Panoramas and nodal points

"Roland Karlsson" wrote in message
...
[]
So - if you have objects nearer than 5 meter you must find
the nodal point with an accurace of 3 mm to assure better
than one pixel accuracy.


/Roland

Roland, thanks for the info. I must confess that I have never had any
problems with this, but most often my nearest objects are 50m rather than
5m away! Suppose one was using a P&S with 9mm actual focal length. Would
that change the accuracy requirement to determine the modal point i.e. you
would need to be more accurate or less in placing the camera?

Cheers,
David

"David J Taylor"
wrote in :

Roland, thanks for the info. I must confess that I have never had any
problems with this, but most often my nearest objects are 50m rather
than 5m away! Suppose one was using a P&S with 9mm actual focal
length. Would that change the accuracy requirement to determine the
modal point i.e. you would need to be more accurate or less in placing
the camera?


Nope - it all scales down. Smaller sensor and shorter focal length
and smaller spacing between the pixels. If you miss the nodal point
with 3 mm, you will get the same effect regardless of size of the
camera.


/Roland

In article , david-
says...
"Tony Spadaro" wrote in message
. com...
Yes the closer the better - but even with perfect there will still be
some
work to do.

If you use software like PanoTools it is unlikely to be an issue. That
will do all the "work" for you.

Cheers,
David

You have never taken a panorama with tiles in the foreground?
You would know how important the nodal point is then for such matters.

It depends on the focal length too.
If you use a wide angle lens to make panos in close distances, very few
"of the shelf" pano programs bring decent results without a lot of work
in Photoshop afterwards.

http://michel.thoby.free.fr/PanoMacc...O_FILTERED.mov
is a good example and the best pano I have seen so far.
http://michel.thoby.free.fr/ is a good place to start with nodal points.

Cheers
Gerhard
--

Looking for a dream wedding?
http://www.palmcoveweddings.com/

On Tue, 29 Jun 2004 12:52:03 GMT, Clyde
wrote:


That depends on the stitching software that you use. Most of them can
handle minor alignment problems in all 3 axis. Some of them can deal
with rather significant problems. A few can't handle much at all.

I would suggest you try it and see.

Thanks for that (and for all the comments from everyone else too!).
Your collective comments are most useful.

I have played with a few designs for my own pano head, and the final
one looks good - and by the sounds of things will be good enough for
most purposes.

I have a Manfrotto pano head that does a great job. I use Hugin and
Photoshop CS for stitching. I will also shoot hand held panos, when the
tripod isn't there or practical. Hugin usually handles it without much
problem. PS CS isn't too bad either - well, for less than 360 degrees.


I have trialled virtually every pano program I can find on the net,
amounting to probably 12 or more - the latest being that Hugin program
you mention. Haven't had a lot of success with it yet - might be the
version or something.

Have you tried PTAssembler? If so, what makes you prefer Hugin (and
which version of Hugin are you running?).

I keep changing my mind on the best pano program because on one set of
images I'll find that a certain program works really well, yet on
another image another program works better - it's a bit confusing.

A couple of the best programs have been Canon's program, PT Assembler
and the Panorama Factory - but even the pano plug-in for ACDSee is
remarkably good.

Bob T.

"Gerhard Beulke" wrote in message
...
[]
You have never taken a panorama with tiles in the foreground?
You would know how important the nodal point is then for such matters.

No, I haven't. 95% of may pano work is turning a few "35mm" distant
landscape shots into a single "17mm" vertically cropped shots. Some are
inside churches etc. and they tend to be "vertical panos".

It depends on the focal length too.
If you use a wide angle lens to make panos in close distances, very few
"of the shelf" pano programs bring decent results without a lot of work
in Photoshop afterwards.

http://michel.thoby.free.fr/PanoMacc...O_FILTERED.mov
is a good example and the best pano I have seen so far.
http://michel.thoby.free.fr/ is a good place to start with nodal points.

Cheers
Gerhard

All of my pano shots are hand held, so I would never get the nodal point
accuracy suggested. Many thanks for the references, though.

Cheers,
David

Frank ess wrote:
Bob Thomas wrote:

Hi,

I'm building my own pano head for taking panoramas - and it might not
be an engineering masterpiece.

Would I be right in saying that the accuracy and effectiveness of the
pano head will be in a direct ratio to my accuracy in building it?

I.e. Would I be right in saying that if my pano head allows rotation
*nearly* around the nodal point, the image will be *nearly* as good as
if I were 100% accurate? Or is it all or nothing ?

Bob T.


I have lost track of it, but somewhere recently I read a cogent argument
that for DigiCams the normal-to-nodal-point distance has shrunk to
insignificance, and that even in ordinary camera scale, the requirement
that pivot and nodal points coincide was always overrated, anyway.

So, who was it said that? Speak up, please.


Frank ess



My Minolta 7Hi does need some nodal point adjustment on my Manfrotto
pano head. Does it matter? Sometimes. If the pano has items that are
both close and far, it can matter.

Clyde

Bob Thomas wrote:

On Tue, 29 Jun 2004 12:52:03 GMT, Clyde
wrote:



That depends on the stitching software that you use. Most of them can
handle minor alignment problems in all 3 axis. Some of them can deal
with rather significant problems. A few can't handle much at all.

I would suggest you try it and see.


Thanks for that (and for all the comments from everyone else too!).
Your collective comments are most useful.

I have played with a few designs for my own pano head, and the final
one looks good - and by the sounds of things will be good enough for
most purposes.


I have a Manfrotto pano head that does a great job. I use Hugin and
Photoshop CS for stitching. I will also shoot hand held panos, when the
tripod isn't there or practical. Hugin usually handles it without much
problem. PS CS isn't too bad either - well, for less than 360 degrees.



I have trialled virtually every pano program I can find on the net,
amounting to probably 12 or more - the latest being that Hugin program
you mention. Haven't had a lot of success with it yet - might be the
version or something.

Have you tried PTAssembler? If so, what makes you prefer Hugin (and
which version of Hugin are you running?).

I keep changing my mind on the best pano program because on one set of
images I'll find that a certain program works really well, yet on
another image another program works better - it's a bit confusing.

A couple of the best programs have been Canon's program, PT Assembler
and the Panorama Factory - but even the pano plug-in for ACDSee is
remarkably good.

Bob T.

I've been using Hugin 0.4 pre. I just use the Windows executables. It
mostly works very well. The only problem I have is that it only
successfully saves to JPEG files. It does let me set the quality as high
as I want though.

I used to use PTMac, as I had a Mac. The concepts of all the PanoTools
frontend tools are basically the same. Yes, there is a learning curve
for all of them. I would find some of the good learning sites on the Web
and then practice a lot.

I liked PTMac because the author gave such good support and it worked
well. I like Hugin because it's free and it works. I thought I'd try it
first before paying more for PTGui or PTAssembler. It's been working. I
really like the auto align feature of Hugin though; that saves a bunch
of time!

Clyde