selmslie Loc: Fernandina Beach, FL, USA

If you base your assumptions on information from a faulty DOF calculator, you are bound to make the wrong choices when it comes to deciding where to focus.

Below is another reason why Cambridge In Colour is a good source for information. It shows that your 20MP 1" sensor is diffraction limited at f/5.6. You would need to open the aperture to f/4 or drop down to a 12MP sensor to avoid this.

But I would not fret over whether the aperture is diffraction limited, especially with such a small sensor. It's not likely that it's going to show up with your built-in zoom lens.

But with a full frame 24MP sensor and a very good lens it might matter if you go beyond f/11. At 45.7MP, f/8 might be the limit.

The only reason I mention diffraction limit is because diffraction might make stuff near the DOF limits look like they are fuzzy.

Personally, I would not consider a compact camera since I can get perfectly fine snapshots from my iPhone or even my X100T. But when I want anything better than a snapshot, I will use a 24MP or 45.7MP camera and a good lens.

Ysarex Loc: St. Louis

I don't.

In the photo of grave markers I didn't use a DOF calculator. I did apply my useful understanding of how DOF distributes around the focus plane and rather than focus on the closest marker to the camera which would have wasted DOF or just used the center focus point in the camera which may have not extended DOF to the closest marker. I chose to focus on the marker behind the closest marker which proved effective and satisfactory.

selmslie Loc: Fernandina Beach, FL, USA

I did not suggest that you used a DOF calculator to guide you in taking the picture.

But if you relied on DOFMster to understand the subject, you could be incorrectly influenced by what you learned.

Ysarex Loc: St. Louis

I understood the subject decades before the Internet and DOFMaster came into existence. In fact it was the very 1/3 DOF rule that Frank brought up that solidly proves you were wrong that started me off on an understanding of DOF. It was the early 1970s and I worked in a camera store. I had by then learned that 1/3 rule-of-thumb and was in the process of showing a customer the DOF calculator on a lens. In doing so I recognized the imprecision in the 1/3 rule and later asked a senior member of the staff. He reached behind his desk and brought down a 1950's vintage copy of The Leica Manual and handed it to me saying, do the math. I did.

selmslie Loc: Fernandina Beach, FL, USA

How did Frank's statement prove that I was wrong about anything? All I did was to recommend the DOF calculator from Cambridge in Colour. I said nothing about the 1/3 assumption.

By the 1970s I had been working as a mechanical engineer for a decade and in the process of changing my career over to software engineering where I finally made some real money. I was never a clerk in a camera store.

As for doing the math, I have just proven that I can still do the math. You have proven nothing. You were not even able to catch the error that DOFMster made that doubled the hyperfocal distance.

One of us is a mathematician, engineer and programmer who can understand the issues clearly. The other is an amateur with a questionable memory and a bad attitude.

I will respond to anyone else who would like to discuss the subject, but I will no longer respond to you.

Ysarex Loc: St. Louis

I posed a question to Longshadow who was professing a desire for less complicated DOF info. I asked, couldn't an understanding that DOF distributes unequally around the focus plane be helpful? You answered: "No, it's not really helpful." You're wrong about that.

I provided some examples of where that understanding can be helpful. And you tried and tried to change the subject and eventually changed your tune saying it's "not really that useful," but never did admit that your original blanket statement was wrong.

Then Frank came along and reminded us of the 1/3 DOF rule-of-thumb -- a clear and simple proof that your original blanket statement; "No, it's not really helpful." is wrong.

Industry wide rules-of-thumb are typically based on some kernel of truth. In this case that fact is how DOF distributes unequally around the focus plane. Rules-of-thumb get adopted and spread throughout an industry because they're helpful to the practitioners of that industry. For many decades the photo industry adopted and spread the 1/3 DOF rule-of-thumb precisely because photographers found it helpful. Frank swears by it and says it works great. And that's how what Frank said proves your original statement; "No, it's not really helpful." is solidly wrong.

Is it time for more DOF calculator smoke now?
Thank heaven.

OldCADuser Loc: Irvine, CA

Gee, that sounds like my life story.

In 1980, after working 14-years as a Mechanical Engineer, I changed jobs and joined a software company where I finally made some real money. 36-years later I retired. And while I never worked in a camera store, I did work a second job one summer selling radios and small appliances at an Arlan's department store (now there's a blast from the past).

selmslie Loc: Fernandina Beach, FL, USA

That scenario may be more common than we might think.

My father started as a civil engineer and so did my daughter. Both of them moved on to better jobs. My son skipped the engineering step, went straight to business and is earning more than either of us.

I guess the lesson is, if you want an interesting career, become an engineer. But if you want to get rich, don't.

OldCADuser Loc: Irvine, CA

Oh, I still considered myself an engineer as the software company that I went to work for was selling software TO engineers and which they used everyday, and my role in the company was to work with these engineers to make sure that we were meeting their needs and keeping up with what we were offering them and that we were keeping up with what they were doing with our software, and so as to maintain my credibility I retained my professional engineering license up until I retired 8-years ago.

selmslie Loc: Fernandina Beach, FL, USA

My engineering background gave me som credibility but I moved into mathematical modeling and financial analysis.

Longshadow Loc: Audubon, PA, United States

One of the nicest things about an engineering background is a well developed analytical ability.
Comes in very handy.

selmslie Loc: Fernandina Beach, FL, USA

Maybe a chicken and egg situation. Your success as an engineer may come from an aptitude for analytical thinking.

Longshadow Loc: Audubon, PA, United States

Well, possibly an intrinsic ability? Genetics?
Who knows.
Still can't figure how I sucked up programming like a sponge. 12 languages under my belt.
Except for JAVA, in my early 50s. In one ear, out the other, without any dancing around in my head.

OldCADuser Loc: Irvine, CA

And as engineers, we also notice everything around us that's not working quite right and how it could hurt you if it goes seriously wrong. And since I worked for McDonnell Douglas for over 11-years, spending a lot time around aerospace engineers, you learn a lot more about airplanes and what can go wrong than you really want to know, like where to look, when boarding a plane, to see how old it is (date the airworthiness certificate was issued) or why, about 8 to 10-rows back, there's always a section of the fuselage where it looks like a window should have gone but there's nothing there.

Yes, sometimes I'm jealous of my wife as she's oblivious of everything that could go wrong around us. In her case, she only notices people's poor dental hygiene (she worked over 30-years in dental practices). I guess it could be worse, she could've worked for a proctologist

Longshadow Loc: Audubon, PA, United States