Uranus C Cool & Brain

[donboy]

Hi Robin,

I don't know if the results with the Brain function was correct when I ran it on the Player One Uranus C Cool IMX585. The results I got were for Maximum Dynamic Range was gain 250 and exposure 90 sec. For Unity Gain it was gain 210 and 915 sec for exposure. For that little difference in gain the exposure is 10 times longer? Doesn't seem correct.

Don

[donboy]

I just opened the sensor library and saw 5 sets of bin files for the Player One 585 camera, I would have only expected only 2, one for the uncooled and one for the cooled cameras.

Don

[admin]

Hi Don,

the read noise for the IMX585 sensor drops by a big margin just beyond gain 210, so you get much lower exposure recommendations beyond gain 210 where you have low read noise available. You can see the read noise graph at the bottom of the model web page on the Player One site - https://player-one-astronomy.com/produc ... ra-imx585/

Additional sensor data files can be required if the camera has multiple read modes - not sure if that is the case with the IMX585 on PlayerOne, but some of their cameras do. What file names are you seeing?

cheers,

Robin

[donboy]

Here is a list of sensor files for imx585.

imx585-Screenshot 2023-10-12 134847.png (70.23 KiB) Viewed 7735 times

[donboy]

still don't get why Brain at gain 250 it calls for 90 sec exposure and at HGV of 210 it calls for 900 sec. Once the gain is at 210 it is in HGV mode and one would expect from PlayerOne graph that the exposure at 250 would be slightly less than 90sec that was indicated by the brain at 210 gain.

Don

[admin]

Hi Don,

having looked into it, I think that what is happening is that sometime the camera is being given a custom name by people and that appears after the default name in the square brackets. My code for collating the sensor data wasn't set up to deal with that, so it sees them as different models of camera, rather than the same model with odd names.

I will have to fix that issue.

On the other issue, that turns out to be because SharpCap by default measures the read noise at equally spread values - for the UranusC it looks like the values picked are 0, 50, 100, 150, 200, 250, etc.

Between those measurement points, SharpCap has to interpolate the read noise and other data, so the calculations that SharpCap does are based on the read noise dropping steadily between 200 and 250 rather than a cliff edge at 210. Choosing the number of measurement points is a trade off in terms of time taken to run the analysis.

cheers,

Robin

[nigeld]

I ran into this problem with my imx585 camera and the cliff edge change in noise. I ended up running a single line script to set sampling points either side of the switch in mode so when the analysis ran it saw the change. Unfortunately I cannot remember what the exact script/line was. Will dig it out if no-one else pipes up with it.

[admin]

Hi folks,

I have actually fixed this one for the PlayerOne cameras in the latest SharpCap 4.1 - it's possible to ask the camera where the cliff edge is going to be, so SharpCap does that and automatically adds sampling points each side.

If you need to add more gains manually, the scripting trick is

Code: Select all

SharpCap.SelectedCamera.SetGainsOfInterestForSensorAnalysis([200,210,220,230,240,250,260,270,280,290,300,310,320,330,340,350])

Change the list of numbers to the numbers you are interested in measuring.

cheers,

Robin