[John Poirier]

i said "dof marks", and backed it up a second time with "no dof marks on the barrel of those lenses", which has been the subject of this discussion for the entire thread.

you came in and effectively claimed that "dof scales"/calculations/measurements done by the lens was the same thing as somebody reading sloppy barrel markings combined with inaccurate focusing, trying to calculate it themselves, i disagreed.



you were asked to back that claim up with an example of a physical plane that has no depth... mee had to do it for you, lol

i claimed that perfect focus could be measured, and i provided a 100% crop proving how much of it was sharp, maybe ~4ft. in that case, and then both steve and i calculated it to be somewhere around 71-80ft of sharpness(??), using the stupid dof calculators

you came in and claimed that sharpness in a focal plane didn't exist, despite the 100% crop proving that it did, and then contradicted yourself by claiming that, well, sharpness could actually be calculated after all with a dof calculator, which is defined as: "Depth of field refers to the section of a photograph that appears to be in sharp focus"

---------- Post added 04-19-16 at 09:41 PM ----------



the o.p., reh, and others in this thread think that they can set one focus, and it'll be enough sharpness for when the subject moves, within the range of dof, without re-focusing on the subject.

not the same thing.

as for modern vs. old, if i have enough time, i'll always use manual everything over af/auto anything, and i don't need a dof calculator to do it... ymmv, especially for anyone using an ovf instead of liveview.

Ya know what? After reading this last posting I'm leaning toward thinking that you are bogged down in a serious misunderstanding of the theory behind all this rather than being deceitful. I'd like to give you the benefit of the doubt.

The funny thing is, I know from experience that using focus magnification to check DOF with the A7r is actually a good technique. I do it sometimes when dealing with tricky DOF scenarios. However, its usefulness is mainly for relatively static situations such as landscape work on a tripod. Your racing car scenario is also somewhat static in that you position yourself so that the distance of the vehicle from your location changes very little. Your practice appears to be fine, but the way you try to explain the theory behind it is hooped. Your attempts to shove your theories down others' throats, and your putdowns of those who think differently, are unacceptable.

I also make use of classic methods for determining DOF and plane of focus as appropriate to circumstances and equipment. I find it useful to be fluid in responding to unexpected situations, so I regularly practice with a variety of methods. Do these classic methods work? I think photographic evidence accumulated since 1816 shows that properly focused pictures with appropriate DOF were quite commonplace before the invention of the A7r. I've even done the odd sharp picture myself.

With that, I'm out of this discussion. I need to concentrate on arrangements for several shows.

[osv]

Ya know what? After reading this last posting I'm leaning toward thinking that you are bogged down in a serious misunderstanding of the theory behind all this rather than being deceitful. I'd like to give you the benefit of the doubt.

"A camera lens can only focus on one plane of the subject. This is the only area of the scene that is really sharp." Depth-of-field - Canon Professional Network

there is no doubt that a sharp plane of focus can be seen... i don't get how you could think otherwise.

The funny thing is, I know from experience that using focus magnification to check DOF with the A7r is actually a good technique.

of course it is.

next time just spare us all of your condescending little remarks like "Nothing compared to your skills, of course", because it doesn't leave you any moral high ground

[reh321]

contrast that with the o.p., reh, etc., who want to take one semi-measured focus point only, throw some sloppy unmeasured dof at it, and then take multiple photos, without re-focusing on objects that have moved within the dof region.

No! No! No!
I never said anything about taking multiple shots.
The issue is getting just one shot of a moving subject.
Here are several scenarios that involve taking just one picture, but a deep assured DOF is needed, and there is no way to use LiveView or "chimping" to provide that assurance:

(1) I already described taking pictures of my daughter playing basketball. That description had nothing to do with taking multiple pictures .... I was trying to get just one picture of her, using an MF lens. Keeping her in focus by moving me was not a viable option, because I was in a gym with rows of seats and various steel railings that limited mobility. Since she would not stay put long enough for me to focus on her, I had to draw a DOF box around her, so I knew if she stayed in a certain region she would be "in acceptable focus". That is not perfect, but it is better than nothing.

(2) I take pictures of wildlife Often the animal will start to leave just after I have focused on it. Take the picture now, or never, because most likely it won't come back. An appropriate DOF assures that the {one} picture taken just after it has started to move will be essentially as good as the {one} picture that wasn't taken just before it started to move. The entire process doesn't leave sufficient time to use LiveView or "chimping" to evaluate DOF

(3) Sometimes I visit Indianapolis Motor Speedway. Cars come around the corners at high speed; you can hear the car coming, but either you cannot see it at all, or your view is insufficient to tell which "line" it is following. I don't know until the car actually arrives whether it is following the specific line I had focused for, leaving insufficient time to move to maintain current focus or to refocus, even if I could determine what changes need to be made. They keep the track clean and smooth, so there is very little to use for evaluating focus in advance using LiveView or chimping, but an appropriate DOF assures that the car will be "in acceptable focus" regardless of which line it is following.

(4) You take pictures of drag racers; I take pictures of trains. Your pictures appear to be taken roughly perpendicular to the vehicle, so virtually everything is close to the plane of focus. My pictures are often taken at 30- 45 degrees away from perpendicular; an 80' passenger car or locomotive will extend nearly 30' on either side of the plane of focus, so I need significant and assured DOF to get the entire object in acceptable focus in the {one} picture I take.

---------- Post added 04-20-16 at 10:42 AM ----------

"A camera lens can only focus on one plane of the subject. This is the only area of the scene that is really sharp." Depth-of-field - Canon Professional Network

there is no doubt that a sharp plane of focus can be seen... i don't get how you could think otherwise.

I haven't seen anyone here doubt that a plane of focus exists. The issue is that you keep insisting that it is a physical entity, and at times have acted as though it has actual depth. It is a reference entity, like a longitude marking. It is a mathematical construct, the locus of points a certain distance away, and being a mathematical plane, it has two dimensions, height and width, only. It has no meaningful depth - you are into DOF as soon as you are any measurable distance from it.

[osv]

No! No! No!
I never said anything about taking multiple shots.
The issue is getting just one shot of a moving subject.

that fits the exact scenario that i described, you aren't re-focusing to follow the subject movement.

(1) I already described taking pictures of my daughter playing basketball.

you need 1/800th bare minimum, so if you set up any significant dof, you'll have to jack the iso to the moon, the pic will look like ****.

worst case, the place to pre-set focus and a thin dof is in the area under one side of the basket, facing the camera.

(2) I take pictures of wildlife Often the animal will start to leave just after I have focused on it.

do i need to link up some mf bif pics here? that have thin dof?

(3) Sometimes I visit Indianapolis Motor Speedway.

people were using mf at that track decades ago, with primitive gear, it most certainly can be done better with mf on modern cameras, using liveview, pre-focused at the right spot... roundy-round cars are easy, because you can also run a slow shutter and pan the shot.

(4) so I need significant and assured DOF to get the entire object in acceptable focus in the {one} picture I take.

again, that's not relevant to setting the correct focal point... i don't understand the drama, i've shot trains, it's the most predictable thing you can imagine.

---------- Post added 04-20-16 at 07:55 AM ----------

I haven't seen anyone here doubt that a plane of focus exists. The issue is that you keep insisting that it is a physical entity, and at times have acted as though it has actual depth. It is a reference entity, like a longitude marking. It is a mathematical construct, the locus of points a certain distance away, and being a mathematical plane, it has two dimensions, height and width, only.

i posted a 100% crop of measurable dof; there are millions of better examples all over the internet.

proof is not a mathematical construct.

[pacerr]

A broken clock is 'perfectly' correct twice a day at a time we choose . . . and every lens is always in 'perfect' focus whether it's at a point we choose or not.

A useful way to think of, and a practical way to apply, 'DOF' is to consider it a 'window of acceptable sharpness chosen for a specific situation'.

Regardless of the point of focus, 'DOF' is a function of aperture and aperture is a compromise between a 'window of acceptable sharpness' and a proper exposure chosen by the 'pitchure-taker' -- or maybe even by the Green Button or a Scene Mode -- but it, too, is always present.

It's up to you how intelligently you chose to use it, abuse it or ignore it.

Here's a fairly uncommon example (thanks, Dave, I don't have one. ) of what results if you ignore the 'DOF window' -- some ugly 'foreground bokeh' there regardless of the relative sharpness at the point of focus.

[reh321]

that fits the exact scenario that i described, you aren't re-focusing to follow the subject movement.

No time to do that, and certainly no time to use LiveView / chimp to examine constantly changing focus

you need 1/800th bare minimum, so if you set up any significant dof, you'll have to jack the iso to the moon

The NCAA Final pictures posted on MSNBC were taken using f/6.3, and they looked very good. Believe it or not, many of us have found 1/250 to be more than adequate for floor play.

worst case, the place to pre-set focus and a thin dof is in the area under one side of the basket, facing the camera.

The program listed her as 5'2"; actually she was a 5'1' guard who never got anywhere close to the basket; the only way to get a reasonable shot of her was from the side of the court.

people were using mf at that track decades ago, with primitive gear, it most certainly can be done better with mf on modern cameras, using liveview, pre-focused at the right spot... roundy-round cars are easy, because you can also run a slow shutter and pan the shot.

obviously you have never been there.

again, that's not relevant to setting the correct focal point... i don't understand the drama, i've shot trains, it's the most predictable thing you can image

And if you got the entire thing in focus, you were either lucky or else you thought about DOF in advance

proof is not a mathematical construct.

Huh?? Mathematics is all about proofs. Points, Lines, and Planes are mathematical concepts, and when these sites you point us to use these terms, they are using the mathematical definitions for those terms. A point has no dimension. A line has one dimension. A plane has two-dimensions.

[osv]

I haven't seen anyone here doubt that a plane of focus exists. The issue is that you keep insisting that it is a physical entity, and at times have acted as though it has actual depth. It is a reference entity, like a longitude marking. It is a mathematical construct, the locus of points a certain distance away, and being a mathematical plane, it has two dimensions, height and width, only.

i'm not sure what part of the picture you aren't getting, but the dof there is easily measured.

[reh321]

i posted a 100% crop of measurable dof; there are millions of better examples all over the internet.

i'm not sure what part of the picture you aren't getting, but the dof there is easily measured.

Nobody questions ability to measure DOF. The question is determining appropriate DOF in the field under time constraints and with limited static markings {in the target area to be used in LiveView / chimping}.

[osv]

No time to do that, and certainly no time to use LiveView / chimp to examine constantly changing focus

that's a personal limitation that you are placing on yourself only... your inability to get a shot isn't relevant to the rest of us.

The NCAA Final pictures posted on MSNBC were taken using f/6.3, and they looked very good..

if you are trying to compare settings, it's a game you'll lose, because you don't have any idea how to shoot sports.

Believe it or not, many of us have found 1/250 to be more than adequate for floor play.

as usual, that's wrong, but thanks for proving my point.

The program listed her as 5'2"; actually she was a 5'1' guard who never got anywhere close to the basket; the only way to get a reasonable shot of her was from the side of the court.

of course you'll be shooting from the side of the court, very few school courts are big enough to have seats behind the basket.

so much negativity... since you clearly can't focus a camera, you should be using af, like most people do.

---------- Post added 04-20-16 at 08:46 AM ----------

Nobody questions ability to measure DOF. .

you and john both claim that there is no such thing as perfect focus, it's hilarious

---------- Post added 04-20-16 at 08:57 AM ----------

Here's a fairly uncommon example (thanks, Dave, I don't have one. ) of what results if you ignore the 'DOF window' -- some ugly 'foreground bokeh' there regardless of the relative sharpness at the point of focus.

all i see there is a bad pic of nothing; there isn't any subject of interest, it doesn't tell a story, the lighting is wrong, the foreground adds nothing to the shot, etc... f/1.0? you can't even tell what the aperture was, so what's the point?

---------- Post added 04-20-16 at 09:09 AM ----------

The NCAA Final pictures posted on MSNBC were taken using f/6.3, and they looked very good. Believe it or not, many of us have found 1/250 to be more than adequate for floor play.

that bogus claim needs to be corrected, so that people don't get confused and misled.

"Because you’re indoors shooting fast action, you need wide aperture (“fast”) lenses. The two favorites are the 300mm f/2.8 for action at the far end and a 70-200mm f/2.8 for the near end. Most photographers also have a wide-angle zoom (my preference is the 24-70mm f/2.8).

Shutter speeds of 1/1000 or faster are necessary to stop the action"
How to photograph basketball | Reed Hoffmann

[reh321]

that's a personal limitation that you are placing on yourself only... your inability to get a shot isn't relevant to the rest of us.

No, that is a limit on us humans. Not even you can do all the LiveViewing/chimping you advocate in the few seconds needed to prepare for some pictures

if you are trying to compare settings, it's a game you'll lose, because you don't have any idea how to shoot sports.

Wrong again. My point was that this professional had obviously thought about DOF before he took the picture, and went to a fairly high ISO so he could get one with deep DOF. The setting was such that he could not have used your method, because nothing was hanging in the air that he could have used for your recommend LiveViewing/chimping before his shot.

as usual, that's wrong, but thanks for proving my point.

Not having seen the shots, as usual you are speaking out of ignorance

of course you'll be shooting from the side of the court, very few school courts are big enough to have seats behind the basket.
so much negativity... since you clearly can't focus a camera, you should be using af, like most people do

Again you are speaking out of ignorance. Actually, I am very good at this, and part of being good is in figuring out how to make DOF work for you even if you cannot use Liveview/chimping to check your work.

you and john both claim that there is no such thing as perfect focus, it's hilarious

As usual, you are repeatedly misrepresenting what we say. It is very sad. You really do need to learn to read for content. None of us has ever made that claim. What we do state is that absolutely perfect focus is limited to an area so thin that it is of no practical use, that most actual pictures are in the DOF area of adequate focus.

[victormeldrew]

No, that is a limit on us humans.

I'd give up now...you're wasting your time. We all get what you mean...actually he knows what you mean too, he's just baiting you for fun. Typical trolling.

It matters not how you make a shot, just that you enjoy yourself and are happy with the results. Any photographer worth his salt understands the concept of using DoF to give yourself focussing leeway, but if he doesn't get it, fine...it doesn't matter for his set piece shots anyway.

[pacerr]

. . . so what's the point?

The point? Perhaps that you seem to have entirely missed the point? That image obviously wasn't intended as an aesthetic work of art for C&C!

Quite the contrary: MY point, specifically, was to illustrate that disregarding a very predictable "window of sharpness" (DOF) has predictable consequences . . . and that some ugly 'foreground bokeh' may result.

And the implication was that it's wise to acquire a working knowledge of DOF effects and to practice using same.

And as for " f/1.0 "? Are you not familiar with how EXIF data reports certain 'not-modern', non-AE-reporting lenses? The aperture used isn't relevant to the point of the example which was that ignoring DOF limits has consequences regardless of the aperture.

In this instance he was using an SMC M 40/2.8 lens mounted via a 'dumb' adapter on an Olympus Om-d e-M10 ; which I suppose only proves that while he was casually exploring legacy lenses on a 'modern' Interchangeable Lens Mirrorless System Camera it's still possible to achieve unintended results if you're not paying attention.

---------- Post added 04-20-16 at 12:54 ----------

I'd give up now...you're wasting your time.

Oh, I think we all understand that. To a certain extent most of the commentary in threads such as this is posted for the subliminal edification of interested lurkers who may be new to the topic(s) -- and for the casual entertainment of others that know better. Sort of a weird Q&A FAQ board that, like a Wiki, gets weeded over time by exposure to light and the laws of physics.

At some point though it's wise to recall this piece of wisdom:

"Never, never try to teach a pig to whistle. It wastes your time and annoys the pig!"

And even if you should succeed, it's best to remember not that the critter whistles so well that counts, but that he whistles at all that's amazing.

Hey, as Granny sez, it's all just good, clean fun 'til someone gets poked in the eye with a sharp reply.

[osv]

No, that is a limit on us humans. Not even you can do all the LiveViewing/chimping you advocate in the few seconds needed to prepare for some pictures

wrong, i've posted sharp mf action shots that were difficult to shoot, i proved that focusing works, you posted nothing face it, *you* just can't focus with the gear *you* have... give it up and go af, like everyone else does.

i'll post another sharp mf action pic, just to show you that manual focusing on the run can be done :-) without any stupid dof calculators.

Wrong again. My point was that this professional had obviously thought about DOF before he took the picture,

wrong again, you posted nothing, you made unsubstantiated claims that you couldn't back up, not even with a link.

anyone who thinks that 1/250th is optimal for shooting basketball doesn't know how to use a camera, that's just plain ignorant, and it's misleading to noobs who are trying to learn.

None of us has ever made that claim. What we do state is that absolutely perfect focus is limited to an area so thin that it is of no practical use

it's certainly of no use to people who can't focus a camera, we can agree on that, lol



---------- Post added 04-20-16 at 12:22 PM ----------

Quite the contrary: MY point, specifically, was to illustrate that disregarding a very predictable "window of sharpness" (DOF) has predictable consequences . . . and that some ugly 'foreground bokeh' may result.

ugly bokeh is ugly because of the way that the lens is designed, period.

what you proved was that if you use the wrong lens the wrong way, yeah, you might get ugly bokeh... that's not a dof issue, it's a noob mistake, we've all done it.

[emalvick]

It seems that some people are too literal, some are too technical... You'd swear photography is rocket science that only someone with a PhD should participate in.

The funny thing is I have a PhD (not in photography), but I realize that most science and math are constructs to try to explain things simply but rarely exactly. I suspect man opinions in this thread are correct and many might be incorrect. But a lot of opinions are being passed off as facts, and that is where the errors lie.

When all is said and done, the photo you have is the only product you have. How you get to it doesn't matter very much as long as you know how to get there. When I go through a gallery, I don't look at a photo on the wall and wonder whether the photographer used AF or MF. I rarely know what lens, camera, shutter speed, aperture, or distance the shot was taken from. If the photo is good, it's good.

For my own shooting, I know what the math says about DOF and Focus distance. As an engineer, I understand how the math is approximate. The focal plane is just a construct to help people understand focus. In physical terms that plane should be the surface of a sphere, which for most photography can be approximated by a plane. The DOF is just a way to give depth to what's in focus, but it is a function of so many items including our eyes and our minds that arguing in exacts is futile. I see nothing wrong with focusing and even trying to gauge DOF with live-view as long as people recognize that what you see up close in terms of DOF may not be the same as what you see once you print an image or even look at a screen. It doesn't mean it won't be, but as long as we understand when it isn't, who cares? If it works for you, it works for you.

I know that as someone that has taken up street photography with very limited extent in the past year, that I like these old ancient technology lenses like the FA 31 or FA 43. I like having the DOF available on the lens. It gives me an idea of what I'll get and it allows me to miss focus when I'm rushing to get the street shot that is in front of me as I walk around. I like the idea of using Live View or my OVF to nail exact focus, but I also don't want to miss shots. Pre-setting focus and DOF allow me to get pretty good shots with both those lenses, and I am happy as are most of the people that see the photo. My audience isn't going to know if the person crossing the street is not at the exact focal distance.

And, the real point is that I am having fun getting the shot. I love that DOF allows me to get more shots than I might if I chose to shoot at f/2 only. I don't need to obsess over my subject being at the exact focal distance. If I did, I might never get the shot, and I would give up on photography a long time ago. Street photography (and wildlife photography) are teaching me that. I spend a ton of time shooting landscapes, but I am learning that I get too OCD with it just like this thread, and it isn't as much fun as it used to be. Life is about living and having a bit of fun with.

[MarkJerling]

It seems that some people are too literal, some are too technical... You'd swear photography is rocket science that only someone with a PhD should participate in.

The funny thing is I have a PhD (not in photography), but I realize that most science and math are constructs to try to explain things simply but rarely exactly. I suspect man opinions in this thread are correct and many might be incorrect. But a lot of opinions are being passed off as facts, and that is where the errors lie.

Thanks for summing that up!