MF lens on digital body

John Honan wrote in
:

However, it
will still act like a 28mm in the way it treats perspective in
foreground objects (for example)

the focal length is irrelevant to perspective -- only camera position is. A
28mm lens, corresponding to a 42mm lens on a film body (because of the
cropping) will behave exactly like a "true" 42mm lens on that film body.

So you can't just put a 28mm lens on a digital body, and use it like
you would use a 50mm lens on a manual body.

That's fortunately exactly the way it is. You just have to multiply with
1.5 to get the "new" equivalent focal length. Nothing else changes.

John Honan wrote in
:

However, it
will still act like a 28mm in the way it treats perspective in
foreground objects (for example)

the focal length is irrelevant to perspective -- only camera position is. A
28mm lens, corresponding to a 42mm lens on a film body (because of the
cropping) will behave exactly like a "true" 42mm lens on that film body.

So you can't just put a 28mm lens on a digital body, and use it like
you would use a 50mm lens on a manual body.

That's fortunately exactly the way it is. You just have to multiply with
1.5 to get the "new" equivalent focal length. Nothing else changes.

"John Honan" wrote in message
...
Chris B wrote:
It still has the same focal length, but the field of view changes -
generally digital camera CCDs have a smaller sensors than a 35mm frame,
so
less of the rendered image is recorded by the CCD than by 35mm film.

You can talk about '35mm equivalent' focal lengths though - IIRC if you
put
a 50mm lens on a DSLR it would probably be roughly equivalent to an 80mm
lens on 35mm film. You should understand, though, that the focal length
hasn't really changed, it's just less is recorded by the sensor.

Hope that made sense.

That makes sense, thanks Chris.

I can understand the piece about the digital sensor area being smaller
than the film area (and therefore only 'seeing' a smaller part of the
image), which is why I asked the question.

So in moving from film to digital body, your existing wide-angle lenses
would become medium-ish. i.e. put your old 28mm on the digital body and
you'll get a field of view equivalent to a 50mm. However, it will still
act like a 28mm in the way it treats perspective in foreground objects
(for example)

So you can't just put a 28mm lens on a digital body, and use it like you
would use a 50mm lens on a manual body. They would give roughly the same
field of view, but they would treat perspective in different ways.

Yep, you've got it!

:-)

Chris.

"John Honan" wrote in message
...
Chris B wrote:
It still has the same focal length, but the field of view changes -
generally digital camera CCDs have a smaller sensors than a 35mm frame,
so
less of the rendered image is recorded by the CCD than by 35mm film.

You can talk about '35mm equivalent' focal lengths though - IIRC if you
put
a 50mm lens on a DSLR it would probably be roughly equivalent to an 80mm
lens on 35mm film. You should understand, though, that the focal length
hasn't really changed, it's just less is recorded by the sensor.

Hope that made sense.

That makes sense, thanks Chris.

I can understand the piece about the digital sensor area being smaller
than the film area (and therefore only 'seeing' a smaller part of the
image), which is why I asked the question.

So in moving from film to digital body, your existing wide-angle lenses
would become medium-ish. i.e. put your old 28mm on the digital body and
you'll get a field of view equivalent to a 50mm. However, it will still
act like a 28mm in the way it treats perspective in foreground objects
(for example)

So you can't just put a 28mm lens on a digital body, and use it like you
would use a 50mm lens on a manual body. They would give roughly the same
field of view, but they would treat perspective in different ways.

Yep, you've got it!

:-)

Chris.

"John Honan" wrote in message
...
Chris B wrote:
It still has the same focal length, but the field of view changes -
generally digital camera CCDs have a smaller sensors than a 35mm frame,
so
less of the rendered image is recorded by the CCD than by 35mm film.

You can talk about '35mm equivalent' focal lengths though - IIRC if you
put
a 50mm lens on a DSLR it would probably be roughly equivalent to an 80mm
lens on 35mm film. You should understand, though, that the focal length
hasn't really changed, it's just less is recorded by the sensor.

Hope that made sense.

That makes sense, thanks Chris.

I can understand the piece about the digital sensor area being smaller
than the film area (and therefore only 'seeing' a smaller part of the
image), which is why I asked the question.

So in moving from film to digital body, your existing wide-angle lenses
would become medium-ish. i.e. put your old 28mm on the digital body and
you'll get a field of view equivalent to a 50mm. However, it will still
act like a 28mm in the way it treats perspective in foreground objects
(for example)

So you can't just put a 28mm lens on a digital body, and use it like you
would use a 50mm lens on a manual body. They would give roughly the same
field of view, but they would treat perspective in different ways.

Yep, you've got it!

:-)

Chris.

"John Honan" wrote in message
...
Chris B wrote:
It still has the same focal length, but the field of view changes -
generally digital camera CCDs have a smaller sensors than a 35mm frame,
so
less of the rendered image is recorded by the CCD than by 35mm film.

You can talk about '35mm equivalent' focal lengths though - IIRC if you
put
a 50mm lens on a DSLR it would probably be roughly equivalent to an 80mm
lens on 35mm film. You should understand, though, that the focal length
hasn't really changed, it's just less is recorded by the sensor.

Hope that made sense.

That makes sense, thanks Chris.

I can understand the piece about the digital sensor area being smaller
than the film area (and therefore only 'seeing' a smaller part of the
image), which is why I asked the question.

So in moving from film to digital body, your existing wide-angle lenses
would become medium-ish. i.e. put your old 28mm on the digital body and
you'll get a field of view equivalent to a 50mm. However, it will still
act like a 28mm in the way it treats perspective in foreground objects
(for example)

So you can't just put a 28mm lens on a digital body, and use it like you
would use a 50mm lens on a manual body. They would give roughly the same
field of view, but they would treat perspective in different ways.

Yep, you've got it!

:-)

Chris.

Chris B wrote:

"John Honan" wrote in message
...

Chris B wrote:

It still has the same focal length, but the field of view changes -
generally digital camera CCDs have a smaller sensors than a 35mm frame,

so

less of the rendered image is recorded by the CCD than by 35mm film.

You can talk about '35mm equivalent' focal lengths though - IIRC if you

put

a 50mm lens on a DSLR it would probably be roughly equivalent to an 80mm
lens on 35mm film. You should understand, though, that the focal length
hasn't really changed, it's just less is recorded by the sensor.

Hope that made sense.

That makes sense, thanks Chris.

I can understand the piece about the digital sensor area being smaller
than the film area (and therefore only 'seeing' a smaller part of the
image), which is why I asked the question.

So in moving from film to digital body, your existing wide-angle lenses
would become medium-ish. i.e. put your old 28mm on the digital body and
you'll get a field of view equivalent to a 50mm. However, it will still
act like a 28mm in the way it treats perspective in foreground objects
(for example)

So you can't just put a 28mm lens on a digital body, and use it like you
would use a 50mm lens on a manual body. They would give roughly the same
field of view, but they would treat perspective in different ways.


Yep, you've got it!

ALL lenses, regardless of focal length or format, have the same perspective from
a given shooting position. The FOV (and lens dependant distortions) do change,
of course depending on FL and sensor area. FOV and perspective are two differnt
items.

Cheers,
Alan


--
-- rec.photo.equipment.35mm user resource:
-- http://www.aliasimages.com/rpe35mmur.htm
-- e-meil: there's no such thing as a FreeLunch.--

Chris B wrote:

"John Honan" wrote in message
...

Chris B wrote:

It still has the same focal length, but the field of view changes -
generally digital camera CCDs have a smaller sensors than a 35mm frame,

so

less of the rendered image is recorded by the CCD than by 35mm film.

You can talk about '35mm equivalent' focal lengths though - IIRC if you

put

a 50mm lens on a DSLR it would probably be roughly equivalent to an 80mm
lens on 35mm film. You should understand, though, that the focal length
hasn't really changed, it's just less is recorded by the sensor.

Hope that made sense.

That makes sense, thanks Chris.

I can understand the piece about the digital sensor area being smaller
than the film area (and therefore only 'seeing' a smaller part of the
image), which is why I asked the question.

So in moving from film to digital body, your existing wide-angle lenses
would become medium-ish. i.e. put your old 28mm on the digital body and
you'll get a field of view equivalent to a 50mm. However, it will still
act like a 28mm in the way it treats perspective in foreground objects
(for example)

So you can't just put a 28mm lens on a digital body, and use it like you
would use a 50mm lens on a manual body. They would give roughly the same
field of view, but they would treat perspective in different ways.


Yep, you've got it!

ALL lenses, regardless of focal length or format, have the same perspective from
a given shooting position. The FOV (and lens dependant distortions) do change,
of course depending on FL and sensor area. FOV and perspective are two differnt
items.

Cheers,
Alan


--
-- rec.photo.equipment.35mm user resource:
-- http://www.aliasimages.com/rpe35mmur.htm
-- e-meil: there's no such thing as a FreeLunch.--

Chris B wrote:

"John Honan" wrote in message
...

Chris B wrote:

It still has the same focal length, but the field of view changes -
generally digital camera CCDs have a smaller sensors than a 35mm frame,

so

less of the rendered image is recorded by the CCD than by 35mm film.

You can talk about '35mm equivalent' focal lengths though - IIRC if you

put

a 50mm lens on a DSLR it would probably be roughly equivalent to an 80mm
lens on 35mm film. You should understand, though, that the focal length
hasn't really changed, it's just less is recorded by the sensor.

Hope that made sense.

That makes sense, thanks Chris.

I can understand the piece about the digital sensor area being smaller
than the film area (and therefore only 'seeing' a smaller part of the
image), which is why I asked the question.

So in moving from film to digital body, your existing wide-angle lenses
would become medium-ish. i.e. put your old 28mm on the digital body and
you'll get a field of view equivalent to a 50mm. However, it will still
act like a 28mm in the way it treats perspective in foreground objects
(for example)

So you can't just put a 28mm lens on a digital body, and use it like you
would use a 50mm lens on a manual body. They would give roughly the same
field of view, but they would treat perspective in different ways.


Yep, you've got it!

ALL lenses, regardless of focal length or format, have the same perspective from
a given shooting position. The FOV (and lens dependant distortions) do change,
of course depending on FL and sensor area. FOV and perspective are two differnt
items.

Cheers,
Alan


--
-- rec.photo.equipment.35mm user resource:
-- http://www.aliasimages.com/rpe35mmur.htm
-- e-meil: there's no such thing as a FreeLunch.--

Chris B wrote:

"John Honan" wrote in message
...

Chris B wrote:

It still has the same focal length, but the field of view changes -
generally digital camera CCDs have a smaller sensors than a 35mm frame,

so

less of the rendered image is recorded by the CCD than by 35mm film.

You can talk about '35mm equivalent' focal lengths though - IIRC if you

put

a 50mm lens on a DSLR it would probably be roughly equivalent to an 80mm
lens on 35mm film. You should understand, though, that the focal length
hasn't really changed, it's just less is recorded by the sensor.

Hope that made sense.

That makes sense, thanks Chris.

I can understand the piece about the digital sensor area being smaller
than the film area (and therefore only 'seeing' a smaller part of the
image), which is why I asked the question.

So in moving from film to digital body, your existing wide-angle lenses
would become medium-ish. i.e. put your old 28mm on the digital body and
you'll get a field of view equivalent to a 50mm. However, it will still
act like a 28mm in the way it treats perspective in foreground objects
(for example)

So you can't just put a 28mm lens on a digital body, and use it like you
would use a 50mm lens on a manual body. They would give roughly the same
field of view, but they would treat perspective in different ways.


Yep, you've got it!

ALL lenses, regardless of focal length or format, have the same perspective from
a given shooting position. The FOV (and lens dependant distortions) do change,
of course depending on FL and sensor area. FOV and perspective are two differnt
items.

Cheers,
Alan


--
-- rec.photo.equipment.35mm user resource:
-- http://www.aliasimages.com/rpe35mmur.htm
-- e-meil: there's no such thing as a FreeLunch.--