Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Computing > Digital Photography > Photographing Book Pages

Reply
Thread Tools

Photographing Book Pages

 
 
Rebecca
Guest
Posts: n/a
 
      08-12-2004
Greetings. I am relatively new to digital photography. I am using a
digital camera (Canon PowerShot A80, 4.0 megapixels) as a scanner (for
OCR-ing), and it is working like a charm (much faster than a flatbed
scanner). However, whenever I take a picture of a page from a book
(with MACRO selected), the white page comes out somewhat gray
(definately not what I expected: that is, black print on a white
background). I am taking pictures in outdoors, that is, my camera is
set up near a window where there is adequate sunlight. Could someone
please tell me which functions I should adjust or select so the white
pages come out, well, a lot whiter? Thanks.
 
Reply With Quote
 
 
 
 
John Bean
Guest
Posts: n/a
 
      08-12-2004
On 12 Aug 2004 02:11:11 -0700, Rebecca wrote:

> Greetings. I am relatively new to digital photography. I am using a
> digital camera (Canon PowerShot A80, 4.0 megapixels) as a scanner (for
> OCR-ing), and it is working like a charm (much faster than a flatbed
> scanner). However, whenever I take a picture of a page from a book
> (with MACRO selected), the white page comes out somewhat gray
> (definately not what I expected: that is, black print on a white
> background). I am taking pictures in outdoors, that is, my camera is
> set up near a window where there is adequate sunlight. Could someone
> please tell me which functions I should adjust or select so the white
> pages come out, well, a lot whiter? Thanks.


Hi Rebecca. The same thing happens if you photograph anything that's mainly
light coloured and bright, like snow for instance. The camera's meter
assumes an average scene, and under exposes. If your camera has an exposure
compensation function, sometimes also called "EV adjustment", set it to +1
or maybe a little more and see what the results look like. A bit of trial
and error is needed here.

--
John Bean

Part of the inhumanity of the computer is that, once it is competently
programmed and working smoothly, it is completely honest (Isaac Asimov)
 
Reply With Quote
 
 
 
 
Joseph Meehan
Guest
Posts: n/a
 
      08-12-2004
John Bean wrote:
> On 12 Aug 2004 02:11:11 -0700, Rebecca wrote:
>
>> Greetings. I am relatively new to digital photography. I am using a
>> digital camera (Canon PowerShot A80, 4.0 megapixels) as a scanner (for
>> OCR-ing), and it is working like a charm (much faster than a flatbed
>> scanner). However, whenever I take a picture of a page from a book
>> (with MACRO selected), the white page comes out somewhat gray
>> (definately not what I expected: that is, black print on a white
>> background). I am taking pictures in outdoors, that is, my camera is
>> set up near a window where there is adequate sunlight. Could someone
>> please tell me which functions I should adjust or select so the white
>> pages come out, well, a lot whiter? Thanks.

>
> Hi Rebecca. The same thing happens if you photograph anything that's

mainly
> light coloured and bright, like snow for instance. The camera's meter
> assumes an average scene, and under exposes. If your camera has an

exposure
> compensation function, sometimes also called "EV adjustment", set it to +1
> or maybe a little more and see what the results look like. A bit of trial
> and error is needed here.


Correct, and it also can be corrected in post exposure processing.
Increase the contrast and brightness.

--
Joseph E. Meehan

26 + 6 = 1 It's Irish Math



 
Reply With Quote
 
David Dyer-Bennet
Guest
Posts: n/a
 
      08-12-2004
http://www.velocityreviews.com/forums/(E-Mail Removed) (Rebecca) writes:

> Greetings. I am relatively new to digital photography. I am using a
> digital camera (Canon PowerShot A80, 4.0 megapixels) as a scanner (for
> OCR-ing), and it is working like a charm (much faster than a flatbed
> scanner). However, whenever I take a picture of a page from a book
> (with MACRO selected), the white page comes out somewhat gray
> (definately not what I expected: that is, black print on a white
> background). I am taking pictures in outdoors, that is, my camera is
> set up near a window where there is adequate sunlight. Could someone
> please tell me which functions I should adjust or select so the white
> pages come out, well, a lot whiter? Thanks.


Manual exposure. Or I suppose you could do it with exposure
compensation, probably about +1.5 or +2.

Exposure metering makes the scene come out, on the average, 18% grey.
If the scene doesn't, in fact, average 18% grey, it'll look wrong, and
auto-exposure won't do what's needed.
--
David Dyer-Bennet, <(E-Mail Removed)>, <http://www.dd-b.net/dd-b/>
RKBA: <http://noguns-nomoney.com/> <http://www.dd-b.net/carry/>
Pics: <http://dd-b.lighthunters.net/> <http://www.dd-b.net/dd-b/SnapshotAlbum/>
Dragaera/Steven Brust: <http://dragaera.info/>
 
Reply With Quote
 
HRosita
Guest
Posts: n/a
 
      08-15-2004
Hi,

Experiment with the white balance settings, since there is no film involved,
check which setting gives you the best white.
The camera is trying to average the "scene" so that is why it makes the white
look gray.
Rosita


 
Reply With Quote
 
Joseph Meehan
Guest
Posts: n/a
 
      08-15-2004
HRosita wrote:
> Hi,
>
> Experiment with the white balance settings, since there is no film

involved,
> check which setting gives you the best white.
> The camera is trying to average the "scene" so that is why it makes the
> white look gray.
> Rosita


Acturally if it is true gray, the white balance is just right. If it
were yellow gray or blue gray, then white balance would be part of the
problem.

The real problem is overall exposure. If the white shows gray, then it
is under exposed, or you have a display problem.

--
Joseph E. Meehan

26 + 6 = 1 It's Irish Math



 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Photographing book. Mick Breen Digital Photography 2 07-18-2005 07:11 AM
Photographing Mars Kulvinder Singh Matharu Digital Photography 44 08-09-2003 01:03 AM
photographing something through a chain link fence Eigenvector Digital Photography 22 08-08-2003 02:23 PM
Re: Photographing Silverware Andy Digital Photography 0 07-17-2003 04:09 PM
Re: Photographing Silverware Jim Polaski Digital Photography 6 07-13-2003 05:40 AM



Advertisments