Depth of Field Preview feature ?

Started Jul 16, 2013 | Discussions
will222 Forum Member • Posts: 71
Depth of Field Preview feature ?

At face value, this seems like a useful feature to look for in a camera.

Is the implementation of this pretty consistent across cameras, or do certain models do an excellent job and on others it's not very useful?

Is this something you guys use pretty often, and wouldn't get a new camera without it? Or not all that useful after the initial novelty wears off?

thebustos Veteran Member • Posts: 3,316
Re: Depth of Field Preview feature ?

I use it from time to time, but check out this article....

http://www.naturephotographers.net/articles0905/rb0905-1.html

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Cailean Gallimore Veteran Member • Posts: 6,083
Re: Depth of Field Preview feature ?

will222 wrote:

At face value, this seems like a useful feature to look for in a camera.

Is the implementation of this pretty consistent across cameras, or do certain models do an excellent job and on others it's not very useful?

Is this something you guys use pretty often, and wouldn't get a new camera without it? Or not all that useful after the initial novelty wears off?

If you shoot with a mirrorless camera, you have DOF preview on all the time.

And yes, it's very useful.

KCook
KCook Forum Pro • Posts: 13,862
Re: Depth of Field Preview feature ?

My DSLR has it, but I've never bothered to even try it.  Could be useful for head shots, which I don't do.  When in doubt about DOF I just chimp instead.

Kelly Cook

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dsjtecserv Veteran Member • Posts: 3,692
Re: Depth of Field Preview feature ?

Cailean Gallimore wrote:

will222 wrote:

At face value, this seems like a useful feature to look for in a camera.

Is the implementation of this pretty consistent across cameras, or do certain models do an excellent job and on others it's not very useful?

Is this something you guys use pretty often, and wouldn't get a new camera without it? Or not all that useful after the initial novelty wears off?

If you shoot with a mirrorless camera, you have DOF preview on all the time.

Rally? So lenses on mirrorless cameras are stopped down all the time?

Dave

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NexOffender Regular Member • Posts: 328
Re: Depth of Field Preview feature ?

Yep, you can watch the aperture open and close as you adjust the dial.

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Cailean Gallimore Veteran Member • Posts: 6,083
Re: Depth of Field Preview feature ?

dsjtecserv wrote:

Cailean Gallimore wrote:

will222 wrote:

At face value, this seems like a useful feature to look for in a camera.

Is the implementation of this pretty consistent across cameras, or do certain models do an excellent job and on others it's not very useful?

Is this something you guys use pretty often, and wouldn't get a new camera without it? Or not all that useful after the initial novelty wears off?

If you shoot with a mirrorless camera, you have DOF preview on all the time.

Rally? So lenses on mirrorless cameras are stopped down all the time?

Dave

Yes, that's right.

Confused of Malvern Senior Member • Posts: 1,291
Re: Depth of Field Preview feature ?

DOF Preview was an essential feature when shooting film - it was the only way you had of visualising what the eventual image would look like.  However, it is something I use far less often with digital - nowadays you just take the image and review it on the screen.  This is far more accurate than the DOF preview feature and if the result isn't quite right you can just retake it.

You might find digital preview - where the camera allows you to preview the shot before saving it to the memory card more useful than DOF preview although personally it's not something i have ever used.

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gollywop
gollywop Veteran Member • Posts: 8,283
not likely to be the case

NexOffender wrote:

Yep, you can watch the aperture open and close as you adjust the dial.

I seriously doubt that this is due to an aperture preview function. The LCD/VF image brightness on some cameras changes in live view to reflect the meter reading to help you see the effects of your exposure, but the aperture remains wide open throughout. Mirrorless cameras use cdaf (contrast detect auto focus) which requires the lens be wide open to work most effectively.

Check to see if your camera has a "preview" feature to assign to a function button and use it to see what happens when the lens is actually stopped down.  But, when you test it, be sure to set an aperture that is down several stops from wide open, or you won't see much difference when you press the preview button.

If you find that your mirrorless camera live view is actually showing the result of stoping down the aperture, I would appreciate knowing what camera you are using.

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gollywop

BBbuilder467 Veteran Member • Posts: 3,332
Re: not likely to be the case

When I stop down to f/22 and press the DOF preview button, I can see the aperture stop-down from f/5.6 to f/22. There is no full time DOF preview in a Panasonic m4/3.

Try macro or close-up at f/22. It's not even close to what you see in the EVF with an autofocus lens. I get the depth of field with an all manual aperture legacy lens at the aperture set, but not an AF lens beyond the physical aperture prior to the auto stop-down, unless I use DOF preview. Then add Shutter Speed Effect to see the exposure and the full effect of the film mode used.

There are so many enhancements with the micro 4/3 that it's hard to distinguish the individual effects, but there is no constant DOF preview. Most users just never stop down enough to notice, or rely on the Quick Review to make adjustments shot by shot.

NexOffender Regular Member • Posts: 328
Re: not likely to be the case

I didn't mean the screen brightness. If you look into the front of the lens while adjusting the aperture, you can watch the iris opening and closing.

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gollywop
gollywop Veteran Member • Posts: 8,283
Re: not likely to be the case

NexOffender wrote:

I didn't mean the screen brightness. If you look into the front of the lens while adjusting the aperture, you can watch the iris opening and closing.

What camera, please.

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gollywop

NexOffender Regular Member • Posts: 328
Re: not likely to be the case

It's a NEX-6 by the way.

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Leonard Migliore
Leonard Migliore Forum Pro • Posts: 16,222
Re: Depth of Field Preview feature ?
1

will222 wrote:

At face value, this seems like a useful feature to look for in a camera.

Is the implementation of this pretty consistent across cameras, or do certain models do an excellent job and on others it's not very useful?

Is this something you guys use pretty often, and wouldn't get a new camera without it? Or not all that useful after the initial novelty wears off?

I find DOF preview quite useless on the optical viewfinder of an autofocus SLR. That's because the screen is too clear to show focus. It is, however, useful in live view.

But now we have to look at how live view is implemented. On Canon DSLR's, live view defaults to having the lens wide open; the DOF preview button stops the lens down to the set aperture. This works pretty well. On Nikon DSLR's, live view defaults to having the lens stopped down to the taking aperture. But what's really bad is, if you change the taking aperture, the diaphragm does not respond until you take the picture. So you can't look at the effect of changing aperture.

So to summarize, I find DOF preview useless with the optical finder on DSLR's. I find DOF preview useless on Nikons in live view. I find DOF preview somewhat useful on Canons in live view.

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gollywop
gollywop Veteran Member • Posts: 8,283
Re: not likely to be the case

NexOffender wrote:

It's a NEX-6 by the way.

Perhaps so with the APS-C, hybrid AF systems -- I have no personal experience with them. But it is surely not so for the E-M5 with AF lenses or, I believe, any other Olympus or Panasonic mFT camera. My objection was to the blanket statement that implied that all mirrorless cameras have constant DoF preview, which is clearly incorrect.

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gollywop

OP will222 Forum Member • Posts: 71
Re: Depth of Field Preview feature ?

Leonard Migliore wrote:

I find DOF preview quite useless on the optical viewfinder of an autofocus SLR. That's because the screen is too clear to show focus. It is, however, useful in live view.

On Nikon DSLR's, live view defaults to having the lens stopped down to the taking aperture. But what's really bad is, if you change the taking aperture, the diaphragm does not respond until you take the picture. So you can't look at the effect of changing aperture.

I'm not sure I understand what you mean by the screen is too clear to show focus. Would you mind elaborating a bit?

That's strange re: the Nikon. Seems to defeat the purpose if you can't see the effect of adjusting the aperture.

I guess the Nikon (according to the D7000 manual) has an option called "modeling flash" which, if I'm reading it correctly, lights the subject (I would asssume continuous light not a flash so it seems like an odd name for it) when you press DOF preview so the effect of small aperture can be seen (i.e. not darkened). I could be wrong on that though.

Still, if you can't adjust aperture from there, to see the effect, it doesn't seem to add much and you might as well just take the photo and review it and repeat.

PS, does live view refer to using the LCD screen not the viewfinder?

OP will222 Forum Member • Posts: 71
Re: not likely to be the case

NexOffender wrote:

It's a NEX-6 by the way.

Is it correct that the NEX 6 does not have DOF preview through the viewfinder? I searched in the manual and there's no mention of DOF preview (I'm assuming DOF preview is always associated with the viewfinder but I could be wrong on that) but they might call it something else.

The manual says practically nothing about live view. There's this sentence on pg 58: "Allows you to choose whether or not to show the value of exposure compensation, etc. on the screen display." but that's the (vague) extent of the description.

Barrie Davis
Barrie Davis Forum Pro • Posts: 21,460
Re: Depth of Field Preview feature ?

Leonard Migliore wrote:

will222 wrote:

At face value, this seems like a useful feature to look for in a camera.

Is the implementation of this pretty consistent across cameras, or do certain models do an excellent job and on others it's not very useful?

Is this something you guys use pretty often, and wouldn't get a new camera without it? Or not all that useful after the initial novelty wears off?

I find DOF preview quite useless on the optical viewfinder of an autofocus SLR. That's because the screen is too clear to show focus. It is, however, useful in live view.

Quite so. Even if it worked properly, the image is too dim to see. Better shoot a frame and examine that.

But now we have to look at how live view is implemented. On Canon DSLR's, live view defaults to having the lens wide open; the DOF preview button stops the lens down to the set aperture. This works pretty well. On Nikon DSLR's, live view defaults to having the lens stopped down to the taking aperture. But what's really bad is, if you change the taking aperture, the diaphragm does not respond until you take the picture. So you can't look at the effect of changing aperture.

So to summarize, I find DOF preview useless with the optical finder on DSLR's. I find DOF preview useless on Nikons in live view. I find DOF preview somewhat useful on Canons in live view.

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Barrie Davis Forum Pro • Posts: 21,460
Re: Depth of Field Preview feature ?

will222 wrote:

Leonard Migliore wrote:

I find DOF preview quite useless on the optical viewfinder of an autofocus SLR. That's because the screen is too clear to show focus. It is, however, useful in live view.

On Nikon DSLR's, live view defaults to having the lens stopped down to the taking aperture. But what's really bad is, if you change the taking aperture, the diaphragm does not respond until you take the picture. So you can't look at the effect of changing aperture.

I'm not sure I understand what you mean by the screen is too clear to show focus. Would you mind elaborating a bit?

Modern focusing screens are made to be as transparent as possble, in order to be as bright as possible.... closer in brightness to the viewing experience enjoyed in full frame 35mm cameras of 30 years ago. This transparency means they tend to look "in focus" all the time, even when they are not.

Why are they not so bright as 30 years ago?

a) The APSc mirror and screen assembly is not so big, so it gathers less light... some being diverted to AF system.

b) Lens maximum apertures are generally rather smaller in today's zoom kit lenses, f/3.5 is typical, where 30 years ago our fixed f-length 50mm would likely have been an f/2

That's strange re: the Nikon. Seems to defeat the purpose if you can't see the effect of adjusting the aperture.

I guess the Nikon (according to the D7000 manual) has an option called "modeling flash" which, if I'm reading it correctly, lights the subject (I would asssume continuous light not a flash so it seems like an odd name for it) when you press DOF preview so the effect of small aperture can be seen (i.e. not darkened). I could be wrong on that though.

Still, if you can't adjust aperture from there, to see the effect, it doesn't seem to add much and you might as well just take the photo and review it and repeat.

PS, does live view refer to using the LCD screen not the viewfinder?

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Baz
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NexOffender Regular Member • Posts: 328
Re: not likely to be the case

will222 wrote:

NexOffender wrote:

It's a NEX-6 by the way.

Is it correct that the NEX 6 does not have DOF preview through the viewfinder? I searched in the manual and there's no mention of DOF preview (I'm assuming DOF preview is always associated with the viewfinder but I could be wrong on that) but they might call it something else.

The manual says practically nothing about live view. There's this sentence on pg 58: "Allows you to choose whether or not to show the value of exposure compensation, etc. on the screen display." but that's the (vague) extent of the description.

The NEX-6 always has DOF preview through the EVF and on the screen because the lens is already stopped down. I guess there is no mention of it in the manual because it's not something you can turn on and off, and because it's a terrible manual. Turning off live view only stops the display brightness and colour from changing as you adjust the settings.

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