topic Re: Depth of field info in view finder? in EOS DSLR & Mirrorless Cameras

Depth of field info in view finder?

iND — Thu, 15 Nov 2012 18:48:45 GMT

When my 5DIII is connected to an canon L lens, there is certainly a communication regarding F stop and focal length

When I am using a single focus point there is or could be data exchanged about distance.

Would it then be a stretch to have the computing power on board determine the depth of field and display this information in the viewfinder?

Re: Depth of field info in view finder?

jfo — Thu, 15 Nov 2012 18:54:26 GMT

This is an interesting idea.

I know that focusing is based on finding contrast, and so it might not be an exact or direct way to translate that to distance?

Re: Depth of field info in view finder?

iND — Thu, 15 Nov 2012 19:11:59 GMT

But I can find a laser device at Lowes or Home Depot to accuately measure distance to 165 feet with 1/16 inch accuracy.

Could this not be put on board with the 5DIII to at least give me a distance to subject?

Knowing this DOF would imporve my keeper/out-of-focus ratio.

Re: Depth of field info in view finder?

Bazsl — Thu, 15 Nov 2012 21:01:55 GMT

Doesn't the DOF preview button help?

Re: Depth of field info in view finder?

iND — Thu, 15 Nov 2012 21:14:35 GMT

Not really,

Not when we are dealing with lenses with aperatures like 1.2, 1.4, 1.8.

The display, especially when combined on location scenerios is not 'fine' enough to capture that fine of a detail.

Ever shoot a two person scene and one is in fine focus and the other is relatively close but is just a bit soft?

The exact mathematical information could give me enogh of a nudge to change a 1.4 to a 2.0.

Re: Depth of field info in view finder?

BDeKid — Thu, 15 Nov 2012 21:42:24 GMT

I use a Bosch Laser Meter for 3D Projekts and I can ensure You that this thing is very expensive ( ca 1000$ US or 700€ )

Also it would make not too muche sense to use it on a moving Objekt , also the sureface have to be refelctiv or flat for a good messurment.

The Idea that come to me in the Past would be to have a Laser "Fächer" ( don t know the word in English sorry) which means that U have a kind of LaserScanner , this Idea we had doing a lot of MoCap over here in my Studio.

This would make sence if u use it during recording of video , means a LaserScanner appears every second Frame of say 100FpS - so 50FpS would be Video / Picture and the other 50FpS would be Data to provide for 3D MoCap

For u r IDea the cam would have to scan and calculate the Distance and the Fieeld of Depth , here the Prob could be that u have to send the laser straight from the middle of the lense to the Objekt.

Fact = Nice Idea for the Future but at the Moment I guess it is not realy possible

Greets

B.DeKid

Re: Depth of field info in view finder?

shoot_ric — Fri, 16 Nov 2012 04:41:49 GMT

You can find a DOF calculator on-line, buy a hard copy or download an app for the Android OS.

Re: Depth of field info in view finder?

jfo — Fri, 16 Nov 2012 06:41:16 GMT

@iND wrote:
But I can find a laser device at Lowes or Home Depot to accuately measure distance to 165 feet with 1/16 inch accuracy.

Could this not be put on board with the 5DIII to at least give me a distance to subject?

Knowing this DOF would imporve my keeper/out-of-focus ratio.

Considering how big and bulky that laser device probably is, I don't think that's something that can just be integrated into a DSLR.

@shoot_ric wrote:
You can find a DOF calculator on-line, buy a hard copy or download an app for the Android OS.

Its not that iND is looking for a tool to calculate how big the depth of field is for certain settings (lens, aperture, and distance to focus point), but he's wondering since the camera knows the first two #'s, if it also figure the third and then automatically display the depth of field.