Agreed. But LF cameras don’t “move” whilst taking the shot, you adjust the movements (tilt, shift, swing) to perfectly frame and focus the image before taking the single shot.
Emphatically, no you can’t use one when movements have been applied, because DoF calculators only work when the lens and film plane are parallel.
The DoF is made up of the distances yn and yf, which are measured vertically at any given point on the DoF wedge. Notice that the lines DoFn and DoFf describe the wedge, within which, falls the DoF.
Closing down the aperture increases the combined DoF distance yn + yf, but opening up the aperture too far can adversely affect tall buildings…
So to compare the two systems at their best, you’d have to compare the D850 at f/10 and the LF at f/32 without tilt-shift.
What would be the result ?
And you’d have to compare the 2 systems with tilt-shift under the same conditions, with their minimum diffraction-free aperture.
Given the equipment you show on your first photo, I assume you don’t have it for the D850.
Aren’t you tempted? And what do you think this comparison would yield?
It all depends on finished print size and quality of scanning as well. Most of us LFers use old-fashioned “suck it and see” methodology to determine what suits us best and then stick with it.
Digital is much more fussy due to the small dimensions of everything.
With the D850, the “ultimate” diffraction free aperture, given the pixel pitch is f/5, but this usually gives far too small a practical DoF the f/10 is the best compromise “optimum” aperture.
The big difference between 35mm and 5" x 4" has to be the physical image size. It is far easier to adjust tilt, aperture and focus on the larger format. The D850 does have a focus peaking display, which helps, but isn’t the same as a 7x loupe on a ground glass screen. Which is why I tend to stick with avoiding diffraction by controlling the aperture on the D850.
You mean with movements the setting of the tilt/shift lens? And not the movements of the subject?
But again when comparing the two cameras one has to take care that both have identical settings. Like @JoPoV mentioned.
Now you are talking about the use of the tilt/shift sec.
I know enough of math to read the images.
Of course. That is what the word “movements” always indicates in the LF world. Except you don’t just tilt the lens, you tilt the entire front standard, which gives much finer control.
Maybe tests during shooting with a tablet or other screen could replace the magnifying glass, using the D850’s ability to send live images produced by wifi (at least jpg).
No!! We compare the two systems based on measurable differences such as the difference in dof. Concerning the diffraction I looked at the calculator of Photpill.
…, which is the equivalent of a 50mm digital camera lens???
Not forgetting that diffraction limit is more correctly calculated on a blur circle of twice the pixel pitch, rather than the outdated CoC of 30µm that was a guesstimate based on print viewing distance.
And then there’s the problem of viewing an LCD screen in bright sunlight. At least, with an LF camera, we can drape a black focusing cloth over our heads and the ground glass screen.
Then there’s the issue of being able to see the screen and adjust the movements at the same time. How many hands is that going to take?
Not sure what your “no” means.
If it is no about adding diffraction in the 'equation", it depends what you want to compare. For me the idea is to compare DOF at the best sharpness the sensors can provide so when no refraction limits the maximum sharpness of the image (ok here we have film - which is of course lot more complicated to asses and less consistent and maybe not really possible to compare - would need some scientific measure on film(sss)).
Does it make sense for you ?
On the left side the reference camera , on the right side another camera. I didn’t go further as the medium. But even in the medium there are different sensor sizes.
The reference camera focuses on a subject 20 meter far, lens 70mm f-nr 2. When I want to take that frame with another camera, another sensor size, then I have the possibility to do that with a lens with the same focal length but another distance or the same distance and another focal length. But the framing of the subject must be the same.
You can see the figures.
