Originally Posted by
William W
It is not that the wide angle lens, per se, always gives you a larger depth of field than a telephoto lens – but rather it is the framing of the subject.
That’s why I gave you a specific example in my reply, here, which references a specific FRAMING of one person standing up:
“For making a vertical orientation, full length photograph with your camera of someone standing keeping a little bit of ground space and a little bit of air over the top (i.e. Field of View of about 7ft):
> using F/2.8 you’ll get about 3ft Depth of Field (DoF)
> using F/1.8 you’ll get about 2ft DoF
The point being made is that’s not much shallow DoF gain by using an F/1.8 lens at F/1.8 as compared to using an F/2.8 Lens at F/2.8.”
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In the Opening Post you were asking about taking a photo of “people up close” and wanting to blur the background.
On this last weekend if you took the same framing of the photo of people “up close” with the 17mm end of the lens as the 50mm end of the lens, and you used F/2.8 for both shots, then the background would be equally out of focus in both shots.
But I suspect that you did not do that, but rather, I suspect that made a very wide shot of the person when you used the 17mm end of the lens and you did not move in closer to the person to frame them tightly in exactly the same framing as you did when you were making the shot with the 50mm end of your lens: and thus there is a greater Depth of Field when you made the shot with the 17mm end of the lens .
WW