100-400L Bahtinov Mask

[johndevane]

For any of you out there using a 100-400 for astrophotography, here's a treat... A 24 ounce container of "Daisy Sour Cream" lid will snap perfectly onto the lens cap of your 100-400 lens. Use the free printable cut-out of a 66mm Bahtinov Mask, trace the lines onto the lid, and cut the lid with an exacto knife. It snaps on the lens hood like it was made for it, and it works perfectly.

[Catanonia]

Sweet :)

[ejicon]

cool.....

[FelixDeSouze]

And for the non astro photographers, what does this do? :)

[Pete]

Wikipedia has the answers...

http://en.wikipedia.org/wiki/Bahtinov_mask

(always my first port of call in cases of confusion)

[johndevane]

It becomes a lousy lid for your sour cream. :)

[TheBigDog]

interesting, so it helps focus better? Would you use this on something like a moon shot or more shooting constellations?
I'm guessing you would put this on the lens, focus and then remove it for the shot?

[johndevane]

You wouldn't need it for the moon. It helps to focus on stars. You're right about using it to focus, then take it off. The neat thing is that it fits so well on the lens hood.

[Tdragone]

Interesting. I'd like to try this; but my google-fu isn't perfect. Can I get a link to the template please?

[johndevane]

Merry Christmas... http://www.focus-mask.com/Free_Templates.html