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Question about focus

Started Oct 8, 2012 | Discussions thread
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loupi New Member • Posts: 1
Question about focus

My Canon 450D is front focusing not with Canon 50mm not with Canon 18-55 F3.5-5.6 IS, but with 28-105mm EF, 24-105 mm EF, 24-85 mm EF

We made tests with this camera and another, with 18-55 mm and 28-105 mm lenses.

A tripod was used with an external trigger. Autofocus was set to one shot and center focus. They were shot in Av so shutter speed occasionally changes a bit to keep lighting constant.

I looked for Depth of Field in dofmaster.com depending on conditons of shoot.

I would appreciate to check if you see the same focus :

1/ IMG_8771-c.JPG

http://www.lesarbres.fr/600/IMG_8771-c.JPG

28mm, F3.5, distance: 45 cm,  dofmaster.com depth of field  :- 1,7 cm to + 1,58 cm.

It seems a field of depth between + 3 cm to + 6 cm and FF of 4.5 cm

2/ IMG_0956-c.JPG:

http://www.lesarbres.fr/600/IMG_0956-c.JPG

28mm, F3.5, 45 cm, dofmaster.com depth of field  : - 1,7 cm to + 1,58 cm. It seems a field of depth between + 4 cm to + 7 cm and FF of 5.5 cm

3/ IMG_8774-c.JPG

http://www.lesarbres.fr/600/IMG_8774-c.JPG

105mm, F4.5, 45 cm, dofmaster.com depth of field:  + - 0,12 cm. It seems a field of depth between - 0,9 cm to 1,1 cm. FF =  1 cm ?

4/IMG_0959-c.jpg

http://www.lesarbres.fr/600/IMG_0959-c.jpg

105mm, F4.5, 45 cm, dofmaster.com depth of field:  + - 0,12 cm. It seems a field of depth between +2 cm and + 3 cm. FF= 2,5 cm ?

5/ IMG_0955-c.JPG

http://www.lesarbres.fr/600/IMG_0955-c.JPG

55mm, F5.6, 1,5 m, dofmaster.com depth of field  :  +- 3 cm. It seems a field of depth between - 0 cm to 2 cm. FF = 1 cm ?

thks to give me your measurement of FF.

Canon EOS 450D (EOS Rebel XSi / EOS Kiss X2) Panasonic Lumix DMC-F5
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