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From: Neil Harrington on 17 Mar 2010 19:10

"D.J." <nocontact(a)noaddress.com> wrote in message
news:86kup5hsq5kvdjbb632iepigk20rgmp6t5(a)4ax.com...
> On Sat, 13 Mar 2010 12:57:35 -0500, "Neil Harrington" <never(a)home.com>
> wrote:
>
>>
>>"Lobster" <davidlobsterpot601(a)hotmail.com> wrote in message
>>news:0Pxmn.377994$UQ6.315102(a)newsfe04.ams2...
>>> Draco wrote:
>>>> On Mar 12, 2:47 pm, Lobster <davidlobsterpot...(a)hotmail.com> wrote:
>>>>> I've been playing around with the 'photomerge' function in Photoshop
>>>>> Elements, attempting to take a wide-angle-type view of a room.
>>>
>>>>> However, the results are hopeless, as you can see from the results of
>>>>> the pan at 'middle' height uploaded below. Ignoring other issues for
>>>>> now, the perspective is all wrong - why is this? Is it simply due to
>>>>> inaccurate leveling of the tripod or am I doing something else wrong?
>>>
>>>> From my point of view, it looks like you didn't swivel on the lens
>>>> nodel point. This is where the light come to a point in the lens before
>>>> it "widens" again to cover the "film plane" or digital sensor. It will
>>>> give a tilt to the image and distort the panorama. Also you should over
>>>> lap each shot by at the least 1/3 of the frame. This will give you and
>>>> the
>>>> program more to work with in aligning the images.
>>>
>>> Thanks for the responses. Sounds like the above would fit; especially by
>>> having rotated the bracket on the camera head through 90 deg to do the
>>> shots portrait-style, I could have swiveling the camera about 2-3" from
>>> the nodal point. I suppose taking pictures only a short distance away
>>> (the
>>> room is 3 or 4 yards wide) as opposed to a landscape shot will only
>>> execerbate that problem.
>>
>>It is true that rotating the camera around the lens's first nodal point
>>becomes more important for panoramic shots at closer distances, while it's
>>not very important at all with distant scenes.
>>
>>However, this is not your main problem. You cannot take a panoramic shot
>>in
>>this way and have it fully rectilinear, which is apparently what you are
>>trying to do. That is, you cannot ROTATE the camera and keep the same
>>perspective as if you had not rotated it.
>>
>>You can keep the verticals straight (and parallel if the camera is kept
>>level), but the horizontals must curve in order to get the whole stitched
>>scene in without obvious angular breaks; that is, the perspective changes
>>continuously from one side of the picture to the other.
>
> PTGUI and other good panorama stitcher utilities allow for straightening
> these types of problems.

You can't "straighten these types of problems" no matter what you do or what
you use. Horizontals (other than a central one, e.g. the horizon) from a
single camera position must curve since the perspective changes continuously
across the picture.

> So much so that I don't even bother with a tripod
> anymore to do panoramas.

You "don't even bother with a tripod" or a camera or anything else because
you don't do any of this stuff. You are just the same old troll that you've
always been. Today you're "D.J." -- how many names do you go through in a
week? (Never mind. It's what we call a rhetorical question.)

> Not even for nearby wide-angle subjects that
> exhibit parallax problems (fixing that with smart-blend plugin). It sounds
> like you've not created many panoramas nor used many panorama utilities.
> But then, that's expected of 99% of the people that hand out advice in
> forums and newsgroups. They know all about it from reading about it but
> have never actually done any of it. Armchair experts abound.

Still the same old P&S troll; change names as often as you like, you are
still instantly recognizable.


From: N on 18 Mar 2010 03:19

"D.J." <nocontact(a)noaddress.com> wrote in message
news:0gv2q5dnjqu0pacafn6fnkt440q75rcans(a)4ax.com...
>
> Here's a hand-held 12-frame pano of Long Lake in Shoshone National Forest.
> The true horizon runs perfectly straight through the mountain range. This
> is exactly how the land appears at that location, as proved by a few
> wide-angle shots taken later for comparison. I used them as reference for
> straightening the horizon.
>
> http://farm3.static.flickr.com/2701/4441563399_a36468c91a_b.jpg
>
> Unfortunately Flickr downsized this "for the web" 4529x600 pixel image to
> 1024x136.

Rubbish. Flickr doesn't downsize images for real people. Only for those
who are too tight to pay for their accounts and expect to get everything for
nothing.

The water looks wrong in that image and the image is extremely
uninteresting.


>
> Here's another hand-held 7 or 8-shot pano 2688x600 web-sized version
> (downsized by Flickr again). Just in case you don't believe the
> straightness possible when done that way.
>
> http://farm5.static.flickr.com/4022/4441563401_a0a8478d6c_b.jpg
>
>

This image is dull and lifeless.


From: Chris Malcolm on 19 Mar 2010 06:01
Neil Harrington <never(a)home.com> wrote:

> "D.J." <nocontact(a)noaddress.com> wrote in message
> news:86kup5hsq5kvdjbb632iepigk20rgmp6t5(a)4ax.com...
>> On Sat, 13 Mar 2010 12:57:35 -0500, "Neil Harrington" <never(a)home.com>
>> wrote:
>>>"Lobster" <davidlobsterpot601(a)hotmail.com> wrote in message
>>>news:0Pxmn.377994$UQ6.315102(a)newsfe04.ams2...
>>>> Draco wrote:
>>>>> On Mar 12, 2:47 pm, Lobster <davidlobsterpot...(a)hotmail.com> wrote:
>>>>>> I've been playing around with the 'photomerge' function in Photoshop
>>>>>> Elements, attempting to take a wide-angle-type view of a room.

>>>However, this is not your main problem. You cannot take a panoramic shot
>>>in
>>>this way and have it fully rectilinear, which is apparently what you are
>>>trying to do. That is, you cannot ROTATE the camera and keep the same
>>>perspective as if you had not rotated it.
>>>
>>>You can keep the verticals straight (and parallel if the camera is kept
>>>level), but the horizontals must curve in order to get the whole stitched
>>>scene in without obvious angular breaks; that is, the perspective changes
>>>continuously from one side of the picture to the other.
>>
>> PTGUI and other good panorama stitcher utilities allow for straightening
>> these types of problems.

> You can't "straighten these types of problems" no matter what you do or what
> you use. Horizontals (other than a central one, e.g. the horizon) from a
> single camera position must curve since the perspective changes continuously
> across the picture.

Provided the angle of view does not exceed the maximum angle of view
possible in a linear wide angle lens all horizontals (and verticals)
can be straightened and made parallel. In this case what is possible
is limited by what is tolerable. A pinhole camera is in effect using a
linear perspective projection lens. The theoretical maximum possible
from a pinhole is close to 180 degrees, but the amount of edge
stretching involved in preserving linearity increases exponentially as
180 degrees is approached. So in practice the maximum angle of view is
limited by what is visually tolerable.

The maximum tolerable angle is probably around 112 degrees horizontal
or 120 diagonal, which is around what the widest ultra wide linear
lenses deliver

If you restrict your panorama pan to what is a tolerable linear
projection wide angle view a panorama program will be able to stitch
together a linear result. Many real estate photographers without a
linear wide angle lens already do that for the odd occasion when they
want one.

--
Chris Malcolm
From: LOL! on 19 Mar 2010 15:21
On Fri, 19 Mar 2010 14:34:19 +1100, "N" <N(a)onyx.com> wrote:

>
>I've learned a significant amount of knowledge about camera hardware and
>photography in general from these groups, though none of that came from you.
>

The really funny part?

I'M ALSO THOSE THAT YOU LEARNED FROM.

LOL!

The only time you don't check headers (or even know which posting hosts,
software, and names I use) is when you all agree to what I have said. Which
happens all too often. If you could only see it from this side you'd
realize what gigantic idiots you really are. It's so much fun playing with
you idiots at times.

Jump, fools, jump!

LOL!!!!!!!!!!!

From: Robert Spanjaard on 19 Mar 2010 15:32
On Fri, 19 Mar 2010 14:21:28 -0500, LOL! wrote:

> On Fri, 19 Mar 2010 14:34:19 +1100, "N" <N(a)onyx.com> wrote:
>
>
>>I've learned a significant amount of knowledge about camera hardware and
>>photography in general from these groups, though none of that came from
>>you.
>>
>>
> The really funny part?
>
> I'M ALSO THOSE THAT YOU LEARNED FROM.
>
> LOL!
>
> The only time you don't check headers (or even know which posting hosts,
> software, and names I use) is when you all agree to what I have said.

Nope. Your posts are easily recognised without checking headers. But when
you post something sensible, like the Granger-chart thread, you'll get a
normal response. That doesn't mean I didn't recognise you.

> Which happens all too often.

What happens all too often is that you post nothing but bullshit, because
your brain is too primitive to handle anything more complex than "LOL!".

--
Regards, Robert http://www.arumes.com
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