11-20-2017, 08:57 AM
I also was thinking about and got a sample to try very briefly the Irix 11/4. Less heavy, less costly and adjustable focus stop for ∞. THis is where I am sceptical - even if the Sigma would be great for astro-stuff, how to focus it at ∞ ?
If a lens like this needs AF is something everyone should decide for himself*. For landscape I don't see much of a benefit. For other stuff it's helpful, especially in LiveView ad with electronic shutter (I don't think, with an OVF one gets the focus right at f/1.8) and at this kind of weight, it's easier to manouever with AF.
*but if the answer is "yes", it's good to adjust it at more than only one distance. I feel this feature falls very short in most tests of Tamrons or Sigmas. -_-
As well as I say: If I have AF, I also have a focus motor and can remote control the lens. Meaning, the camera can be so close at the floor, that I don't see properly the screen, or I need to but it back to the wall to get the full room. Then it becomes handy, controlling the camera with a smartphone or tablet and setting the focus ring.
Oh, and dave: you forgot in your list "no filter thread"
If a lens like this needs AF is something everyone should decide for himself*. For landscape I don't see much of a benefit. For other stuff it's helpful, especially in LiveView ad with electronic shutter (I don't think, with an OVF one gets the focus right at f/1.8) and at this kind of weight, it's easier to manouever with AF.
*but if the answer is "yes", it's good to adjust it at more than only one distance. I feel this feature falls very short in most tests of Tamrons or Sigmas. -_-
As well as I say: If I have AF, I also have a focus motor and can remote control the lens. Meaning, the camera can be so close at the floor, that I don't see properly the screen, or I need to but it back to the wall to get the full room. Then it becomes handy, controlling the camera with a smartphone or tablet and setting the focus ring.
Oh, and dave: you forgot in your list "no filter thread"