Bipod

Maxwell Smart had a telephone in his shoe. Many people today have a camera in their (cellular) telephone. :-)

Miniaturization is all the rage--and not just in cellphone cameras. Even "camera cameras" are getting smaller.
For example, small size seems to be one of the big selling points of mirrorless cameras over DSLRs.

Pity the poor fool who is still using a large format view camera! He will never know the pleasure of snapping
a "selfie" in a bar or restaurant. :-)

But consider: f/64 was reasonably sharp on a large format (film) camera. (Remember the "f/64 Group"?)
That was some serious depth-of-focus! But now f/22 has disappeared from cellphone cameras---because
on thee small cameras, it's too fuzzy.

Alas, not everything can be minauturized without loss of quality. For example: a minature loudspeaker will
not do a very good job of reproducing bass (low frequency) tones. Very clever technical tricks can be used,
but they all take a toll on quality. For the best bass reproduction, you need big speakers.

That's because sound waves have a certain size. Concert A (440.00 Hz) has a wavelenth of 2.5 feet. But low A
on the 88-key grand piano (55.00 Hz.) has a wavelength of 20.5 feet. It's hard to get a big wave out of mall
box!

Similarly, light has a wavelength. Even though light is a transverse wave and the wavelength of visible light
is measured in nanometers (400 to 700 nanometers, roughly), it still has a fixed size. You can minaturize a
camera, but you can't minaturized a light wave unless you want to take photos by ultraviolet light or X-rays.

Why should photographers care? Because f/22 on a "full frame" (we used to call that "miniature format")
camera is a bigger hole (aperature) than f/22 on a dinky APS-C sensor.

As most here will know, f-number is defined as the ratio of lens focal length to the diamter of the aperture.
Small format (or sensor) cameras must use shorter focal lengths for each type of lens: wide, standard or
telephoto. Therefore, the aperture is smaller for a given f-stop.

And when you try to push light though a too small hole, something awful happens: it splits (defracts) into its
composite wavelenths! Each is defracted at a differnt angle. So a dot of light becomes a blob of light
on the sensor or film, which gives you a fuzzy image.

There is absolutely nothing one can do about defraction, except to use a bigger aperature. (It's a fact
of quantum physics: built into the universe.)

This is why large and medium-format pinhole cameras are much shaper than 35-mm pinhole cameras.
It's easy to make a 35-mm pinhole camera: drill a hole in the center of a body cap, and mount the correct
size pinhole over it. But the resulting image will be fuzzy (but still kinda nice): the usual pinhole
fuzziness plus diffraction.

Few of us want to produce fuzzy images. So if minaturizatoin continues to conquer the camera market,
will depth-of-focus soon be a thing of the past?

I hope not. I don't want to have to use a camera whose smallest aperature is f/16 or f/11. But that's
"progress": in the electronic gizmo world, "smaller and cheaper" has totally replaced "bigger and better".

RWR Loc: La Mesa, CA

Depth of focus has nothing whatever to do with the aperture.

Bipod

Sorry, I meant depth of field.

therwol Loc: USA

Cell phones with their ever-improving cameras have made a huge dent in the point and shoot camera market. They have not conquered the camera market.

So long as they sell full frame cameras (and larger) you will see lenses that offer f/22 or even higher. Sometimes you need the depth of field of smaller apertures, particularly for macro shots. (Focus stacking doesn't really work if the subject you're taking a picture of is moving.)

Cameras (and phones with cameras) having tiny sensors use lenses with very short focal lengths, and with their great depth of field, you don't need tiny apertures. In fact, it may be hard to obtain shallow depth of field if you want it shallow with that equipment, even if you can control the aperture.

I may notice some loss of sharpness with my own lenses at f/22 and f/32, but it isn't that significant compared with the blurring of not having the depth of field I need in a macro shot.

RWR Loc: La Mesa, CA

I was sure that’s what you meant. Depth of focus is a term not used much, just wanted to clear it up for anyone who’s unfamiliar with the difference.
I cannot comment much on the miniaturization craze, except I’m not impressed - I shoot mostly 6 x 7 and 6 x 9 and have no compunctions about stopping down to f/45 when I need the depth of field.

Pablo8 Loc: Nottingham UK.

We see too many uses of the term 'Depth of Focus' when 'Depth of Field' should have been used. Also the misconception about "apertures smaller than f/16 cause diffraction". That may be correct in crop sensor / mini size sensor cameras, but Medium/Large format cameras and their lenses are computed to perform well at smaller apertures. Yes, I contemplated joining the f/64 group, when I got my first 5 x 4 camera, way back.

chrisg-optical Loc: New York, NY

If f/22 disappeared I wouldn't miss it - I usually avoid f/22 - my max is f/11 or /16 - most lenses perform best in the midrange, and some perform well wide open.

russelray Loc: La Mesa CA

On the other side of the coin, the electronic gizmo world seems to be coming up with solutions to the problem. To wit, artificial intelligence and Topaz AI Clear.

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

Smaller sensors use shorter lenses for similar angles of view, so while a M4/3 sensor is tiny, some interesting things happen when you compare the two. A 10mm lens on a M4/3 has an angle of view similar to a 20 mm on a full frame camera.

At the same subject to sensor plane distances, the M4/3 camera with a 10mm lens will have less depth of field than a 10mm lens on a full frame camera - when compared at the same apertures.

However, if you increase the distance to take in the same field of view as the 20mm lens the effect of moving back will increase depth of field, but the change in distance changes the perspective.

If the goal is to have great depth of field, the smaller cameras, even with larger minimum apertures, the smaller sensors will deliver that.

RWR Loc: La Mesa, CA

Capn_Dave

Well not to start a war or anything but aperture most assuredly does effect DOF ( Depth of Field) There are many articles
on this subject, so no need for me to recite what is already known, We have this amazing tool called Google.

JohnSwanda Loc: San Francisco

f64 didn't disappear. It's still there on lenses for 8x10 view cameras.

jerryc41 Loc: Catskill Mts of NY

I don't care about the f/ numbers. They're just derived from a formula based on the size of the lens. As long as the aperture varies from large to small, I'm happy.

jerryc41 Loc: Catskill Mts of NY

"The lower the f/#, the more the depth of focus is reduced and the more impact tilt has on achieving best focus across the sensor."
https://www.edmundoptics.com/resources/application-notes/imaging/depth-of-field-and-depth-of-focus/

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

Most lenses are sharpest in there mid F stops, ie. if the lens is a 1.8, usually it should be sharpest from say f4 to f8. Most lenses fall off in image quality when you stop down to f22. And I believe you will see more and more focus stacking software on newer camera's making it easier to get sharp for ground and back ground at lesser F stops.