Since my camera doesn't have live view, I have to focus through the little viewfinder. I figured a focusing aid might help me out. I read that a
Bahtinov mask could help take some of the guessing out of trying to focus. I found a helpful
post about making one yourself, and even a
Bahtinov Focusing Mask Generator. I didn't have any black plastic, but I tried my best making one out of paper and it actually wasn't too bad.
![Bahtinov Focusing Mask Bahtinov Focusing Mask](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_nwHbnqzGBLGiNb5UCyV68pAHFUbzYUuSg6PDT5vu8ZDjycCrSbvGWHJT9tYHw-JB7TXjM5XdtQVaeyiRJv2GSjDNtlKJEn-mBIWVdruDXM7MAjiF4xGiwdB_Bc1OTWaYZ8Hn4JvVM6TU/s400/Photo+Sep+26,+8+14+20+PM.jpg) |
I printed the image from the Bahtinov Focusing Mask Generator on cardstock |
![Bahtinov Focusing Mask Bahtinov Focusing Mask](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRxXUWNiGjKvCoqYVxgiuYFHISmLumDG26W2wDyFOOkBVyurSO_NDOvws_d4Z34PWP73EO87k21_b3d2ZkOpjC5pKiHRrVnvCwOi1aLwp6SERqZIjz58itXbjaYZ7Xz8GLiFBC4d4jPfI4/s400/Photo+Sep+26,+8+17+22+PM.jpg) |
...and cut out the white spaces... |
![Bahtinov Focusing Mask Bahtinov Focusing Mask](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQCZJdhBRkFu4gO9VgbwpGY4h-4ftAnHASFYgVti730igsAxrsXDDT3kNsfFekm2lbdm1cdDAqYQDdzmw4Jc2OLRnsRc66rNFpBg9jB6ZYCqpTTUtu0AYmvg7SwNFay7v06gVlYyX6ukk7/s400/Photo+Sep+26,+8+31+51+PM.jpg) |
...which took me about 20 minutes. |
![Bahtinov Focusing Mask Bahtinov Focusing Mask](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUvbCb45M2d1rlUMQQRbLm_QhCKelEuSxP25-I9cpYvRn6Ao4pc-4t56JDgNxUgHxNZCC1GTTqZHCe1dz7kUTW_fgVQ7AziXA8gdSu3tviTUm4ZAL42zzhSE3Yihk3do-bTOIJlX903cz7/s400/Photo+Sep+26,+8+33+46+PM.jpg) |
Then I cut out the disk itself. |
![Bahtinov Focusing Mask Bahtinov Focusing Mask](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgV_pacFxEVNPvc9DBoh2JQExGVRgrjh3r_JHWFbB7JVAOgSfCREqsBnRM3Ti0hwUNbtSLjlJ4SHU5Z_jMVZm8TAKinvyWws53sAQhwmk7fLKmOwuaNs4caIJnH96HFpoDbG-9aNdp8V1_b/s400/Photo+Sep+26,+8+40+54+PM.jpg) |
I wrapped paper around the end of my telescope and taped it for size, then attached the focusing mask with tape. |
![Bahtinov Focusing Mask Bahtinov Focusing Mask](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiOlCPA3C8jH3Io_Dd5njTiOiC8Ue-gjOnZv2LrJKFhxD0Lz4KwnygxfaVZ7NMTF8hFeAtIRpflcVxo6PQWSfbEyEwLkSip24kxugySEDPlW7zcI6Nbh9pjPpaIZ1NKfKAsFnlbHmOskIoC/s400/Photo+Sep+26,+9+04+49+PM.jpg) |
I figured it doesn't really matter if the white or black side faces out. Looks kinda badass. |
Even this paper one works in principle - it "produces three angled diffraction spikes at the focal plane of the instrument" (
Wikipedia). The problem is that my focuser sticks and jumps, and I only have a course focus. Knowing where focus is doesn't help if you can't accurately make adjustments - I just shoot past it in both directions but can't fine tune it. Oh well, not a bad little project!
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