Variable Filter

[LDW1]

I just bought this Variable Polarizing Filter for about $55 C, the 1.25" ep fits into it and then it inserts into the diagonal. You filter the ep by varying / rotating its built in filter to the intensity that you prefer without having to remove the ep each time. Suposedly it varies between 5-25%, I can hardly wait to test it against my 3 other variables incl in my WL scope. If it performs the convenience is obvious. I don't know how long this model has been out there but I just heard about it in the last couple of weeks ?

[Don Pensack]

Meade discontinued this filter 10+ years ago.  If you bought it new, it is new old stock, which is fine.

The issue with it is that it pulls the eyepiece back by a large amount and requires in travel at the focuser equal to its height.  Most people don't have that much additional travel available.

Most people simply thread a variable polarizing filter onto the eyepiece, but that is not as convenient as the Meade product you have.

If it works in your scope, it's a good find.

 

 

[LDW1]

12 minutes ago, Don Pensack said:

Meade discontinued this filter 10+ years ago.  If you bought it new, it is new old stock, which is fine.

The issue with it is that it pulls the eyepiece back by a large amount and requires in travel at the focuser equal to its height.  Most people don't have that much additional travel available.

Most people simply thread a variable polarizing filter onto the eyepiece, but that is not as convenient as the Meade product you have.

If it works in your scope, it's a good find.

Those are my thoughts as well but for $55C its worth the try. There is virtually nowhere to research them, maybe if I kept digging ? I bought it from Meade, it must be old stock hidden away, lol.

 

 

Edited February 9, 2022 by LDW1

[Don Pensack]

Well, I was wrong.  Meade brought the filter back in the late 2010s when they were owned by Sunny.

It's still available new from many suppliers.  It's $40 to $64 in the US, so you got a good price.

I hope it works in your scope.

 

[LDW1]

12 minutes ago, Don Pensack said:

Well, I was wrong.  Meade brought the filter back in the late 2010s when they were owned by Sunny.

It's still available new from many suppliers.  It's $40 to $64 in the US, so you got a good price.

I hope it works in your scope.

 

The only info I could find is that they don't work in many reflector diagonals because of the short travel. Most of my 10 scopes are various size refractors, it will be interesting if nothing else.

Edited February 9, 2022 by LDW1

[Louis D]

Wouldn't it be vastly cheaper and simpler to just thread a single polarizer on the eyepiece and a single polarizer on the front of the diagonal?  Then, just rotate the eyepiece in the holder to vary the darkening effect?  This would require no additional in-focus as an additional benefit.

I do something similar with my Herschel wedge.  I set the variable polarizer to the maximum brightness I want for the session by trial and error inserting and removing it a few times, rotating the two component filters wrt each other.  Once set, I leave the eyepiece in the wedge and rotate the eyepiece to further vary the brightness based on what I'm observing on the sun, taking advantage of the partial polarization of the light from the wedge's prism interacting with at least one of the variable polarizer's filters.

This Gosky variable polarizer can be separated into two filters and costs only $16 shipped from China.

[LDW1]

1 hour ago, Louis D said:

Wouldn't it be vastly cheaper and simpler to just thread a single polarizer on the eyepiece and a single polarizer on the front of the diagonal?  Then, just rotate the eyepiece in the holder to vary the darkening effect?  This would require no additional in-focus as an additional benefit.

I do something similar with my Herschel wedge.  I set the variable polarizer to the maximum brightness I want for the session by trial and error inserting and removing it a few times, rotating the two component filters wrt each other.  Once set, I leave the eyepiece in the wedge and rotate the eyepiece to further vary the brightness based on what I'm observing on the sun, taking advantage of the partial polarization of the light from the wedge's prism interacting with at least one of the variable polarizer's filters.

This Gosky variable polarizer can be separated into two filters and costs only $16 shipped from 

1 hour ago, Louis D said:

Wouldn't it be vastly cheaper and simpler to just thread a single polarizer on the eyepiece and a single polarizer on the front of the diagonal?  Then, just rotate the eyepiece in the holder to vary the darkening effect?  This would require no additional in-focus as an additional benefit.

I do something similar with my Herschel wedge.  I set the variable polarizer to the maximum brightness I want for the session by trial and error inserting and removing it a few times, rotating the two component filters wrt each other.  Once set, I leave the eyepiece in the wedge and rotate the eyepiece to further vary the brightness based on what I'm observing on the sun, taking advantage of the partial polarization of the light from the wedge's prism interacting with at least one of the variable polarizer's filters.

This Gosky variable polarizer can be separated into two filters and costs only $16 shipped from China.

Every time you want to change eps, which you do almost every time, you still have to unscrew the one half that is attached to the ep and then screw it on to the other ep, with this you just slide the eps in and out, fast and slick.  My 2" wedge ( Altair Astro ) has a built in rotable polarizer. I am sure you knew all of that ?  Cheaper, $16 vs about $40 US ?  Simpler ?

Edited February 10, 2022 by LDW1

[Louis D]

10 hours ago, LDW1 said:

Every time you want to change eps, which you do almost every time, you still have to unscrew the one half that is attached to the ep and then screw it on to the other ep, with this you just slide the eps in and out, fast and slick.  My 2" wedge ( Altair Astro ) has a built in rotable polarizer. I am sure you knew all of that ?  Cheaper, $16 vs about $40 US ?  Simpler ?

I looked at the Altair wedge and thought it was pretty slick, but I ended up going with the 1.25" Hercules wedge since I never use 2" eyepieces to view the sun.  I also couldn't justify the extra $300 at the time for the Altair for as little solar observing as I do.  I also looked at the Lacerta wedge, but decided that didn't I want to crouch behind my telescope and look up most of the time since the sun peaks at around 83 degrees above the horizon during the summer here.  I was surprised how polarized the light from a 90 degree wedge is with the Hercules wedge.

I assumed that you were doing solar observing if you were using a variable polarizer.  I suppose you could use it for full moon lunar observing as well, but I just use binoviewers in that case.

I rarely swap eyepieces once I find the magnification I want to solar observe at.  At that point, I don't feel too bad about the inflexibility of my system.

I did put a 2" polarizer in my 2" to 1.25" adapter's M48 filter threads and a 1.25" polarizer on an eyepiece for variable solar dimming on my Dob when using a Baader solar filter.  Since I only have 20mm of in-focus available on it with the CC in place, the Meade solution is a non-starter.

Let us know how well the Meade solution works for you.

[LDW1]

4 hours ago, Louis D said:

I looked at the Altair wedge and thought it was pretty slick, but I ended up going with the 1.25" Hercules wedge since I never use 2" eyepieces to view the sun.  I also couldn't justify the extra $300 at the time for the Altair for as little solar observing as I do.  I also looked at the Lacerta wedge, but decided that didn't I want to crouch behind my telescope and look up most of the time since the sun peaks at around 83 degrees above the horizon during the summer here.  I was surprised how polarized the light from a 90 degree wedge is with the Hercules wedge.

I assumed that you were doing solar observing if you were using a variable polarizer.  I suppose you could use it for full moon lunar observing as well, but I just use binoviewers in that case.

I rarely swap eyepieces once I find the magnification I want to solar observe at.  At that point, I don't feel too bad about the inflexibility of my system.

I did put a 2" polarizer in my 2" to 1.25" adapter's M48 filter threads and a 1.25" polarizer on an eyepiece for variable solar dimming on my Dob when using a Baader solar filter.  Since I only have 20mm of in-focus available on it with the CC in place, the Meade solution is a non-starter.

Let us know how well the Meade solution works for you.

Will do. I like trying different pieces of gear not that I really needed it, lol !