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Photography Question 
Kickoff 3pm

Simple Novice question about curved edges

  example of problem
example of problem
© Kickoff 3pm
Canon PowerShot G2...
Just found this site and although I'm sure I'll get time to discuss this as an hobby my first question relates to taking images of products for an online shop.

The products are small and to get good lighting without spending money I simply used a box with a light in the top. I feed the digital camera though a hole on the top.

Simple enough, it has to be because I take 100s of images. The thing is sometimes the side of the images come out curved sort of like this ( )

Can anyone tell me how to avoid this ? The camera I use is a Canon G2 contect to a PC using cannon remote software. I've adjusted all the setting looking for annswer but no luck. I'm sure it's simple but I'm no expert so any help is very much aprciated.


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6/19/2007 5:35:44 AM

Jon Close
BetterPhoto Member Since: 5/18/2000
  Assuming the program is lying absolutely flat and not curled up itself...
The camera is not quite perpendicular to the subject, so there is some "keystone" perspective effect (the left side is closer so appears longer than the right side). The curving of straight edges that is also exhibited is due to "barrel" distortion inherent in the lens. This is typical for a zoom lens is set for its shortest focal length. Try setting the lens to a mid-range zoom setting where this type of distortion is minimal.

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6/19/2007 6:18:05 AM

Kickoff 3pm   Accully I should have taken more care with choosing the image because that one is a bit curled up I see but that is the effect I'm getting.

Problem is if I set the focal length longer I'll need a taller light box to allow for taking the camera further away from the product.

I don't understand why this doesn't happen all the time. Could it also be something to do with the lighting be too strong ?

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6/19/2007 12:32:46 PM

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