View Full Version here: : Lack of Infocus with Baader Herschel wedge ?
Cliff
03-05-2022, 10:33 AM
Hoping there is an easy solution now I can actually see the Sun :)
Took over 6months to get my Herschel wedge and now using my Tak 76DS I am finding for visual anyway not tried photography yet I can just reach focus all the way in on the focuser when wearing my glasses and have no way of using it without ?
I thought a barlow might work in front of the eyepiece but no go.
Would a 2X barlow/or my telecentric 2X work in front of the wedge , I use them with a Combo quark ok.
Appreciate any ideas ,
Cliff
astro744
03-05-2022, 12:08 PM
Is this a 2" wedge? If so a 1.25" with shorter light path would likely be needed. I'm not sure I'd want to put the Barlow or Powermate before the wedge as it will take all the concentrated energy before it is diverted by the wedge.
I'm not familiar with the Quark light path requirements. Is there an energy rejection filter at the front of the objective for it? If not then its the same as what you're proposing. Perhaps some solar gurus can chime in.
Edit: If in doubt check the instructions. I found this in the Baader instructions for their solar wedge:
"4. When using auxiliary optics (barlows, telecompressors, etc), always place them into the beam behind the
Herschel Wedge - not ahead of the Herschel. Any optic placed ahead of the Herschel would be exposed to
unfiltered solar energy and most likely will be damaged by the potential heat buildup"
Cliff
04-05-2022, 09:01 AM
Yes it is a 2” and there are no problems using a 2x or 4x in the light path , you can place a uv/ir cut filter on either the quark or powermate but at 76mm not essential bigger scopes do, I have experienced no heating issues at all, so should work with a wedge ?
1.25” wedge would give more infocus correct
astro744
04-05-2022, 09:41 AM
I highly recommend you contact Baader for advice and also download their user manuals for both 2" and 1.25" solar wedges from their web site and follow any safety warnings/recommendations.
The 2" solar wedge is suitable for refractors 90-110mm I believe. The 1.25" solar wedge would be for smaller refractors but best to get this info from Baader. The 1.25" will have a smaller light path should would help you with focus provided you still have the focuser travel but being smaller it cannot handle larger refractors.
I'll have a look myself later when I get more time but I suggest you contact Baader for direct advice.
It is possible Baader do not sell a 1.25" version but I know Lunt do or used to.
astro744
04-05-2022, 12:27 PM
I found this old thread at CN: https://www.cloudynights.com/topic/576421-lunt-solar-herschel-wedge-2-vs-125/
A 1.25" wedge will heat up quicker due to smaller dissipation area so is recommended for smaller aperture telescopes. See post #6 in above link.
Not sure that Baader even make a 1.25" version. Lunt do. I have not been able to find light path lengths but normally a 1.25" diagonal path is considerably shorter than a 2" diagonal path and this would likely be the same with a solar prism wedge. You would be limited to smaller aperture viewing which a 76mm telescope would come under.
The recommendation from Baader though is not to place the Barlow in front of the wedge to avoid excessive heating of the Barlow (or Powermate) lens elements.
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