Comparing Olympus 4/3lenses to FX "Full Frame" offerings

Started 11 months ago | Discussions thread
Ian Stuart Forsyth
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Re: remaining "ignorant"
In reply to surfingmaltman, 11 months ago

surfingmaltman wrote:

Ian Stuart Forsyth wrote:

Doctor Lecter wrote:

I beg to differ. *You* can remain ignorant on the subject if you wish... DOF changes, but fstops/apertures are the same regardless of sensor size. It's simple physics — the amount of light passing through the lens.

Exactly physics, the 50mm F2.8 has a larger front element than the smaller 25mm F2.8 front element now are you going to try and convince me that the same amount of light will pass thru the smaller 25mm F2.8 as a 50mm F2.8. Has the 25mm F2.8 have some special power that allows it to suck more light thru its smaller opening.

It's been that way since 8x10 view cameras vs. 4x5 vs. 35mm... did anyone used to say, "yeah, but f5.6 is REALLY f8 if you move to medium format, dude..."

FF fanboys love to use this fstop equivalence BS. It probably takes away some of the sting of having spent $4,000 bucks on a lens.

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Dr. Lecter

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The Camera is only a tool, photography is deciding how to use it.
The hardest part about capturing wildlife is not the photographing portion; it’s getting them to sign a model release

Yes but that light would need to spread over a larger surface area. So more light is needed to achieve exposure across the whole frame.

No because F stop holds the same light intensity hitting the sensors but do to the size difference one captures more light for the same F stop

Are people confusing the brightness of the light and the amount of light here?

10 Ev worth of light passing through a 2mm diameter hole will be 10 EV on the other side at 2mm size image circle. (keeping things telecentric for simplicity)

10Ev worht of light passing through a 8 mm diameter hole will be 10 EV on the other side at 8 mm but it will be more light by sheer size but not brightness.

see below for more detail

But hey maybe I am wrong.

Ric

"Let’s look at light as if it was paint coming from a spray can. The lens AP controls the intensity of the paint being applied to the surface of the sensor and they both receive the same duration. At the end of that time which sensor has received the most amount of paint ?

Sure they have the same thickness of paint applied to their surface but one has more paint applied to its total surface any guess which one?

Now what would it take for that smaller surface to receive the same total amount of paint if the duration was held the same. One could try and amplify the paint but that won’t work as we cannot create matter. Then I guess all that we can do is increase the intensity of the paint hitting the surface of the sensor by opening up the lens equal to the size ratio of the 2 sensors."

a copy paste from here

http://www.dpreview.com/forums/post/52979908

Yes the 2 sensors will receive the same light intensity but one has a surface larger than the other

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The Camera is only a tool, photography is deciding how to use it.
The hardest part about capturing wildlife is not the photographing portion; it’s getting them to sign a model release

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