Y-masks 3 and 4 no better

The first focusing Y-mask I designed and made for the camera, the one with the medium thick wire, is still the best.

Tonight, I made a new mask with very thin copper wire. I thought thinner wire would prove better than thicker. The image is bright, the diffraction pattern is visible, but the pattern is less precise. This may be due to bends in the wire. I found it very difficult to keep the thin wire perfectly straight.

Perhaps if I made the Y slightly differently so to keep tension on the wires... That is, make a sharp V. Then solder a wire to the apex or point in the V. And finally tighten the new line. That might keep them very straight...

Made another mask with plastic transparency film laser-printed with very thin black lines (Visio line weight 1 or 0.24pt) for the Y-pattern. The image quality was poor. Obviously the plastic was messing with the light. I almost missed it—the "classic" diffraction pattern is still produced but it is very difficult to see, lost in the glare and scatter.

Would glass be better? Silly idea.

Both tested, Y3 and Y4, with a false star.

I'll test all in the field. But it looks like Y1 is the winner.

I think what I really need to do now is try Y1 again, outdoors, combined with all the other tricks I've learned. That is:

• Y-mask with medium wire
• camera in simulated exposure mode
• EOS Utility Zoom View window maximised
• EOS Utility Zoom View image at 200%
• Magnifying Glass Free software running
• and, if diffraction pattern visible on bright star, Bahtinov Grabber software running

I do think all these things together will work...