DoF and hyperfocal distance calculators and charts

There will be some situations out in the middle of nowhere when I may
need to calculate the hyperfocal distance. But despite all the smarts
built into my Nikon D700, and with the lenses that I have, there does
not appear to be any way of calculating the hyperfocal distance using
the D700. That's a real pity.

I'd have thought it would be elementary to set the required circle of
confusion and save this in the camera, and then when required
activate a "hyperfocal lock" function (let's call it "HF-L") and then
point the camera at the closest feature that you want in focus and
the camera then locks focus to the hyperfocal distance. But the D700
doesn't do this. So…

I've looked at software. I currently use a BlackBerry Curve device
which I nearly always have with me so I could use that using suitable
DoF software. Can you advice which is the best software to use?
Preferably free!

But even so, sometimes I might not have the BlackBerry device with
me. So I'm thinking of some kind of small mechanical calculator kinda
like a slide-rule or disc which I can attach to my camera or lenses.
I've seen this but it's limited in the number of focal lengths that
it can use so some guesswork may be required for zooms:

http://www.dofmaster.com/custom.html

What I think may be better (but bowing to your superior experience
and knowledge!) is using some charts. Again, at the same site I came
across this:

http://www.dofmaster.com/charts.html

I think that I can print one or two of these charts to cover my
lenses that I can then print very small and then laminate. I'd really
like to attach these to my camera strap. What do you think of this
idea? Or do you think that I should be approaching this differently?

Thanks for reading this far. Hope to get some valuable feedback from
everyone but with the holidays I know that some of you may be a bit
distracted over the next few days.

Happy holidays!
--
Kulvinder Singh Matharu

Website : www.metalvortex.com
Contact : www.metalvortex.com/contact/

Brain! Brain! What is brain?!

On Wed, 24 Dec 2008 22:46:48 +0000, Kulvinder Singh Matharu
wrote in
:

There will be some situations out in the middle of nowhere when I may
need to calculate the hyperfocal distance. ...

Why not just focus in the middle distance?
Then shoot, and examine focus across your image.
If necessary, refocus and re-shoot.
Knowing the hyperfocal distance will not necessarily
give you better results than that,
especially when there's too much distance to be covered.

--
Best regards,
John
Panasonic DMC-FZ8, DMC-FZ20, and several others

"Kulvinder Singh Matharu" wrote in message
...
There will be some situations out in the middle of nowhere when I may
need to calculate the hyperfocal distance. But despite all the smarts
built into my Nikon D700, and with the lenses that I have, there does
not appear to be any way of calculating the hyperfocal distance using
the D700. That's a real pity.

I'd have thought it would be elementary to set the required circle of
confusion and save this in the camera, and then when required
activate a "hyperfocal lock" function (let's call it "HF-L") and then
point the camera at the closest feature that you want in focus and
the camera then locks focus to the hyperfocal distance. But the D700
doesn't do this. So.

I've looked at software. I currently use a BlackBerry Curve device
which I nearly always have with me so I could use that using suitable
DoF software. Can you advice which is the best software to use?
Preferably free!

But even so, sometimes I might not have the BlackBerry device with
me. So I'm thinking of some kind of small mechanical calculator kinda
like a slide-rule or disc which I can attach to my camera or lenses.
I've seen this but it's limited in the number of focal lengths that
it can use so some guesswork may be required for zooms:

http://www.dofmaster.com/custom.html

What I think may be better (but bowing to your superior experience
and knowledge!) is using some charts. Again, at the same site I came
across this:

http://www.dofmaster.com/charts.html

I think that I can print one or two of these charts to cover my
lenses that I can then print very small and then laminate. I'd really
like to attach these to my camera strap. What do you think of this
idea? Or do you think that I should be approaching this differently?

Thanks for reading this far. Hope to get some valuable feedback from
everyone but with the holidays I know that some of you may be a bit
distracted over the next few days.

Happy holidays!
--
Kulvinder Singh Matharu

Website : www.metalvortex.com
Contact : www.metalvortex.com/contact/

Brain! Brain! What is brain?!

A quick but dirty way to set hyperfocal distance is to run your lens to
infinity focus; then, after pressing your DOF preview gbutton, slowly back
off
the focusing ring until the horizon starts to go blurry. Bringing the
horizon back into focus will establish the hyperfocal range of your lens for
whatever aperture you are stopping down to.

Just curious why you're trying to hyperfocal an autofocus camera...

"In the old days," hyperfocusing was done to save time and eliminate the
need for having to manually focus the lens in extreme situations -- i.e.
very low light, fast action, shooting over crowds, etc.

Using modern cameras, it seems to me that most situations can be covered
with modes like aperture priority, shutter priority, or scene modes.

Are you working with subjects which are hard to autofocus on? Or, is it
that you are just into manual shooting?

Take Care,
Dudley

Kulvinder Singh Matharu wrote:

But the D700 doesn't do this. So…

Trial & error with an educated guess. Live view could be your shortcut
with the D700, zoom in & scroll around while focusing & stopping down.
Hmm, a quick check shows I must have something set funny because I can't
scroll around once zoomed in live view... I'm sure that can be changed
though.

--
Paul Furman
www.edgehill.net
www.baynatives.com

all google groups messages filtered due to spam

"Paul Furman" wrote:
Kulvinder Singh Matharu wrote:

But the D700 doesn't do this. So…

Trial & error with an educated guess.

I'd say careful and thoughtful planning ahead and testing would be way
betterg.

Two points.

(1) Using the hyperfocal distance is simply defocusing from infinity focus
by as much as possible. So all the CoC calculations are bogus if they don't
correspond to your eye and needs. So you need to test, for each focal length
and f stop, how far you can defocus from infinity while retaining acceptable
sharpness for detail at infinity. Sounds painful, but it doesn't take all
that long with digital. You should put together things like this:

http://www.pbase.com/davidjl/image/93232600/original

(2) If you remember that DoF changes with the _square_ of the focal length,
you'll realize that the hyperfocal distance changes radically with the focal
length. So, again, you need to test, for each focal length and f stop, how
far you can defocus from infinity while retaining acceptable sharpness for
detail at infinity.

Live view could be your shortcut with the D700, zoom in & scroll around
while focusing & stopping down.

That will take way too much time in the field. If you know what you are
doing, you just do it.

It is way faster to remember that with a 12MP FF camera, a 20mm lens, and
f/16, you can set focus manually to 1 meter and still get decent pixel-level
sharpness at infinity. With a 24 MP camera, that'll be f/11 (to avoid
diffraction) and 2 meters. (Since my goal is "decent pixel-level sharpness",
the CoC is smaller for the higher-res camera, and DoF narrower.)

Hmm. I think that the 1m bit is a bit overly optimistic: 1.5m (3m on the
5D2) would be more reasonable.

Hmm, a quick check shows I must have something set funny because I can't
scroll around once zoomed in live view... I'm sure that can be changed
though.

Works fine on the 5D2. This is incredibly useful with the 24mm TSE lens.
With a 24mm on the 5D2, the focal length squared term plus the smaller CoC
mean that you really have to play tilt games, and putting the magnified view
at the bottom of the frame means you can get to the optimal tilt quickly.
Here's more detail on this:

http://forums.dpreview.com/forums/re...ssage=30457586

--
David J. Littleboy
Tokyo, Japan

David J. Littleboy wrote:

Using the hyperfocal distance is simply defocusing from infinity focus
by as much as possible.

This procedure should work with live view. Stop down, zoom into
something at infinity & turn the focus ring closer till it softens.


Live view could be your shortcut with the D700, zoom in & scroll around
while focusing & stopping down.

This is incredibly useful with the 24mm TSE lens.
With a 24mm on the 5D2, the focal length squared term plus the smaller CoC
mean that you really have to play tilt games, and putting the magnified view
at the bottom of the frame means you can get to the optimal tilt quickly.
Here's more detail on this:

http://forums.dpreview.com/forums/re...ssage=30457586



--
Paul Furman
www.edgehill.net
www.baynatives.com

all google groups messages filtered due to spam

Paul Furman wrote in
:

David J. Littleboy wrote:

Using the hyperfocal distance is simply defocusing from infinity
focus by as much as possible.

This procedure should work with live view. Stop down, zoom into
something at infinity & turn the focus ring closer till it softens.

ONLY with magnified live view. There is no way on Earth you can judge
where the blurring begins in an optical viewfinder or a non-magnified live
view screen so you won't see it at 100% on a computer screen.

Kulvinder Singh Matharu wrote:
There will be some situations out in the middle of nowhere when I may
need to calculate the hyperfocal distance. But despite all the smarts
built into my Nikon D700, and with the lenses that I have, there does
not appear to be any way of calculating the hyperfocal distance using
the D700. That's a real pity.

I'd have thought it would be elementary to set the required circle of
confusion and save this in the camera, and then when required
activate a "hyperfocal lock" function (let's call it "HF-L") and then
point the camera at the closest feature that you want in focus and
the camera then locks focus to the hyperfocal distance. But the D700
doesn't do this. So…

I've looked at software. I currently use a BlackBerry Curve device
which I nearly always have with me so I could use that using suitable
DoF software. Can you advice which is the best software to use?
Preferably free!

But even so, sometimes I might not have the BlackBerry device with
me. So I'm thinking of some kind of small mechanical calculator kinda
like a slide-rule or disc which I can attach to my camera or lenses.
I've seen this but it's limited in the number of focal lengths that
it can use so some guesswork may be required for zooms:

http://www.dofmaster.com/custom.html

What I think may be better (but bowing to your superior experience
and knowledge!) is using some charts. Again, at the same site I came
across this:

http://www.dofmaster.com/charts.html

I think that I can print one or two of these charts to cover my
lenses that I can then print very small and then laminate. I'd really
like to attach these to my camera strap. What do you think of this
idea? Or do you think that I should be approaching this differently?

Thanks for reading this far. Hope to get some valuable feedback from
everyone but with the holidays I know that some of you may be a bit
distracted over the next few days.

Happy holidays!

DOF is not simply a function of lens and focus distances. It includes
also the circle of confusion, the diameter of which is chosen to be
'almost' a point taken to be acceptably sharp in the final image or
print. Therefore, CoC is not a fixed size, but varies with the
magnification ratio between the camera image and the print size, and
complicated by the intended viewing distance of the final print. It is
said that smaller images like those from P&S or cropped sensor cameras
have greater DoF than larger images, but this is offset to some degree
by the need for greater magnification to give a similar-sized print to
that from a larger sensor.

The original concept of DoF was Leica's, calculated for a 35mm negative
enlarged to 10x8, and viewed at a distance equal to the print diagonal.
Other sizes of film/sensor, print size, and viewing distance require a
different CoC diameter. Some digital camera makers assume a CoC based
on their sensor size, and a print viewing distance equal to the print
diagonal, which tends to cancel the magnification factor (but is by no
means guaranteed with very small or very large prints).

Canon uses these assumptions with their DEP function on their dslrs,
whereby placing one focus area on a near object and another on the
farthest object and taking a half-pressure allows the camera to
instantly calculate the required aperture, which can then be set using
Av, a very handy function that I use frequently.

The older lenses with DoF scales were calibrated more or less according
to the Leica standard, and if used on cropped-sensor cameras will not
be accurate unless allowance is made.

BTW, viewing an image at 100% gives no idea at all of the DoF, since it
applies only to a print at screen resolution, 72 ppi, which implies an
image more than a metre across with most dslrs.

Colin D.

Colin.D wrote:
...
The original concept of DoF was Leica's, calculated for a 35mm negative
enlarged to 10x8, and viewed at a distance equal to the print diagonal.

Wouldn't it be the same numbers for any size print at a viewing distance
equal to the diagonal of the print? (assuming full frame sensor in this
case).

Other sizes of film/sensor, print size, and viewing distance require a
different CoC diameter. Some digital camera makers assume a CoC based
on their sensor size, and a print viewing distance equal to the print
diagonal, which tends to cancel the magnification factor (but is by no
means guaranteed with very small or very large prints).

Ah, OK, yep (generally).


Canon uses these assumptions with their DEP function on their dslrs,
whereby placing one focus area on a near object and another on the
farthest object and taking a half-pressure allows the camera to
instantly calculate the required aperture, which can then be set using
Av, a very handy function that I use frequently.

The older lenses with DoF scales were calibrated more or less according
to the Leica standard, and if used on cropped-sensor cameras will not
be accurate unless allowance is made.

BTW, viewing an image at 100% gives no idea at all of the DoF, since it
applies only to a print at screen resolution, 72 ppi, which implies an
image more than a metre across with most dslrs.

I'm amazed how much nasty pixely stuff disappears in a print, even at
200dpi or more magnification.

--
Paul Furman
www.edgehill.net
www.baynatives.com

all google groups messages filtered due to spam

Paul Furman wrote:
Colin.D wrote:
...
The original concept of DoF was Leica's, calculated for a 35mm
negative enlarged to 10x8, and viewed at a distance equal to the print
diagonal.

Wouldn't it be the same numbers for any size print at a viewing distance
equal to the diagonal of the print? (assuming full frame sensor in this
case).

Yes, for a FF sensor, maybe, but the Leica standard was for film, and I
think that a higher standard may be desired for a high-megapixel camera,
which means a smaller DoF. I was trying to make the point that DoF and
COC pertain to particular setups, and are by no means universal.


Other sizes of film/sensor, print size, and viewing distance require
a different CoC diameter. Some digital camera makers assume a CoC
based on their sensor size, and a print viewing distance equal to the
print diagonal, which tends to cancel the magnification factor (but is
by no means guaranteed with very small or very large prints).

Ah, OK, yep (generally).


Canon uses these assumptions with their DEP function on their dslrs,
whereby placing one focus area on a near object and another on the
farthest object and taking a half-pressure allows the camera to
instantly calculate the required aperture, which can then be set using
Av, a very handy function that I use frequently.

The older lenses with DoF scales were calibrated more or less
according to the Leica standard, and if used on cropped-sensor
cameras will not be accurate unless allowance is made.

BTW, viewing an image at 100% gives no idea at all of the DoF, since
it applies only to a print at screen resolution, 72 ppi, which implies
an image more than a metre across with most dslrs.

I'm amazed how much nasty pixely stuff disappears in a print, even at
200dpi or more magnification.

Compared with 100% view on a monitor, yes. At 200 ppi the image is only
a third as much enlarged as at 100%.

Actually, I don't know where this 100% idiom came from. What it means
is simply that the image is enlarged to give a 1:1 relationship between
the image and the monitor ppi, i.e. each image pixel is displayed by one
monitor pixel.

This also means that comparisons of camera and lens performance judged
by 100% images is false, since the magnification is a function of pixel
density. A true comparison can only be made when the images are the
same size, which doesn't happen with 100% crops.

Colin D.