My star present was an Irix 11mm Blackstone lens.
The Irix 11mm is a manual focus lens, that doesn't report distance to my Canon cameras, hence my Focus Bar script wont work. But, as we will see that is irrelevant with this lens.
Unlike many/most modern AF lenses, the Irix lenses (they do a 15mm prime as well) come with a hyperfocal scale. The lens can also be infinity calibrated, if needed. The (Swiss) manufacturers have decided to use a very high quality circle of confusion to create the focus scale. I estimate a CoC of some 9 microns.
The 11mm is an F/4 lens and the focus ring has two really nice features. A 'click' at infinity and an ability to lock the focus. The barrel distortion is low at just over 3% and the diagonal angle of view is a very meaty 126 degrees.
Although my Focus Bar script doesn't work with this lens, the depth of field scale gives you a simple way to achieve your hyperfocal distance, infinity distance and do focus stacking. For example, here is a four image focus stack, taken from a Magic Lantern ETTR exposure and a 100/800 Dual ISO.
The closest object was less than a foot away.
I hope to be taking the 11mm Irix out into the field over the coming months and will report my findings in future posts.
No comments:
Post a Comment