DPReview.com is closing April 10th - Find out more

Micro 4/3rds vs. Full Frame

Started 10 months ago | Questions thread
c h u n k
c h u n k Senior Member • Posts: 2,042
Re: Micro 4/3rds vs. Full Frame

AeroPhotographer wrote:

It's common to say that small sensors have greater DOF. That's usually so, but to be precise, the sensor size is not the reason. The greater DOF comes from the shorter focal length lens.

For macro work, you can convert focal length and distance (from camera to subject) into magnification.

DOF = k * f# (1 + M) / M^2 M=Magnification

f# is the number you set on the lens. The (1+M) term corrects for the effective f number. So for example at 1x, the effective f number doubles and (1+1) = 2, which corrects for this.

k depends on how much blur you tolerate, but k=.02 is pretty reasonable when DOF = millimeters.

This formula is correct regardless of sensor size or lens focal length. But small sensors allow lower magnification because the pixel spacing is smaller. And lower magnification results in greater DOF.

Alan

Huh? Not following just the bit about smaller sensors allowing lower mag bc of pixel spacing?

-- hide signature --

**********-*-*-*-*-*-*-*-*-**********
Some of my photos here: https://flic.kr/ps/2i6XL3
“You're off to Great Places! Today is your day! Your mountain is waiting, So... get on your way!” --Dr. Seuss

 c h u n k's gear list:c h u n k's gear list
Canon EOS 70D Canon 6D Mark II Canon EF 85mm F1.8 USM Canon EF 100mm f/2.8 Macro USM Tamron AF 28-75mm F/2.8 XR Di LD Aspherical (IF) +7 more
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow