Using Test Cameras to try out sensor analysis

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Rocket_Guy
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Using Test Cameras to try out sensor analysis

#1

Post by Rocket_Guy »

Is there any way to perform a sensor analysis on the test cameras to practice using the feature to find correct exposures on the test photographs?
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admin
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Re: Using Test Cameras to try out sensor analysis

#2

Post by admin »

Hi,

no, this is pretty unlikely to work because the test cameras don't have a real gain control and they won't respond to changing exposure in the same way that a real camera does.

The best bet for this sort of thing is to buy a small lens to connect to your camera and test indoors with your camera. Many smaller astro cameras have a 'C' (or CS) thread and you can buy suitable lenses fairly cheaply online. I have a 25mm CS lens with variable aperture which is great for testing as you can close it down to a pinprick and use long exposures even in brightly lit rooms. It's the same as this one https://www.ebay.co.uk/itm/Television-T ... SwR6RaRHAi (although I didn't buy from that seller). If you have a C mount camera (17.5mm back focus instead of 12.5mm) then you need a 5mm spacer ring too.

cheers,

Robin
edgar619
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Re: Using Test Cameras to try out sensor analysis

#3

Post by edgar619 »

Hello

I have located the same lens you recommended on UK eBay in the USA. Will it work on my Toupcam IMX 224. It looks like the thread and size will work.

Thanks
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Re: Using Test Cameras to try out sensor analysis

#4

Post by admin »

I think it will fit - I don't have any ToupTek cameras personally but have some similar ones and they all take this type of lens.

That lens has a 17.5mm back focus - if your camera has a 12.5mm distance from the front of the screw thread to the sensor then you will also need a 5mm spacer ring with the same thread to achieve focus ( I may have got that the wrong way round in my previous post)

cheers,

Robin
edgar619
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Re: Using Test Cameras to try out sensor analysis

#5

Post by edgar619 »

Robin thank you for your reply

Just to be clear, I am using 2.9 now. I see that to get the smart histogram I need to upgrade to Pro...which is fine by me. Looking at the manual it doesn’t show how the test camera can be used or the settings to control it. And when I look at the camera layout with 2.9:Open there seems to be no way to adjust color to effect the histogram. And an example of the user manual being silent on a subject would be there is no explaination of what something like ST4 might ne or mean. Am I looking in the wrong place or will the feature allowing color adjustment , gain, gamma, etc appear once a I get Pro

and my IMX 224 camera’s color space is RGB 24 only...will the sensor analysis work on that ? ..or do,I need raw or mono

Not sure


All the best
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Re: Using Test Cameras to try out sensor analysis

#6

Post by admin »

Hi,

the manual only covers features in SharpCap 2.9 so far (not perfect I know, but it's all about how best to spend a limited amount of time...)

You won't see features like gain, gamma etc magically appear when you get pro - the list of pro features in 3.0 is found here - http://www.sharpcap.co.uk/sharpcap/shar ... harpcappro - there are some more like smart histogram in 3.1, but I won't be updating the published list until 3.1 is fully released.

The sort of things that you are describing are a function of whether SharpCap supports your camera directly or not. In the case of the ToupTek cameras the answer to that question is 'Not' - you can access the cameras using the DirectShow drivers or the ASCOM drivers provided by ToupTek, but you will not get to access the full range of camera features. This isn't a deliberate limitation on my part - it's just that those common ways of talking to cameras like ASCOM don't provide direct ways to control all the features of modern cameras - lots of things can only be done using the camera setup dialog. To take an example, ASCOM provides no way for SharpCap to directly control the black level (offset) value of a camera - if it is controlled at all it has to be through the camera setup dialog.

I wouldn't recommend using sensor analysis/smart histogram with a colour camera if you cannot get it into RAW mode - it will give incorrect results as the pixel measurements it sees are averages of the raw pixel values which has a big impact on the noise levels (and measuring noise correctly is what the sensor analysis is all about).

cheers,

Robin
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turfpit
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Re: Using Test Cameras to try out sensor analysis

#7

Post by turfpit »

Edgar

From https://docs.sharpcap.co.uk/2.9/#Testing%20Controls "The Testing Controls group is specific to the two test cameras included with SharpCap. The controls allow for the simulation of atmospheric conditions"'.

The function of these test controls is described here https://docs.sharpcap.co.uk/2.9/#Test%20Cameras.

Setting up the 'right' atmospheric conditions via the controls would allow, for example, the ability learn about live stacking without needing a telescope or going outside.

Sensor Analysis came after v2.9. The text will be edited to cater for this when I update the manual. This won't happen until after 3.1 is released, as it is not easy to document a moving target.

Dave
edgar619
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Re: Using Test Cameras to try out sensor analysis

#8

Post by edgar619 »

Thank you for this information Dave

Very helpful... I will wait for 3.1 offcial release and buy it for all the new enhancements including sensor analysis

And thank you for your contribution to our hobby

All the best

Edgar
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Re: Using Test Cameras to try out sensor analysis

#9

Post by admin »

Just an update on the state of 3.1 - I had hoped to release by now, but I am still chasing down out-of-memory errors that happen when people are live stacking with very high resolution cameras (35 megapixels!). I am also fixing small issues that are reported in the meantime. I still hope to have a release candidate next week which will then turn into the actual released version of 3.1 if no bugs come up.

cheers,

Robin
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