Remember that “exposure” is just the exposure time, which for a digital camera isn’t terribly meaningful. If you turn off auto-exposure, do you have manual gain, brightness, and contrast? Do specific settings of those give you something you can work with? If your camera is incompetent, you can certainly compensate in software. As I mentioned before, gain, brightness and contrast are all very easy to implement in software.
@Tim_Roberts said:
Remember that “exposure” is just the exposure time, which for a digital camera isn’t terribly meaningful. If you turn off auto-exposure, do you have manual gain, brightness, and contrast? Do specific settings of those give you something you can work with? If your camera is incompetent, you can certainly compensate in software. As I mentioned before, gain, brightness and contrast are all very easy to implement in software.
As I understand it, the exposure time allows charge to accumulate on the sensor pixels, so a fast exposure would accumulate less charge and proivide a darker picture - or prevent a picture from saturating the sensor. Once the sensor has saturated nothing in the software can fix it, because all (or far too many) of the pixels are maxed out. Like it’s sending all pixels at brightness 255 to the software. No?
No settings give me a picture I can work with. In Theremino Spectrometer, I can un-tick EXP auto and the slider is no longer greyed out, but I can’t move it. (I though it did move before, but it doesn’t now, and either way it doesnt do anything).
In other software, I can move it but it doesn’t change the picture.
If I open the “Source panel” I get the WDM video input control Properties dialogue which I can also get from Amcap.
Here, the Brightness slider moves but doesn’t affect the preview. Same with gain, contrast, saturation, white balance, backlight comp. Hue won’t move.
If you have special requirements, pair a cheap modern camera with a cheap modern microcontroller and have it process the picture as you like.
Connect this thing to the PC by standard USB or Ethernet interface (the same microcontroller again) and that’s it.
Full control and 100% satisfaction.
If this sounds too complicated - many good folks around can offer affordable help.
(Sorry, cannot elaborate on the last phrase… it is against the rules of this forum. Google.)
– pa
@Pavel_A said:
If you have special requirements, pair a cheap modern camera with a cheap modern microcontroller and have it process the picture as you like.
Connect this thing to the PC by standard USB or Ethernet interface (the same microcontroller again) and that’s it.
Full control and 100% satisfaction.
If this sounds too complicated - many good folks around can offer affordable help.
(Sorry, cannot elaborate on the last phrase… it is against the rules of this forum. Google.)
– pa
THanks for oyur thoughts.
I can’t find where to buy camera modules like the OV2710 without IR filters glued ot the chip, and I don’t know how to remove them.
ESPCAM has this sensor (HD) and I have written a program which retrieves bitymaps - from where the rest is easy, but the IR filters, bonded to the sensor die itself - are a killer. I know they can be obtained becuase expensive camera board sellers offer alternatives wiht no IR.
I even rang the makers, but they will nt deal with anyone who wants less than thousands of these cameras.
I can buy chearp USB webcams, but these days none of them have manual expoure control from the USB cable, so that’s a killer.
It seems, from USB viewer, that the board does exposure the manual controls, but the driver does not provide access to them.
I have tried to get someone to write a Windows sriver, but that was not promising. So I came here tro explore writing my own.
I can buy expensive webcams which do, and I am currently thinking I’ll have to do that, and I have one coming from China.
But it smashes the profit margin on my product, which is why I’m looking for a better answer.
Anwyhooo - onward, ever onward.
Can you drop me an email? I have a suggestion.