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Who is waiting for the Baader Maxbright Mark 2?

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#51 BillP

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Posted 16 October 2019 - 01:49 PM

And I just called Takahashi America and they’re telling me I have 223mm of backfocus on my FC100DL. How is that possible? So it looks like I don’t need a Barlow or GPC to use a binoviewer. 

True.  I don't need one with my TSA-102 either.  However, if you are doing serious planetary observing you will want to use the GPC or Barlow.  Long prism paths add a little SA and the GPC or Barlow remedies that.  Not noticeable at low and medium magnifications but easy for me to see when I am up at 150x and more.


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#52 StarAlert

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Posted 19 October 2019 - 08:41 AM

True.  I don't need one with my TSA-102 either.  However, if you are doing serious planetary observing you will want to use the GPC or Barlow.  Long prism paths add a little SA and the GPC or Barlow remedies that.  Not noticeable at low and medium magnifications but easy for me to see when I am up at 150x and more.

What is the difference between a Barlow and a GPC? The package comes with 1.85x and 3x Barlows 


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#53 emilslomi

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Posted 19 October 2019 - 09:24 AM

What is the difference between a Barlow and a GPC? The package comes with 1.85x and 3x Barlows 

The path of the light through the prisms and beam splitter of the binoviewer cause a color error. The GPC, i.e. glas path corrector works a bit like a barlow, but its elements have also been calculated to offset the color error that the large amount of glas in the binoviewer causes.

 

Emil



#54 Eddgie

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Posted 19 October 2019 - 11:49 AM

Two important things to keep in mind with light path.

 

The first is super minor, but when a millimeter or two can make the difference between reaching focus and not reaching focus, every millimeter counts.  The light path figures are always given with both diopters at their fully compressed length.  If you don't wear glasses and need to raise a diopter to reach focus, then add that distance.

 

The other one is in fact more serious.  Many eyepieces require additional inward travel and this can be more than just one or two millimters.  For example, the Baader zooms take several millimeters of inward focuser travel (Six, I think??) and some other zooms do as well.   Another example is the 17mm and 14mm Delos, which takes 5mm of inward travel.

This will probably not really affect most people, but it could make the difference for someone using a pair of Delos eyepeices right now and contemplating going to a bigger prism unit.

 

Now, one other issue.  The light path is stated from what I would guess to be the T2 opening.  This means that to achieve this light path, the BV would have to be mounted directly to the diagonal, which is fine.  If though, one wants to be able to easily move the binoviewer, one would need to put the quick connector on to the diaognal and with the dovetail, you have some added light path.  I have not really seen the specifics of the interface so I don't know if this is how it will work out, but it is something to keep one's eyes if one wants to have the convenience of using the quick connector for moving the device between scopes.



#55 Eddgie

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Posted 19 October 2019 - 11:59 AM

And just to give a good example of this last point.. I recently bought an AT 106LE.  Using my home made T2 diagonal with a 60mm light path, a T2 adatper, and a pair of 99mm path length binoviewers (96mm but with the T2 adatper, you add about 3mm), I can only barely reach focus.

 

If I went to the T2 prism, I would save 21mm on the diagonal, and if I went to the new Baaders, assuming it will attach in the same way as the Maxbright 1 did, that would be 110m, so now I have 11mm.  Now this is cutting it close by the time you add the dovetail and Quick Connector.  I think it is probably enough, but only just enough.

 

If I can use the Quick Connector, this makes it easy to change from the refractor to using the Televue 2x amplifier when I use the binoviewer in the dob.   If I can't then that would mean having to thread the binoviewer on and off of these components when I wanted to move them back and forth.

 

For people that have not used the Baader Quick Connector system, it is hard to understand how important it is to be able to easily move the binoviewer, but it really does matter to me.  I even have a dedicated binoviwer for my Lunt 80 because I dislike having to take it off and deal with the threaded connector and GPC.

 

Just trying to help people that have not used this kind of system to know about these things.  For people with plenty of flange to focal plane distance, none of this matters, but for someone like me that is really tight on focuser travel, it becomes much more important.

 

Since we do not have all of these details about the interface though, it is hard to know exactly what is what. 


Edited by Eddgie, 19 October 2019 - 12:11 PM.


#56 Eddgie

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Posted 19 October 2019 - 02:40 PM

To make it a bit more clear, hear are the components I mentioned.

 

From the description on the web, it sounds like the new Maxbright II will have the same interface as the original Maxbright, which was a T2 threaded flange, which allowed it to be connected directly to the diagonal.

 

In the text, it also says that a Zeiss Micro Bayonet is going to be included and here is what the bayonet looked like for the original Maxbright:

 

bad-t2-07.jpg

This part would then attach to the Quick Changer ring, and the purpose is to allow one to easily disconnect the BV and move it to another component that is also equipped with the quick change ring.  Here is the ring.

 

bad-t2-06.jpg

 

Now Baader lists the light path for these as 15mm, but I think there is some double counting here in that the top of the threads on the first component would screw into the threads at the bottom of the BV, and the bottom internal treads on the Quick Connector would go over the mounting flange on the top of the T2 diagonal..  I think then that the light path is more like 10mm or so but I forget.  As I said though it if is over 11mm, I would probably not reach focus.

 

t26_t27connected.jpg

 

And that would be too bad because the quick connect ring is a pretty amazing feature of the Baader system but it is not at all essential to use it.  It just makes it amazingly simple to remove the BV from the diagonal so it can be used with other components like the 1.7x Newtonian GPC. 



#57 StarAlert

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Posted 21 October 2019 - 10:29 PM

True.  I don't need one with my TSA-102 either.  However, if you are doing serious planetary observing you will want to use the GPC or Barlow.  Long prism paths add a little SA and the GPC or Barlow remedies that.  Not noticeable at low and medium magnifications but easy for me to see when I am up at 150x and more.

 

My Arcturus arrived today (as well as my T2 Amici prism diagonal). I put the diagonal together this afternoon and tried out the binos on a distant tree at native power with the 30mm eyepieces that came with the viewer. Wow! It came to focus with about 5-7mm of in-travel left on the focuser.

 

Tonight, I used it on Saturn. With a focal length of 900mm, The view at 30x was awesome and using both eyes was a treat.

 

So here is where things get weird. I put the 1.85x Barlow in the nose of the bino and I wasn’t able to focus. Then I tried the 3x Barlow and this actually worked. And it worked by moving the focuser out only about 25mm from where I was able to focus without a Barlow. I guess I thought the 1.85x Barlow would focus somewhere between the native focus and the 3x focus. Why is that not the case? 

 

I dropped in a single 18mm BCO to see if I could get that to focus. Wasn’t able to at native (I think I need about a 25-30mm extension tube), but I was able to focus at 3x (not at 1.85x). Go figure! Also, at 3x I saw lots of weird colors around Saturn (kinda like a rainbow). Never seen that before when I was doing mono-viewing. I guess this may be what a GPC fixes? 



#58 emilslomi

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Posted 22 October 2019 - 04:28 AM

Strange indeed! If it comes to focus native and with more in-focus available with the 3x, it absolutely ought to come to focus with the 1.85x. I have no clue - maybe the lenses in the 1.85x are mounted the wrong way around. Does it barlow an eyepiece correctly without the binoviewer? Where are you Eddgie?

Rainbow color at 3x sound a little strange too. What was the final magnification - thereabouts? Could be that it is the color error introduced by the glass in the binoviewer, but if the colors were asymmetric, blue on the one side and red on the other, it could also be athmospheric dispersion, which is easier to see at high magnifications. It is difficult to judge from your description.

 

Emil



#59 StarAlert

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Posted 22 October 2019 - 08:16 AM

Strange indeed! If it comes to focus native and with more in-focus available with the 3x, it absolutely ought to come to focus with the 1.85x. I have no clue - maybe the lenses in the 1.85x are mounted the wrong way around. Does it barlow an eyepiece correctly without the binoviewer? Where are you Eddgie?

Rainbow color at 3x sound a little strange too. What was the final magnification - thereabouts? Could be that it is the color error introduced by the glass in the binoviewer, but if the colors were asymmetric, blue on the one side and red on the other, it could also be athmospheric dispersion, which is easier to see at high magnifications. It is difficult to judge from your description.

 

Emil

Yep... exactly, blue on one side, red on the other. 

I don’t know how I would try the 1.85x without the binoviewer. It’s threads directly into the unit.

Maybe I’ll call CCTS and explain it to them. I bet it’s the Barlow. 



#60 Eddgie

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Posted 22 October 2019 - 08:58 AM

If you can reach focus at native with no Barlow, and you can reach focus at 3x, then yes, you should be able to reach focus with a 1.85x unit.  I would not have a guess as to why this did not work.

 

As for the blue on one side and red on the other, are you sure it was not atmospheric dispersion? If the planet was low in the sky, this is the most likely cause of the red/blue fringing. Otherwise, try a standard diagonal to eliminate the Amici diagonal as a possible source of spectrum.

 

A GPC corrects axial error, and in specific, it addresses spherochormatism, which is spherical aberration that differs by wavelength.  Spherochromatism is actually hard to see and it is more a "leap of faith" in that while it would usually be difficult to see the damage, the leap of faith is that with the GPC, you will be getting the best possible performance out of your binoviewer. 

The one place were spherochromtism is easy to see is when doing white light solar observing. Using an FPL-53 triplet and a solar wedge, when using a single eyepeice, the sun is color free.  With a Binoviewer with no GPC, there is a subtle fringe that shows on the limb and on fine penumbral detail.  Putting the GPC in returns the sun to color free.

 

In most normal viewing though, the effects of spherchromatism are hard to see and the effect is axial (in all directions, the same as spherical aberration, which is also hard to see on an in focus star, but we know that it can be a far more serious error because it affects all colors equally.)

 

I suspect atmospheric dispersion though.  Saturn is low in the sky. 



#61 StarAlert

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Posted 22 October 2019 - 08:19 PM

I called CCTS. They are sending me another 1.85x. They think it’s defective. 



#62 StarAlert

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Posted 29 October 2019 - 10:21 PM

If you can reach focus at native with no Barlow, and you can reach focus at 3x, then yes, you should be able to reach focus with a 1.85x unit.  I would not have a guess as to why this did not work.

 

As for the blue on one side and red on the other, are you sure it was not atmospheric dispersion? If the planet was low in the sky, this is the most likely cause of the red/blue fringing. Otherwise, try a standard diagonal to eliminate the Amici diagonal as a possible source of spectrum.

 

A GPC corrects axial error, and in specific, it addresses spherochormatism, which is spherical aberration that differs by wavelength.  Spherochromatism is actually hard to see and it is more a "leap of faith" in that while it would usually be difficult to see the damage, the leap of faith is that with the GPC, you will be getting the best possible performance out of your binoviewer. 

The one place were spherochromtism is easy to see is when doing white light solar observing. Using an FPL-53 triplet and a solar wedge, when using a single eyepeice, the sun is color free.  With a Binoviewer with no GPC, there is a subtle fringe that shows on the limb and on fine penumbral detail.  Putting the GPC in returns the sun to color free.

 

In most normal viewing though, the effects of spherchromatism are hard to see and the effect is axial (in all directions, the same as spherical aberration, which is also hard to see on an in focus star, but we know that it can be a far more serious error because it affects all colors equally.)

 

I suspect atmospheric dispersion though.  Saturn is low in the sky. 

I received the replacement 1.85x Barlow from CCTS today so I spent the afternoon trying to figure out how these barlows affect focusing. So I started again with the binoviewer at native power, and was able to focus with about 12mm left of in-focus. 

 

It’s my understanding that using a Barlow in a binoviewer reduces the amount of in-focus needed to get the binoviewer to focus... and using the 3x Barlow will reduce the in-focus more than the 1.8x Barlow (meaning I’ll have to extend the draw tube more with the 3x than with the 1.8x). Correct? 

 

What I found instead is when I use the 3x Barlow, I need to extend the draw tube LESS than with the 1.8x. The 3x requires about 35mm more than when I used native (about 2” of total in-travel left). When I use the 1.8x Barlow, I’m unable to extend the draw tube enough to gain focus. 

 

I switched to my mirror diagonal (110mm of light path vs 47mm with the T2 prism diagonal) and was able to focus with the  1.8x with the draw tube almost fully extended... and then switched to the 3x and had to move the draw tube in about 35mm to achieve focus. With the mirror, I was not able to focus at native power. Not enough in-focus. 

 

This is is the opposite of what I thought would be the case. What am I missing? 

 

On another point. I was unable to merge BCO 18mm eyepieces. I think the FOV was just too narrow for me. 



#63 Eddgie

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Posted 30 October 2019 - 09:03 AM

Well, I don't know what is wrong but it sounds like the Barlows are reversed.

 

First, yes, you are exactly right.  With a Barlow, as you add magnfication, you have to rack out the focuser, and with a standard Barlow type optic (not a telecentric), the more amplification, the more outward focuser travel or spaces you should require.

 

The Baader 1.7x GPC, which actually gives closer to 1.5x than 1.7x, will extend the light path by about 31mm to 32mm so it sounds like your "3x" GPC is actually the 1.8x GPC.  A 2.6x GPC extends the light path about 88mm or so (I forget, you can look it up in the Baader Maxbright owner's guide).

 

A true 3x would probably extend the light path to the same as the binoviewer so in other words, it would make the binoviewer about parfocal to a regular eyepiece.

 

So, it sounds like they are marked wrong. 

This should be easy to test.   If the 3x is actually working at 1.8, you should be able to measure the actual magnifcation (count pickets in a fence or roof tiles or something and compare at native and 1.8x to see if you only have about half the number visible).

 

If it is a case of the elements being reversed you can contact the seller and ask them to send you a pair that they have tested, or if possible, you could just change the elements yourself.

 

I don't know if this is your problem, but it sounds like it could be your problem.  A 1.8x should only shorten the light path to something close to what you report the 3x doing, and since the 1.8x is taking far to much out-travel, then it seems to be a real possibility that they are reversed or mis-marked.



#64 StarAlert

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Posted 30 October 2019 - 09:07 AM

Well, I don't know what is wrong but it sounds like the Barlows are reversed.

 

First, yes, you are exactly right.  With a Barlow, as you add magnfication, you have to rack out the focuser, and with a standard Barlow type optic (not a telecentric), the more amplification, the more outward focuser travel or spaces you should require.

 

The Baader 1.7x GPC, which actually gives closer to 1.5x than 1.7x, will extend the light path by about 31mm to 32mm so it sounds like your "3x" GPC is actually the 1.8x GPC.  A 2.6x GPC extends the light path about 88mm or so (I forget, you can look it up in the Baader Maxbright owner's guide).

 

A true 3x would probably extend the light path to the same as the binoviewer so in other words, it would make the binoviewer about parfocal to a regular eyepiece.

 

So, it sounds like they are marked wrong. 

This should be easy to test.   If the 3x is actually working at 1.8, you should be able to measure the actual magnifcation (count pickets in a fence or roof tiles or something and compare at native and 1.8x to see if you only have about half the number visible).

 

If it is a case of the elements being reversed you can contact the seller and ask them to send you a pair that they have tested, or if possible, you could just change the elements yourself.

 

I don't know if this is your problem, but it sounds like it could be your problem.  A 1.8x should only shorten the light path to something close to what you report the 3x doing, and since the 1.8x is taking far to much out-travel, then it seems to be a real possibility that they are reversed or mis-marked.

Thanks. That has crossed my mind. I guess I have some tests to run today. 



#65 25585

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Posted 03 November 2019 - 03:52 PM

If using a Baader Diamond Steeltrack focuser, are there any exclusive Baader system fittings, apart from Clicklock, that help with Baader binoviewers particuarly?



#66 Eddgie

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Posted 03 November 2019 - 04:51 PM

If using a Baader Diamond Steeltrack focuser, are there any exclusive Baader system fittings, apart from Clicklock, that help with Baader binoviewers particuarly?

No. Almost all focusers made today are used with a 2" visual back, and all of the Baader stuff that would normally be used for binovewers would be using the 2" nose piece. 

 

The clicklock visual back on a refractor generally eats a lot of flange to focal length distance. A telescope equipped with this that is not quite able to reach focus would probably reach focus if the Quicklock back was removed and a standard 2" compression ring back were used.  So in that respect, it may not be a good component to use if one was added to a scope in place of a standard 2" compression back. 


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#67 Usquebae

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Posted 08 November 2019 - 11:32 AM

I called CCTS. They are sending me another 1.85x. They think it’s defective. 

I have an Arcturus purchased from CCTS some years ago, maybe 5 yrs.  It also came with a 1.85x that seems defective, massive color smear as you describe.  I could not get a sharp image.  The OCS marked 3x works fine, though I have a vague memory that something made me think its mag power was closer to 2x.  I will have to test that.

 

Regarding the varying focal plane locations of certain eyepieces, my Arcturus came with two 30mm plossls that are basically 1.25" barrels with the lens assemblies inside them.  The lightpath requirements when using these is much shorter than with any other EPs I own.  I don't know where such eyepieces could be bought, but making them might not be difficult, or you could probably special order a pair from Gary Russell.




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