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PHD2 Guiding Breakthrough

Paul and Chrissy

After months and months of trying to improve guiding I have nailed it. The magic for me was putting an I.R. filter in the guide scope. This improved focusing beyond my dreams and hey presto 0.5 total error. Never got close to this figure ever. 😉

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From the album:


· 38 images
  • 38 images
  • 8 image comments

Photo Information

  • Taken with Apple iPhone 5s
  • Focal Length 4.2 mm
  • Exposure Time 1/25
  • f Aperture f/2.2
  • ISO Speed 320

Recommended Comments

Refutes the perception by some that defocusing helps guiding.

The PHD2 developers often have to tell users with problems to improve their focusing, going for minimum HFD reading in the Star Profile.


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Cheers Michael

I have always thought slight de focus was a good idea, but this proves the point that good focus is a must. Just achieved 0.40” tonight. I got the idea of putting an I.R. filter on from my experience of photographing the moon. I could never get crisp focus until the nice man at Atik advised using an I.R. filter, so I tried the same thing on the guide camera. I wonder how many people are guiding with mono cameras and no filter. 

Clear Skies Paul.


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My HFD at 3.87 arcsecs per pixel is about 3.5, your HFD at 4.8 as/p is 5.99, so it might be worth giving your focus a tweak too.


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