Digital vs Film - just give in!

"jjs" wrote in message
...
"David J. Littleboy" wrote in message
...

If you don't understand how DOF changes with format, you might want to
take
your own advice.

Now David, let's sit down here with our favorite beverage and think this
through. I'll have coffee, thanks.

Okay, here's the case. I have two cameras side-by-side. One is Hasselblad
SWC (38mm), the other is a 4x5 with a 3" (76mm) lens. Now I know that
these
formats do not correspond perfectly, but using the 5" dimension of the
later
the later suffices to give about twice the size format of the former.

Each is shot at F16 with a subject that will demonstrate DOF adequately. A
good example would focus at an object at, say, 10 feet with objects in the
background diminishing gradually to infinity.

Print the outcome from each to, say, 16" (the 5" side of 4x5 to 16" which
gives a slighly cropped image.) That's close enough for our example.

Do you see any significant difference in the DOF?

You should if you've done the experiment right. And the difference gets
really noticeable if you compare formats that differ by a factor of four or
larger.

The point being that looking from the point of outcome: the print (and
what
other method matters?), two cameras side by side with different formats
and
corresponding (equivalent for each format) focal length lenses at the same
Fstop will produce the same DOF in the same sized prints.

Still wrong. Look it up.

Or do I need to have an Alzheimer's test?

You need to look it up.

David J. Littleboy
Tokyo, Japan

"jjs" wrote in message
...
"David J. Littleboy" wrote in message
...

If you don't understand how DOF changes with format, you might want to
take
your own advice.

Now David, let's sit down here with our favorite beverage and think this
through. I'll have coffee, thanks.

Okay, here's the case. I have two cameras side-by-side. One is Hasselblad
SWC (38mm), the other is a 4x5 with a 3" (76mm) lens. Now I know that
these
formats do not correspond perfectly, but using the 5" dimension of the
later
the later suffices to give about twice the size format of the former.

Each is shot at F16 with a subject that will demonstrate DOF adequately. A
good example would focus at an object at, say, 10 feet with objects in the
background diminishing gradually to infinity.

Print the outcome from each to, say, 16" (the 5" side of 4x5 to 16" which
gives a slighly cropped image.) That's close enough for our example.

Do you see any significant difference in the DOF?

You should if you've done the experiment right. And the difference gets
really noticeable if you compare formats that differ by a factor of four or
larger.

The point being that looking from the point of outcome: the print (and
what
other method matters?), two cameras side by side with different formats
and
corresponding (equivalent for each format) focal length lenses at the same
Fstop will produce the same DOF in the same sized prints.

Still wrong. Look it up.

Or do I need to have an Alzheimer's test?

You need to look it up.

David J. Littleboy
Tokyo, Japan

"David J. Littleboy" wrote in message
...

Or do I need to have an Alzheimer's test?

You need to look it up.

I think it's worse than that. Bummer.

"David J. Littleboy" wrote in message
...

Or do I need to have an Alzheimer's test?

You need to look it up.

I think it's worse than that. Bummer.

I believe you're correct, but it's not the aperture value that has to be
the same but the actual size of the aperture opening. f16 for 35mm is
smaller than f16 for 6x6. Let's say f32 for MF is equal to f16 for 35mm
in actual aperture size then, I've read, you will get the same DOF, all
else being equal.

jjs wrote:

"David J. Littleboy" wrote in message
...

Or do I need to have an Alzheimer's test?

You need to look it up.

I think it's worse than that. Bummer.

I believe you're correct, but it's not the aperture value that has to be
the same but the actual size of the aperture opening. f16 for 35mm is
smaller than f16 for 6x6. Let's say f32 for MF is equal to f16 for 35mm
in actual aperture size then, I've read, you will get the same DOF, all
else being equal.

jjs wrote:

"David J. Littleboy" wrote in message
...

Or do I need to have an Alzheimer's test?

You need to look it up.

I think it's worse than that. Bummer.

wrote:

I believe you're correct, but it's not the aperture value that has to be
the same but the actual size of the aperture opening. f16 for 35mm is
smaller than f16 for 6x6. Let's say f32 for MF is equal to f16 for 35mm
in actual aperture size then, I've read, you will get the same DOF, all
else being equal.



And diffraction effects the longer lenses less so this smaller fstop doesn't
hurt anything.
--

Stacey

wrote:

I believe you're correct, but it's not the aperture value that has to be
the same but the actual size of the aperture opening. f16 for 35mm is
smaller than f16 for 6x6. Let's say f32 for MF is equal to f16 for 35mm
in actual aperture size then, I've read, you will get the same DOF, all
else being equal.



And diffraction effects the longer lenses less so this smaller fstop doesn't
hurt anything.
--

Stacey

"jjs" wrote in message ...
"RolandRB" wrote in message
om...

Another one of these trolls. But yes, digital cameras are geting
better. I like the ultra-small format digital because of the increased
depth of field (not all digital cameras use that small format and so
lack that increased depth of field).

Presuming you print to the same size print, then they do not have different
DOF. You might as well "throw those hasselblads away" right now if you can't
handle the principles of photography by now.

Would you mind if I framed your reply and hung it on my wall?

"jjs" wrote in message ...
"RolandRB" wrote in message
om...

Another one of these trolls. But yes, digital cameras are geting
better. I like the ultra-small format digital because of the increased
depth of field (not all digital cameras use that small format and so
lack that increased depth of field).

Presuming you print to the same size print, then they do not have different
DOF. You might as well "throw those hasselblads away" right now if you can't
handle the principles of photography by now.

Would you mind if I framed your reply and hung it on my wall?