look this image, how to make it better

[Jane.Yu]

Can anyone help me to have a look at this picture? It was captured by the camera, and the camera is connected with NI 1427. The middle of the image is so bright. The gap in the middle can not be recognized. Please give some advices on how to make the image better. There must be something with the hardware setting. What should I need to do with that? Thanks for any help.

Jane

[Robert_Eastlund]

What lens is mounted on the NI 1427 camera?

What are you using for an illuminator?  Where is the illuminator positioned in relationship to the camera and object?

[BruceAmmons]

Robert is heading in the right direction.  Your lighting is too bright in the center, so you need to find a way to make the lighting more even.  I have found that Robert always seems to figure out the best light for the job once somebody explains what they are trying to do.  You might have to spend more than you expected on lighting, but it makes the rest of the job so much easier that it is worth it.

Bruce

[Jane.Yu]

Hi, thanks for your suggestions.

The camera seems to be VK CCD 1020CL. I am not sure about the other two issues.

Regarding to the lighting, what can I do for that? I am still confused.

[BruceAmmons]

Answer Robert's questions.  What kind of light are you using now?  Describe the surface you are illuminating, stuff like that.  What constraints do you have (limited space, limited time, etc.)?

Bruce

[Jane.Yu]

The module sits in a big Chamber. There is a lamp on the top of chamber, seems not adjustable. Actually the module (solar cell) itself glows when a photo is taking on it.

[BruceAmmons]

I assume you need to have the overhead lamp on for testing the solar cell?  If you could turn it off during photos, that would improve your images.  Right now I am guessing you are getting a good reflection of the overhead lamp in the center of your image.  Having diffuse lights (like long flourescent bulbs) in multiple places would greatly improve your image quality.  A general rule in lighting for shiny surfaces is to avoid placing a light where you can see its reflection in the image.  This way you won't get any bright spots in the image.

If you could even tip the solar cell or camera a little bit so the overhead light is not reflected directly into the camera, that would help.

It is hard to make recommendations without knowing the limitations.

Bruce

[Jane.Yu]

Hi Bruce,

There is another problem I'd like to ask. I feel the image seems not very well focused. I don't know how to adjust the camera to get a clear image. The camera used is VOSSKUHLER CCD1020. How can I calculate the pixel resolution?

Regards,

Jane

[BruceAmmons]

I can't tell how good the focus is.  Most of the time you adjust the lens to improve the focus, but some lenses are fixed focus and can't be adjusted.  For those lenses, you need to change the distance between the camera and the object until the focus is best.

The simplest way to measure pixel resolution is to take an image of a measuring device, such as a ruler, and count the number of pixels between two marks on the measuring device.  Selecting two marks that are far apart gives the best accuracy.  Divide the measurement by the number of pixels to get the scale per pixel.

Bruce