Perspective 7-14 vs 14-24

Big Ga said:

ajmeeker said:

I think what i'm going to have to do is find someone in town who has a 7-14 and shoot the same image on my D700 and rent the 14-24, They'll be different for sure, and i would assume the 14-24 would stretch out the sides and corners more since it's a larger format.

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Let me help you.

First image is the 7-14 mm oly on a E510 @7mm

Then its a D3 @ 15mm (very close to the same angle, and I think it was actually 15.5mm)
Then its a D3 @ 12mm (a good bit wider).
(these two are with the 12-24 Sigma, not the nikon lens though)

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That is EXACTLY What I was looking for, YOU SIR ARE AWESOME!!

Big Ga said:

Hmmmm, interesting. I wonder whether this is a difference in the definition of AOV v FOV.

When I've looked through 'equivalent' wide angle lenses on 3:2 and fourthirds, the 3:2 format seems to give a fairly significant 'wider' image. Its as if the height is pretty much the same with both formats, but the additional 'length' of the ratio means that you do record a not insignificantly wider images from the 3:2 camera.

So the AOV of the lenses might very well be the same, but the resultant image has captured a greater angle .... if you see what I mean!

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Having used the Panasoinc 7-14mm on the GH1 which supports 4:3, 3:2 and 16:9 modes through its oversized sensor I do understand what you're saying - changing from 4:3 to 3:2 doesn't seem to lose much off the top and bottom in proportion to the gains at the side. Going to 16:9 mode it's still the same angle of view but it 'looks' much wider although the height loss is more noticeable:





Not a scientific comparison obviously, just to give a rough idea.

John

Sam Bennett said:

According to B&H's website, here's the AoV for each lens:

Nikkor 14-24mm f/2.8 (on an FX camera)
Angle of View 114-84°

Panasonic 7-14mm f/4
Angle of View 114-75°

So, they both have the same AoV on the wide end, with the Panasonic being narrower on the long end, as predicted since it's 28mm equivalent.

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there is a difference in framing between 3x2 and 4x3

and since the FoV commonly used is across the diagonal, this makes a difference in the apparent width of an image even at the same EFL

data for horizontal FoV between 4x3 and 3x2 systems
using a 7mm on 4/3rds gives horizontal 102 degrees FoV
using 14mm on FF gives horizontal 104.3 degrees FoV

so there is a width difference of 2.3 degrees between formats on the same EFL
the same FoV on 4/3rds would require a lens of 6.76mm

however, the 4/3rds frame will be taller, AoV in height is
7mm on 4/3rds 76.5 degrees AoV
14mm on FF gives 69.53 degrees AoV

data for horizontal and vertical FoV 7mm on 4/3rds 102 x 76.5 degrees
14mm on FF 104.3 x 69.53 degrees

--
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The angle of view of both lenses can't possibly the same at the long end if it is the same at the short end (as it is, diagonally).

The Panasonic is a 2x zoom, and the Nikon a 1.7x zoom

Big Ga said:

Hmmmm, interesting. I wonder whether this is a difference in the definition of AOV v FOV.

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Angle of view is normally defined across the image diagonal, which is independent of aspect ratio.

Big Ga said:

When I've looked through 'equivalent' wide angle lenses on 3:2 and fourthirds, the 3:2 format seems to give a fairly significant 'wider' image. Its as if the height is pretty much the same with both formats, but the additional 'length' of the ratio means that you do record a not insignificantly wider images from the 3:2 camera.

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The horizontal angle will be wider in 3:2, but the vertical angle will be wider in 4:3. Your impression that the vertical angle is the same in both formats is wrong.

Big Ga said:

So the AOV of the lenses might very well be the same, but the resultant image has captured a greater angle .... if you see what I mean!

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No, not true.

Why is the vertical AOV about the same for the 7-14mm?

I would expect it to be a bit wider.
--
Jeff Taylor
http://www.pbase.com/jltaylor

JLTaylor said:

Why is the vertical AOV about the same for the 7-14mm?

I would expect it to be a bit wider.

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I think if you look at the top, it is a little bit.

I probably lined it up by eye using the edge of the box hedging on the bottom, and the tree on the right as the constant reference points. If you look at the top E510 pic, compared to the middle one, there is indeed a little more of the tree branches showing.