99 replies to this topic

[Werckmeister]

Hey again everybody.  I took delivery of something special today that brought this classic wedge truly back to life.  

 

A purpose made Vixen ND filter for use with un-filtered Hershel Wedges.

 

This is similar to the common "Sun Glass" we're familiar and often warned of, though it is less optically dense (More akin to the modern ND3's that are built into today's wedges).  It threads into any Vixen-style .965 eyepiece and allows safe use of unfiltered hershel wedges.

I used it in my C80 with "ScopeTown" orthos, which paired wonderfully and produced a comfortable and extremely sharp image.  The picture below is slightly less sharp than what it looked like through the eyepiece.
 

 

 

Great! I use the same wedge and Vixen filter almost daily and views are absolutely wonderful. To make things more fool-proof, I fixed the filter in the wedge.

Edited by Werckmeister, 22 May 2024 - 01:12 PM.

[mpsteidle]

Great! I use the same wedge and Vixen filter almost daily and views are absolutely wonderful. To make things more fool-proof, I fixed the filter in the wedge.

I'm thinking about doing exactly this.  Did you just super glue it in place?

[deSitter]

I'm thinking about doing exactly this.  Did you just super glue it in place?

Remember the filter needs to come AFTER the prism/wedge. So I'd do it the normal way.

 

-drl

[Werckmeister]

I'm thinking about doing exactly this.  Did you just super glue it in place?

Glueing fixes the filter kind of irreversibly. I drilled and tapped a thread in the prism housing. A little M3 screw locks the filter in place. The filter is easily replaced or removed if desired. And yes, after the wedge.

Edited by Werckmeister, 22 May 2024 - 03:43 PM.

[LU1AR]

I'm thinking about doing exactly this.  Did you just super glue it in place?

Remember that Cyanoacrylate glues, evaporate a white sublimation around them.
Better use a non-anaerobic glue.
Regards
Edgardo

[deSitter]

Remember that Cyanoacrylate glues, evaporate a white sublimation around them.
Better use a non-anaerobic glue.
Regards
Edgardo

Agreed, I would not use super glue anywhere near optics.

 

-drl

[photoracer18]

Right now I have a 2" Lunt Herschel Wedge complete with the built in ND3 and a adjustable polarizer. For about 30 years I had an old school Optica b/c wedge I bought right from their store in SF for my Unitron 128. It had the typical hole in the back and included 3 ND filters, .1, .01, and .001 so marked in their throughput and not the esoteric ND ratings hardly anyone understood. Sold it finally a couple of years ago to someone looking for one. I originally bought a 1.25" Lunt to replace it but then found someone who wanted to swap his 2" straight up for a 1.25" due to fitment issues (not to mention he gave me the 2" variable polarizer for free). The one thing I can't do anymore is use my Lunt as a full Moon anti-glare diagonal as the ND filter is non-removeable.

[mpsteidle]

The one thing I can't do anymore is use my Lunt as a full Moon anti-glare diagonal as the ND filter is non-removeable.

I am definitely trying this.

[PawPaw]

Recently acquired this Hershel wedge from circa 1980.  I am sure it was never used as the packaging looks untouched and no dust or scratches on any surfaces.  Not exactly sure what the filters are but it has two dark filters and one clear filter all separated by spacers.  All the filters are arranged inside the eyepiece barrel with the clear one closest to the prism.   Its a hefty piece with the hershel prism itself is surrounded by metal on the internal sides.  Looking forward to trying it out but first I want to know what type of density the filters are.

 

 

 

 

 

 

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[jgraham]

The dark ones are likely neutral density filters. The clear one may be a polarizer.

[PawPaw]

Some info on the Nikon wedge:

 

 

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[deSitter]

Some info on the Nikon wedge:

Yes the clear filter is to absorb heat. That could probably be dispensed with, but it depends on the aperture of the scope. One of the dark filters is likely a polarizer, and the other an ND3. Light from the prism reflection is completely polarized, and adding a polarizer provides a way to fine tune the brightness by rotating the eyepiece.

 

-drl

[apo130max]

I have the same Nikon Solar Wedge. I remove one of the ND filters for photography. Taken through an FC100DL with Lumix G9 @1/25,000 sec.

 

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[PawPaw]

Beautiful image thank you for sharing.  

 

Do you leave the heat absorbing element in place?

[apo130max]

Beautiful image thank you for sharing.  

 

Do you leave the heat absorbing element in place?

Yes, I leave the heat absorbing element and one of the ND filters in place.

[RichA]

It's a tough problem.  If you put a deflector in back, it'll heat up even if it's a mirror.  Heat resistant frosted glass, if it exists, would work.

 

 

This thing does have one glaring quirk - there's a laser beam coming out the back.  Of course this is an exaggeration, as long as you're more than about 6 inches from the rear of the diagonal it wont affect your body at all, as the beam defocuses.  You must remain aware of it though and its probably best not to use it around kids.

Enjoy these pictures of the wedge in use, along with a crappy out of focus snap with my cellphone.  Is anyone else using these still?

 

[SporadicGazer]

It's a tough problem.  If you put a deflector in back, it'll heat up even if it's a mirror.  Heat resistant frosted glass, if it exists, would work.

Modern ones all use a ceramic plate and often a heatsink to contain and dissipate the heat.

 

I've seen older ones which incorporate a metal flap to block the direct beam, perhaps reflect some of the heat downward and to dissipate the rest.  It seems like some aluminum flashing would be easy to try and might be enough.  If it heats up enough to cause problems a second air-spaced piece could serve as a shield for the hot piece.

[deSitter]

Modern ones all use a ceramic plate and often a heatsink to contain and dissipate the heat.

 

I've seen older ones which incorporate a metal flap to block the direct beam, perhaps reflect some of the heat downward and to dissipate the rest.  It seems like some aluminum flashing would be easy to try and might be enough.  If it heats up enough to cause problems a second air-spaced piece could serve as a shield for the hot piece.

I've got one coming at long last, a 24.5mm classic with no guard, just the Dennis the Menace aperture. So I've been looking through my junk for metal I can fashion into a deflector. You could just put tinfoil pants on the diagonal, but i hope to improve on that.

 

BTW when I was painting my big hunk of aluminum the other day, I left that out unpainted yet in the direct sunshine. It was amazingly cool before I hit it with paint. The best deflector would be a thin plate of bare aluminum.

 

-drl

Edited by deSitter, 26 June 2024 - 07:21 AM.

[deSitter]

Sigh. My Baader ND3 filter is here. My Herschel wedge is somewhere in my fair city. My adapters are all ready. But i can't find my polarizer filter. I had them out just recently to clean them. And my old old brain put the set somewhere unknown to it as of now.

 

George Carlin - "Did you ever find yourself standing in the middle of a room and think - 'What the frick am I doing here?' and the word ALZ-HEI-MERS comes to mind..." Yeah.

 

-drl

Edited by deSitter, 26 June 2024 - 06:44 PM.

[mpsteidle]

I've got one coming at long last, a 24.5mm classic with no guard, just the Dennis the Menace aperture. So I've been looking through my junk for metal I can fashion into a deflector. You could just put tinfoil pants on the diagonal, but i hope to improve on that.

 

BTW when I was painting my big hunk of aluminum the other day, I left that out unpainted yet in the direct sunshine. It was amazingly cool before I hit it with paint. The best deflector would be a thin plate of bare aluminum.

 

-drl

Just wear one of these when you use it.

[deSitter]

Just wear one of these when you use it.

 

That's me attempting to paint an eyepiece tray. You should see when I do a tube.

 

-drl
 

[deSitter]

Sigh. My Baader ND3 filter is here. My Herschel wedge is somewhere in my fair city. My adapters are all ready. But i can't find my polarizer filter. I had them out just recently to clean them. And my old old brain put the set somewhere unknown to it as of now.

 

George Carlin - "Did you ever find yourself standing in the middle of a room and think - 'What the frick am I doing here?' and the word ALZ-HEI-MERS comes to mind..." Yeah.

 

-drl

Found in a tub that was supposed to go to the eclipse. ARGH.

 

-drl

[DouglasPaul]

Hey again everybody.  I took delivery of something special today that brought this classic wedge truly back to life.  

 

A purpose made Vixen ND filter for use with un-filtered Hershel Wedges.

 

This is similar to the common "Sun Glass" we're familiar and often warned of, though it is less optically dense (More akin to the modern ND3's that are built into today's wedges).  It threads into any Vixen-style .965 eyepiece and allows safe use of unfiltered hershel wedges.

I used it in my C80 with "ScopeTown" orthos, which paired wonderfully and produced a comfortable and extremely sharp image.  The picture below is slightly less sharp than what it looked like through the eyepiece.

 

It's too bad these are rather rare. They do work very well with the wedges, which seem to be much easier to find.

[Jim Curry]

I've always wondered why a Hwedge wouldn't work with a reflector?

[Terra Nova]

I've always wondered why a Hwedge wouldn't work with a reflector?

Back in the day Edmund and/or Jaegers used to sell a Herschel wedge secondary for Newts.