Overview:  Making High Definition Mosaics

(One person’s workflow)

 

Purpose:

1.      Larger high quality prints

2.      Change aspect ratio

 

In the field:

1.      Choose your subject carefully

a.      Avoid objects in motion

b.      Avoid changing light conditions

c.      Plan desired aspect ratio

2.      Use a tripod

a.      Helps with composition

b.      Helps with overlaps

c.      Minimizes camera shake

d.      Possible without it, but more difficult

3.      Level the tripod

a.      Level tripod keeps camera level with rotation

4.      Level the camera

5.      Avoid parallax

a.      Rotate around “nodal point” of lens

b.      Panorama head ideal for rotation around “nodal point”

c.      Less of a problem if nothing in foreground

6.      Maximize depth of field

a.      Focus at hyperfocal distance

7.      Expose all images the same

a.      Preview exposure range, then choose an average value

b.      Set camera on manual

c.      Avoid polarizer  (or use very carefully)

8.      Capture all images you might need

a.      Generous margins

b.      Bracket exposures if needed

c.      Change depth of focus if needed

9.      Overlap images by 20-25%

           

At the Computer:

1.      Avoid correcting individual images

a.      Wait until mosaic is assembled

2.      Assemble mosaic (stitch images together)

a.      Can use Photoshop (File|Automate|Photomerge)

b.      Alternatives: PanoTools, PTAssembler, etc. etc.

3.      Resolve stacked images

a.      Exposure blending

b.      Deep focus

4.      Clean up

a.      Hide seams

b.      Check focus

c.      Can defects be swapped from overlapped image?

d.      Key technique: Layer mask with white/transparent gradient

5.      Crop

6.      Make global edits

a.      Color balance

b.      Exposure

c.      Contrast

7.      Make local edits

8.      Continue usual workflow

 

Some Links:

 

Overview:

www.dchung.com

www.tawbaware.com/maxlyons/

 

Technical details:

www.cambridgeincolour.com/tutorials.htm

 

Finding lens entrance pupil or “nodal point”:

www.outline.be/quicktime/tuto/

 

PT Assembler Tutorial:

www.tawbaware.com/ptasmblr_tutorial.htm#colors

 

Panorama Wiki:

http://wiki.panotools.org/

 

Online Forum:

www.tawbaware.com/forum2/

 

Examples:

www.yosemite-17-gigapixels.com/

www.gigapan.org/viewGigapan.php?id=17217

www.judyarndt.ca

 

John Taylor

jtay66@gmail.com

October, 2009