Full frame?

[NikonD80user]

what does "full frame" meen? i saw a movie reviewing the first Nikon full frame camera (i think) and had no idea what full frame was so i decided to ask you guys/girls.

[Yarddog]

It means the sensor is roughly the same size as a 35mm slide or negative. That also means lenses used on such a camera will have the same apparent view as with 35mm.

[NikonD80user]

oh ok. thank you for the explanation.

[MarkD]

To add to what yarddog said, most DSLR's, like your D80, use a sensor smaller than a 35mm slide or negative. That causes the field-of-view of a given lens to be narrower on such a DSLR than on a 35mm SLR.

[hughlite]

To add to what yarddog said, most DSLR's, like your D80, use a sensor smaller than a 35mm slide or negative. That causes the field-of-view of a given lens to be narrower on such a DSLR than on a 35mm SLR.

Not exactly. Depth of field will be greater with a lens on a smaller sensor than with the same lens on a 35mm equivalent sensor assuming you use the same aperture.

Message Edited by hughlite on 07-06-2008 02:55 PM

Message Edited by hughlite on 07-06-2008 02:58 PM

[peirceman]

Hugh,

Do a search on field of view and you will see that Mark is correct. By the way, you are correct as well.

[AstroImager]

---

Not exactly.  Depth of field will be greater with a lens on a smaller sensor than with the same lens on a 35mm equivalent sensor assuming you use the same aperture.

---

Umm, Scott...frankly neither of them are correct

 

The field of view of a *lens* doesn't ever change, no matter what the size of the "thing" behind it you're using to capture light.  Put the same lens on a 35mm film camera, APS-C DSLR, or P&S digital (if that were possible) -- the lens (and what it delivers behind it as it's "field of view") never changes.  The only thing that's different is how much of the lens' field of view you capture with your sensor/film.  Yeah, I know, I'm nit picking...but saying it backwards such that the meaning indicates that it's the lens that changes leads to all kinds of confusion...

 

Like Hugh's statement.  Take the same lens, use it on a full-frame DSLR or 35mm film camera, and on an APS-C DSLR, at the same aperture.

There is NO difference in the depth of field. 

Shoot two images from the same spot with the same lens at the same aperture -- only difference between the two is that the APS-C DSLR image is a cropped version of the full-frame image.  No depth of field difference. 

 

There's nothing magical about an APS body that changes the properties of lenses, or what they project behind them.  The same lens will always project the same field of view and the same depth of field -- no matter what body you stick it on.  All that changes is how much of that you see in your image, and that depends on your sensor/film size.

 

Now, if you physically move yourself so that your APS camera's sensor shows the same cropping as the full-frame camera (by moving back), then you *will* have more depth of field at the same aperture...but that doesn't have anything to do with the lens or the sensor, it happens simply because you moved further back...

 

 

Paul

 

[BobF]

---

hughlite wrote:

Depth of field will be greater with a lens on a smaller sensor than with the same lens on a 35mm equivalent sensor assuming you use the same aperture.

---

No, it won't. Depth of field is a product of aperture and magnification. Putting the same lens on a camera with a smaller sensor and standing at the same place using the same aperture will generate the same DOF. Where DOF will differ is if you want the same scene framed in which case you have to move further away from the subject. This reduces magnification which increases DOF. But you have to move position to change DOF.

EDIT: I should have read Paul's comments before posting.

Message Edited by BobF on 07-07-2008 09:58 AM

[AstroImager]

---

BobF wrote:

But you have to move position to change DOF.

---

...or change focal lengths on a zoom lens.

No worries, Bob -- I think you and I were posting the same thing at the same time!

 

Paul

 

[hughlite]

Wow. Some amazing misinformation on this thread. Depth of field does indeed change regardless of crop factor. Look at the link below. Then scroll down to the DOF calculator which correctly requires sensor size to determine depth of field. Keep the lens, aperture, and subject distance all the same and note the differences in the calculated DOF.


http://www.cambridgeincolour.com/tutorials/depth-of-field.htm

or even here...

http://www.dofmaster.com/dofjs.html

Even Norman Koren in his rather famous plethora of DOF calculations normalized what he explained into 35mm film terms, as so not to confuse those working with medium or large format.

http://www.normankoren.com/Tutorials/MTF6.html

One of the reasons that the Canon 5D (and all FF cameras since then) really appealed to wedding and portrait photographers when it was introduced was that the photographer could use, say, an f1.4 lens, and get the narrower DOF that you couldn't get with the same lens on an APS-C or 4/3 sensor.

Message Edited by hughlite on 07-07-2008 03:13 PM