Coronado PST and FOCUS

Use this section to discuss "standard" Baader/Coronado/ Lunt SolarView/ Daystar, etc… filters, cameras and scopes. No mods, just questions/ answers and reviews.
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Lunam
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Coronado PST and FOCUS

Post by Lunam » Thu Apr 28, 2016 8:40 am

I have been using my Coronado PST and have been able to do visual of the sun and very pleased with the results. Using my 3.5mm Orion Stratus Wide-Field Eyepiece got amazing views

However I have not been able to image because of the back focus issue with the telescope.

I tried the ZWO 120 mono camera and I was able to get a nice white circle but no detail at all (could not see sunspots or flares at all I reach the end of the focusing to get the white circle)

I tried doing eye piece projection with my Nikon and Celeston Deluxe tele extender but could never get to focus.
I have ordered a 1.25 Shorty Barlow to see if this helps
Any suggestions/pointers will be greatly appreciated
LS

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Merlin66
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Re: Coronado PST and FOCUS

Post by Merlin66 » Fri Apr 29, 2016 2:51 am

Welcome on board.
The PST was designed as a visual instrument.
To achieve the backfocus you need for a camera there are a couple of options...
Add a barlow lens to the eyepiece section or look at removing about 5mm from the end of the eyepiece section (very very carefully - the final blocking filter should be protected from damage.)
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.yahoo.com/neo/groups/ast ... scopy/info
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer

Lunam
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Re: Coronado PST and FOCUS

Post by Lunam » Fri Apr 29, 2016 3:02 am

Thanks I just ordered a 2x Barlow. Will try it as soon as I get it I have a 5x but have not tried it. Will let tou know what I achieve when I get it
Appreciate the help

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Montana
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Re: Coronado PST and FOCUS

Post by Montana » Sun May 01, 2016 5:47 pm

5x will be way too much for the PST. A 2x and 1.6x will be great. I use a very short shoulderless nose piece on my camera to get focus at native focal length. However on the newer versions of the PST the eyepiece holder is 5mm longer than mine so even the shoulderless nosepiece won't work, you have to shave that 5mm off.

Alexandra

Lunam
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The Sun?
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Re: Coronado PST and FOCUS

Post by Lunam » Tue May 03, 2016 7:34 pm

Thank you guys for your help
I was able to finally get some pics (even tried afocal)
Waiting for the 2x Barlow to arrive.
Got something now have to work on making them better.
Wished the Newton rings could be avoided
Attachments
SUNspot1.jpg
SUNspot1.jpg (36.79 KiB) Viewed 1241 times
sun flares BW.jpg
sun flares BW.jpg (32.11 KiB) Viewed 1241 times
Afocal attempt.jpg
Afocal attempt II.jpg
Afocal attempt II.jpg (49.25 KiB) Viewed 1241 times

Lunam
The Sun?
The Sun?
Posts: 4
Joined: Thu Apr 28, 2016 8:35 am

Re: Coronado PST and FOCUS

Post by Lunam » Tue May 03, 2016 7:34 pm

Thank you guys for your help
I was able to finally get some pics (even tried afocal)
Waiting for the 2x Barlow to arrive.
Got something now have to work on making them better.
Wished the Newton rings could be avoided
Attachments
Afocal attempt II.jpg
Afocal attempt II.jpg (49.25 KiB) Viewed 1241 times

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Montana
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Re: Coronado PST and FOCUS

Post by Montana » Wed May 04, 2016 9:28 am

These are great, what did you do?

Alexandra

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