New Altair 585M Sensor Analysis Q's & Issues

[SteveC]

Just received the new 585 mono from Altair and ran the sensor analysis to try and figure out the best gain settings but it hasn''t helped.
The gain range is from 1-15000 but after 199 everything goes off a cliff with no inbetween.
Those stupid LED's will not turn off (have a hyperstar, so its a problem)
Any help would would be appreciated.

535 Mono Sensor Analysis.JPG (380.78 KiB) Viewed 3803 times

[admin]

Hi Steve,

please update to the newest version of SharpCap (4.1.12893, released today) - that contains an Altair SDK update and also changes in SharpCap to the parameters for the conversion gain switchover for the 585 that *should* fix the issue you are seeing. There is also code that tries to give you controls over the LEDs, but support for that is model dependent ( I can turn off the LED on my ToupTek 585 colour using that feature though).

You will need to do a manual download and install of this new version - it's not available by auto-update yet.

cheers,

Robin

[SteveC]

Thanks Robin, I've done the update and got almost identical results. The gain slider now seems to operate in a more "even" manner but maybe ts in my head. I thought i might be able to see a changeover point from LCG to HCG if this is the way it works. but with a range of 30,000 it'd be a bit of a needle in a haystack. The problem is there's nothing to reference it against.

cheers

Steve

PS Lights are stll shining brightly

[admin]

Hi Steve,

OK, I think I see the problem - basically SharpCap has to recognize what sensor is on the camera from the camera name - once it knows it is a 585 then it knows the LCG/HCG changeover parameters that are required. I don't think the current version is recognizing the name AA585MTEC - it was looking for Altair585....

I will update this for the next release on Monday.

cheers,

Robin

[SteveC]

Thanks again Robin. Fingers crossed

all the best

Steve

[admin]

Hi Steve,

please try the latest update - 4.1.12925 - available from the usual download page. Hopefully this will correctly recognize your camera as having the IMX585 sensor and will not switch into HCG mode until gain 1365.

cheers,

Robin

[SteveC]

Hi Robin, I thank you for your efforts, unfortunately we have pretty much idendical results

Altair 585M Dec 23rd 0.0C.JPG (69.37 KiB) Viewed 3773 times

I've took some 60s darks using Altair capture from 199 gain to 202 and there are inconsistencies there. Altair capture modes are RGB24/Raw/RGB48 no mono, no hardware binning a few other oddities. The Ascom driver runs at just over 2fps.

I don't think this cam was quite ready for the market yet, But I know it will eventually.

Have a great Christmas

Steve

[admin]

Hi Steve,

oops, that was my mistake - I put the right code to recognize the camera name in the wrong place, so it didn't get used I will have that right for the next update.

Unfortunately I don't have anything to help with the lights if they are still an issue - there are two different ways that you can try to turn off the lights on these cameras, some models support one way, some the other and some neither (or at least neither works). SharpCap tries each and will make the control available if it looks like one will work. Some black tape may be the best bet.

cheers,

Robin

[Olivier-Fantasy]

Hello from France


I juste received my new Altair 585M and, of course, I've done a sensor analysis.

At first, this was my result:

Before-update.png (191.03 KiB) Viewed 3761 times

I was happy with that (unity gain about 200-250?)...

But, no "HDR" menu... And I saw that I haven't updated SC...

After updating, another sensor analysis gave me that:

SC-updated.png (184.04 KiB) Viewed 3761 times

...Lot of read noise around the unity gain... The HCG at 1365 with a lot of relative gain (too much?) and just a little full well...
It does not look very good, does it?

Is it ok?... Or is there a problem with this SDK? What gain should I choose?

Thank you for your help.
Olivier


Ps: and you have not seen the HDR analysis... So weird! Is this usable? I don't know if this plot is really normal... (maybe they didn't program HDR?) On a QHY camera, HDR gives a flat plot, the gain remains at 1 everywhere.

HDR.png (212.3 KiB) Viewed 3761 times

[admin]

Hi,

the older version of SharpCap incorrectly changed to HCG mode at gain 200, resulting in the step changing in e/ADU and relative gain that occurs in the first set of measurements between gains 190 and 200. The updated version of SharpCap correctly changes to HCG at gain 1365 - that correctly balances the additional gain from HCG mode with dropping back to a lower basic gain, meaning the e/ADU and relative gain values are basically the same on each side of the changeover - just the read noise drops.

As regular readers of the forum will know, I am not a great believer in there being anything special about unity gain - I can't see how it matters that one electron leads to 1 ADU when the random errors in reading the value (from a combination of read noise and shot noise) are always far higher than 1 ADU (at least in cameras released so far).

The HDR results do not look correct, but I have heard that the current SDK in SharpCap is not quite right yet for the Altair585, so perhaps that is the thing that needs correcting? I do have a ToupTek 585M (not Altair, but very similar) - I don't have the data for that in HDR mode to hand at the moment, but will try to measure it later and post to compare.

cheers,

Robin