About DOF in RED ONE

[Redefinition]

Hello David,
as far i know one of the best features in RED ONE is having the same depth of field we get on 35mm film cameras,
but some DP´s have told me that in RED ONE DOF is less than in 35mm

please solve me this doubt

Thanks
Karim

[Nano-25]

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[Redefinition]

?????????????

what part do you don't understand?

[Stephen Williams]

Hi,

With Digital cameras you have to be more accurate with focus than on film. Being slightly off is very much more obvious than with film.

Stephen

[Dylan Macleod, CSC]

Check out Brook's FAQ...

http://www.reduser.net/forum/showthread.php?t=1487&page=2

Depth of field is covered near the bottom of the page.

[Roberto B]

Hi,

With Digital cameras you have to be more accurate with focus than on film. Being slightly off is very much more obvious than with film.

Stephenfunny.. checking you being so condescend-ing recognizing red as having superior resolution than any other 35 film camera..

your fanboy yours sincerely

[Karim Iglesias]

ok, let me understand this, RED has more resolution than film and then DOF is more obvious

[Benni Diez]

Depends on how much of the chip you use, which depends on the mode you shoot in. Full 4,5k would pretty much be like 35mm in terms of width, and thus DoF. M.I.right?

[Pawel Achtel]

Depends on how much of the chip you use, which depends on the mode you shoot in. Full 4,5k would pretty much be like 35mm in terms of width, and thus DoF. M.I.right?

No.

DOF depends on CoC, which for RED One can be assumed to be as small as 7 microns. Thus, DOF on Red One will be smaller than that on 35mm film, which generally assumes as much as 30 microns CoC.

Knowing CoC, aperture, focal length and subject distance you can calculate DOF, easy :whistling:

[Giancarlo Bianchi]

Pawel, could you please post the formula (With the microns variable)?

[Charles Angus]

Just get a depth of field calculator - I remember googling it, there's a dashboard widget for it that (indirectly) lets you set the CoC.

[Stephen Williams]

Pawel, could you please post the formula (With the microns variable)?

Hi,

Basically you have to test and use what works for you. Same issue with other 35mm sensor cameras and High end 2/3" chip cameras using very sharp lenses like DigiDrimes. I have been caught out using a Viper due to there being far less DOF than I was expecting.

I also believe moving grain helps you get away with more error.

Stephen

[BASSAM MSSALATIE]

No.

DOF depends on CoC, mes as much as 30 microns CoC.

Knowing CoC, aperture, focal length and subject distance you can calculate DOF, easy :whistling:

Slowly please what is CoC ?:waaa:

[Dominic Cochran]

Slowly please what is CoC ?:waaa:

Circle of confusion:

http://en.wikipedia.org/wiki/Circle_of_confusion

Decent entry, but more in depth information is available in many photography/cinematography books.

[Edmundo Díaz]

Pawel, could you please post the formula (With the microns variable)?

Have a tour in a virtual calculator here:
http://www.dofmaster.com/dofjs.html

The CoC in Circle of Confusion is 0.025 like 35mm

mundods.

[Daniel S Williams]

Hi,

With Digital cameras you have to be more accurate with focus than on film. Being slightly off is very much more obvious than with film.

Stephen

That doesn't make sense. Perhaps the silicone is physically shallower in depth than a slide of 35mm film, thus decreasing the maximum permissible COC

[Mitch Gross]

Film emulsion has thickness. I believe Kodak stock is something like 22 layers deep. As light travels through the layers it diffuses and disburses. This is part of the reason that it can be difficult to get identical registration of different colors as they are different frequencies and on different emulsion layers. We regularly set the depth of certain lenses a little negative or "deep" by a few microns to "dig into" the emulsion a bit.

An electronic sensor has an imaging surface. It is an absolute singular depth (that is unless you count the distance from lens to center of sensor as shorter than lens to corer of sensor, but that's another discussion).

The effect of this is a shallower depth of field (or to be technically more accurate, a less-forgiving depth of field) but not a higher resolution image.

[Jeff Kilgroe]

Film emulsion depth vs. sensor surface considerations aside, there's also the FOV. RED One 4K is a cropped area of the S35mm frame. It's actually just a fuzz larger than academy 35mm, but about 10% smaller than S35. Cropping into the imaging plane has an effect on the perceived DOF, the same way shooting 2/3" or 16mm has deeper perceived DOF than 35mm and even more so with 1/3" sensors, etc..

[Perry Ho]

well, after few commercial projects shooting,
the Red Cam definitely less DOF then any of 35mm film cameras

Cheers

[Gavin Greenwalt]

RED is also much more sensitive than your average daylight stock.

If you're shooting outside without ND you'll probably be stopped down more than with 35mm.

[Stephen Williams]

That doesn't make sense. Perhaps the silicone is physically shallower in depth than a slide of 35mm film, thus decreasing the maximum permissible COC

Hi,

Test, Test, Test look at the results and make an informed desision based on what you see.

Stephen

[David Wyatt]

Definitely shallower in my experience...has anyone actually calculated it based on tests? I'd hazard a guess it's something like 1/2000th of an inch CoC, maybe even more??

[Eric Haase]

After several projects on RED I have noticed the DOF of RED is either more shallow or somehow more critical than 35mm. Buzzing the focus at a T2.8 on a 40mm @ 3K with several very experienced 1st ACs. There was definitely a disturbance in the force and it didn't sit right with me. The focus is somehow more critical.