A Question About 'Default' Aperture...

[BirgerH]

You can argue that - but it's wrong. Dof is not a specific value to be determined exactly. Dof (of the same image after capturing) changes with the coc-value you determine to use, the number of times you want to enlarge it to the final viewing size and the viewing distance.

I think we all understand that when viewing a smaller image you have to extrapolate to what that image wil look like when bigger, this of course includes estimating the final DOF. The important thing is that you have an accurate 'smaller picture' from which to make this extrapolation.

So - it's not accurate and exact - which was my starting points.

No difference here between using the view finder to see what your image will look like when printed on a 100m long wall. You have to extrapolate in pretty much exactly the same way, and any photog can do it.

Then again - my statement: the dof you see through the viewfinder is the dof of an image at about the same size as the sensor (24x36mm) viewed very close.

BirgerH.

 

[theonetruepath]

One of the things no one has commented on is the simple fact that today's "less than perfect" focusing screens do not show you an accurate DoF. Back in the old days with manual focusing and excellent ground glass screens you got a much better preview of the what the DoF would be. Today's screens will show you some preview of DoF. But not really that accurate.

Not sure why you think this... every Nikon I've had has shown me a perfect picture with accurate focus (and hence DOF), I've never had any trouble unless trying to preview a tiny aperture wich just gets too dark.

 

[theonetruepath]

For lenses that the camera can control the F-stop, the largest aperature (or the smallest number) is what you see in the viewfinder.

Unless that "smallest number" is lower than f2.8, because your viewfinder can't show you apertures lower than that. Apparently an aperture limitation of the lightpath to the viewfinder.

So there's no way to preview say an f1.4 aperture unless you go to live view.

Which will not be specifically more accurate either - it really depends

The OP asked in specific to the D810 - and that camera allows him to change aperture during LV - other cameras will show only the dof of the aperture set, when LV was entered.

The D810 and the D800 both show you the correct lens aperture on the live view screen, and both allow you to zoom in to pixel level to check focus and hence DOF.

Whenever you zoom (in or out) you change dof. (You change magnification, in this case digital, but it is analog to change focal length).

Once again, this is not a useful thing to say. Every photographer knows that a reduced magnification view of his scene looks more in focus. Every photographer makes the required interpolation to estimate whether DOF will be sufficient in the final image. And they do this from the provided tools - either the excellent viewfinder image, or the magnifiable viewfinder image. There's no 'extra' penalty built in to these tools apart from the obvious one, that you are not seeing a full wall-printed image. You can stll get plenty of information from your tools, enough to estimate the final result.

The D810 allows you to change aperture while recording movies, and this change can be seen on the screen, the D800 does not allow aperture changes during recording but still shows you accurately the DOF.

That's what I said about the D810, But the dof you see is related to a 3.2" screen - it will be very different (changed) when you watch it on a 42" TV screen - even if you do not you keep the viewing distance at about 25cm.

That's not quite what you said - you said only the D810 (ie not the D800) could change aperture while in live view. Both can, and so can probably all the other LV-capable cameras. And you seem to be arguing that the 3.2 inch screen picture suffers from lack of magnification and ignoring the fact that it can be zoomed in to where it shows one 'image pixel' across four display pixels. And that is enough to pixel-peep all the way to whatever final image size you use.

No matter the camera - you are still not seeing the dof of the fInal image, unless this is an 3.2" 2x3 ratio.

Disagree entirely, see above comment

That's okay - agreeing is not necessary in this forum.

That would be a turgid forum indeed.

 

[BirgerH]

For lenses that the camera can control the F-stop, the largest aperature (or the smallest number) is what you see in the viewfinder.

Unless that "smallest number" is lower than f2.8, because your viewfinder can't show you apertures lower than that. Apparently an aperture limitation of the lightpath to the viewfinder.

So there's no way to preview say an f1.4 aperture unless you go to live view.

Which will not be specifically more accurate either - it really depends

The OP asked in specific to the D810 - and that camera allows him to change aperture during LV - other cameras will show only the dof of the aperture set, when LV was entered.

The D810 and the D800 both show you the correct lens aperture on the live view screen, and both allow you to zoom in to pixel level to check focus and hence DOF.

Whenever you zoom (in or out) you change dof. (You change magnification, in this case digital, but it is analog to change focal length).

Once again, this is not a useful thing to say. Every photographer knows that a reduced magnification view of his scene looks more in focus. Every photographer makes the required interpolation to estimate whether DOF will be sufficient in the final image.

They do? So every photographer knows from the start the final size of their images.

And they do this from the provided tools - either the excellent viewfinder image, or the magnifiable viewfinder image.

No - they use their "dof-calculators" - or they simply know from experience.

There's no 'extra' penalty built in to these tools apart from the obvious one, that you are not seeing a full wall-printed image. You can stll get plenty of information from your tools, enough to estimate the final result.

Sure - haven't said. I just said, that the dof they see in the viewfinder is not the same dof, they will end up with in the final image.

Seems after all that we do agree.

The D810 allows you to change aperture while recording movies, and this change can be seen on the screen, the D800 does not allow aperture changes during recording but still shows you accurately the DOF.

That's what I said about the D810, But the dof you see is related to a 3.2" screen - it will be very different (changed) when you watch it on a 42" TV screen - even if you do not you keep the viewing distance at about 25cm.

That's not quite what you said - you said only the D810 (ie not the D800) could change aperture while in live view. Both can, and so can probably all the other LV-capable cameras.

Sorry - that's my English (and how you read me ). I referred to the D810, because, that's the OP's camera - and said, that "other cameras" - not "every other cameras". Yes - the D800 (which I have) also has an aperture motor - but i.e the D750 and D6x0 has not.

And you seem to be arguing that the 3.2 inch screen picture suffers from lack of magnification and ignoring the fact that it can be zoomed in to where it shows one 'image pixel' across four display pixels. And that is enough to pixel-peep all the way to whatever final image size you use.

No - I don't argue that.

I argued, that every time you change the magnification/enlargement - you change the dof. I'm pretty sure, you will change the enlargement from the 3.2" screen image and to the final image size

If I had argued this - it would have been another discussion, that does not fit the context of this thread.

No matter the camera - you are still not seeing the dof of the fInal image, unless this is an 3.2" 2x3 ratio.

Disagree entirely, see above comment

That's okay - agreeing is not necessary in this forum.

That would be a turgid forum indeed.

BirgerH.

 

[briantilley]

That's not quite what you said - you said only the D810 (ie not the D800) could change aperture while in live view.

That's your interpretation - what Birger actually said was the the D810 (which the OP was asking about) can do this, and that other cameras cannot.

Both can, and so can probably all the other LV-capable cameras.

No - whilst the D800 can, Birger is quite correct that other cameras cannot. The D600 and D7000 are among the many cameras with LV that cannot do this.

 

[BirgerH]

The OP asked in specific to the D810 - and that camera allows him to change aperture during LV - other cameras will show only the dof of the aperture set, when LV was entered.

The D810 and the D800 both show you the correct lens aperture on the live view screen, and both allow you to zoom in to pixel level to check focus and hence DOF.

The D810 allows you to change aperture while recording movies, and this change can be seen on the screen, the D800 does not allow aperture changes during recording but still shows you accurately the DOF.

I should also point out... when I was using my D800E I distinctly remember being in Live View mode and reducing the aperture, and watching the screen go darker briefly until the auto ISO caught up and made it bright again. With increased DOF and noise of course.

Of course.

I don't have first hand experience with the other live view capable cameras (except my D810) but I imagine they are the same.

They are not - only the cameras with an aperture stop-down motor are able to change aperture on all lenses - including "G"-lenses while being in LV. Some cameras can show the changes of aperture using Ai(s)-lenses with/without a cpu - and some only with Ai(s) lenses without a cpu.

BirgerH.

 

[theonetruepath]

No - I don't argue that.

I argued, that every time you change the magnification/enlargement - you change the dof. I'm pretty sure, you will change the enlargement from the 3.2" screen image and to the final image size

Then you are apparently arguing that the size of the pixels makes a difference to DOF?

If I can zoom my display to 1:1 then I can show every useful magnification and see precisely the resultant DOF *for every useful magnification of the final printed image*.

All I can't do is show the whole image at that magnification at the one time. And I can easily work around that by panning around the image where required.

Can you explain to me what is magical about DOF that it can't be seen by zooming in on a 3.2" screen as opposed to say a 55" screen?

Oh... and perhaps someone with a D750 and/or a D600 could confirm that you can't change aperture while in LV mode?

Specifically, you should see the image briefly get darker if you go from say f4.0 to f8.0, and if you select the scene carefully (focussed on a near object) you should see the background get slightly more in focus.

 

[BirgerH]

No - I don't argue that.

I argued, that every time you change the magnification/enlargement - you change the dof. I'm pretty sure, you will change the enlargement from the 3.2" screen image and to the final image size

Then you are apparently arguing that the size of the pixels makes a difference to DOF?

Yes - the sizes of the image "pixels", which is not "pixels, but "dot's" is what we refer to as coc.

But this is the other discussion - what you see on the screen in LV has very little to do with the image sensor "pixels".

If I can zoom my display to 1:1 then I can show every useful magnification and see precisely the resultant DOF *for every useful magnification of the final printed image*.

No - you can't. You are enlarging a streamed low resolution video jpg. In preview it will be a lot better and more useful. Another discussion, though.

All I can't do is show the whole image at that magnification at the one time. And I can easily work around that by panning around the image where required.

Can you explain to me what is magical about DOF that it can't be seen by zooming in on a 3.2" screen as opposed to say a 55" screen?

Nothing is magical - dof it's just different.

Oh... and perhaps someone with a D750 and/or a D600 could confirm that you can't change aperture while in LV mode?

I was a bit fast there - seems the D750 has the aperture stop-down motor - though the D6x00 has not.

Specifically, you should see the image briefly get darker if you go from say f4.0 to f8.0, and if you select the scene carefully (focussed on a near object) you should see the background get slightly more in focus.

Yes - never said, that you couldn't see the dof on the screen - only said, that the dof will be changed in your final image - unless your final image has the same size as the screen.

BirgerH

 

[Rabbson78]

I think the number of comments illustrates! perfectly the real problem, that Nikon cameras don't perform the relatively trivial calculation of DOF and display it in the viewfinder. Yes you would have to set the acceptable circle of confusion and print size in a menu, but other than that the camera has access to all the other required data with a modern lens. D760?

 

[theonetruepath]

I was a bit fast there - seems the D750 has the aperture stop-down motor - though the D6x00 has not.

It has nothing to do with aperture stop down motors. Every modern Nikon camera can set the aperture on all except the oldest lenses. The only reason that some of them can't dynamically change aperture under some conditions is they implemented it that way for whatever reason Nikon does these things - differentiate 'higher level' cameras possibly.

In other words, if the aperture works on your camera/lens combination, and they bothered to program it properly, aperture changing whether during live view or just while holding down the DOF preview button, would work as well with no extra hardware required.

 

[BirgerH]

I was a bit fast there - seems the D750 has the aperture stop-down motor - though the D6x00 has not.

It has nothing to do with aperture stop down motors. Every modern Nikon camera can set the aperture on all except the oldest lenses. The only reason that some of them can't dynamically change aperture under some conditions is they implemented it that way for whatever reason Nikon does these things - differentiate 'higher level' cameras possibly.

Wrong. Operating the aperture on "G" lenses in LV (and movie) demands a stop-down motor.

Operating the aperture on Ai(s) lenses can be done manually using the aperture ring - but some cameras refuses to work with operating the aperture ring manually, if the lens has a cpu.

In other words, if the aperture works on your camera/lens combination, and they bothered to program it properly, aperture changing whether during live view or just while holding down the DOF preview button, would work as well with no extra hardware required.

That's unfortunately not the case, when speaking LiveView. I would like (actually I do not care - I never use Live View ) my D7000 to operate my "G" lenses that way. There's no way, the camera can change the aperture physically - and there's no way to do it manually.

If you want it to be a software programmed aperture change - not a physically aperture change - the view on the screen will be a simulated view by brightening/darkening the screen - it will not change dof - this has to be simulated by software too - as it is with EVF's - might be doable - but I'm not sure you want the video (I wouldn't care, again) being done with software simulated aperture :-(

BirgerH.

 

[theonetruepath]

I was a bit fast there - seems the D750 has the aperture stop-down motor - though the D6x00 has not.

It has nothing to do with aperture stop down motors. Every modern Nikon camera can set the aperture on all except the oldest lenses. The only reason that some of them can't dynamically change aperture under some conditions is they implemented it that way for whatever reason Nikon does these things - differentiate 'higher level' cameras possibly.

Wrong. Operating the aperture on "G" lenses in LV (and movie) demands a stop-down motor.

That motor is in the lens, not the camera. To set the aperture on a G lens the camera sends an electronic signal. Nikon could (relatively) easily have arranged to send that signal at any time. They chose not to on certain cameras. Canon chose to allow it on pretty well all their cameras.

Operating the aperture on Ai(s) lenses can be done manually using the aperture ring - but some cameras refuses to work with operating the aperture ring manually, if the lens has a cpu.

In other words, if the aperture works on your camera/lens combination, and they bothered to program it properly, aperture changing whether during live view or just while holding down the DOF preview button, would work as well with no extra hardware required.

That's unfortunately not the case, when speaking LiveView. I would like (actually I do not care - I never use Live View ) my D7000 to operate my "G" lenses that way. There's no way, the camera can change the aperture physically - and there's no way to do it manually.

If you had a D5 it too would not have an aperture motor, it can only change G lenses by sending an electronic signal, but Nikon chose to implement this feature on that camera but not yours, and not for lack of any hardware on the D7000.

If you want it to be a software programmed aperture change - not a physically aperture change - the view on the screen will be a simulated view by brightening/darkening the screen - it will not change dof - this has to be simulated by software too - as it is with EVF's - might be doable - but I'm not sure you want the video (I wouldn't care, again) being done with software simulated aperture :-(

The fact that you're wrong about this is proven by the fact that 'G' lenses can have their aperture set *only* electronically by *any* camera (well, those that can handle G lenses which is all modern cameras). If you don't believe this just Google the difference between 'D' and 'G' lenses, the evidence will mount up rapidly. There simply is no such thing as setting a G lens aperture 'physically' except by sending it the electronic signal.

BirgerH.

 

[briantilley]

The fact that you're wrong about this...

I'm afraid you're the one who is wrong about this.

...is proven by the fact that 'G' lenses can have their aperture set *only* electronically by *any* camera (well, those that can handle G lenses which is all modern cameras).

"G" lenses, like older lenses, have their diaphragm controlled by the camera via a mechanical lever. Only the new "E" lenses have the diaphragm controlled by an electronic signal from the camera.

If you don't believe this just Google the difference between 'D' and 'G' lenses, the evidence will mount up rapidly.

I did Google, just to make sure, and the evidence (that you are wrong) did indeed mount up rapidly. For example: wikipedia

 

[BirgerH]

I was a bit fast there - seems the D750 has the aperture stop-down motor - though the D6x00 has not.

It has nothing to do with aperture stop down motors. Every modern Nikon camera can set the aperture on all except the oldest lenses. The only reason that some of them can't dynamically change aperture under some conditions is they implemented it that way for whatever reason Nikon does these things - differentiate 'higher level' cameras possibly.

Wrong. Operating the aperture on "G" lenses in LV (and movie) demands a stop-down motor.

That motor is in the lens, not the camera. To set the aperture on a G lens the camera sends an electronic signal. Nikon could (relatively) easily have arranged to send that signal at any time. They chose not to on certain cameras. Canon chose to allow it on pretty well all their cameras.

No - wrong again - Nikon lenses and lenses for Nikon does not wear an aperture stop-down motor (the new E-type lenses are an exclusion). Aperture settings is done and controlled by the aperture controller in the camera - and the aperture motor is mechanically activated by the shutter/mirror activation. To activate a stop down without a shutter activation, the aperture motor has to be "powered" as Nikon calls it - and differently controlled.

Operating the aperture on Ai(s) lenses can be done manually using the aperture ring - but some cameras refuses to work with operating the aperture ring manually, if the lens has a cpu.

In other words, if the aperture works on your camera/lens combination, and they bothered to program it properly, aperture changing whether during live view or just while holding down the DOF preview button, would work as well with no extra hardware required.

That's unfortunately not the case, when speaking LiveView. I would like (actually I do not care - I never use Live View ) my D7000 to operate my "G" lenses that way. There's no way, the camera can change the aperture physically - and there's no way to do it manually.

If you had a D5 it too would not have an aperture motor, it can only change G lenses by sending an electronic signal, but Nikon chose to implement this feature on that camera but not yours, and not for lack of any hardware on the D7000.

No - not right. The D5 certainly have an in-camera aperture controller and aperture motor.

If you want it to be a software programmed aperture change - not a physically aperture change - the view on the screen will be a simulated view by brightening/darkening the screen - it will not change dof - this has to be simulated by software too - as it is with EVF's - might be doable - but I'm not sure you want the video (I wouldn't care, again) being done with software simulated aperture :-(

The fact that you're wrong about this is proven by the fact that 'G' lenses can have their aperture set *only* electronically by *any* camera (well, those that can handle G lenses which is all modern cameras). If you don't believe this just Google the difference between 'D' and 'G' lenses, the evidence will mount up rapidly. There simply is no such thing as setting a G lens aperture 'physically' except by sending it the electronic signal.

"G" lenses are not set "electronically". They are controlled by the electronic controller in the camera and "set" by the mechanically shutter released aperture lever or in LiveView by a powered aperture stop-down - if this exist in the camera. That's why you still have the Aperture pin on "G"-lenses - try to remove it - and the lens aperture will not work.

The new "E-type" lenses does not have that pin - and is fully controlled and set by the electronic aperture stop-down motor in the lens.

That said - you are confusing lens-types too.

"G" lenses are lenses built without a mechanically "Automatic Metering System" contrary to Ai(s) lenses. "G" lenses are "D" (Distance Information )type too - Ai(s)-lenses can be "D" type (AF-D). The mechanically "Automatic Metering System" forces an aperture ring to be used.

With a cpu on the Ai(s) lenses, the lenses work just like the "G"-lenses, not using the "Automatic Metering System" on the lens. Only - the Ai(s) lenses gives some fewer informations - among them, the physically distance between the min. and max aperture - that's why they have to be "locked" in a "known" position at min. aperture.

BirgerH.

BirgerH.

 

[theonetruepath]

The fact that you're wrong about this...

I'm afraid you're the one who is wrong about this.

...is proven by the fact that 'G' lenses can have their aperture set *only* electronically by *any* camera (well, those that can handle G lenses which is all modern cameras).

"G" lenses, like older lenses, have their diaphragm controlled by the camera via a mechanical lever. Only the new "E" lenses have the diaphragm controlled by an electronic signal from the camera.

If you don't believe this just Google the difference between 'D' and 'G' lenses, the evidence will mount up rapidly.

I did Google, just to make sure, and the evidence (that you are wrong) did indeed mount up rapidly. For example: wikipedia

Darn it you're right. However it doesn't change my point: That all Nikon cameras can set the aperture on a G lens, and they set it in the same way. There is no class of modern Nikon camera which is incapable of setting the aperture dynamically, it was a Nikon decision to not allow the aperture to change while DOF preview button is pressed, or in LV mode. No 'missing hardware' influenced this decision.

 

[theonetruepath]

No - wrong again - Nikon lenses and lenses for Nikon does not wear an aperture stop-down motor (the new E-type lenses are an exclusion). Aperture settings is done and controlled by the aperture controller in the camera - and the aperture motor is mechanically activated by the shutter/mirror activation. To activate a stop down without a shutter activation, the aperture motor has to be "powered" as Nikon calls it - and differently controlled.

It doesn't help my case much (ie the point I'm trying to make) that I got the coupling of 'G' lenses wrong. However, answer me this: What exactly happens when you press the DOF preview button on a D600? I will be unimpressed if you tell me that the viewfinder darkens and the DOF changes 'by software simulation'.

No - not right. The D5 certainly have an in-camera aperture controller and aperture motor.

It has the same aperture control lever as any modern Nikon. What is this aperture motor you speak of that -say- the D600 has not?

"G" lenses are not set "electronically". They are controlled by the electronic controller in the camera and "set" by the mechanically shutter released aperture lever or in LiveView by a powered aperture stop-down - if this exist in the camera. That's why you still have the Aperture pin on "G"-lenses - try to remove it - and the lens aperture will not work.

The new "E-type" lenses does not have that pin - and is fully controlled and set by the electronic aperture stop-down motor in the lens.

I got that roundly wrong.

That said - you are confusing lens-types too.

No... 'G' lenses are simply lenses with no aperture setting ring. They can only have aperture set by the camera. By any modern camera. And if that camera has a working DOF preview button, then in theory it could allow you to press that button, hold it, and change aperture with the command dial, and watch the DOF change. But you can't on some Nikon cameras, you can on others, and there's no valid mechanical/engineering reason for this. It appears to be a 'marketing' decision, or a 'it was easier to implement' decision or something. Nikon aren't telling us.

"G" lenses are lenses built without a mechanically "Automatic Metering System" contrary to Ai(s) lenses.

This sentence is not correct. 'G' means no aperture control ring, nothing else.

"G" lenses are "D" (Distance Information )type too - Ai(s)-lenses can be "D" type (AF-D). The mechanically "Automatic Metering System" forces an aperture ring to be used.

With a cpu on the Ai(s) lenses, the lenses work just like the "G"-lenses, not using the "Automatic Metering System" on the lens. Only - the Ai(s) lenses gives some fewer informations - among them, the physically distance between the min. and max aperture - that's why they have to be "locked" in a "known" position at min. aperture.

 

[BirgerH]

The fact that you're wrong about this...

I'm afraid you're the one who is wrong about this.

...is proven by the fact that 'G' lenses can have their aperture set *only* electronically by *any* camera (well, those that can handle G lenses which is all modern cameras).

"G" lenses, like older lenses, have their diaphragm controlled by the camera via a mechanical lever. Only the new "E" lenses have the diaphragm controlled by an electronic signal from the camera.

If you don't believe this just Google the difference between 'D' and 'G' lenses, the evidence will mount up rapidly.

I did Google, just to make sure, and the evidence (that you are wrong) did indeed mount up rapidly. For example: wikipedia

Darn it you're right. However it doesn't change my point: That all Nikon cameras can set the aperture on a G lens, and they set it in the same way. There is no class of modern Nikon camera which is incapable of setting the aperture dynamically, it was a Nikon decision to not allow the aperture to change while DOF preview button is pressed, or in LV mode. No 'missing hardware' influenced this decision.

This is absolutely wrong.

The Nikon decision was not to put in a "powered" motor in all bodies to change the aperture.

The mechanically setting (and changing) can be done only while releasing the aperture lever. The Dof-button does that - but it cant be done while the shutter is open (because of the connection with the shutter) so it can't be done in LV.

The way Nikon solved that problem, was to "power" the aperture motor independent of the shutter mechanism. The controller and motor of my D800 is definitely different from the same in my D7000. Nikon would have avoided a lot of criticism with the D71/7200, if this would just have been a firmware upgrade.

BirgerH.

 

[theonetruepath]

This is absolutely wrong.

Well despite this statement, I feel we are approaching resolution.

The Nikon decision was not to put in a "powered" motor in all bodies to change the aperture.

The mechanically setting (and changing) can be done only while releasing the aperture lever. The Dof-button does that - but it cant be done while the shutter is open (because of the connection with the shutter) so it can't be done in LV.

The way Nikon solved that problem, was to "power" the aperture motor independent of the shutter mechanism. The controller and motor of my D800 is definitely different from the same in my D7000. Nikon would have avoided a lot of criticism with the D71/7200, if this would just have been a firmware upgrade.

I never claimed a firmware upgrade could do it, I just said a design decision was made, without adequate justification. This decision was apparently to 'link' the operation of the aperture control lever with the shutter release. To design without such a link would be more logical, especially since this was done in various 'higher' models.

I don't see why an extra motor would be required...if they doubled up and used the same motor as for the mirror/shutter then simply add a tiny actuator that 'delinks' the shutter mechanism while you want to operate the diaphragm. The fact that the diaphragm can be operated currently without moving the mirror implies that they have already implemented such a 'dodge'. I can't see why they are prevented from doing the same with shutter open.

 

[BirgerH]

No - wrong again - Nikon lenses and lenses for Nikon does not wear an aperture stop-down motor (the new E-type lenses are an exclusion). Aperture settings is done and controlled by the aperture controller in the camera - and the aperture motor is mechanically activated by the shutter/mirror activation. To activate a stop down without a shutter activation, the aperture motor has to be "powered" as Nikon calls it - and differently controlled.

It doesn't help my case much (ie the point I'm trying to make) that I got the coupling of 'G' lenses wrong. However, answer me this: What exactly happens when you press the DOF preview button on a D600? I will be unimpressed if you tell me that the viewfinder darkens and the DOF changes 'by software simulation'.

It's not done with "software simulation" - I referred to LV and EVF with that remark.

When you press the dof-button, the camera releases the aperture lever as it would, if you used the shutter button. The lens aperture stops down, and you will see a change in the dof in the viewfinder image according to the aperture, you have the lens set to.

No - not right. The D5 certainly have an in-camera aperture controller and aperture motor.

It has the same aperture control lever as any modern Nikon. What is this aperture motor you speak of that -say- the D600 has not?

All the cameras has an aperture motor or mechanism that releases the aperture lever to the set aperture. That mechanism is electronically controlled but is mechanically activated by the shutter (some models, the mirror) mechanism.

"G" lenses are not set "electronically". They are controlled by the electronic controller in the camera and "set" by the mechanically shutter released aperture lever or in LiveView by a powered aperture stop-down - if this exist in the camera. That's why you still have the Aperture pin on "G"-lenses - try to remove it - and the lens aperture will not work.

The new "E-type" lenses does not have that pin - and is fully controlled and set by the electronic aperture stop-down motor in the lens.

I got that roundly wrong.

Yes - an often made mistake.

That said - you are confusing lens-types too.

No... 'G' lenses are simply lenses with no aperture setting ring. They can only have aperture set by the camera. By any modern camera. And if that camera has a working DOF preview button, then in theory it could allow you to press that button, hold it, and change aperture with the command dial, and watch the DOF change. But you can't on some Nikon cameras, you can on others, and there's no valid mechanical/engineering reason for this.

Yes - there is.

If there is not a "powered" "aperture-changer" - the camera has to redo the aperture release operation to set a new aperture. Can be done only by repressing the Dof-button.

It appears to be a 'marketing' decision, or a 'it was easier to implement' decision or something. Nikon aren't telling us.

No - that's right.

"G" lenses are lenses built without a mechanically "Automatic Metering System" contrary to Ai(s) lenses.

This sentence is not correct. 'G' means no aperture control ring, nothing else.

No - but let it be. It's another discussion. Ken Rockwell means, that "G" stands for "Crippled"

"G" lenses are "D" (Distance Information )type too - Ai(s)-lenses can be "D" type (AF-D). The mechanically "Automatic Metering System" forces an aperture ring to be used.

With a cpu on the Ai(s) lenses, the lenses work just like the "G"-lenses, not using the "Automatic Metering System" on the lens. Only - the Ai(s) lenses gives some fewer informations - among them, the physically distance between the min. and max aperture - that's why they have to be "locked" in a "known" position at min. aperture.

BirgerH.

 

[BirgerH]

This is absolutely wrong.

Well despite this statement, I feel we are approaching resolution.

The Nikon decision was not to put in a "powered" motor in all bodies to change the aperture.

The mechanically setting (and changing) can be done only while releasing the aperture lever. The Dof-button does that - but it cant be done while the shutter is open (because of the connection with the shutter) so it can't be done in LV.

The way Nikon solved that problem, was to "power" the aperture motor independent of the shutter mechanism. The controller and motor of my D800 is definitely different from the same in my D7000. Nikon would have avoided a lot of criticism with the D71/7200, if this would just have been a firmware upgrade.

I never claimed a firmware upgrade could do it, I just said a design decision was made, without adequate justification. This decision was apparently to 'link' the operation of the aperture control lever with the shutter release. To design without such a link would be more logical, especially since this was done in various 'higher' models.

Ooh yes - but that was a decision made back in, I think, 1935 - a little before anybody was thinking of LiveView and video.

It is the problem for Nikon - they all the time want backwards compatibility - sometimes they have a hard day delivering

I don't see why an extra motor would be required...if they doubled up and used the same motor as for the mirror/shutter then simply add a tiny actuator that 'delinks' the shutter mechanism while you want to operate the diaphragm. The fact that the diaphragm can be operated currently without moving the mirror implies that they have already implemented such a 'dodge'. I can't see why they are prevented from doing the same with shutter open.

Sure - I don't know the exact engineering - but I know that if it would have been "just" - Nikon would have saved their own backs and made the change at least with the D7200. I'm very certain, it's not a "crippling" decision.

BirgerH.