SV305 gain issues

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brisguy
Posts: 44
Joined: Fri Mar 26, 2021 4:08 am

SV305 gain issues

Post by brisguy »

I have two instances of SharpCap: Version 3.2 on a PC and version 4 on a Laptop (both Windows 64-bit). I am having two issues with version 4. I want to upgrade to 4 on both eventually.

1. The gain settings on Version 3.2 went from 1 to 30, but the settings on Version 4 go from 1 to 720. Why was this change made and how can I match gain settings from 3.2?
2. I am getting errors when trying to set the gain. Normally I will just click on the gain slider or the entry field, but I was getting an error saying 'cannot set gain to X' where X was usually a number completely unrelated to where the slider was or to where I was trying to set it. I can eventually set the gain, but the errors make me nervous. See attached log file.

I also find that I cannot change the gain at all when Auto exposure is ON, but I think that occurred in version 3.2 as well. Is that expected?

Thanks!
Attachments
sharpcap-log.txt
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admin
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Re: SV305 gain issues

Post by admin »

Hi,

SVBony decided to change how they measured the gain values in a recent SDK update, which explains why the ranges have changed.

Old way (SharpCap 3.2):

Range was 1 to 30
1 was the minimum gain, gain 2 was 2x as bright as 1, gain 5 was 5x as bright as 1, gain 30 was 30x as bright...

New way (SharpCap 4.0):

Range is now 0 to 730
Zero is minimum gain.
Gain 200 is 20dB of gain, which is 10x brighter than minimum gain
Gain 400 is 40dB, which is 10x brighter again or 100x brighter than minimum
Gain 600 is 60dB, which is 1000x brighter than minimum gain.

To be honest, anything above about gain 500 is not much use as it is too noisy, but it doesn't hurt to be there.

Anyway, the real issue is why are you getting errors from changing the gain... I can only make those errors occur when the camera is in auto exposure mode, which I think means that auto-exposure also activates auto-gain on the camera - so really the gain control should be disabled completely in auto-exposure mode. I will fix that in a future update to properly disable the gain when auto exposure is enabled.

If you are getting the errors when not in auto exposure mode then try changing one of the other controls (black level, contrast, etc) to see if they produce an error too. Errors from all controls would indicate the camera is not responding correctly as opposed to a problem with the gain specifically.

cheers,

Robin
brisguy
Posts: 44
Joined: Fri Mar 26, 2021 4:08 am

Re: SV305 gain issues

Post by brisguy »

Thanks for the prompt reply. Yes, I believe Auto exposure was on when the error occurred, but the gain slider moved and the number changed, so it is certainly not clear that Gain is disabled. Perhaps it should be greyed out? And while you are at it, perhaps the Gain control could be altered to make it more visible? I can NEVER find it, despite having used the program many times. I think this is because Exposure and Gain are so closely linked (in function) that I keep expecting it to be in the same 'box' as Exposure. Also having it below the 'quick picks' dropdown means it is covered up whenever that control is used.

Thanks for the info on the new gain numbers, I think I can translate to get back to the old numbers (which allow me to reuse some darks)
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Re: SV305 gain issues

Post by admin »

Hi,

the gain control should be just next to the exposure - like this
Capture.JPG
Capture.JPG (24.55 KiB) Viewed 137 times
Admitedly it can hide under the dropdown, but the dropdown is normally not open for much of the time. You can see here that the gain is now properly disabled when auto exposure is active - I will be releasing this update later today. Thanks for finding this glitch!

cheers,

Robin
brisguy
Posts: 44
Joined: Fri Mar 26, 2021 4:08 am

Re: SV305 gain issues

Post by brisguy »

Yes, I know where it is, it just seems to disappear when I need it! I did notice that the simulated camera control is laid out more to my liking, but this is just my preference. See attached and thanks for the update. I will watch for it.

Regards, Stan
cam ctl.jpg
cam ctl.jpg (17.27 KiB) Viewed 128 times
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