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  •  » Minimum Percetage overlap for >400mm lens

#1 2012-03-13 05:43:46

nikfan
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Registered: 2012-03-13
Posts: 2

Minimum Percetage overlap for >400mm lens

Hi,

Are there any people who make pano/ mosaic using a >400mm (35mm eq.)? I want to know the practical minimum percetage overlap you use in the field. I can imagine some vibration in the tripod and pano/tripod head due to mirror flipping and/ or some winds. This may change the angle of the lens (let's call it vibration angle) and reduce the overlap in some direction. Depending on the angle of view of lens (fov), this vibration angle can be a significant % of fov. On the other hand, due to the small fov and the large number of shots to take, I would like to keep the overlap to minimum.
So any one have some real experience to share?

Thx a lot in advance.


Nick

Last edited by nikfan (2012-03-13 05:46:31)

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#2 2012-03-13 09:45:34

gkaefer
Member
From: Salzburg
Registered: 2009-06-09
Posts: 2676
Website

Re: Minimum Percetage overlap for >400mm lens

well, only standard sentences like to avoid shaping & slipping and achieve sharp images...

using a rock sturdy tripod
using mirror up functions to reduce shaking
using of external tools like the promotecontrol device which takes over your canon or nikon camera, so mirror up once and than shoot all your images and mirror down when all images are done; you can use this tool for stacking, focus stacking, hdr and timelapse cases.
use automated panoheads that can handle the wheight (VR drive; Josefs panoneed head)
for calculating the overlap: to be true I'm lazy doing that manually and for me theres no difference using fisheye or 400mm: panogear does have an optional handheld controller (which comes from Josef too...) and here you only have to set your cam,lens values (and for the overlap I choose always 20-30% mostly 20%) and the device is calculating the movements and also the number of image per row and column automatically.

touchcontroller:
http://www.typeandcolour.de/index.php?t … mp;up=cont
http://www.kolor.com/buy/photo-hardware … onome.html

promote control:
http://www.promotesystems.com/products/ … ntrol.html

tripod:
http://www.manfrotto.com/super-professional-tripod-mk2

heads:
http://german.roundshot.ch/xml_1/intern … 8/f961.cfm
http://www.kolor.com/forum/t14256-now-finally

PS: minimum overlap: below 20% overlap I often encounter problems finding control points... so for me the 20% is my personal minimum

Liebe Grüße,
Georg

Last edited by gkaefer (2012-03-13 09:58:50)

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#3 2012-03-13 10:30:12

a a gruntpuddock
Member
Registered: 2011-09-27
Posts: 62

Re: Minimum Percetage overlap for >400mm lens

Not used over 300mm but I would think that any vibration severe enough to significantly affect the overlap would ruin your shots unless you were using a VERY high shutter speed.

I prefer to use a surveying tripod as they are much more stable than photographic tripods, you needan adaptor since they use a largethread but the effort is worth it..

If you are getting a lot of vibration I would suggest mirror lock is the worst culprit (apart from the wind). I have actually seen watched the scene 'bouncing' when I did not have everything screwed down tight.

You could also try keeping the center post of the tripod down and locked.

Required overlap really depends on the variability and nature of the scene, the 'rougher' it is the more chance of getting matching points.

I personally prefer to use at least 25%. After all, you only need one mismatch to require a lot more time and effort to sort it out than you woul spend shooting at a larger overlap.

If the pano does not work at all, then the entire time spent travelling to the site, taking pictures, going home, downloading pictures, trying to get a stitch, etc is entirely wasted.

If conditions are favourable, why not shoot the pano twice at different overlaps? If the small overlap works you can just bin the other shots.


A sophistical rhetorician, inebriated with the exuberance of his own verbosity, and gifted with an egotistical imagination that can at all times command an interminable and inconsistent series of arguments to malign an opponent and to glorify himself.

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#4 2012-03-13 10:46:03

leifs
Member
From: Ørsta Norway
Registered: 2009-09-06
Posts: 464
Website

Re: Minimum Percetage overlap for >400mm lens

Use a mirrorless camera ! smile

I have shot a small partial pano at 800mm equiv using my VR drive 2.
Since it was small I used 30% overlap. Using the XML for papywizard import the stitching was no problem.
Maybe the overlap could be reduced to 20%, I will try that some day.

http://www.rundskuer.no/panotour/saudeh … index.html

leifs


Olympus OM-D E-M5, Panasonic 8mm f3.5 fisheye, Olympus 12mm f2.0, Leica 25mm f1.4, Zeiss 50mm f1.4, Canon FD 85mm f1.8, Canon 100-400mm f/4.5-5.6 L
Seitz VRdrive2
Intel i7 980X, 48GB RAM, Win7 64bit, SSD RAIDs

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#5 2012-03-13 13:52:58

klausesser
Member
From: Düsseldorf, Germany
Registered: 2006-05-22
Posts: 6430
Website

Re: Minimum Percetage overlap for >400mm lens

nikfan wrote:

Hi,

Are there any people who make pano/ mosaic using a >400mm (35mm eq.)? I want to know the practical minimum percetage overlap you use in the field. I can imagine some vibration in the tripod and pano/tripod head due to mirror flipping and/ or some winds. This may change the angle of the lens (let's call it vibration angle) and reduce the overlap in some direction. Depending on the angle of view of lens (fov), this vibration angle can be a significant % of fov. On the other hand, due to the small fov and the large number of shots to take, I would like to keep the overlap to minimum.
So any one have some real experience to share?

Thx a lot in advance.


Nick

Hi Nick!

As Georg said already: at least 20%, better 25-30% with long lenses. Mirror-lock is an absolute must and also is a very sturdy tripod and pano-head. I sometimes put some weight to the tripod-legs and hang an additional weight
to the end of the center-colum to pull the mass-center down deeper.

IF you have vibrations that might influence the overlap you can be absolutely sure that the shots are ruined anyway - so the overlap is one of your minor problems . . . winkcool Josef´s new had has built-in sensors which realize any kind of vibration and fire the camera only then, when they´re gone (can be deactivated of course for fast shooting using short exp. times).

What head are you using?

best, Klaus

Last edited by klausesser (2012-03-13 13:56:03)


If you want something you´ve never had,
then you´ve got to do something you´ve never done.

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#6 2012-03-15 13:59:11

fma38
Moderator
From: Grenoble, France
Registered: 2005-12-07
Posts: 6174
Website

Re: Minimum Percetage overlap for >400mm lens

The other problem is the accuracy of the Merlin (~0.3-0.5°); you need an overlap greater than this to be sure to have an overlap!


Frédéric

Canon 20D + 17-40/f4 L USM + 70-200/f4 L USM + 50/f1.4 USM
Merlin/Orion panohead + Papywizard on Nokia N800 and HP TC-1100

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#7 2012-03-15 16:33:06

nikfan
New member
Registered: 2012-03-13
Posts: 2

Re: Minimum Percetage overlap for >400mm lens

Thx a lot for the help. So mirror lock up and heavy rigid tripod are essential. and with them a 25-30% overlap is enough.
I will be using a slurdy manual pano head that I build.

nick

Last edited by nikfan (2012-03-15 16:34:16)

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