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Mark V diopter adjustment

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#1 johnnyha

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Posted 13 February 2012 - 03:30 PM

There has been some more discussion lately over the confounded diopter eyepiece adjusters on the Baader Mark V binoviewers, and whether they are indeed micro-focusers. I spent a little time experimenting with them again and my suspicions were again confirmed. The Mark V diopters CAN be used individually for fine tuning the focus - without unlocking them.

The main issue as I have always seen it is, when you lock the collar of the diopter adjustment it changes the focus position very slightly. So it is an iterative process to check the view on one side, unlock the collar, adjust the diopter, lock the collar, and check the view again to see where it ends up.

HOWEVER, the diopters can be adjusted without unlocking the collars - but only INWARDS. The trick is remembering which way is which, since the Mark V left and right side diopters adjust in opposite directions. So if you can remember that the RIGHT side is "normal" with a clockwise rotation screwing the diopter IN, you can start with the focus slightly OUT on the right side, lock the collar, and fine tune the diopter by screwing it in normally. The left side is of course opposite, so to screw it IN you have to rotate the diopter counter-clockwise. That is the whole secret, just remembering that the RIGHT side is normal and the LEFT side is reversed. And the diopters can only be adjusted INWARDS. Unscrewing the diopters OUTWARDS will unlock the collar... screwing them INWARDS will fine focus the eyepiece.

Naturally you don't have to adjust these diopters often but I do find it helpful to be able to do it with some precision. To make this even easier, obviously, all you need to do is focus the left side with the telescope focuser... then adjust the right diopter side to match - just remember the right side screws in "normally" (clockwise) and you can only focus INWARDS.

If anyone has any other "tricks" for using the Mark Vs I would appreciate hearing about it. :p

#2 Doug D.

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Posted 13 February 2012 - 04:01 PM

The process for me is pretty much as you describe but I have to say it is hopeless for me to remember which way to turn. On those infrequent occasions when I feel it necessary to readjust I kind of have to re-learn the process over again. Luckily, I don't have to go through it very often. Even the Maxbrights I own are easier (i.e., more intuitive) to adjust, as are all the microscope binocs I use in my day job. I suppose there is a reason for the peculiar MkV design but it isn't obvious to me.

#3 Astrojensen

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Posted 13 February 2012 - 04:29 PM

If you lock the collar and adjust the microfocusers inward, the eyepiece itself doesn't move, as it is being held tightly by the collar...

Actually the OPPOSITE is true - it's possible to adjust the microfocusers with a locked collar, but only OUTWARDS! And only if the collar is gently tightened. By turning the microfocuser outwards, it gently pushes the eyepiece outwards, while it slips smoothly in the locking collar.

I don't have a pair of Mark V's, but I do have a 1.25" Baader clicklock, which is identical to the ones used on the Mark V.


Clear skies!
Thomas, Denmark

#4 Doug D.

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Posted 13 February 2012 - 08:55 PM

This is confusing. But curiosity got the best of me and I'm sitting here fiddling with my MkV's and a pair of Pan 24's. The fact is, I think you are both right.

The actual clamping to barrel occurs at the level of the lower ring. If you lock EP tightly, you can focus inward (bearing in mind each side turns inward or outward opposite from the other) but the EP stays put (i.e., the diopter ring moves downward relative to the EP, which is held in place by lower clamp). If the EP is clamped less vigorously and you move the diopters in the outward direction (as Thomas describes), the EP will move upward with the diopter ring. If clamped tightly the upward rotation feels very stiff because the EP is clamped and you are pushing against this resistance.

So, the way I now recall adjusting is to keep the lower ring clamps loose. Holding the lower clamp ring open with one hand (to prevent it turning) and raising or lowering the diopter ring with the other allows you to move EP up or down until focused and then you can clamp. As Johnny points out though, locking causes a slight focus shift but in practice I haven't found this to be much of a problem.

I focus the scope with my left eye open and then use diopter adjustment to bring my right eye to focus (with left closed).

The separate 1.25" clickstop adapter I have uses same motions as the right side clickstop on the MkV. It isn't immediately obvious to me why Baader designed the MkV to use clickstops EP holders with opposite threadings....?

#5 johnnyha

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Posted 13 February 2012 - 09:47 PM

Arg! By golly you are right Thomas! I thought I had that figured out, but I didn't have eyepieces in the holders when I tested it. :p At any rate the Mark V are a little confusing to me still. I'll have to experiment with dialing the eyepieces UP while locked... I've had several Denk IIs and those are perfect, you can precisely dial in either side. :bow:

#6 mark8888

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Posted 13 February 2012 - 10:32 PM

All of this mess is why I decided to order the parfocalizing rings rather than adjust the diopter if I don't need it for fine focus. It's indeed confusing and I'd rather just leave "the confounded diopter eyepiece adjusters" down. They also get stuck way too easily if you tighten them just slightly too much, and are scary to untwist as they really do get stuck tightly, and as many people have commented it's difficult even to remember which way you need to turn them. Rings are on the way. :grin:

#7 k5apl

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Posted 13 February 2012 - 11:03 PM

My left and right eyes focus diffferently too. I focus with
my left eye, release the right side and shift the eyepiece
up and down to focus, then lock it. A little cumbersome but
less frustrating than the fine adjustments.

Wes

#8 Stellarfire

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Posted 14 February 2013 - 02:45 AM

My left and right eyes focus diffferently too. I focus with
my left eye, release the right side and shift the eyepiece
up and down to focus, then lock it. A little cumbersome but
less frustrating than the fine adjustments.

Wes



I do it the same way like you.

According the Manual, it sounds easy. Baader calls it symmetric diopter adjustment: right hand collar rises with counterclockwise action, left hand collar rises with clockwise action.
But after my first frustrating attempts to become more experienced with those diopters, I realised that the symmetric diopter adjustment system is not user-friendly enough for real-life use in the dark. At least not user-friendly enough to me... :)

I consider focus fine adjustments with those reverse threaded diopter rings a mess, it is a source of endless confusion, so I leave the diopters in gently screwed-down position and do not touch them any longer.
If any focus fine adjustments between both eyepieces are necessary, I just release the eyepiece clamp very slightly and fine-shift the eyepiece, and hold it with one hand whilst tightening the eyepiece clamp.

The Mark V binoviewer is a terrific tool, I don't want to be without it anymore. The only drawback of the Mark V is the annoying diopter function, which should be corrected by another more practical diopter system. It would be great if Baader will offer in the future an diopter upgrading service for existing Mark V's.

Stephan

#9 ryderc1

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Posted 14 February 2013 - 07:07 AM

I bought a pair of Mark V's soon after AP started selling them several years ago. I found the diopter adjustment routine too confusing and cumbersome and replaced the Mark V's with a pair of Mark IV's having the Lapides eyepiece holders. I may have theoretically sacrificed some small optical advantage of the Mark V's that I'd probably never be able to discern in my less than perfect skies anyway. But the ease of adjustment of the Mark IV/Lapides combination made the switch a no brainer for me.

#10 Paul G

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Posted 14 February 2013 - 09:39 AM

I bought a pair of Mark V's soon after AP started selling them several years ago. I found the diopter adjustment routine too confusing and cumbersome and replaced the Mark V's with a pair of Mark IV's having the Lapides eyepiece holders. I may have theoretically sacrificed some small optical advantage of the Mark V's that I'd probably never be able to discern in my less than perfect skies anyway. But the ease of adjustment of the Mark IV/Lapides combination made the switch a no brainer for me.


You are losing little. You give up the self centering eyepiece holders, not a big deal, diopter adjustment on both sides, also not a big deal, more accurate prisms, not a big deal unless you use short focal length eyepieces in the bv, and about 8% light transmission, not a big deal since it is just at the physiologic threshold of detection so it would not be a visible difference unless you are under superb skies and have an identical scope with the MkV next to yours for comparison in which case the difference would still be slight if visible at all.

I had a Mk IV from the first production run and found two problems inherent in the bv, reported them to Roland, and they were solved in subsequent production runs. First, the openings in the original eyepiece holders were EXACTLY 1.25" (love that German precision!). If one uses an eyepiece with a barrel of exactly 1.25" like the ZAO's it can become stuck in the bv. This problem is temperature dependent and was only an issue in warm temperatures or solar observing. Due to differential expansion the eyepieces could be unstuck by putting the unit in the refrigerator or freezer for a few minutes. Roland bored mine out a couple thousandths of an inch and they worked fine after that. The second problem involved eyepieces with long barrels, like Radians and some others. Since the Lapides eyepiece holders cannot be threaded outwards like the Mk V's to pull the eyepiece out a bit the barrel would bottom out inside the bv. On one side it hits a lip in the metal frame, on the other side it hits the face of the prism. The solution was a plastic insert on that side that catches the end of the barrel before it hits the glass. The first problem is eliminated by the Lapides holders. You can check for the second by looking into the eyepiece opening, if not you can pull off the housing of the bv and see if the insert is in place. IIRC, the early production runs said Carl Zeiss Jena on the hinge cap while later runs did not (here's a pic from Company 7's web site of my Mk IV prior to installing the Lapides holders, my photo used by C7 with my permission):

Posted Image

I keep the diopter adjustments on the Mk V threaded out enough to prevent long barrel eyepieces from bottoming out, set the diopter adjustment for the differences between my eyes, and leave it alone after that and have had no problems with it. I fine focus with the scope's focuser. My one complaint with the Mk V is that if one isn't careful one can turn the diopter adjustment instead of the lock, screwing up the diopter setting. Otherwise I only mess with the diopter setting about once a year as my eyes slowly change.

#11 Eddgie

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Posted 14 February 2013 - 09:39 AM

If you lock the collar and adjust the microfocusers inward, the eyepiece itself doesn't move, as it is being held tightly by the collar...



This is the way it seems to work for me.

Also this. The small twist needed to lock the eyepiece does indeed cause the focuser to move with the lock ring.

But this is not an issue at all. When you move an eyepiece very very very slightly inward (and this is all the eyepiece moves because the threading on the focuser is super duper fine), you are moving the eyepiece in a direction that still allows the eye to accommodate the change in focus.

Anyone that reads my posts on visual accommodation will know that I have stressed the importance of always approaching focus using an inward movement of the focuser knob. This is because if you slightly over-shoot, your eye can still accommodate the defocus on its own. This keeps the observer from changing focus.

On the Mark Vs, even though the lock knob rotates the micro-focusing ring with it and as a consequence, the eyepiece "Should" follow it (more on that later) and this means that while it does indeed cause the field stop of the eyepiece to move oh so very slightly inside the focal plane, the amount of movement is so tiny that any observer should have the visual accommodation required.

I have tested it many times and this is the way it works for me.

Here is my advice on how to set the mirco-focusers.

First, screw them both all the way out, then screw them each in about 3 or 4 turns, but as equally as possible.

Now, focus the scope using the dominant eye only and don't touch the micro-focuser on that eye. Focus using just the telescope knob.

Now, see if the other eyepiece is in focus. If it is not, determine if it is inside of the focal plane by unlocking the twist lock and slipping the eyepiece outward. If it is indeed inside of focus, screw the microfocuser out until it lifts the eyepiece outside of focus.

Hint.. It is easy to know which way because inside is the same for both sides in that it is the same direction of the locks. The motion towards inside is the same direction as the clamp direction on both clamps. Counterclockwise on the "Left" and "Clockwise" on the right.

Now that the field stop of the second eyepiece is outside of focus, once again, start slowly adjusting the focuser toward best focus (turning it in the same direction required to turn the clamp ring).

When you do this, you will notice that the clamp ring tends to follow the focuser, but it will not get tight.

Important note... Press on the top of the eyepiece as you do this... Unless the binoviewer is straight up, the friction of the eyepiece against the lock ring (because it is cocked in the focuser tube) will prevent it from following the focuser down sometimes. Just use a little pressure to ensure that it does.

Continue adjusting the focuser until you hit best focus.


Even if the clamp ring did not rotate towards the lock position with the focuser (mine usually does) once you get the focus, don't worry about the fact that it will rotate a bit more when you do the lock. The small amount that the eyepiece moves is in the proper direction for each diopter so that it moves inside of focus and again, this is the right direction so that the eye can now accommodate the change.

I don not think that the Zeiss setup of having the barrels turn in opposite directions and the focuser turn the same way is an accident at all. I think that it is 100% intentional, and that the designers know quite well that a 20% turn of the focuser ring inward will never result in so much focus change that any observer will not be able to accommodate that change. Again, the design is consistent with the best method for final focus used by experienced observers, which is to always approach final focus using inward motion of the focuser knob.

At least this is my own belief.

Once set, it seems to stay pretty well in place though I do have to tweak mine from time to time. In particular, I have a pair of 32mm Plossls that seem to have a very very slightly different focus. When I put these two in, my right eyepiece will be out of focus.

My other eyepieces all seem fine.

I think the Mark V is superbly well designed ergonomically because of the way the diopters are coupled to the focusers. It is exactly the right way to do it and for someone that knows how visual accommodation works, it is a brilliant design.

Oh.. Why start with the focusers on the scope mostly out? Some eyepieces with long barrels can bottom against the aperture inside the bino. It is better to bite the bullet on the 5mm of back focus to ensure that all eyepieces fully bottom before hitting the focuser.

It is better to set the bino up using the method above and leave it alone. Remember to always approach final focus by using inward motion of the telescope's focuser first, and the non-dominant eye's mirco-focuser second.

And for all scopes, it is best to approach final focus by using inward travel of the focuser tube (counter-clockwise for SCTs). This prevents the observer from chasing focus and results in the sharpest possible image. Even if you oevershoot a tiny amount, the eye can re-focus the center of the field using visual accommodation.

#12 johnnyha

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Posted 14 February 2013 - 01:47 PM

Very nice Eddgie, that's pretty close to my method. On my MKVs when I clamp down though, it seems to gently squeeze the eyepiece up or something - my focal position changes more when I lock it down than just the expected quarter turn of the fine focus threads. Mine changes the equivalent of several turns of the fine focus threads.

#13 Eddgie

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Posted 14 February 2013 - 01:55 PM

You know, I have experienced that with some eyepieces (squeezing up).

This I think happens almost exclusively on the Hyperions and I think it is a combination of weight (way out from the diopter) and the undercut. I believe that the little plastic centering ridges may be having some kind of interaction with the undercuts. They appear to be long enough to bridge the safety cuts, but perhaps if the eyepiece is not deep enough, they only partially span the undercut??? I don't know, but I have indeed had it happen.

Never happens with my Plossls though.

But this is why I always put a little pressure on the ends of my eyepieces with my finger so I can ensure they stay fully seated.

You are not alone though. I have totally experienced the same thing.

Maybe measuring the distance from the bottom of the housing and then adjusting the starting position for the micro-focusers to ensure that the little lock ridges completely overlap the safety cut???? Don't know but I may do a quick measurement on them.

#14 johnnyha

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Posted 14 February 2013 - 02:26 PM

Maybe measuring the distance from the bottom of the housing and then adjusting the starting position for the micro-focusers to ensure that the little lock ridges completely overlap the safety cut????


That, or buy the new Binotron 27s. ;)

#15 suburbanskies

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Posted 14 February 2013 - 11:14 PM

I consider focus fine adjustments with those reverse threaded diopter rings a mess, it is a source of endless confusion...
Stephan


Fully agreed. I ignored the diopters very quickly. I'm surprised that Baader has been so stubborn and has stuck with this design. Why do we even have this thread where the OP asks about "tricks" about using the Baader binoviewer?

Mark

#16 Doug D.

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Posted 15 February 2013 - 12:10 AM

I need to use the diopter adjustment, I don't like to view with my eyeglasses on and each eye focuses differently. I think we all agree the diopter mechanism is a real pain with the MkVs but it can be made to work. And I've got it written down somewhere in my ep case which way the clamping rings and diopters have to turn.... Despite many attempts to commit to memory I just seem to forget if I haven't viewed in a while.

#17 DaveJ

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Posted 15 February 2013 - 08:39 AM

Fully agreed. I ignored the diopters very quickly. I'm surprised that Baader has been so stubborn and has stuck with this design. Why do we even have this thread where the OP asks about "tricks" about using the Baader binoviewer?


I must really be odd - I like the diopter adjustments on the Mark Vs and find them extremely easy to use. :shrug:

#18 denis0007dl

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Posted 15 February 2013 - 09:26 AM

Fully agreed. I ignored the diopters very quickly. I'm surprised that Baader has been so stubborn and has stuck with this design. Why do we even have this thread where the OP asks about "tricks" about using the Baader binoviewer?


I must really be odd - I like the diopter adjustments on the Mark Vs and find them extremely easy to use. :shrug:


+1

#19 Eddgie

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Posted 15 February 2013 - 09:36 AM

Me too. The more I used it, the more credit I gave to Zeiss for understanding optical design. As I said in my earlier post, the configuration and operation is 100% consistent with how visual accommodation works.

And once it is set, it rarely needs fussing with.

#20 Paul G

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Posted 15 February 2013 - 09:55 AM

Fully agreed. I ignored the diopters very quickly. I'm surprised that Baader has been so stubborn and has stuck with this design. Why do we even have this thread where the OP asks about "tricks" about using the Baader binoviewer?


I must really be odd - I like the diopter adjustments on the Mark Vs and find them extremely easy to use. :shrug:


Same here. Different strokes, I guess.

#21 johnnyha

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Posted 15 February 2013 - 01:10 PM

Truly different strokes apply here. For me there is no contest - in the field side by side, the Denks win hands down in the diopter adjustment department. This has nothing to do with the confusion of the left and right side of the MkV being reversed either. This is due to the Denk's beautiful ability to allow the user to incrementally adjust either side in or out while viewing without any clamping/ unclamping or guesswork. It also doesn't hurt that the adjustment is smooth as silk and the helical threading isn't so ultra-fine as the Mark Vs.

#22 Doug D.

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Posted 15 February 2013 - 01:54 PM

I use Zeiss microscopes in my day job almost everyday and each is equipped with diopter adjustments that work beautifully - the diopters are built into the eyepieces, however (same is true of binoculars, of course, where at least one ep typically allows diopter adjustment). Granted, this is not the case for typical astro eyepieces and thus the need to raise or lower (i.e., focus) the eyepiece in a BV like the MkV.

This is perhaps another reason for why I love using Zeiss microscope eyepieces in my MkV - the MkV diopters can be seated fully and the eps adjusted quickly and easily with no shifting/squeezing/failure to remember which direction to turn, etc..

#23 johnnyha

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Posted 15 February 2013 - 02:07 PM

Yes I had Zeiss microscope eyepieces with diopters and they adjust exactly the same as the Denks, a simple fluid helical system that you can adjust "on the fly" as you view, without having to avert your eyes from the eyepiece.

#24 Doug D.

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Posted 15 February 2013 - 02:24 PM

It's true - even granting that the MkV clamp and diopter adjustment mechanisms are arguably well "designed" to accommodate eye differences, in practice the experience is nothing like the adjustment you get with a Zeiss microscope eyepiece and apparently, as Johnny points out, the Denk mechanism.

#25 johnnyha

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Posted 15 February 2013 - 03:07 PM

It's analogous to using a zoom in that the Denk helicals allow you to eek out the very last possible bit of detail. I don't know about y'all but my individual eyes's focus seems to change ever so slightly at times, and a little turn of the Denks back and forth assures me I have the crispiest possible view. It may be just a mental thing but with the Denks I enjoy "dialing it in" and I know each eye is always perfectly focused. :cool:

Ah! Another point - eyepiece pairs are not always perfectly matched to the nth degree as far as length and focus position. And they don't always seat perfectly the same way. The Denks allow the user to quickly and cleanly adjust this discrepancy out while viewing. :cool: :cool:






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