Question about aspect ratios in regards to wide angle lenses

Started Feb 6, 2013 | Discussions thread
jkjond
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Re: Question about aspect ratios in regards to wide angle lenses
In reply to bartjeej, Feb 12, 2013

bartjeej wrote:

jkjond wrote:

bartjeej wrote:

KyleSlamchez wrote:

I have a question, and I'm asking it here, because I hope you guys landscape guys will know.
Ok, most camera sensors are either 3:2 (typical dslr) or 4:3 (m4/3, many point-and-shoots).

Now, of course a 4:3 image will give a more "square" photo (not an exact square, but closer to it).

My question is this: give the same focal length, will the aspect ratio affect how much of scene is photographed? For example, if I'm taking a picture of a bus, and I shoot it in the same place on a full frame camera with a 28mm lens (at a 3:2 ratio) camera and on a m4/3 camera (effectively doubling the focal length) with a 14mm lens (at a 4:3 ratio), will the 3:2 camera capture more of the sides of the bus and less of the sky?
Hope this wasn't too confusing. Thanks!

Re-hashing the answer I gave to a similar question a month ago:

Using the Pythagoran theorem you can calculate that for any 3:2 sensor with a given diameter, a 4:3 sensor with the same diameter will have a width (and horizontal field of view) of 0.96 the 3:2's width / fov, and a height (and vertical fov) of 1.08 the 3:2 sensor's height / vert. fov.

So, a 28mm equivalen lens on a 3:2 sensor will have the same diagonal field of view as a 14mm lens on a m43 sensor, but for the horizontal fov to be the same, you'd have to use a lens of 14mm*0.96 = 13.46mm. That would mean the diagonal fov of the 4:3 lens would be the same as on a 27mm equivalent lens.

Similarly, if you wanted the vertical fov to be the same as a full frame's 28mm, you'd need a lens of 14mm*1.08 = 15.14mm, which has the same diagonal fov as a 30.3mm lens on a full frame sensor.

Interesting info. I think in real terms, this means its too complex to really matter and the only solution if you find it is worth knowing is to use a zoom!

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UK wedding photographer in the Lake District
http://www.johnleech-weddingphotography.co.uk
For my landscapes and fine art photography:
http://www.johnleechstudio.co.uk

I have numbers in my head all the time and couldn't stand not knowing the answer to an earlier question like this, so I calculated it... but indeed, in real life situations, the difference in coverage is pretty much negligable.

There's a major difference between 4:3 and 3:2 in "feel" though, with 3:2 forcing the eye more in a certain direction, and 4:3 leaving the eye free to wander off in all directions.

Personally I find 3:2 neither fish nor fowl, I much prefer either 4:3 or 16:9, but (sadly for me) there're a lot of really nice cameras made with 3:2 sensors...

I was surprised at how little each seemed to vary when drawing the set in a circle, though there's no mistaking all the ratios when viewed separately.

Having been brought up on 3:2 and generally not cropping any of my images, I find 4:3 and 5:4 look too square, I'm more likely to crop exactly square than either of those, and could certainly not compose for anything but 3:2 or 1:1 on location.

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UK wedding photographer in the Lake District
http://www.johnleech-weddingphotography.co.uk
For my landscapes and fine art photography:
http://www.johnleechstudio.co.uk

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