SvBony sensor analysis fail

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brisguy
Posts: 66
Joined: Fri Mar 26, 2021 4:08 am

SvBony sensor analysis fail

#1

Post by brisguy »

I just started using Sharpcap (3.2.6482 free version) with my first sensor - a SvBony 305. I have been having some success, but at times the program seems to hang temporarily or do odd things. The following is a case in point.

I cannot get through the sensor analysis. I started by trying to point the sensor at the sky, well away from the sun, with a translucent lens cover on it. This resulted in a 200ms exposure time and a warning to use less light. Tried stacking various pieces of paper on top - still too bright. Saw a YouTube video where they used an iPad as the light source, so used that. Still too bright. Reduced the backlight setting to minimum. Still too bright. Note that I hit cancel and start after every change. Fiddled with the gamma setting and was able to get the magic number and able to proceed. However, after the dark measurements, I put it back on the iPad, but stopped an would not activate the proceed button. The last message in red stated 'target brightness achieved', which would think means it is ready, but could not click the proceed button. The only thing I was allowed to do was hit cancel, at which point all measurements are lost.

Does Sharpcap fully support the SvBony 305?
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admin
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Re: SvBony sensor analysis fail

#2

Post by admin »

Hi,

yes, the SV305 should work nicely - do make sure that you have the latest drivers from the SVBony site (there were some issues once with one of the older ones, but this was a while back).

First I should mention that there should be no need to do the analysis with the SV305 - SharpCap includes analysis data for this camera (and lots of others) as part of the install. In my experience the variation between different cameras of the same model is generally tiny - not worth worrying about.

Of course, if you do want to run the analysis, that should work too. To get good results, you should leave the 'Image Controls' at their defaults - that is

Contrast = 50, Gamma = 1.0, Saturation =? Sharpness = 0, All White Balance = 100

I suspect that saturation should be zero, but I'm not sure - it seems to act as a boost to saturation in the image (zero still has colour).

A good starting point is to find an illumination level that gives a well exposed (~60% histogram peak level) image with minimum gain at about 300-400ms exposure. That should run through the rest of the measurements just fine. I have just done this in testing with my SV305 while writing this reply with no problems.

Hope this helps,

Robin
brisguy
Posts: 66
Joined: Fri Mar 26, 2021 4:08 am

Re: SvBony sensor analysis fail

#3

Post by brisguy »

Thanks very much for the reply.

I did try the settings you mentioned and set the saturation to zero since it did not really change the auto exposure time. Leaving the Green setting at 100 seems problematic though since it makes the green sensor values twice as high as red or blue on the histogram (i.e. near the top). However, this did not change my results in any meaningful way. Once again, I had trouble getting my iPad to produce a low enough backlight to allow the analysis to go forward. I tried setting the exposure to 250ms manually and was then able to proceed. However, I got stuck at the resumption of the test after the dark tests. Again the only option was to cancel. I wonder if there is an issue with my camera?

How do I go about accessing the sensor information you mentioned?

Thanks!
brisguy
Posts: 66
Joined: Fri Mar 26, 2021 4:08 am

Re: SvBony sensor analysis fail

#4

Post by brisguy »

UPDATE:

I noticed that simply taking the sensor out and laying on my desk (with the translucent cover) resulted in getting a light level in the magic range, so I tried to run the tests again. This time, I was able to complete the tests, even though they may not be accurate since background was not white and had a gradient to it. I suspect the reason I was not able to get past the dark tests is that the level used to start the tests was borderline too bright. I don't understand why getting the correct light level is so difficult for this sensor and that is certainly not what I saw on the You Tube video.

I would still like to know how to access the sensor information mentioned in the previous email.

Thanks
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Re: SvBony sensor analysis fail

#5

Post by admin »

Hi,

the built in data for this sensor (and many others) are used for the Smart Histogram functionality - https://docs.sharpcap.co.uk/3.2/#Smart%20Histogram - you can see the data in the Sensor Data tab of the 'Brain Window' - https://docs.sharpcap.co.uk/3.2/#The%20 ... n%20Window

On the subject of getting the right exposure, this tends to be harder for cameras that have a wide gain range, since you have to find a starting point that isn't so long that the analysis takes ages but is long enough that when you turn up the gain (and turn down the exposure to compensate) you do not end up near the minimum exposure time of the camera.

cheers,

Robin
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