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#1 2008-09-09 06:06:54

irpano
Member
Registered: 2008-08-20
Posts: 347

Learner - dynamic range

Hi, still learning the art of Panoramas. My question is How much variation in exposure can APP handle in auto mode with Canon raw images before some pre stitching  is needed.

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#2 2008-09-09 10:53:48

GURL
Member
From: Grenoble
Registered: 2005-12-06
Posts: 3501

Re: Learner - dynamic range

irpano wrote:

[..] How much variation in exposure can APP handle in auto mode [..]

The main point is the difference in exposure between a source image and the next one(s): in a series where the variation from one shot to the next is at most 1 EV, APP should be able to care with the global variation even if it's higher than 2 EV. On the contrary when the variation between two contiguous shots is higher than 2 EV, poor results are the rule. Manual placement of one or more yellow anchor helps.

In the following example the exposure difference between the top and bottom was higher than 5 EV yikes so that I see the result I got using AUTO and manual anchors placement as something encouraging...


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Last edited by GURL (2008-09-10 12:05:47)


Georges

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#3 2008-09-10 01:28:28

tived
Member
From: Dane in Western Australia
Registered: 2008-07-11
Posts: 837

Re: Learner - dynamic range

looks like I need to read up about those anchor's and their usage too!

thanks

Henrik

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#4 2008-09-11 00:44:14

johntom@actewagl.net.au
Member
Registered: 2008-05-20
Posts: 25

Re: Learner - dynamic range

Thanks for the quick reply and thqank you to those members who are willing to hep out a new member. I hope the questions are sensible.
One more if I may,
Whe taking a panorama inside a room where the camera is 4 metres from the front subject but one element is behind the depth of field for the lense (Near = 3.39M, Far 4.87 M) Do I select a smaller apeture say f22 and accept the Long exposure times or will APP in auto mode cope with different focus
Thanks again

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#5 2008-09-11 01:45:11

klausesser
Member
From: Düsseldorf, Germany
Registered: 2006-05-22
Posts: 6600
Website

Re: Learner - dynamic range

johntom@actewagl.net.au wrote:

Thanks for the quick reply and thqank you to those members who are willing to hep out a new member. I hope the questions are sensible.
One more if I may,
Whe taking a panorama inside a room where the camera is 4 metres from the front subject but one element is behind the depth of field for the lense (Near = 3.39M, Far 4.87 M) Do I select a smaller apeture say f22 and accept the Long exposure times or will APP in auto mode cope with different focus
Thanks again

Hi John!

better use a small aperture and choose a focus-point between near and far. Dof increases faster at longer distance and slower at closer distances. So as a "rule of thumb" choose your focus not halfways between the closest and the remotest point but about 1/3 way nearer to the closest than to the remotest point.
Depending on the focal-lenghts of your lens f:22 gives a very good dof.

best, Klaus


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

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#6 2008-09-11 06:07:08

marco-pano
Member
From: Paris
Registered: 2006-11-16
Posts: 922
Website

Re: Learner - dynamic range

johntom@actewagl.net.au wrote:

Whe taking a panorama inside a room where the camera is 4 metres from the front subject but one element is behind the depth of field for the lense (Near = 3.39M, Far 4.87 M) Do I select a smaller apeture say f22...

You can increase DoF with smaller aperture. Several calculator on line, by example:
http://www.dofmaster.com/dofjs.html
http://www.tawbaware.com/maxlyons/calc.htm
http://www.cambridgeincolour.com/tutori … -field.htm

but at f:22, you will probably get diffraction bad effect:
http://www.cambridgeincolour.com/tutori … graphy.htm


Marco, Paris wink
Canon EOS 40D, EF-S 10-22, EF 24-105 LIS, EF 70-200 LIS - Canon G9 (wide-converter)
DxO v7.5, Autopano Pro 2.6, PS CS5 and time

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#7 2008-09-14 20:49:28

foundation
Member
Registered: 2007-01-15
Posts: 275

Re: Learner - dynamic range

To some extent refocusing will be handled by autopano. The problem is in the overlap areas. Smartblend or multiblend may choose to blend in the out of focus layer rather than in focus. You can get around this by outputting layers and reblending manually in photoshop.

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