You guys need to google Canon's Lenswork book. It explains this in detail. A large part of it is *magnification/needed enlargement* of the sensor/film. The more you enlarge the film/sensor area to the print size, the more depth seems in-focus. The Lenswork book has photos that illustrate this.
skid00skid00 wrote:
You guys need to google Canon's Lenswork book. It explains this in detail. A large part of it is *magnification/needed enlargement* of the sensor/film. The more you enlarge the film/sensor area to the print size, the more depth seems in-focus. The Lenswork book has photos that illustrate this.
When you say "enlarge the film/sensor area to the print size", are you referring to making the medium larger (e.g. crop to full frame) or are you referring to the magnification needed to go from a medium to a print.
kakomu wrote:
Then, what exactly are you trying to refute from my posts?
I wasn't refuting anything, you were!
gdanmitchell wrote:
Larger formats provide shallower DOF.
kakomu wrote
This isn't true in the least.
I was clarifying the situation in which most people who ask this question find themselves. They want to take a specific picture and have a choice of formats. They are often not concerned with the technical explanations of the dots in the following: If they use a larger format, ... ... ... they get shallower DoF (for a given aperture).
We both understand DoF and the factors controlling it. Someone learning and asking about the issue may want a simple answer for now and not the whole circles and confusion thing (they'll get there sooner or later). If you say to them "technically using a larger format gives you more DoF" - but you don't also say to them "but you won't get the same picture because you didn't change FL" they will be more confused than when they started.
I have just experienced this with my new 35L, an example to help clarify I hope... The first week with this wonderful lens I was shooting in on vacation with my 5D2, and the background blur was wonderful/dreamy when combined with the relative wide angle. And it being relatively wide I had to move closer to my subject or ask my subject to move closer to me, increasing the effect/decreasing the DOF by decreasing the subject to camera distance or increasing the subject to background distance or both. Then last night I had to use the lens for a work gig on my 1D4 to shoot some indoor action. The 1.3 crop factor is by itself fairly irrelevant when looking strictly at amount of background blur relative to FF, but I had to back up to get the same framing I was experiencing on my 5D2, which changed the distance relationship significantly enough that the dreamy OOF effect of the lens was lessened by this action... So I will be adding a 24L to the lineup, to shoot such scenarios with my 1D4, and hope the effect is similar enough to my 5D2/35L combo.
