dSLR picture size

[mustang85]

Hi,

was just looking at photos i've taken with a dig point and shoot and realised that the images from the point and shoot are not as wide as the ones from my dSLR. Is it common for dSLRs to have a wider picture than point and shoot cameras?

Thanks

[Shosta]

P&S are 3x4 ratio usually and dSLR ar 2x3 (like 35mm film).

[Riley]

not so sure about that
surely 28mm (35mm equiv) is 28mm in either format....comments ?

if thats the case, then the 3x4 frame is taller
but the essence of what is said is true, dSLRs are 3x2, with the exception of four-thirds dSLRs

Riley

[ktixx]

P&S are 3x4 ratio usually and dSLR ar 2x3 (like 35mm film).
This is true


not so sure about that
surely 28mm (35mm equiv) is 28mm in either format....comments ?

if thats the case, then the 3x4 frame is taller
Not really sure what the above is trying to convey, can you clarify?

[Ray Schnoor]

not so sure about that
surely 28mm (35mm equiv) is 28mm in either format....comments ?

Riley
Not sure about what? I'm not sure what you are saying here. You can always put a 35mm equivalent value on any camera/lens, but that says nothing about the size/ratio of the camera sensor.

The vast majority of P&S cameras I have seen do have a native 3x4 sensor ratio. A few of them do have a setting for 2x3 ratio which in essence crops off pixels from the top and bottom of the photo. The vast majority of dSLR cameras I have seen have a native 2x3 sensor ratio.

When a 3x4 sensor ratio is printed out on a 4x6 sheet of paper(which is what I assume the OP is referring to), the photo will be printed out at 4"x5.3" with a 0.35" white strip on either end of the photo. In this sense, photos from a 4x3 ratio sensor are not as wide as those from a 2x3 ratio sensor.

On the other hand when printed out on 8x10 paper, a 3x4 ratio will print out at 7.5"x10" with a white strip on the top and bottom, while a 2x3 ratio sensor will be printed out at 6.7"x10". In this case the 3x4 photo is "taller" than the 2x3 photo.

Whichever format you use, you need to crop the photo to the ratio you want printed, or use a paper with the closest ratio of your format. That way you will minimize the white strips on the top/bottom/sides of your prints.

A 2x3 ratio sensor does not make photos which are wider than a 4x3 sensor. It only appears that way if they are printed out "full frame" on paper which favors the 2x3 ratio.

Ray.

[Riley]

sure
if a lens for a given system from four thirds is 28mm
and a comparative lens on say a canon is 28mm
while i dont deny that four thirds are 4x3, and the canon dslr is 3x2
'surely then the field of view is the same
hence the difference is, that the four thirds frame (4x3) is taller than 3x2

im not sure about this, but 28mm is 28mm yes?

Riley

[Riley]

Hi,

was just looking at photos i've taken with a dig point and shoot and realised that the images from the point and shoot are not as wide as the ones from my dSLR. Is it common for dSLRs to have a wider picture than point and shoot cameras?

Thanks

Ray Schnoor,
sorry but i dont see him asking about printing anything, but as to what is wider

Riley

[Ray Schnoor]

Ray Schnoor,
sorry but i dont see him asking about printing anything, but as to what is wider

Riley
You are right, in that he didn't mention anything about printing, but since a digital image doesn't have height or width until it is printed, I assumed the OP was referring to a printed image. In this case everything I said is true.

If you don't want to talk about a printed image, lets talk pixels.

Canon Rebel XT - 3456 pixels x 2304 pixels - 8 MP 2x3 ratio camera
Olympus EVOLT E-500 - 3264 pixels x 2448 pixels - 8 MP 3x4 ratio camera
Canon Powershot S80 - 3264 pixels x 2448 pixels - 8 MP 3x4 ratio camera

If you take the first dimension as width, the 2x3 ratio camera is "wider" than the 3x4 ratio cameras.

If you take the second dimension as height, the 3x4 ratio cameras are "taller" than the 2x3 ratio camera.

On the other hand, if you take the first dimension as height and the second as width, then the opposite is true. Who cares? This means nothing until you print out the photo.

I stand by my statement. Either crop a photo to fit the paper, or print on a sheet of paper that favors the ratio of your photo.

What do you say Mustang85, were you talking about printed photos?

Ray.

[cdifoto]

Given the same height, then OP you are correct. dSLRs are almost always wider with a few exceptions. :)

[cwphoto]

You are right, in that he didn't mention anything about printing, but since a digital image doesn't have height or width until it is printed, I assumed the OP was referring to a printed image. In this case everything I said is true.

If you don't want to talk about a printed image, lets talk pixels.

Canon Rebel XT - 3456 pixels x 2304 pixels - 8 MP 2x3 ratio camera
Olympus EVOLT E-500 - 3264 pixels x 2448 pixels - 8 MP 3x4 ratio camera
Canon Powershot S80 - 3264 pixels x 2448 pixels - 8 MP 3x4 ratio camera

If you take the first dimension as width, the 2x3 ratio camera is "wider" than the 3x4 ratio cameras.

If you take the second dimension as height, the 3x4 ratio cameras are "taller" than the 2x3 ratio camera.

On the other hand, if you take the first dimension as height and the second as width, then the opposite is true. Who cares? This means nothing until you print out the photo.

I stand by my statement. Either crop a photo to fit the paper, or print on a sheet of paper that favors the ratio of your photo.

What do you say Mustang85, were you talking about printed photos?

Ray.

Good answer Ray.

[Riley]

irrespective of the number of Mp, be it 6, 8, 10 or 144 million
the field of view of the lens you used to take the image is the same

http://www.dpreview.com/learn/?/Glossary/Optical/Picture_Angle_01.htm

given the field of view is the same, per 35mm equiv, the 4x3 frame must be taller. and that is as demonstrated below

http://www.dpreview.com/learn/?/Glossary/Optical/Aspect_Ratio_01.htm

result: if both lenses are the same field of view, they are images of the same width

Riley

[cwphoto]

That last bit's not right Riley. For a given lens, all formats are the same diagonal (to maximise the lens' image circle), not the same width. This obviously excludes cameras supporting multiple formats.

So what 4:3 gains on one side it loses on the other when compared to other formats (in this case 3:2).

[Riley]

That last bit's not right Riley. For a given lens, all formats are the same diagonal (to maximise the lens' image circle), not the same width. This obviously excludes cameras supporting multiple formats.

So what 4:3 gains on one side it loses on the other when compared to other formats (in this case 3:2).

lets be clear on this
are you saying that a four-thirds with 28mm is not the same viewing angle as say a canon 3x2 dSLR and 28mm?
(both 35mm equiv)

Riley

[cwphoto]

lets be clear on this
are you saying that a four-thirds with 28mm is not the same viewing angle as say a canon 3x2 dSLR ?

Riley

No that's not what I am saying - but for the record that's not right either.

The focal length of the lens is only part of the FoV story. FoV must also be referenced to the size of the imager for it to have any meaning.

But unless I missed something I didn't think that was the debate. :confused:

[Riley]

umm
is it not right because it makes a double negative (language)

or did you just say that a four-thirds and 28mm are not the same viewing angle as say a canon and 28mm

surely the 35mm equivalence accounts for that

Riley

[cwphoto]

OK, I think you mean 28mm in 35mm camera terms.

Meaning an Olympus with a 14mm lens would have the same FoV as a Canon 5D with 28mm lens.

If so, then that is correct.

But I still think we haven't cleared up my piece about the diagonal etc.

[Riley]

oh ofcourse
i edit added the 35mm equiv, but you beat me too it

so what you are saying is, the viewing angle is the same across the diagonal
that makes sense to me

Riley

[Ray Schnoor]

irrespective of the number of Mp, be it 6, 8, 10 or 144 million
the field of view of the lens you used to take the image is the same

http://www.dpreview.com/learn/?/Glossary/Optical/Picture_Angle_01.htm

given the field of view is the same, per 35mm equiv, the 4x3 frame must be taller. and that is as demonstrated below

http://www.dpreview.com/learn/?/Glossary/Optical/Aspect_Ratio_01.htm

result: if both lenses are the same field of view, they are images of the same width

Riley
I am aware that MP does not matter, which is why I used the ~same MP value for all cameras listed. In this way, I am trying to use the more universal diagonal field of view.

As to your examples, there are 3 different field of view angles listed(horizontal, vertical and diagonal). It also states that since aspect ratios differ between formats, the more universal value(diagonal) is used.

Also, from your examples, your result is only valid if you use the horizontal field of view. Your result is not true if you use the vertical field of view or "the more universal diagonal field of view"

Is there some reason you prefer to use the horizontal over the vertical field of view or even the more universal diagonal field of view?

Here are a few examples:

Width field of view

W = 3

4/3's sensor would have W=3, H=4, diagonal=5
2/3's sensor would have W=3, H=2, diagonal=3.61

Height field of view

H=4

4/3's sensor would have W=3, H=4, diagonal=5
2/3's sensor would have W=6, H=4, diagonal=7.21

As you can see from the large disparity of the diagonal values, this is why the more universal diagonal value is normally fixed when comparing differing formats.

Diagonal field of view

diagonal=5

4/3's sensor would have W=3, H=4, diagonal=5
2/3's sensor would have W=4.16, H=2.77, diagonal=5

Now as you can see, you are correct only of you use the horizontal field of view, which is not the preferred method when comparing differing aspect ratios.

If you use the horizontal field of view, the 4/3's system is indeed taller.
If you use the vertical field of view, the 2/3's system is indeed wider.
If you use the (once again this is from your example) more universal diagonal field of view, the 4/3's system is taller and the 2/3's system is wider. As I have said before, but I will change terminology since printing was not mentioned by the OP, it doesn't make a whole lot of difference until the photo is displayed, either on a monitor or on a print.

Ray.