DoF with Vibrating vs Rotating GG

djkarn105

djkarn105

Well-known member
I have a question about the difference between vibrating and rotating adapters. From what I understand, with vibrating adapters the depth of field is fixed whereas with rotating glass the depth of field can be adjusted by changing the f-stop.

maybe I'm misunderstanding this?
 
you do! DOF depends on f-stop, focal length, camera to "subject" distance and the properties of the GG of your adapter. Spinning adapters allow generally a higher f-stop without the structure of the GG becoming visible. When stopping down past f5.6 with a vibrating adapters you often see the structure of the GG.
 
The f-stop will not be changed by whether the GG is vibrating or spinning. What determines if you can change your f-stop is the lens you get, not your adapter.
 
"Spinning adapters allow generally a higher f-stop without the structure of the GG becoming visible. When stopping down past f5.6 with a vibrating adapters you often see the structure of the GG."

perhaps someone could add this line to the sticky in the post about adapter construction and function pros and cons.

Also, I've read that spinning adapters can leave the bokeh with a spiral look. perhaps that should be mentioned in that post as well?
 
djkarn105 said:
Also, I've read that spinning adapters can leave the bokeh with a spiral look. perhaps that should be mentioned in that post as well?
Click to expand...

In my experience this is true and not true. I recently shot a camera test with my M2 which has a spinning GG. When I played straight from tape to HD tv through the RCA cables, there was a spiral look on the bokeh all of my footage. I was a bit worried. However, when imported into Adobe Premiere using the proper HDV 1080i settings, it all disappeared.

I'm not sure why. Anyone with insight to this?
 
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