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Imaging with Coronado PST - Can't find focus

ZWO ASI120MM Mini ZWO ASI533MC Pro ZWO ASI178MM Acquisition Solar System
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Craig Dixon avatar
Craig Dixon avatar
I know it's possible to image with this scope but I just can't get anywhere near focus. here's what I've tried:

ASI662MC - 1.25" nosepiece inserted straight into the eyepiece holder. I can't seem to get the sensor close enough.

ASI178MM - Same as above.

ASI533MC Pro - Same as above.

Add the lens of a 2x Barlow to the end of the nosepiece - still can't find focus.

ASI120MM Mini - This camera can be inserted all the way into the eyepiece holder but I still couldn't find focus. I also set the gain to 0 and exposure to 1ms but the whole disc was blown out.

Can anyone who uses a Coronado PST for imaging offer any advice?

TIA.
Jan Erik Vallestad avatar
Jan Erik Vallestad avatar
I have no personal experience with this setup, but have you browsed CN? If not you might find this helpful: https://www.cloudynights.com/topic/816236-drop-in-camera-for-coronado-pst/
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Craig Dixon avatar
Craig Dixon avatar
I've had a look on cloudy nights as well as some other places but haven't been able to find a solution that works. Most threads are just a lot of similar comments saying either it is or it isn't possible but there isn't much in the way of any instruction.
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Craig Dixon avatar
Craig Dixon avatar
I’ve got the lens element from a 2x Barlow on the end of an ASI178MM nosepiece and inserted this all the way into the eyepiece holder on the Coronado PST but I can’t get anywhere near focus.
Steven Fanutti avatar
Steven Fanutti avatar
I used to have this telescope. I couldn't get a focus for imaging, not even with eyepiece projection. The only success I had was afocally with a smartphone. In principle, stacking multiple images can greatly improve the results just like any other type of imaging. I recommend a smartphone eyepiece adapter if you want to try it that way.
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Lorenzo Siciliano avatar
Lorenzo Siciliano avatar
You may want to unscrew the eyepiece holder where the BF filter is, unscrew the underlaying barrel and then screw the BF filter directly to the PST black box.
Ciao.
Lorenzo
Craig Dixon avatar
Craig Dixon avatar
I just wanted to update this. I managed to find focus with my 120mm Mini. The key was adding a UV/IR cut filter (Astronomic L3 in my case). Without the filter, I couldn't get anywhere near. Here's literally my first attempt at getting an image. I'm kind of blown away if I'm honest. I know it's not framed very well but this was just a test image and has shown me that it's worth continuing.
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Lorenzo Siciliano avatar
Lorenzo Siciliano avatar
Very good first light indeed!
Glad to know that you have addressed the focusing issue.
Ciao
Lorenzo
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Peter avatar
Peter avatar
@Craig Dixon 
That's brilliant first image. Congratulations.
I will try that with my Lunt LS35THa it's blocking filter is a B400.
If i ever get a clear day

Peter
Eddie Bagwell avatar
Eddie Bagwell avatar
Finding focus the first time in Solar Photography with new cameras or accessories is always a challenge. Make sure to record all settings so next time you can get right to imaging. Congrats on your image. Looks great.
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