it turns out, when you push things to the extreme ends, the Mark V actually holds up better than most people realize. The 1.7x GPC sounds like a big handicap, but for getting the lowest power field without vignetting, the big prisms of the Mark V allows you to use something like the 35mm Ultimas, and suddenly you are in the same game.

And the Baader GPC was designed as a coma corrector as well, and it is very effective. Even using Hyperions, the field is very sharp right to the edge in the 17 and 13s.

In fact, the performance is so good that I think I may have made an error rushing to the 24 ES eyepeices. I would like to try the 24 Hyperions with this setup. The 24mm Hyperions have a full 28mm field stop, so the true field would be almost as big as the Denks using the D21s.

Once again though, I love the powerswitch in a Dob or Newt. In that type of scope it is at its very best. The off axis illumination is not great with low power arm in (The Mark V with 1.7x GPC is better here too) but under darker skies this is harder to see and less of a bother, and the ability to so easily change powers is hard to dismiss.

And the Binotron is a first class unit optically and mechanically. There is a great deal to love there, and I can completely understand it when people say they love their Binotron.


Post Extras: Print Post   Remind Me!   Notify Moderator  
crazyqban
Carpal Tunnel
*****

Reged: 12/16/08

Loc: Miami, Florida
Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: Eddgie]
      #6068409 - 09/07/13 07:32 PM

I would like to try the Binotrons but I think that it will be difficult for me to leave the Mark Vs. I had adapted a Denk Power Switch to use with my Mark Vs and was put off by the amount of re-focusing required when I would change the Power Switch arms. I find it easier to to swap out the eyepieces since most of the ones I have are parfocal. The one thing that I did miss from the Power Switch was the low power setting but I am able to get the same low power with the Mark Vs by using a Siebert 1.3X Multi OCA. I have been using this setup for a few years now and I am very happy with it.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Eddgie
Postmaster
*****

Reged: 02/01/06

Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: crazyqban]
      #6069192 - 09/08/13 10:11 AM

I did not like refocusing, but I do prefer it to changing eyepeices. At the dob, I generally have to get out of my chair and go get the eyepecies.

The Baader GPC though does provide a better off axis illumination than I was getting with the Binotron.

I think it is just a consequence of the long light path of the Binotron/Powerswtich. This configuration is maybe 25mm longer than the Mark V, and the OCS is a couple of millimeters less clear apeture (45 vs 47 for the Baader), and I think it is difficult to get all of the off axis ray bundle to make it to the field stop in such a long light path, and especially using smaller prisms.

And that is my struggle. I love my Mark Vs and they work well in all of my scopes.

But I love the powerswitch on the Binotron and the ability to easliy dial in multiple magnificaitons.

Even if I get the Binotron (and I want one), I don't know if I could bring myself to sell the Mark V.

And that now has become the issue. I have so much money invested in telescope stuff that somethign would have to go. I have enough money to buy a pair of binotrons right now out of pocket, but my ethic has been that this is a hobby, and these days, I try not to throw any more money into it.. If I want something new, I have told myself that I have to sell something to finance the new purchase.

And for now, I am not willing to do that. So the Binotron is on hold.

If the 12" dob works out, I will sell the C14 and either the LXD-750 mount (and move the 5" APO to the CGE) or the CGE.

But until I am ready to let something else go, the Binotron has to wait.

Maybe Santa will bring me a Binotron though... LOL.


Post Extras: Print Post   Remind Me!   Notify Moderator  
George9
sage


Reged: 12/11/04

Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: Eddgie]
      #6079027 - 09/13/13 04:21 PM

I think for a new binoviewer owner, the Denk Supersystem is a really great, high-quality way to get into it. I added a 1.25" OCS and an extra adaptor for a Lunt diagonal, and I can reach focus with all my scopes and all the scopes I visit (refractors, small to large reflectors, solar scopes, Herschel wedges, etc.). There is always some way to come to focus with the available parts. And, because of the PowerSwitch, you can start off with just one high-quality eyepiece pair (e.g., D21s). Add a 2" Barlow and you have 6 magnifications. And if you drop it, which is not uncommon in the first week, it is back like new in another week.

If I wanted to spend the money, long term I would end up with the Baader Mark V. But then I would be figuring out which OTAs I have to cut, which scopes have to be replaced, etc. Not that you couldn't just mimic the Denk's optical train, but you wouldn't do that because the point of getting the Baader is to produce the cleanest path without all the correction lens (like the low power reducer).

George


Post Extras: Print Post   Remind Me!   Notify Moderator  
SteveH
member


Reged: 08/17/05

Loc: Texas
Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: George9]
      #6140940 - 10/16/13 01:35 PM

Off topic a bit, but does anyone have experience with how these two compare to the TeleVue BinoVue?

Post Extras: Print Post   Remind Me!   Notify Moderator  
Eddgie
Postmaster
*****

Reged: 02/01/06

Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: SteveH]
      #6141407 - 10/16/13 05:54 PM

The Televue Bino has several pluses and minuses.

Pros:

Very high quality

Fully compatiable with the Baader T2 system, so you can use components like the Baader T2 Prism which has a very short light path, allowing full aperture in SCTs and the Baader Coma corrector for Newts (which works nicely). It can also be fitted with a Quick Connect ring to make swapping it back and forth very easy. I have two Mark Vs and I have four telescopes I use them on, and all are equipped with T2 Prisms or the Newt GPC, so I can swap the binoviewers very easily.

And finally, they have a 27mm prism to allow completely unvignetted operation with 24m Pans or ES 24/68s. This is compared to the 26mm of the Denk IIs (28mm for the Mark Vs, and yes there are eyepieces out there with 28mm field stops, so this is indeed a real advantage for the Mark V).

The downside. A longer light path than the Maxbright or the Mark V. If you are using it in a refractor, the shorter the light path, the more likely you are to reach focus without requiring a GPC, or if you do need the GPC, the shorter the light path, the less GPC you may need (lower magnification).

Next, while the quality is excellent, I don't think they have coatings that are in the same league as the Binotron or Mark V. There is a lot of glass in a binoviewer and coatings can make a difference.

Finally, they do not have adjustable diopters. This does not sound like all that big a deal, but then again, this means that you use them by slipping one eyepiece out 4mm or 5mm, then focusing the scope with that one eyepiece. Then you have to slip the other eyepiece in and out of its holder to reach focus for the other eye.

This is not all that hard to do, but the Binotron and Mark V allow you to set the proper focus for each eye once, then not have to mess with it. With the Binovue, every time you change eyepeices, you have to do this dance.

My biggest objection to the Binovue is the diopters (or lack of).

I love the big prism and the T2 compatibility.

If using a refractor though, the Maxbright with a T2 Prism may reach focus without a GPC, where the Binovue will almost always require one.

And if the Maxbight only needs a 1.25x GPC, the Binovue might need 1.5x due to the longer light path.

So, you pay more for a bigger prism so you can use a lower power wide field, but at the end of the day, you might get as big a true field using the Maxbright with shorter focal length eyepeices because it might not need a GPC or might need a less powerful one.

For an SCT though, I would go with the Binovue over the Maxbright because of the ability to use 24mm Pans with no vignetting.


Post Extras: Print Post   Remind Me!   Notify Moderator  
junomike
Carpal Tunnel
*****

Reged: 09/07/09

Loc: Ontario
Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: Eddgie]
      #6141586 - 10/16/13 07:07 PM Attachment (29 downloads)

Also, The TV's allow for easy use of eyepieces whether under-cut or not. This is due to the "splines" that clamp down on the eyepiece.

(TV's on left, WO on right)

Mike

Edited by junomike (10/16/13 07:08 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Eddgie
Postmaster
*****

Reged: 02/01/06

Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: junomike]
      #6141620 - 10/16/13 07:23 PM

In fact this could be a big Plus. I use the ES 68s and they do not sit square always in the Mark V. They want to tilt into the stupid taper on the barrel. I have to hold the tops down when I tighten the eyepiece clamps on the Mark V or they may not bottom and then they won't be always be at the right focus and then I have trouble merging.

I hate those tapered undercuts. May go to 24mm Pans just for that reason.

Anyway, yes, this is a big plus...


Post Extras: Print Post   Remind Me!   Notify Moderator  
junomike
Carpal Tunnel
*****

Reged: 09/07/09

Loc: Ontario
Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: Eddgie]
      #6141630 - 10/16/13 07:29 PM

Ah, Eddgie, My 24mm Pans HAVE under-cuts as well as most I've seen for sale used?

Even the New versions look to have tapered under-cuts?

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
SteveH
member


Reged: 08/17/05

Loc: Texas
Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: junomike]
      #6142358 - 10/17/13 07:20 AM

Guys,
thanks for the comments. Being I more of a refractor junkie (TV102 & TEC140) your comments in regards to use in refractors were most helpful.

Steve


Post Extras: Print Post   Remind Me!   Notify Moderator  
Eddgie
Postmaster
*****

Reged: 02/01/06

Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: junomike]
      #6142509 - 10/17/13 09:28 AM

If the Televue has a shoulder above the taper then it will still be better than the ES 24.

The ES 24 has a reduced diameter at the top of the barrel, and this allows it to tip over to the side in the Mark V.


If the BVs are not vertical with respect to the ground, the weight of the eyepiece can cause it to not lay flat in the eyeppiece holder of the BV.

The bottom will be not flush aginst the eyepeice stop of the BV, and when you tighten, it tends to lift the barrel of the EP and pull it away from the EP stop, and unevenely. One eyepiece might come to rest a half millimeter above the stop, while the other might come to rest 1mm above the stop.

Most eyepeices with undercuts have exactly that. The undercut is a grove in the barrel but there is still a top, full width ring. When you insert the eyepeice, it is still supported in the eyepeice holder by that top ring.

When I use Hyperions, which are heavier than the ES eyepeices, I have no problem. I push them in until they stop and when I tighten, they star in position.

But the ES eyepeices simply don't do this. They tilt into the undercut and don't stay put when you tighten.

I hate this about them.

If Televue now has the same issue then of course I would not want them anymore than the ES.

But I believe they have simply beveled the bottom edge fo the groove and still maintain a top, full diameter ring.

I am sorry if I have done a poor job of explaining it, but you have to trust me on this. The taper does not work well with the Mark V, especially in a dob where the BV is always leaned over at a prett steep angle.

I really like the performance of the ES eyepeices, but the tapered undercut makes for some fussing about that I don't have with eyepeices that have a fill diameter ring at the top of the barrel.

In fact, the Mark V really doesn't care about traditionsl undercuts. There is noting to snag them.


Post Extras: Print Post   Remind Me!   Notify Moderator  
RAKing
Postmaster
*****

Reged: 12/28/07

Loc: West of the D.C. Nebula
Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: Eddgie]
      #6142702 - 10/17/13 11:04 AM

The 24 Pans have a shoulder and drop into the Mark V with no issues. They were my favorite eyepieces with the binos.

Cheers,

Ron


Post Extras: Print Post   Remind Me!   Notify Moderator  
Eddgie
Postmaster
*****

Reged: 02/01/06

Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: RAKing]
      #6142721 - 10/17/13 11:18 AM

Yes, the Mark V works great with traditional undercuts.

I know many hate undercuts, but they have saved my bacon many times.

I could do without then on 1.25" eyepieces, but not on 2".

I am sure that for most use though, the beveled style is fine, but I had trouble with this design in both the Maxbright bino (three screw model) and the Mark V.

They are excellent tough, and unless used prices for 24mm Pans fall, I will just stick with them.

Also, I hope to go to a Binotron for the dob, and if I do, using the 20mm ES with the slope won't matter because in a perfect world, I would not change eyepeices....


Post Extras: Print Post   Remind Me!   Notify Moderator  
Dex Wolfram
journeyman


Reged: 11/28/12

Re: Baader Mark V vs Denkmeier Binotron binoviewer ? new [Re: Eddgie]
      #6255476 - 12/15/13 11:30 PM

Quote:

Yes, the power switch can be removed. It unscrews from the bino body. The nose can then be threaded directly into the bino body.




Hey Eddgie, can you tell me what kind of threading this is? Need to know in advance!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | (show all)


Extra information
4 registered and 1 anonymous users are browsing this forum.

Moderator:  TG, Geo557 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 3869

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics