Image-stitching and virtual tour solutions My account Updates
It is currently Fri Oct 31, 2014 11:22 pm

All times are UTC + 1 hour




Post new topic Reply to topic  [ 29 posts ]  Go to page Previous  1, 2
Author Message
 Post subject: Re:
PostPosted: Mon Oct 07, 2013 7:06 pm 
Offline
Member

Joined: Mon May 22, 2006 12:18 am
Posts: 7813
Location: Duesseldorf, Germany
yiorgos wrote:
Klaus, have you actually shot a pano with a 8mm fisheye lens on a 2.5-3sec continuous rotation?


Oh yes - i did :cool:

yiorgos wrote:
In my tests it looked pretty sharp . .


Which exposuretime did you use?

yiorgos wrote:
The point is to be able to capture fast action and street panos if one so chooses. If your ultimate concern is sharpness you can also use it to leisurely shoot supersharp bracketed scenes with a tripod.


It´s all related to the exposuretime and spin-time.

Exp.Time because the camera doesn´t stop as usual when it shoots. So depending on the spin-velocity you need at lest 1/1000sec. using a fisheye when you want real sharp shots. You also might use 1/500sec when you don´t want tack-sharp images.
Preferably you use an aperture which gives you some DOF. Let´s say f5,6/8 with a fisheye. So you need much light.

Rotatingtime: if it´s fast you´ll have a second poblem besides the exp.time: moving persons will appear multiple times close to the previous shot/stage of movement.
Rotating slower allows them to seperate better and so you can mask them more perfectly.

That´s why i suggest manual heads and fisheyes in crowdy places. I can set my Panoneed head for two different rotating speeds.
I used it here in speed-mode: http://www.360impressions.de/ArchivKoenigsallee2/ (right image at the top, called "Jui2012")

Took me quite a time to mask out moving objects (people, bikers, cars) in PTGui - APG´s masking tool wasn´t precise enough because the "ghosts" were close to each other.

Using a manual=slower head would have the ghosts seperated more and the masking would have been much easier.

(5D2/15mm fisheye, 1/800sec f5,6 and 5+1 shots @20%)

Klaus


Top
 Profile  
 
PostPosted: Mon Oct 07, 2013 7:24 pm 
Offline
Member
User avatar

Joined: Wed Mar 22, 2006 1:39 pm
Posts: 11
Location: Greece
For very sharp photos with a fisheye on a 3-sec rotation you need a shutter speed of 1/1500.
With ISO 400 and f5.6 you're ok on an outdoors scene, in some cases you can go to f8.

The trick to avoid ghosts on a fast rotation is to shoot more images than you actually need.
So, if you need 4 images, shoot 8 or even 12 if your camera can handle it.
Then pick and choose the ones that fit best without ghosts.
I use an ancient Canon 400D and it has no problem to capture 12 RAW images in 3-4 seconds.

If you prefer a slower approach, you can always use a shoot-move-shoot style, it's up to you.

The point is the motorized head can work the way you like.


Top
 Profile  
 
PostPosted: Mon Oct 07, 2013 7:38 pm 
Offline
Member

Joined: Mon May 22, 2006 12:18 am
Posts: 7813
Location: Duesseldorf, Germany
yiorgos wrote:
The trick to avoid ghosts on a fast rotation is to shoot more images than you actually need.
So, if you need 4 images, shoot 8 or even 12 if your camera can handle it.
Then pick and choose the ones that fit best without ghosts.


Of course - but what advantage gives a motorized head in speed-mode when you need to shoot lots of more images - which takes more time??
None. :cool:

yiorgos wrote:
The point is the motorized head can work the way you like.


Sure . . . as you said: it´s up to everyone individually.

Klaus

Besides: i like your construction! Very well done!


Top
 Profile  
 
PostPosted: Mon Oct 07, 2013 8:03 pm 
Offline
Member
User avatar

Joined: Wed Mar 22, 2006 1:39 pm
Posts: 11
Location: Greece
klausesser wrote:
...but what advantage gives a motorized head in speed-mode when you need to shoot lots of more images - which takes more time?? None. :cool:


Klaus,

4 images or 8 images, the time for a fast rotation is the same, it doesn't take more time. The only thing that changes is the number of images you capture in the time it takes to make one fast rotation.

klausesser wrote:
Besides: i like your construction! Very well done!

Thank you! :)


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 29 posts ]  Go to page Previous  1, 2

All times are UTC + 1 hour


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group