DOF questions

Question #1
Smaller sensored cameras have deeper DOF ..because ??

APSC have deeper DOF than FF??

Would a FF camera be able to replicate the deeper DOF of smaller sensors
via smaller F stop choice ..or does diffraction kill this as a viable option??

How do FF cams manage to capture deep DOFs in landscape shots which they appear to be able to do ? F stop choice alone ?

Thanks if you have a comment on these Photography 101 questions..
g

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painterdude said:

Question #1
Smaller sensored cameras have deeper DOF ..because ??

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going to dinner can't type fast enough

painterdude said:

APSC have deeper DOF than FF??

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yes

painterdude said:

Would a FF camera be able to replicate the deeper DOF of smaller sensors
via smaller F stop choice ..or does diffraction kill this as a viable option??

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d800 shows visible degradation from 5.6 onward....f11 starts to seriously impact sharpness but depending on the final size this might not be visible

painterdude said:

How do FF cams manage to capture deep DOFs in landscape shots which they appear to be able to do ? F stop choice alone ?

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f stop + good glass

painterdude said:

Thanks if you have a comment on these Photography 101 questions..
g

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wj
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painterdude said:

Question #1
Smaller sensored cameras have deeper DOF ..because ??

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I just read up the explanation on Wikipedia. As near as I can make out its something to do with the magnification of the subject on the sensor so a bigger sensor has greater magnification of the subject for a given composition than does a smaller sensor. But why that affects DOF, I am not sure.

painterdude said:

APSC have deeper DOF than FF??

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Yes

painterdude said:

Would a FF camera be able to replicate the deeper DOF of smaller sensors
via smaller F stop choice ..or does diffraction kill this as a viable option??

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Yes a FF frame camera needs 1 stop less of aperture than a APSC camera and 2 stops less than a M43 camera to achieve the same DOF

Diffraction is worsened by a combination of smaller apertures and/or smaller individual pixels so a FF frame camera will have less diffraction for a given pixel count than a APSC camera. This is because the individual pixels on the FF camera will be larger.

Nikon D800 has about the same size of pixels as a D7000 so diffraction effects will be about the same. The new D600 has bigger pixels therefore diffraction will be less at a given aperture.

But diffraction is not an on or off sort of thing, its quite a fuzzy thing that kicks is gradually. Some diffraction on a large sensor may be less of an issue than camera shake or imperfect camera focus. It can be a pretty subtle effect only visible at 100%

painterdude said:

How do FF cams manage to capture deep DOFs in landscape shots which they appear to be able to do ? F stop choice alone ?

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The best way is to use hyperfocal settings at smaller apertures so you can focus the lens on a point where you know it will reach from infinity down to X feet from the camera. Leica lenses and old Nikon lenses as well as current Sony Alpha lenses make this really easy to do because they have the hyperfocal markings on the lenses. Alas most modern lenses do not.

A camera like the new D600 may be the ideal landscape camera. Its fairly light and compact with a high resolution for lots of detail but quite large pixels that will keep diffraction away even at small apertures.

Hope this helps

painterdude said:

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painterdude said:

Question #1
Smaller sensored cameras have deeper DOF ..because ??

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It's simply matter of the physics, of geometric optics - i.e. the 'lens equation' in combination with the geometry of the lens aperture.

The physics and maths is really beyond brief forum discussion here.

Nevertheless, the general rule to remember, is that the ratio between two different sensor/film sizes, linear (not area), gives the number of 'F-stops' required to produce the same DOF, for the same angle of view and same subject distance.

painterdude said:

APSC have deeper DOF than FF??

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Yes - although not dramatically.

As an example of what I stated above...

35mm FF sensor diagonal = 43.3 mm

APS-C sensor diagonal = 28 mm (typical)

Ratio = 1.54 x (approx)

So the 35mm FF will produce the same DOF when its lens aperture is stopped down about a 'half stop' more than the APS-C camera's lens.

painterdude said:

Would a FF camera be able to replicate the deeper DOF of smaller sensors
via smaller F stop choice ..or does diffraction kill this as a viable option??

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Diffraction will become an issue if the required physical aperture is small - but that depends on how much DOF you are trying to replicate.

You may actually run out of aperture range with some comparisons.

For example - a 2/3rds inch sensor, such as in the X10 or XS-1, has a sensor dimension size of about 1/4 of a 35mm FF camera (11mm versus 43.3mm) - so if you were trying to replicate the smaller sensors' DOF at F11, then the 35mm FF camera's lens would need an aperture setting '4-stops' higher, i.e. 'F44', to match DOF (which may not be available).

painterdude said:

How do FF cams manage to capture deep DOFs in landscape shots which they appear to be able to do ? F stop choice alone ?

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Well, landscape shots tend to require 'acceptable focus' from infinity downward - and in this case the DOF is somewhat less of an issue.

Lack of DOF is most apparent with longer focal lengths (i.e 'telephoto'), or closer focus distance.

'Landscape' photography tends to be done more often with shorter focal length lenses ('wide/normal angle' lenses), and greater focus distances - so this makes it somewhat easier to achieve greater DOF - but that's not to say that smaller aperture aren't still required too (depending on the FL used and the DOF required).

I know plenty about it - as I'm not just a keen photographer, but a physicist/engineer too - and just to satisfy my own curiosity, I've even programmed my own DOF calculator, with my own formulae from 'first principles'...

thanks to all you guys who took the time to answer my quarry ..
Mark a question for you given your stated qualifications..

I would assume from all input and what I know to this point, that if one was shooting a 17mm lens on a FF @ say F .6 with a subject a meter and a half or so away you would get most everything in focus from about a meter out to infinity=huge depth of field = hugely croppable shot..especially with a good FF with higher pixel count??
Forgive/correct me if this is a stupid guess...
thanks
g

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painterdude said:

. . .

I would assume from all input and what I know to this point, that if one was shooting a 17mm lens on a FF @ say F .6 with a subject a meter and a half or so away you would get most everything in focus from about a meter out to infinity=huge depth of field = hugely croppable shot..especially with a good FF with higher pixel count??

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Your numbers don't add up using f5.6, so I'll assume that your "F .6" should be f/16.. Using 17mm, FF, and 1.5m subject distance, you get a DoF range of acceptable sharpness of 0.41m to infinity. But this is acceptable sharpness only if you accept the limits that the DoF is based upon, which includes things like print size, viewing distance, and the viewer's vision. This all goes out the window when you resort to cropping, because this increases the 'magnification', a factor that was already considered when the sensor size (FF in this case) was assumed. You also have to consider the effects of diffraction blurring, and f/16 won't be significant with FF DSLRs like the 12mp D700/D3, but you'll get lots of diffraction blurring at f/16 with the 36mp FF D800, since its photosites are much smaller. For most shooting this won't matter, since 12mp images are plenty sharp, and the D800 will produce images just as sharp as the D700 at f/16. The difference is that it's potential resolution is much higher, and you won't get that unless you put the D800 on a tripod and use a smaller aperture.

Edit: For what it's worth, you'll still get a DoF encompassing infinity using f/8 as long as you don't crop. But the D800 and other full frame cameras start suffering from diffraction blurring at f/9.2, so you probably want to keep the aperture below f/10, and realize that cropping only makes the blurring due to diffraction more noticeable and ugly. TANSTAAFL.

painterdude said:

Mark a question for you given your stated qualifications..

I would assume from all input and what I know to this point, that if one was shooting a 17mm lens on a FF @ say F .6 with a subject a meter and a half or so away you would get most everything in focus from about a meter out to infinity....

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Well, first I'll assume that the above "say F .6" was meant to be 'F5.6' (?).

The short answer is 'yes', or 'possibly' - but it all depends on your 'acceptable sharpness' criteria.

If your 'acceptable sharpness' criteria was .15mm diameter circle-of-confusion on a print size of 6"x4" - then yes, you could set focus on 1.5 metre distance and everything from about 0.75 metres to infinity would be 'acceptably sharp' - 1.5m is, in this case, referred to as the 'hyperfocal distance.

Change the sharpness criteria though, and the DOF is changed...

For example, if we choose a much larger print size of 12"x8", but still want .15mm c-o-c for acceptable sharpness (i.e. perhaps for the same print viewing distance) - then, either the DOF changes to approx only 1m to 3m when focused at 1.5m, or alternatively 1.5m to infinity, if focused on the 'hyperfocal distance' of about 3m.

However, if you allowed the c-o-c to scale with the print size, i.e. an acceptable c-o-c of .3mm in a 12"x8" print (i.e. perhaps for twice the print viewing distance) - then the DOF remains the same as .15mm c-o-c in a 6"x4" print.

painterdude said:

....=huge depth of field = hugely croppable shot..especially with a good FF with higher pixel count??

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Unfortunately, as regards 'cropping', that won't hold true.

When you say 'crop', there is an implication of a proportionate enlargement of the cropped area - and this enlargement simply increases the size of the previously acceptable c-o-c, such that they will no longer be acceptable.

Mark H said:

painterdude said:

Mark a question for you given your stated qualifications..

I would assume from all input and what I know to this point, that if one was shooting a 17mm lens on a FF @ say F .6 with a subject a meter and a half or so away you would get most everything in focus from about a meter out to infinity....

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Well, first I'll assume that the above "say F .6" was meant to be 'F5.6' (?).

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That's probably a bad assumption, given that painterdude wrote (and you quoted) "17mm lens on a FF @ say F .6 with a subject a meter and a half or so away you would get most everything in focus from about a meter out to infinity ", and the DoF given by DoF calculators show that 17mm, FF and f/5.6", focused at 1.5m produces a DoF that extends from 0.78m all the way out to 18.65m. Change some of the standard assumptions, such as using a smaller, more stringent CoC and the DoF shrinks, making a DoF that extends to infinity even more improbable.

Mark H said:

The short answer is 'yes', or 'possibly' - but it all depends on your 'acceptable sharpness' criteria.

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Mark H said:

Unfortunately, as regards 'cropping', that won't hold true.

When you say 'crop', there is an implication of a proportionate enlargement of the cropped area - and this enlargement simply increases the size of the previously acceptable c-o-c, such that they will no longer be acceptable.

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Well at least you got that right, since it's the rare crop that isn't enlarged.

Billx08 said:

Mark H said:

painterdude said:

Mark a question for you given your stated qualifications..

I would assume from all input and what I know to this point, that if one was shooting a 17mm lens on a FF @ say F .6 with a subject a meter and a half or so away you would get most everything in focus from about a meter out to infinity....

Click to expand...

Well, first I'll assume that the above "say F .6" was meant to be 'F5.6' (?).

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That's probably a bad assumption ,...

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No, it is actually a very good assumption - and with a very sound basis.

Billx08 said:

... given that painterdude wrote (and you quoted) "17mm lens on a FF @ say F .6 with a subject a meter and a half or so away you would get most everything in focus from about a meter out to infinity ", and the DoF given by DoF calculators show that 17mm, FF and f/5.6", focused at 1.5m produces a DoF that extends from 0.78m all the way out to 18.65m.

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That would suggest they use an acceptable C-o-C diameter equivalent to about .135mm for a 6"x4" print size.

Increase that acceptable C-o-C diameter by just under 10% to 0.148mm (a tiny increase) and you'll find the DoF increases to .75m to infinity - a tiny, essentially insignificant difference in C-o-C size makes all that difference.

Similarly, try changing the aperture value just 0.25 of a stop to F6.1 (8% smaller diameter), if you can, and you'll soon see that is all it takes to make the DoF '.75m to infinity'.

Billx08 said:

Change some of the standard assumptions, such as using a smaller, more stringent CoC and the DoF shrinks, making a DoF that extends to infinity even more improbable.

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The fact is - my 'assumption' of F5.6 is very soundly based.

Even when changing the C-o-C criteria to the slightly more stringent value of .135mm for 6"x4" print (to match the DoF calculators you quote) - even then, it only requires the aperture value to change a mere 0.25 of a stop to F6.1 in order to return the DoF range to '.75m to infinity'.

So, as I said, my assumption of F5.6 is very soundly based - it's less than 10% different to the calculators you quote, as regards either the C-o-C criteria, or print size, or the aperture diameter (take your pick).

The difference between my calculator figures and the calculators you have used is quite insignificant - and they are actually in very close agreement, and were using very similar C-o-C acceptance size (as 'coincidental' as that is).

Now, as for your own assumption, in your earlier reply to 'painterdude' here...

Billx08 said:

Billx08 said:

Billx08 said:

Billx08 said:

Billx08 wrote:

Your numbers don't add up using f5.6, so I'll assume that your "F .6" should be f/16.. Using 17mm, FF, and 1.5m subject distance, you get a DoF range of acceptable sharpness of 0.41m to infinity.

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... your assumption of 'f16' - well that is way out.

It only requires F5.6 to F6.1, as detailed above - and I've very little doubt that 'painterdude' would confirm he meant to type '5.6'.

Billx08 said:

Billx08 said:

The short answer is 'yes', or 'possibly' - but it all depends on your 'acceptable sharpness' criteria.

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Billx08 said:

Unfortunately, as regards 'cropping', that won't hold true.

When you say 'crop', there is an implication of a proportionate enlargement of the cropped area - and this enlargement simply increases the size of the previously acceptable c-o-c, such that they will no longer be acceptable.

Click to expand...

Well at least you got that right, since it's the rare crop that isn't enlarged.

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I got it all right.

Billx08 said:

painterdude said:

. . .

I would assume from all input and what I know to this point, that if one was shooting a 17mm lens on a FF @ say F .6 with a subject a meter and a half or so away you would get most everything in focus from about a meter out to infinity=huge depth of field = hugely croppable shot..especially with a good FF with higher pixel count??

Click to expand...

Your numbers don't add up using f5.6, so I'll assume that your "F .6" should be f/16..

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For the record - as explained, and as detailed, here...

http://forums.dpreview.com/forums/read.asp?forum=1012&message=42502447

...'painterdudes' numbers do add up just fine by using 'F5.6'.

Billx08 said:

...You also have to consider the effects of diffraction blurring,...

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Not neccessarily...

Diffraction blurring affects the image sharpness independently of the subject distances involved - i.e. it doesn't directly relate to distance or DoF.

Diffraction effects may well begin to limit the overall resolution/sharpness of the image - but it won't really alter the perceived DoF, because it is not a function of either focusing or distance.

Billx08 said:

... and f/16 won't be significant with FF DSLRs like the 12mp D700/D3, but you'll get lots of diffraction blurring at f/16 with the 36mp FF D800, since its photosites are much smaller.

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The size of the photosites doesn't change the amount of diffraction blurring in itself.

It may/will only look more blurred if viewing both at say '100%' on a display monitor - and that is simply because then you would be viewing the same image at 1.7x greater size/magnification in the 36Mp case, compared to the 12Mp case.

Viewed at the same physical image size (e.g. same print size), the diffraction blurring would be the same in both cases, if it can be resolved.

Billx08 said:

...But the D800 and other full frame cameras start suffering from diffraction blurring at f/9.2, so you probably want to keep the aperture below f/10, ...

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The point where diffraction blurring 'starts' is not a particularly hard & fast thing - and it will be at very different aperture values for different focal lengths of lens.

For example, a 17mm lens at F16 has a nominal aperture diameter of just over 1mm, so its diffraction effects will be much greater than say a 160mm lens at F16 with its aperture diameter of nominally 10mm.

Mark H said:

. . .

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. . . that you haven't changed a bit. You work so very hard trying to avoid admitting even the slightest mistake, but in the end you're still wrong, so transparently wrong, as before. <g>

Mark H said:

. . .
I got it all right.

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Despite prodigious twisting and squirming, again, only in your mind.

Billx08 said:

Mark H said:

. . .

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. . . that you haven't changed a bit. You work so very hard trying to avoid admitting even the slightest mistake, but in the end you're still wrong, so transparently wrong, as before.

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Well, maybe you should explain exactly where this supposed "mistake/wrong" is 'Billx08' ?

As always, you abandon any attempt to do so - simply, and very "transparently" , because you are quite unable to.

The only thing that need changing is your unfortunate bad attitude - something that your latest week spent on DPR's 'Naughty Step' doesn't seem to have helped one bit.

Billx08 said:

Mark H said:

. . .
I got it all right.

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Despite prodigious twisting and squirming, again, only in your mind.

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Nah 'Billx08' - and in anyone/everyone else's mind that are capable of understanding the facts presented.

Which self-evidently excludes yourself.

Mark H said:

Billx08 said:

Mark H said:

. . .

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. . . that you haven't changed a bit. You work so very hard trying to avoid admitting even the slightest mistake, but in the end you're still wrong, so transparently wrong, as before.

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Well, maybe you should explain exactly where this supposed "mistake/wrong" is 'Billx08' ?

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I did. Since you were too blind (willfully) to see it or acknowledge it, maybe you should ask someone else to explain what you missed or want to avoid seeing. This is quite the evasive habit you've got.

Billx08 said:

Mark H said:

Billx08 said:

Mark H said:

. . .

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. . . that you haven't changed a bit. You work so very hard trying to avoid admitting even the slightest mistake, but in the end you're still wrong, so transparently wrong, as before.

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Well, maybe you should explain exactly where this supposed "mistake/wrong" is 'Billx08' ?

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I did.

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No - you haven't at all.

Unable to respond yourself, you have simply resorted to, your usual 'M.O.' of, nothing but unwarranted, and ill-mannered, personal remarks - e.g. as you did above, and e.g. as you did, and do again, below...

Billx08 said:

Billx08 said:

Billx08 said:

Billx08 said:

Billx08 wrote:

Despite prodigious twisting and squirming, again, only in your mind.

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Billx08 said:

Billx08 wrote:

Since you were too blind (willfully) to see it or acknowledge it, maybe you should ask someone else to explain what you missed or want to avoid seeing.

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Nobody is likely to "explain" anything of the sort 'Billx08' - because that could only make them appear as as misguided as you.

Billx08 said:

This is quite the evasive habit you've got.

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Only you are being 'evasive' here (not to mention glaringly hypocritical too).

Thanks guys for stepping up and giving me your insights ..

I apologize for the confusion. Yes Mark you were right when you guessed what this idiot meant by F.6!! Yes ..I meant F 5.6.

I get in general the gist of what you are saying re diffraction and DOF and COC issues. It is interesting Mark, as you related, that there are rather vast differences in F stop opening diameters with various lenses..which would result in diffraction differences.

Okay Mark let me spin you another stupid question (that may show a weakness in my even general understanding of what you have written !!)

Why is it that smaller sensors struggle with dynamic range issues - ie they tend to blow out whites and saturate darks (even at base ISO). Too many tiny pixels cramped into too small a space and so interfering with each other when over excited (highlights ) and not sensitive enough to grab all the available light( in shadows) ??

Also why is it smaller sensors do not produce as rich (depth) a color display as FF cams?

Are they simply not picking up as much light? Could this be changed if they had fewer pixels..or longer exposures chosen ?

It seems to me that a smaller sensor with its native wider DOF could be a kick butt landscape devise but every small sensor cam I have had tended to blow the details on WAngle shots. Is that simply a matter of not being able to pick up enough light even with a great resolving lens to make the image sharp sharp..or is itmostly crappy lens issues ? Do you just need longer exposures via Tripod situations for best results ?( ...but then we have the noise demons creeping in???? ..argh.)

thanks again for any time you can give to a response to this flurry..If you choose to chill and not respond ..no probs bro ..and thanks again for your past input

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painterdude said:

Thanks guys for stepping up and giving me your insights ..

I apologize for the confusion. Yes Mark you were right when you guessed what this idiot meant by F.6!! Yes ..I meant F 5.6.

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Then when you wrote that the DoF was extremely wide, extending from a very close range (less than the 1.5m focus distance) to infinity, with a FF camera and a 17mm lens, how did you determine that the DoF was "most everything in focus from about a meter out to infinity=huge depth of field"? I think that it's reasonable to assume that you used one of the common DoF calculators to determine the DoF. The one here :

http://www.cambridgeincolour.com/tutorials/dof-calculator.htm

shows that using an aperture of f/5.6 would give you a DoF ranging from 0.78m to 18.65m, and this clearly isn't anywhere near infinity. You can get to infinity either by using a smaller aperture or by (with this particular DoF calculator) using the advanced mode to change the default assumptions, which include the maximum print size, viewing distance, and "eyesight", which is related to the size of the assumed circle of confusion. Did you really do that? It doesn't seem reasonable to assume that you did.

painterdude said:

I get in general the gist of what you are saying re diffraction and DOF and COC issues. It is interesting Mark, as you related, that there are rather vast differences in F stop opening diameters with various lenses..which would result in diffraction differences.

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For a given camera, it doesn't matter which lens you use. The size of the blur circle is a function of the aperture used, so you get the same blur circle size (aka the diffraction blur) from cheap kit lenses and expensive 'pro' lenses when they're used at the same aperture. The pixel (photosite) size plays a role only when the size of the blur circle is larger than the photosite size. If you have a relatively large D700 photosite, you won't notice diffraction blur as long as the diffraction blur circles are not too much larger than the photosites. But take one relatively large blur circle that's nearly this size and it could be larger than a half dozen D800 photosites (or more) and the potential resolution is squandered, no better than what you'd get from a D700.

Another interesting thing to consider is that the 'conventional wisdom' that the D800e is better for landscapes than the D800 may not be true for many photographers, since they usually shoot at reduced apertures, and this reduces or eliminates D800e's slight resolution advantage over the D800. This has been pointed out by the usual suspects (the 'experts' in the Nikon forums), and Thom Hogan sums it up pretty well in his review :

painterdude said:

So what do we see on the D800 and D800E? At and above f/8 diffraction is being fully recorded (at f/8 the Airy disc diameter is 10.7 microns, while the D800 sensor photosite implied diameter is a bit less than 5 microns). Even at f/5.6 the Airy disc is big enough to be producing clearly visible diffraction.

Okay, so what about the AA (D800) or lack of an AA (D800E)? Does that make a difference. At f/8 and above, not really. Diffraction is a worse sin than anti-aliasing, at least when you use the "visible" criteria. Technically, I measure a bit more resolution on the E than the non-E in these mid-range diffracted apertures. But looking at pixel views of images, the diffraction kills the edge acuity that the E normally provides you. I'm not convinced there's enough gain to warrant the difference if you're shooting at f/5.6 or above all the time. That shouldn't surprise anyone, considering that I concluded the same thing with a D3x (24mp) with and without an AA filter. In that case, the "without" was optical glass, with no fuzz/defuzz system like the D800E has.

Below f/5.6, things are completely different, and surprisingly so. From f/1.4 to f/4 the D800E has crisp, clean edges and is clearly gaining something from the lack of an anti-aliasing filter. But the D800 is different. While the D800 has what I would characterize as a weak AA filter (I've got plenty of moire examples from it, and can produce color fringing with it, too), it exhibits a different pattern than the D800E. From f/1.4 to f/4 there's a small but steady degradation of edges, almost like some form of weak diffraction were in play. That's actually entirely possible, as Nikon claims that there is a waveplate involved in the AA filter, and it may be the culprit.

So basically the conventional guess about who would want an E and who would want a non-E are exactly backwards. If you shoot wide open or near wide open with your lenses all the time (portraits, wildlife, sports, etc.) there's something to be said for having the D800E. If you shoot landscapes and are going for depth of field, diffraction will be your real enemy, not the AA filter.

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http://www.bythom.com/nikond800review.htm

(continued)

(continued)

Billx08 said:

Why is it that smaller sensors struggle with dynamic range issues - ie they tend to blow out whites and saturate darks (even at base ISO). Too many tiny pixels cramped into too small a space and so interfering with each other when over excited (highlights ) and not sensitive enough to grab all the available light( in shadows) ??

Also why is it smaller sensors do not produce as rich (depth) a color display as FF cams?

Are they simply not picking up as much light? Could this be changed if they had fewer pixels..or longer exposures chosen ?

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It's the related problems of not capturing enough photons, both by the photosites and by the entire sensor. Imagine an extremely small photosite, only large enough to capture 4 photons at most. Not much of a dynamic range there. Compare that with some photosites that can record the accumulation of more than 50,000 photons. It's more complicated than this, because the tone curve applied to the sensor data by the camera determines the dynamic range, and theoretically, that sensor whose photosites can only capture 4 photons could have a 10 stop dynamic range, but it would be a thoroughly useless dynamic range because it would be able to display such a tiny number of different tones. This would be great for posterization lovers, but it would be pretty useless for general photography unless you're into solarization.

Billx08 said:

It seems to me that a smaller sensor with its native wider DOF could be a kick butt landscape devise but every small sensor cam I have had tended to blow the details on WAngle shots.

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No, having a small sensor's wider DoF isn't useful if it's diffraction limited. Although you wouldn't shoot too many landscapes with an HS20 at its longest focal length, the tests that I did show that it produced its highest resolution with the lens wide open at f/5.6. With each reduction in the aperture, resolution dropped. You should also understand that no camera will automatically blow details, whether at wide angles or telephoto. Those cameras are compromised by their small sensors, and manufacturers are only making another compromise, giving them metering that will tend to blow highlights. But that's because they have a smaller dynamic range already, due to their small sensors, and if the metering always protected against blown highlights, the photos would be darker. This would be bad because darker photos are underexposed photos (generally) and this results in more noise and cruddy shadow regions. It doesn't take any magic to prevent blown highlights. Just use lots of -EC. But with small sensor cameras, your images will pay a big price for that 'protection'.

Billx08 said:

Is that simply a matter of not being able to pick up enough light even with a great resolving lens to make the image sharp sharp..or is itmostly crappy lens issues ? Do you just need longer exposures via Tripod situations for best results ?( ...but then we have the noise demons creeping in???? ..argh.)

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For sharp photos with small sensor cameras, you need to use wide apertures. As long as you can make the shutter speed slow enough and use a tripod, you'll have enough light. But then you won't be taking pictures of live, active subjects.

painterdude said:

Thanks guys for stepping up and giving me your insights ..

I apologize for the confusion. Yes Mark you were right when you guessed what this idiot meant by F.6!! Yes ..I meant F 5.6.

I get in general the gist of what you are saying re diffraction and DOF and COC issues. It is interesting Mark, as you related, that there are rather vast differences in F stop opening diameters with various lenses..which would result in diffraction differences.

Okay Mark let me spin you another stupid question (that may show a weakness in my even general understanding of what you have written !!)

Why is it that smaller sensors struggle with dynamic range issues - ie they tend to blow out whites and saturate darks (even at base ISO). Too many tiny pixels cramped into too small a space and so interfering with each other when over excited (highlights ) and not sensitive enough to grab all the available light( in shadows) ??

Also why is it smaller sensors do not produce as rich (depth) a color display as FF cams?

Are they simply not picking up as much light? Could this be changed if they had fewer pixels..or longer exposures chosen ?

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There have been massive fights about this point on the forums over the years. The gang of 4 were the ones who showed that bigger pixels were not better pixels as many of us once thought. Smaller pixels mean more smearing but also more resolution, so either way you hit a wall eventually. But overall, they argue that the extra resolution outweighs anything else because the images can be cleaned up in PP, whereas if you don't have the resolution to begin with, PP can do nothing for you.

painterdude said:

It seems to me that a smaller sensor with its native wider DOF could be a kick butt landscape devise but every small sensor cam I have had tended to blow the details on WAngle shots. Is that simply a matter of not being able to pick up enough light even with a great resolving lens to make the image sharp sharp..or is itmostly crappy lens issues ? Do you just need longer exposures via Tripod situations for best results ?( ...but then we have the noise demons creeping in???? ..argh.)

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There is a pretty strong argument for smaller sensors when it comes to deep DOF images. The little Sony RX for example has an unbeatable combination of a f1.8 zoom lens and a 1" sensor big enough for low light work but small enough for really deep DOF. In some ways this is the ideal camera for low light deep DOF work and with 20mp of resolution there is plenty of juice there for landscapes.

painterdude said:

thanks again for any time you can give to a response to this flurry..If you choose to chill and not respond ..no probs bro ..and thanks again for your past input

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