Sunday, December 18, 2022

DoF Hack: the pretty version

In a previous post I showed how one can easily create customised depth of field scales on any lens, eg when wanting to focus stack from near to far, say, from the minimum focus to infinity. The hack allows you to choose a particular circle of confusion, rather than accept the one 'baked into' the lens by the manufacturer.

The reason for wishing to create such a hack is if the lens (manual or AF) doesn't have an apprroiate DoF scale, or the electronic feedback in the camera, once again, doesn't provide the necessary infomation, ie how much to rotate the lens helicoid, to align the previous near DoF with the previous far DoF.

In the original post I showed the basic hack using trusty duct tape:


It's functionally good enough, but it hardly looks pretty or professional ;-)

Luckily my wife has a Brother P-Touch label printer and, as can be seen below, using this you can create a much prettier layout:

As before, to use the DoF hack, all you need to do, according to the direction of focus bracketing, is to rotate the lens focus ring (on the Sigma above there are no hard stops, only soft stops), until the 0, say, aligns with the minimum focus distance: or align the 9 with infinity.  

BTW the DoF above is for a 12mm focal length, at f/8 and with a CoC of 20 microns. All you need to do is to cut the appropriate DoF length, based on focal length, aperture and CoC, using the technique discussed in the first post.

The numbers on the tape are only there to assist in your rotation indexing, eg from the left to the right of the DoF bar.

As usual I welcome any comments on this post, or any of my posts.


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