using a cheap ccd cam to capture on transilluminator

[Massimiliano Baldassarre]

Hi everyone,

this is probably a little bit off topic, but since this is the best audience of camera/imaging experts I know I will try to ask here...
I was trying to use ImageJ to acquire images of my gels/plates that sits on transilluminator (both white light or UV) and I realized that when I try to do that a strange pattern of lines appears on the image. Initially I was thinking that the reason was that I was using a very cheap CCD (a 10 $ webcam), but the same pattern appears if I take a picture with my phone camera. The pattern seems depending on the chip, because if I turn the camera it turns as well. Does any one have an explanation for this? More importantly there is a way around it.
The idea is essentially to image directly on my computer without using a 10 K$ expensive gel doc

Thanks a lot

Max


===============================
Massimiliano Baldassarre    
Department of Pharmacology    
Yale University School of Medicine
Sterling Hall of Medicine
Room B221
333 Cedar Street Box 208066
New Haven CT 06520-8066
Phone [phone]
==============================

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[Andrew Defries]

I got decent results with a transluminator and a 10 megapixel camera. I had
to use an LED soft transluminator to not capture artifacts from lighting.
On May 16, 2013 9:56 AM, "Massimiliano Baldassarre" <
[hidden email]> wrote:

> Hi everyone,
>
> this is probably a little bit off topic, but since this is the best
> audience of camera/imaging experts I know I will try to ask here...
> I was trying to use ImageJ to acquire images of my gels/plates that sits
> on transilluminator (both white light or UV) and I realized that when I try
> to do that a strange pattern of lines appears on the image. Initially I was
> thinking that the reason was that I was using a very cheap CCD (a 10 $
> webcam), but the same pattern appears if I take a picture with my phone
> camera. The pattern seems depending on the chip, because if I turn the
> camera it turns as well. Does any one have an explanation for this? More
> importantly there is a way around it.
> The idea is essentially to image directly on my computer without using a
> 10 K$ expensive gel doc
>
> Thanks a lot
>
> Max
>
>
> ===============================
> Massimiliano Baldassarre
> Department of Pharmacology
> Yale University School of Medicine
> Sterling Hall of Medicine
> Room B221
> 333 Cedar Street Box 208066
> New Haven CT 06520-8066
> Phone [phone]
> ==============================
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

... [show rest of quote]

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[Gabriel Landini]

[hidden email]> wrote:

> Hi everyone,
>
> this is probably a little bit off topic, but since this is the best
> audience of camera/imaging experts I know I will try to ask here...
> I was trying to use ImageJ to acquire images of my gels/plates that sits
> on transilluminator (both white light or UV) and I realized that when I
> try
> to do that a strange pattern of lines appears on the image. Initially I
> was
> thinking that the reason was that I was using a very cheap CCD (a 10 $
> webcam), but the same pattern appears if I take a picture with my phone
> camera. The pattern seems depending on the chip, because if I turn the
> camera it turns as well. Does any one have an explanation for this? More
> importantly there is a way around it.
> The idea is essentially to image directly on my computer without using a
> 10 K$ expensive gel doc

... [show rest of quote]

Without posting an image of the artifacts it is impossible to say, but in
general, you get what you pay for.
Do not know if that is the case here, but many cheap cameras do progressive
scans. So if your light source flickers (like in LEDs intensity controlled by
pulse width modulation or fluorescent tubes) then you might get illumination
artifacts.

Cheers
Gabriel

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