DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Open DV Discussion (https://www.dvinfo.net/forum/open-dv-discussion/)
-   -   Bokeh-Focus-Object Shrinkage Effect? (https://www.dvinfo.net/forum/open-dv-discussion/529863-bokeh-focus-object-shrinkage-effect.html)

Rob Johnson September 26th, 2015 08:43 AM

Bokeh-Focus-Object Shrinkage Effect?
 
Ok, so OCD is acting up and trying to find this is driving me nuts. What is the specific name of the effect when the apparent size/outline of an object out-of-focus (blur, bokeh, blah) seems to appear larger than it really is when it actually comes into focus? The effect is subtle, and it isn't a much-covered subject. I learned about it years ago ... just can't remember the name of the effect. Anybody?

Jim Andrada September 27th, 2015 08:44 PM

Re: Bokeh-Focus-Object Shrinkage Effect?
 
Maybe you're thinking of Focus Breathing???? Google it and see if it's what you're thinking of. Basically image size changing as you focus.

Matt Sharp September 28th, 2015 01:02 AM

Re: Bokeh-Focus-Object Shrinkage Effect?
 
I think you're talking about bokeh. The way objects look in the out of focus areas. I have no idea if there's a specific term regarding the size. Just the correlation of iris, focus distance and lens length to how out-of-focus the background will be.

For example, (from Philip Bloom's speedbooster test.)

Large OOF objects:
http://philipbloom.net/blog/wp-conte...S-670x376.jpeg

Small OOF objects as focus goes closer to them:
http://philipbloom.net/blog/wp-conte...4-670x376.jpeg

Jack Zhang September 28th, 2015 02:44 PM

Re: Bokeh-Focus-Object Shrinkage Effect?
 
It does sound like lens breathing. Cheaper manual focus lens tend to breathe when rack focusing. It gives the illusion that the object is larger when in fact the entire frame is pushed in when the focus "breathes"

High end productions don't like lens breathing, which is why PL lenses in the higher price range rarely focus breathe. If you want focus breathing, any cheap Samyang Prime might do.

Rob Johnson October 2nd, 2015 12:39 PM

Re: Bokeh-Focus-Object Shrinkage Effect?
 
Quote:

Originally Posted by Jim Andrada (Post 1899300)
Maybe you're thinking of Focus Breathing?

Quote:

Originally Posted by Jack Zhang (Post 1899300)
It does sound like lens breathing.

Yes that's it exactly. Len/Focus breathing. Couldn't remember for the life of me! Thanks.

Jim Andrada October 3rd, 2015 10:46 PM

Re: Bokeh-Focus-Object Shrinkage Effect?
 
Glad we could fill in the mental blanks for you. I have more and more of them every year. Now just where did I leave my car keys???


All times are GMT -6. The time now is 05:35 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network