Neilhunt

Non cellphone cameras have one subsystem that controls exposure (PASM, ISO, bracketing, flash, etc.) while a completely separate subsystem controls focus (area, mode, tracking, etc.)

Here are some ideas for integrating those two systems to make some tasks easier.
In particular, informing focus settings based upon depth of field derived from aperture settings, or vice versa.

Set Focus Nearpoint

Landscape photographers often want to include foreground elements as well as distant features all in sharp focus. Three existing approaches are to focus on the near point and “waste” half of the depth of field nearer than that; use a rule of thumb like focusing on some object that you guess is half as far again as the distance of the nearest object; or pull up a smart phone app to calculate DOF and set focus manually (which is next to impossible on most cameras since there is no mechanical or electronic distance scale to rely upon).

What if I could set the back focus button to “near point focus”, and have the camera acquire focus on the near point I'm trying to shoot, then automatically shift focus further out so that the measured near point is just within the depth of field range. Remember that the camera knows what aperture it will choose for the exposure, and it knows the focal length of the lens, and so it can trivially calculate the depth of field, as long as it knows the size of the circle of confusion I am willing to tolerate. In addition, upon performing back button nearpoint focus, the camera could flash a warning if the depth of field does not include infinity as well.

Focus x to Infinity

In a variation, in P mode perhaps, the camera could evaluate the depth of field required to span focus across the designated nearpoint out to infinity, and use that to narrow the aperture as necessary to make the depth of field sufficient.

Focus Bracket

For macro photographers, the depth of field problem can be even more severe - a depth of field of just mm is normal. A modern technique is focus stacking - shooting several images at different focus to stack to build sharpness across the whole subject.

But for most cameras, manually cycling focus through a range in small measured steps is very hard - even if you know what step size is appropriate for the aperture you have chosen.

It would be great if we could have a focus bracket mode which automatically chose, and shot, focus steps to overlap the depth of field of each shot from the designated near focus point to a preset range.

I could imagine using a control to set stack depth of field (in cm) to 1, 2, 5, 10, 20, 50, 100, etc, or (in feet/inches) to .5”, 1”, 2”, 4”, 6”, 1’, 2’, 5’, etc., just like you set the parameters of an exposure bracket.

Set Circle of Confusion

Anticipating the objection that depth of field is not absolute, since at either limit, the scene is not perfectly focused, but is not defocused “enough to matter”, obviously the photographer would have to set up the size of the circle of confusion (the size of the circle on the sensor within which a point of light is blurred) that is acceptable, from a size of one pixel, up to the more conventional definitions of 1/2000 of the sensor diagonal (about 0.03mm for a full frame sensor).

Summary

A few simple additions to camera firmware would add some cool features for serious photographers, particularly landscape and macro photographers, to be able to use focus more creatively with better automation. The usage model would not be a big reach for anyone who is accustomed to back button focus and spot focusing on the critical point of the subject, or anyone who uses exposure bracketing.

Bill_de Loc: US

Auto focus stacking/shifting is already available. In Nikon's D850 it takes the shots to be stacked externally. I have a Panasonic that does the stacking internally and let's you choose the in focus area. You can produce more than one interpretation from the same set.

I believe it is the Panasonic that will also shoot a series at different apertures.

Those are two cameras I own. I'm sure some research will turn up more cameras with even more features.

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Bigmike1 Loc: I am from Gaffney, S.C. but live in Utah.

I'm afraid you are way over my head with all of this. With most of my shots I don't have any problem with focus and depth of field, then I ain't no professional. (:

wildweasel

I have an Olympus EM 1 Mark ll that does focus stacking in the camera, the intent was for macro I believe but it also works for landscape. you can set different focus increments and it shoots 8 raw and jpeg shots and stacks them and produces a final jpeg. It works quiet well, I always use it on macro shots.

rmalarz Loc: Tempe, Arizona

I find it's just as easy to tilt the front standard so that the plane of the lens intersects the ground at the same location as the plane of the film. The further the camera is from the ground the less tilt is required.
--Bob

Pablo8 Loc: Nottingham UK.

My sentiments completely. But I wonder if you have baffled the OP by taking the easier way out, using the Scheimpflug Rule (Theory). I don't think the OP can enjoy photography. Seems to want the camera to do everything for him, without any skill or knowledgeable input.

jackm1943 Loc: Omaha, Nebraska

That's often doable Bob, but only when the subject is relatively flat. It doesn't increase the DOF, it merely alters the plane of focus. The DOF remains perpendicular to the plane of focus so it becomes vertical, up and down from the plane of focus. So, if there are tall trees or buildings, their tops may remain out of focus. I know that you already know all this, but wanted to mention it because I've found that focus stacking landscapes can often remedy this problem.

John Howard Loc: SW Florida and Blue Ridge Mountains of NC.

The Zeiss Batis series of lenses for the Sony A7 series of cameras make focusing for landscape easy. They have an electronic scale that reads the near and far limits to DoF. I simply dial the lens so infinity is just in focus and then close down the aperture until the distance to the foreground element has this in focus also.

So I guess Sony has figured out the firmware issue you suggest. And the distance scale on my manual focus lenses is an important part of my purchase decision. Nikon has gone overboard in down sizing and controlling cost making their scales non functionable. I believe this is also because they want to shrink the degrees of turns needed to focus.

steinr98

Some cameras, ( I have a Canon 7D MK II)one can move the focusing square with out moving anything else & then stack- works for me!! Pretty easy no figuring of anything!

speters Loc: Grangeville/Idaho

I would not need any of that c..., I just look in my viewfinder, put my focus were I want it to be and I'm done (with having the exact DOF that I want)!

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Helicon Focus, and some remote camera controllers like qDSLR Dashboard ( https://dslrdashboard.info/downloads/ ) offers much of what you are looking for.

ballsafire Loc: Lafayette, Louisiana

Right!

amfoto1 Loc: San Jose, Calif. USA

I've got 20 year old Canon film cameras that have "A-DEP" mode. I forget what that stands for, but it's essentially "auto depth of field".

It's been a long time since I've used it, but if I recall correctly it could be used two ways: You could select a single AF point, then focus upon the closest or farthest object you want in focus (or vice versa), then the camera would determine and use an aperture/focus distance combination to try to achieve the desired focus across that range as best possible, depending upon the distances and the focal length being used. Alternatively, you could enable all the AF points and simply let the camera determine the closest and the most distant objects covered by an active AF point, then go through the same process of setting an aperture and point of focus it determined would give depth of field insuring good focus across the entire range, depending upon the distances and focal length being used.

It was only partially successful, in my experience. One problem was that sharp focus is "in the eye of the beholder".... as you noted, the "acceptable circle of confusion" varies from situation to situation and what the camera used was set by Canon, not by the photographer. It might have helped if the user could determine their own desired CoC (or it might have just created more confusion! Pun intended ).

This was with film cameras, too... After some experimentation I didn't use it and really don't recall if any DSLRs I've used have had the A-DEP feature. I strongly suspect it would be really problematic now on digital, simply because many users today are fanatically obsessed with sharpness wwwaaaayyyy beyond what they really need, viewing and judging their images at huge magnifications... Many zoom right to "100%", which with a 24MP camera is like making a five foot wide print and then viewing it from 18 or 20" away....when they actually will only be making 8x10s from the image or, perhaps, sharing a 600x900 pixel version of it on Facebook! With resolutions of 30MP, 40MP and even 50MP becoming more and more common, it just gets worse because that same "100%" is going to be even more massively magnified and the viewers will be overly critical, freaking out if their images aren't "perfect" from near to far. (It ain't easy being a camera manufacturer, in this day and age of over the top user expectations!)

As to the idea of stepped "focus bracketing" for stacking, yes some cameras already have that feature too. In fact, for many others it also may be possible to do. For example, for many Canon DSLRs there is a software "hack" called Magic Lantern, which includes a focus bracketing feature, among other things. As I understand it, the user can choose the increments they want to use and the number of shots necessary, after which it's relatively automated.

Or, for focusing stacking macro shots, there are computer controlled, motorized focusing rails that can be used to generate a series of images, in quantities and increments of the user's choosing.

Or, Helicon Focus is now offering a self-contained hardware solution in the form of a macro extension tube-like device that provides focus bracketing on most Canon and Nikon DSLRs.

Helicon Focus also offers a software program that automates the process with a camera tethered to a computer (which also lets you preview images much larger than the viewfinder or camera's LCD screen).

Either the tube or the tethering software can be complemented by another Helicon software used to assemble multiple shots to achieve an optically impossible depth of field image.

I think a lot of what you are wanting already exists.