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Depth of Field on the D800E

V

Vivek

Guest
One of the hallmark techniques of street shooting has always been using hyper focal distance . On a Leica M you place the infinity mark at the F stop and you can see that everything from your navel to the moon should be in focus . Close inspection would show that this is only true in the most liberal definitions of “in focus “ . With larger sensors (and it appears smaller pixels ) DOF seems to have disappeared .

A recent blog post on Diglloyd (on the free blog) presents a theory ? that DOf should be calculated by using a circle of confusion that mirrors the pixel size .

You could easily see this with MF at wide apertures but I had always considered this a difference in focal lengths . Using an M9 and a S2 the pixel pitch is close and so a 70mm lens has the same DOF on both cameras (but different equivalent FOV)..so all I was seeing was the fact that a 70 on the S2 was a 50 on the M9.

Street shooters are taught to get close and use wide angle lens .....the more you shoot the closer you can get ......but as pixel pitch gets below 5 ... you just don t have adequate DOF to cover subject movement . But the same concept applies to many different subjects .

Add in that optimum aperture is often between f4 and f5.6 and I ve found my limiting factor with the D800E .....
You basically covered what you need to do when shooting with the D800E. So, why bother with the theory which is based on a set of assumptions and is approximate at best? Unlike a manual RF cam, the D800E or a liveview cam offers DOF preview. It is an easy preparation- for a given lens, and a distance range, the required aperture can be found ahead of time and used in practice. Even in case of a mechanical RF cam, it can be worked out ahead of time.
 

Shashin

Well-known member
Add in that optimum aperture is often between f4 and f5.6 and I ve found my limiting factor with the D800E .....
Photography is not an object lesson in resolving power, it is an art. Use your aperture to create the DoF you need, that will always result in the best and sharpest image.
 

glenerrolrd

Workshop Member
Photography is not an object lesson in resolving power, it is an art. Use your aperture to create the DoF you need, that will always result in the best and sharpest image.
Seriously Sahasin are you kidding ? What an insightful comment . The whole discussion is about whether the D800 has adequate DOF for some of its intended uses . Diglloyd put forth POV that the smaller pixel pitch of cameras like the D800 wash t being considered in DOF calculations .

I will be sure to consult your definitions of photography before I go out to shoot.
 

Jack

Sr. Administrator
Staff member
Diglloyd put forth POV that the smaller pixel pitch of cameras like the D800 wash t being considered in DOF calculations .
And my point was now that pixel pitch is finally small enough, I do not think it is a viable determinant of CoC. When pixels were fatter, it made more sense to look at it though... What I believe is now a viable determinant, is how large you plan to print combined with the average viewing distance you expect -- which not too ironically is exactly what we used to do with film :).
 

glenerrolrd

Workshop Member
Jack,

I don't think that you need a flamesuit - as predicted the questions are coming about why can't I get 100% sharp images with the same DoF at f/16 or f/22 (or to be honest f/8 -> f5.6) that people used to with 10 or 12mp cameras. Why are identical images looking softer on screen now with 36mp compared to the same shot with the same settings taken on a D3 or D700 etc etc.

Nothing has changed - you need to treat shooting a D800 (as indeed you did the D3x) as if you are shooting with bigger formats such as MFDBs. It's still all about the tiny pixel pitch and physics/optics.
"As predicted “ ....Jeez Graham thats pretty damn insulting .

Nothings changed except we now have a 36MP Nikon that costs $3000 and looks and handles like a D700 . The objective ...am I just guessing here .. is that most buyers will believe they should get better IQ (however they define it) .

Two related observations :

1. Having some limited experience with the D800E and familiar with the differences between the s2,M9,D3x,D3s etc . I am finding the DOF (as I see it ) extremely restrictive at least as much as the S2 . This makes the D800E less versatile than I anticipated . It will be very hard to use for street shooting and most action photography . (thats my opinion ..not asking for any help ..just a POV) . It is unforgiving with MF focus lenses more than I expected after using a D3X with the same lenses.

Please don t call me a pixel peeper . Lack of sharpness due to missed focus (outside that stingy DOF) is my number one issue in street shooting and action photography . DOF is also critical when you layer a sheet scene ...and you have to know your equipment very well to be able to put the plane of focus where it needs to be . This wash t the purpose of the post so if you disagree on this paragraph lets try a different thread. Maybe how sharp is sharp enough ?

2. Diglloyd put forth POV that we might not be considering pixel size in estimating DOF . I found this interesting and wondered ..how big of a factor is this . I am sure that the physics and formulas have been explained. Camera to subject distance and focal length are what I grew up with ....the DOF scales on my Leica M lenses . Digital adds a new variable or maybe several.

Its obvious that a D800 is a lot like MF and you could do worse that just considering it MF with all it benefits and challenges . But comparing the D800E to my S2 (a number of people seem to want to do this ?) I have the same MPs ..but very different pixel sizes ....4.88 verse 6.8 . So if I shot a 50mm lens on each camera (forgetting the FOV would be different) would the S2 have greater DOF? I expect the answer to be YES .

Does it matter ..I don t know . If I use a 70mm on the S2 to get the same FOV now what . I expect the lens factor outweighs the differences in pixel size . So here the D800 would have more DOF.

My apology for confusing the intent of the thread as its obvious that my attempt to provide context for my observations thru some posters off the track .
 

Shashin

Well-known member
Seriously Sahasin are you kidding ? What an insightful comment . The whole discussion is about whether the D800 has adequate DOF for some of its intended uses . Diglloyd put forth POV that the smaller pixel pitch of cameras like the D800 wash t being considered in DOF calculations .

I will be sure to consult your definitions of photography before I go out to shoot.
That would be very wise to do...

But seriously, sorry if I misunderstood your comment--perhaps a bad attempt at humor.

Pixel pitch and DoF are unrelated. DoF is about perceived sharpness which comes down to the ability of the eye to see detail based on a viewing condition. So the answer to Diglloyd comments are simple; you don't consider pixel pitch because it is irrelevant.
 

glenerrolrd

Workshop Member
And my point was now that pixel pitch is finally small enough, I do not think it is a viable determinant of CoC. When pixels were fatter, it made more sense to look at it though... What I believe is now a viable determinant, is how large you plan to print combined with the average viewing distance you expect -- which not too ironically is exactly what we used to do with film :).
Thank you for an easily understood answer . Then you believe that the differences between the D800 and say the S2 pixel size are immaterial (or not really relevant in practical applications ). And that at the same lens focal length they should be pretty close . I must have misinterpreted Lloyd s POV .
 

Shashin

Well-known member
So if I shot a 50mm lens on each camera (forgetting the FOV would be different) would the S2 have greater DOF? I expect the answer to be YES .
And the answer is yes.

Does it matter ..I don t know . If I use a 70mm on the S2 to get the same FOV now what . I expect the lens factor outweighs the differences in pixel size . So here the D800 would have more DOF.
Yes again.

One of the problems of defining DoF is that it is "acceptable" sharpness. What you think is "acceptable" changes over time, with subject matter, with personal taste, etc, and so it becomes very difficult to look at an image and say DoF stops at that point or this point. Dof scales and calculators are really a guild to help you visualize DoF, but they are not definitive, if that makes sense.

But if you start printing your D800 images next to your M9 images, you should be seeing the same DoF.
 

Jack

Sr. Administrator
Staff member
Thank you for an easily understood answer . Then you believe that the differences between the D800 and say the S2 pixel size are immaterial (or not really relevant in practical applications ). And that at the same lens focal length they should be pretty close . I must have misinterpreted Lloyd s POV .
Roger, *I* believe the differences in pixel-pitch/sensor-size between the D800 and S2 are for most practical photographic purposes, moot. However, since in practical form we'd need to shoot the S2 with the 70 and the D800 with a 50 to get similar framing, the D800 is going to generally going to render deeper DoF if the same apertures are used. But that's a healthy *if.* Ironically, the S2's fatter pixels should allow an extra stop before diffraction sets in, and that is roughly the same extra stop that the S2's longer focal length for same framing requires to get back to the same net DoF as the D800. IOW, it's going to be a DoF toss-up if you use both systems at their respective optimal diffraction limited apertures and lens focals that render the same basic framing. Stated differently, the lone advantage the D800 will have is a net gain of about one stop in shutter speed all else equalized. Starting to sound vaguely familiar? (Reader, if it doesn't familiar to you, then you probably weren't around for the any of the 5 decades of 35mm film to MF film arguments LOL!)

Of course then we start to get into ISO and noise comparison discussions AND lens rendering characteristic discussions which become more and more subjective not to mention personal to the individual artist's needs -- in the end we choose a system based on our own perceptions of artistic and/or technical benefits balanced to our own needs, no right or wrong choices.

..

I'm not going to try and interpret what Lloyd stated because I'm not 100% clear as to what he meant ;)
 

Bob

Administrator
Staff member
Really simple
This should settle it Depth of field - Wikipedia, the free encyclopedia
-bob

All because of the angular resolution as presented to the eye as a result of the whole imaging chain that results in the viewed image.
for a 35mm format, and an un-cropped print viewed at a distance equal to the print's diagonal measure the COC is the same no matter how many pixels are present as long as they cannot be individually resolved at the viewing distance.
The only reason that a larger sensor seems to have a larger COC is that less enlargement is required to obtain a given print size.
The only reason to use a COC less than 30 microns is if the print is viewed at distances closer than the print diagonal, or if the image has been significantly cropped and then enlarged to the same print size.
If one makes it a habit of viewing images at 100% and I confess that I am guilty of this especially when evaluating sharpness, then any COC larger than 1.4-2 pixels pitches just makes it look too soft. but then, if you work it out, I am viewing the image at something like 1/10 of the diagonal measure.

Sometimes there is no really simple explanation.
 
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glenerrolrd

Workshop Member
Roger, *I* believe the differences in pixel-pitch/sensor-size between the D800 and S2 are for most practical photographic purposes, moot. However, since in practical form we'd need to shoot the S2 with the 70 and the D800 with a 50 to get similar framing, the D800 is going to generally going to render deeper DoF if the same apertures are used. But that's a healthy *if.* Ironically, the S2's fatter pixels should allow an extra stop before diffraction sets in, and that is roughly the same extra stop that the S2's longer focal length for same framing requires to get back to the same net DoF as the D800. IOW, it's going to be a DoF toss-up if you use both systems at their respective optimal diffraction limited apertures and lens focals that render the same basic framing. Stated differently, the lone advantage the D800 will have is a net gain of about one stop in shutter speed all else equalized. Starting to sound vaguely familiar? (Reader, if it doesn't familiar to you, then you probably weren't around for the any of the 5 decades of 35mm film to MF film arguments LOL!)


Of course then we start to get into ISO and noise comparison discussions AND lens rendering characteristic discussions which become more and more subjective not to mention personal to the individual artist's needs -- in the end we choose a system based on our own perceptions of artistic and/or technical benefits balanced to our own needs, no right or wrong choices.

..

I'm not going to try and interpret what Lloyd stated because I'm not 100% clear as to what he meant ;)
UNCLE ...:deadhorse: Thanks
 

Shashin

Well-known member
I did a measurement of the area of the 33x44mm sensor I am inspecting when viewing my Pentax 645D files at 100% on a 24" monitor in Photoshop. It was about 9x5mm. Or to put another way, it is like looking a 44"x33" print from about 10"
 

glenerrolrd

Workshop Member
Really simple
This should settle it Depth of field - Wikipedia, the free encyclopedia
-bob

All because of the angular resolution as presented to the eye as a result of the whole imaging chain that results in the viewed image.
for a 35mm format, and an un-cropped print viewed at a distance equal to the print's diagonal measure the COC is the same no matter how many pixels are present as long as they cannot be individually resolved at the viewing distance.
The only reason that a larger sensor seems to have a larger COC is that less enlargement is required to obtain a given print size.
The only reason to use a COC less than 30 microns is if the print is viewed at distances closer than the print diagonal, or if the image has been significantly cropped and then enlarged to the same print size.
If one makes it a habit of viewing images at 100% and I confess that I am guilty of this especially when evaluating sharpness, then any COC larger than 1.4-2 pixels pitches just makes it look too soft. but then, if you work it out, I am viewing the image at something like 1/10 of the diagonal measure.

Sometimes there is no really simple explanation.
I follow the logic and really I look at most stuff on a screen from about 18 inches ....doesn t have to be 100% to find the DOF . The higher the resolution the easier it is to find . But I really notice at normal size that the obvious focus point just isn t as crisp ..then I check and I can find the front and back focus ..but it degrades the IQ . You can see this in portraits in a second ..missed the leading eye and its in the trash bin.

No argument on the definitions ,computations etc and agree sometimes there is no simple explanation. :thumbup:
 

GrahamWelland

Subscriber & Workshop Member
"As predicted “ ....Jeez Graham thats pretty damn insulting .
Sorry that you feel that way but I stand by my comments - many months ago I and others stated that this would happen, and guess what? It has. It certainly wasn't anything personal, just an observation.

If you want an exercise in circular & heated venomous arguments about all of this then take a look at the monster thread that was recently over at LuLa.

Anyway, I think that this subject has been pretty comprehensively covered in this thread. We all get our shorts in a knot over the impossibility of huge DOF rendering on screen at 100% when the reality is that unless you have a 36mp screen it isn't going to matter anything like as much as you think. :thumbup:
 

glenerrolrd

Workshop Member
Sorry that you feel that way but I stand by my comments - many months ago I and others stated that this would happen, and guess what? It has. It certainly wasn't anything personal, just an observation.

If you want an exercise in circular & heated venomous arguments about all of this then take a look at the monster thread that was recently over at LuLa.

Anyway, I think that this subject has been pretty comprehensively covered in this thread. We all get our shorts in a knot over the impossibility of huge DOF rendering on screen at 100% when the reality is that unless you have a 36mp screen it isn't going to matter anything like as much as you think. :thumbup:
Graham

When having a “discussion” it is impolite to start ..by categorizing others observations as “predictable” or establishing them as “amateurs” . This is just a technique to diminish any opinion other than your own .

No one is challenging your right to your own opinion ..but I will push back when you attack my POV by diminishing my credibility . Argue the facts or your experience but not that others don t understand what is obvious to you. This is what is meant by “speak for yourself” .
 

GrahamWelland

Subscriber & Workshop Member
Graham

When having a “discussion” it is impolite to start ..by categorizing others observations as “predictable” or establishing them as “amateurs” . This is just a technique to diminish any opinion other than your own .

No one is challenging your right to your own opinion ..but I will push back when you attack my POV by diminishing my credibility . Argue the facts or your experience but not that others don t understand what is obvious to you. This is what is meant by “speak for yourself” .
Roger,

This is my last communication on the matter since it's transcended from observations to perceived personal attacks on credibility. You are using words here that I didn't use and assuming that I have desire to diminish your opinion - well, they're both news to me.

Anyway, in summary, if want to pixel peep at 100% on screen then you're going to end up determining that the 'acceptable' DoF is rendered using a CoC at close to pixel pitch. If you print or display at different sizes and on different media, the CoC used to estimate your range of acceptable DoF will be a completely different number (typically much larger) unless you want to view it with a microscope.
 

Shashin

Well-known member
Zeiss has a really nice pdf on DoF and bokeh:

http://www.zeiss.com/c12567a8003b8b6f/embedtitelintern/cln_35_bokeh_en/$file/cln35_bokeh_en.pdf
 

Oren Grad

Active member
Zeiss has a really nice pdf on DoF and bokeh:

http://www.zeiss.com/c12567a8003b8b6f/embedtitelintern/cln_35_bokeh_en/$file/cln35_bokeh_en.pdf
+1: It's an excellent paper. Pay special attention to the section at the bottom of page 20, "How precise are tables and depth of field calculators?"

In the same spirit, here's another question to ponder: what does sharpening do to focus transitions, and to our subjective perceptions of DOF?
 
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