Drowning in photos

In article , Hans Kruse
says...

Corners cropped away? I actually wanted to have a look at the corners.

I made a full resolution of the same picture you saw. But why is this so
interesting?

I was curious how the lens performs in the corners wide open. Usually
that is the weakest spot.
--

Alfred Molon
------------------------------
Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site

"Alfred Molon" wrote in message
...

I was curious how the lens performs in the corners wide open. Usually
that is the weakest spot.

Yes, of course, and sharpness as well. Go to a lens test site.
http://www.the-digital-picture.com/R...ns-Review.aspx
and for vignetting compared to the 24mm f/1.4 at f/2.8
http://www.the-digital-picture.com/R...mp=0&APIComp=2
As said it is a very nice lens although on the 1Ds mk3, probably an update
to the lens would be good to have. My copy is pretty sharp on full frame and
also into the corners stopped down to f/8-f/11.
Here the same picture without cropping
http://www.pbase.com/hkruse/image/100298602 and with some vignetting
correction done in Lightroom.

--
Med venlig hilsen/Kind regards,
Hans Kruse www.hanskruse.com, http://hans-kruse.blogspot.com/

In article , Hans Kruse
says...

and for vignetting compared to the 24mm f/1.4 at f/2.8
http://www.the-digital-picture.com/R...mp=0&APIComp=2

4 stops of lights loss in the corners (F1.4) - that's catastrophic. I
guess the main problem here is that the diameter of the lens is by far
too small.

As a comparison, the Olympus 8080 has an F2.4-3.5 24-120mm (equiv.) lens
with a diameter of 58mm. Such a lens diameter is necessary to avoid
vignetting. The Canon Powershot Pro 1 for instance, which uses the same
sensor and has a smaller lens, suffers from vignetting.

Sensor size in the Oly 8080 is 8.8x6.6mm, which means that a full frame
lens with the same parameters (F2.4-3.5, 24-120mm, no vignetting) would
have to have a diameter of 220mm. Yet these Canon lenses have diameters
of just 77mm, and this is why you get so much vignetting.

If a less bright lens is sufficient, consider the Sony R1 with its F2.8-
4.8 24-120mm (equiv.) lens. Again here there is no vignetting. The lens
diameter is 67mm, the crop factor 1.67.

An equivalent full frame lens would have to have a 112mm diameter.
However full frame lenses are far away from that, which is why there is
so much vignetting with the lens wide open.
--

Alfred Molon
------------------------------
Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site

"Alfred Molon" wrote in message
...

4 stops of lights loss in the corners (F1.4) - that's catastrophic. I
guess the main problem here is that the diameter of the lens is by far
too small.

If you shoot at f/1.4 you will not notice in most situations that there is
vigneting to bother about. Many people actually add vignetting in post
processing to close the corners. You also choose f/1.4 for DOF
considerations and if combined with e.g. ISO 1600 or 3200 af f/1.4 you have
so little light that your p&s will not even make a picture ;-) except for
catastrophic smearing of detail. You can't get this level of DOF on a p&s
camera anyway.


An equivalent full frame lens would have to have a 112mm diameter.
However full frame lenses are far away from that, which is why there is
so much vignetting with the lens wide open.

Interestingly enough vignetting have never bothered me. On my longer lenses
there is no vignetting at all visible even full open. My 500 f/4L IS has no
visible vignetting. My 70-200 f/2.8L IS has some vignetting at f/2.8 but
already f/4 it is hardly noticeable. It is not something that bothers me
anyway. In a few cases I have compensated in post processing, but very
seldom.

Do you find this very import for your photography?

--
Med venlig hilsen/Kind regards,
Hans Kruse www.hanskruse.com, http://hans-kruse.blogspot.com/

In article , Hans Kruse
says...

If you shoot at f/1.4 you will not notice in most situations that there is
vigneting to bother about. Many people actually add vignetting in post
processing to close the corners. You also choose f/1.4 for DOF
considerations and if combined with e.g. ISO 1600 or 3200 af f/1.4 you have
so little light that your p&s will not even make a picture ;-)

Tripod + lowest ISO + long exposure...

A P&S with a light-weight tripod still weighs less thah a full frame
DSLR with a bright lens.

Do you find this very import for your photography?

It's important that a photo have no vignetting.
--

Alfred Molon
------------------------------
Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site

Alfred Molon wrote:
In article , Hans Kruse
says...
and for vignetting compared to the 24mm f/1.4 at f/2.8
http://www.the-digital-picture.com/R...mp=0&APIComp=2

4 stops of lights loss in the corners (F1.4) - that's catastrophic. I
guess the main problem here is that the diameter of the lens is by far
too small.

As a comparison, the Olympus 8080 has an F2.4-3.5 24-120mm (equiv.) lens
with a diameter of 58mm. Such a lens diameter is necessary to avoid
vignetting. The Canon Powershot Pro 1 for instance, which uses the same
sensor and has a smaller lens, suffers from vignetting.

Sensor size in the Oly 8080 is 8.8x6.6mm, which means that a full frame
lens with the same parameters (F2.4-3.5, 24-120mm, no vignetting) would
have to have a diameter of 220mm. Yet these Canon lenses have diameters
of just 77mm, and this is why you get so much vignetting.


What you forget is that to get the same amount of light per pixel ... which
is what matters ... for the same field of view, the lens front sizes have
to be THE SAME for the two different sensor sizes. Thus, to get as
much light light as an f/4 lens for a full frame DSLR your example
Olympus minisensor camera would need an f/1 lens (!)

You can't compare equal f/numbers ... you have to compare equal lens
diameters AT THE SAME FIELD OF VIEW (in degrees).

Try to understand this.

Doug McDonald

Hans Kruse wrote:


Interestingly enough vignetting have never bothered me. On my longer lenses
there is no vignetting at all visible even full open. My 500 f/4L IS has no
visible vignetting. My 70-200 f/2.8L IS has some vignetting at f/2.8 but
already f/4 it is hardly noticeable. It is not something that bothers me
anyway. In a few cases I have compensated in post processing, but very
seldom.

Do you find this very import for your photography?


I do because I do a lot of panoramas. There, it matters. Canon's
semi-automatic correction software seems to work excellently. It leaves
little work for the panorama stitching software.

Doug McDonald

Alfred Molon wrote:
In article , Hans Kruse
says...
and for vignetting compared to the 24mm f/1.4 at f/2.8
http://www.the-digital-picture.com/R...mp=0&APIComp=2

4 stops of lights loss in the corners (F1.4) - that's catastrophic.

It's normal for any super fast lens.

I guess the main problem here is that the diameter of the lens is by
far too small.

As a comparison, the Olympus 8080 has an F2.4-3.5 24-120mm (equiv.) lens
with a diameter of 58mm. Such a lens diameter is necessary to avoid
vignetting. The Canon Powershot Pro 1 for instance, which uses the same
sensor and has a smaller lens, suffers from vignetting.

Sensor size in the Oly 8080 is 8.8x6.6mm, which means that a full frame
lens with the same parameters (F2.4-3.5, 24-120mm, no vignetting) would
have to have a diameter of 220mm. Yet these Canon lenses have diameters
of just 77mm, and this is why you get so much vignetting.

If a less bright lens is sufficient, consider the Sony R1 with its F2.8-
4.8 24-120mm (equiv.) lens. Again here there is no vignetting. The lens
diameter is 67mm, the crop factor 1.67.

An equivalent full frame lens would have to have a 112mm diameter.
However full frame lenses are far away from that, which is why there is
so much vignetting with the lens wide open.


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

all google groups messages filtered due to spam

"Alfred Molon" wrote in message
...

Tripod + lowest ISO + long exposure...

I'm not sure it makes to continue this discussion. Let me try again: If you
need the DOF and/or cannot use af tripod and low light then you can only
this type of photography with a dslr and a f/1.4 lens.

A P&S with a light-weight tripod still weighs less thah a full frame
DSLR with a bright lens.

A tripod is not always an option. The reason I carry a full frame dslr is
that it gives me much better quality and flexibility that I need.

It's important that a photo have no vignetting.

You mean for your photography? As a general statement this is not true.

--
Med venlig hilsen/Kind regards,
Hans Kruse www.hanskruse.com, http://hans-kruse.blogspot.com/

wrote in message
...

I do because I do a lot of panoramas. There, it matters. Canon's
semi-automatic correction software seems to work excellently. It leaves
little work for the panorama stitching software.

For a panorama I would say one would use a tripod and a aperture f/8-f/16 on
a dslr, so no issue with vignetting.

--
Med venlig hilsen/Kind regards,
Hans Kruse www.hanskruse.com, http://hans-kruse.blogspot.com/