How I would have liked a replacement to the 15-85 for my R7 but sorry Canon - too late. I got tired of waiting and just three days ago picked up a Sigma 17-40 f1.8.
Yeah I know it's only 40mm at the long end but I've got it and I won't be stuffing around selling it and purchasing another lens.
So the circle of confusion is another concept that you find useless? Lol. You are welcome to your own opinions, but not to your own facts. The fact is that the size of the sensor affects the circle of confusion, and the circle of confusion is one of the factors that determines DoF*.
Next, I suppose you’ll attempt some ridiculous reply about your how your personal definition of DoF doesn’t depend on the circle of confusion, or how you mean the ‘lens DoF’ as if DoF were an intrinsic property of a lens (it isn’t), or some other nonsense.
You really should avoid engaging in discussion of the technical aspects of photography. Frankly, your attempts at it are embarrassing.
Depth of field requires an image to exist, and thus requires a sensor (or other imaging medium), and the size of the sensor matters. However, the other ‘DoF’ —depth of focus— is independent of sensor size. Depth of focus is the image space counterpart to depth of field, and it’s measured in μm at the image plane. It has little relevance to general photography discussions…at least, little relevance for current cameras.
For DSLRs with dedicated phase detect AF sensors, depth of focus was the underlying basis for the specification of some AF points as ‘high precision’, requiring wider lens apertures (typically f/2.8) to achieve focus accuracy within 1/3 of the depth of focus, instead of one depth of focus for ‘standard’ (typically f/5.6) AF points.
So the circle of confusion is another concept that you find useless? Lol. You are welcome to your own opinions, but not to your own facts. The fact is that the size of the sensor affects the circle of confusion, and the circle of confusion is one of the factors that determines DoF*.
Next, I suppose you’ll attempt some ridiculous reply about your how your personal definition of DoF doesn’t depend on the circle of confusion, or how you mean the ‘lens DoF’ as if DoF were an intrinsic property of a lens (it isn’t), or some other nonsense.
You really should avoid engaging in discussion of the technical aspects of photography. Frankly, your attempts at it are embarrassing.
Depth of field requires an image to exist, and thus requires a sensor (or other imaging medium), and the size of the sensor matters. However, the other ‘DoF’ —depth of focus— is independent of sensor size. Depth of focus is the image space counterpart to depth of field, and it’s measured in μm at the image plane. It has little relevance to general photography discussions…at least, little relevance for current cameras.
For DSLRs with dedicated phase detect AF sensors, depth of focus was the underlying basis for the specification of some AF points as ‘high precision’, requiring wider lens apertures (typically f/2.8) to achieve focus accuracy within 1/3 of the depth of focus, instead of one depth of focus for ‘standard’ (typically f/5.6) AF points.
You might want to try learning something, instead of just resorting to personal attacks when your blatantly false statements are challenged with facts.
Or keep making foolish statements…it’s really your choice.
Just to pick one common example, many times someone will comment that a crop sensor is better for macro photography because it gives a deeper DoF. Of course, the deeper DoF is occurring only because the camera is further from the subject, which is fine if that's what you want. But if you want maximum optical magnification (e.g. 1:1), then the camera will be at the same distance from the subject regardless of the sensor size, and the FF camera will deliver a wider FoV at that 1:1 magnification, and the crop sensor will actually have a shallower DoF. Plus, if you're light limited (often the case if you're stopping down to gain DoF), then the crop image will have more noise at the high(ish) ISO you may be using. What all of that means is that 'I use a crop sensor for macro to get deeper DoF' is at best an oversimplification (and note that I haven't even touched on pixel density, diffraction, and other relevant concepts).
It is really important when comparing cameras with non-standard image sensor sizes.
It was really just intended for focal lengths.
The arguments start to come in when we apply depth of field.
Depth of field is not always important.
In fact, sometimes having more in focus can be an advantage.
I think this debate is simply about comapring DOF between APS-C and FF. It requires a larger aperture on APS-C to match the DOF of the equivalent field of view of FF. So if you have an APS-C 50/1.8 * it will never have the same DOF as a FF 80/1.2 for the same field of view - it would have to be a 50/0.75. That is where I think this discussion should have been targetted.
Most people using APS-C are doing so for reach (birding and other wildlife for example) or generally cheaper than FF and won't be concerned about DOF.
*or FF 50/1.8 of course
