269c sensor analysis

Discussion of features and issues relating to Altair Astro Cameras
Post Reply
KeithT
Posts: 6
Joined: Mon May 13, 2019 11:30 am

269c sensor analysis

Post by KeithT »

I'm really hoping someone can help with this.

I've been trying to run the sensor analysis for my Altair Astro 269c via my MiniX computer connected to the Dell laptop (W10) that controls my rig.

I have tried with natural light in a massive variety of brightness levels, a flat panel with varying layers of paper (printing paper and bleached greaseproof 'see through' paper) always with the same result. It starts off ok and then gets to the point where there is either too much light or too little light and aborts. The difference can be just one sheet of bleached greaseproof paper!! - It just will not work.
I have tried varying sizes of sample 'box' and always with the same result - failure.
Surely the whole idea of the sensor analysis is to make it easily useable, so either I am doing something wrong or....
Well, I can't think what!
Please help - all I want to do is analyse the sensor and then use that to judge the best exposures on any given night - if we see a clear night again sometime of course!
Thanks in advance
KeithT
User avatar
admin
Site Admin
Posts: 6667
Joined: Sat Feb 11, 2017 3:52 pm
Location: Vale of the White Horse, UK
Contact:

Re: 269c sensor analysis

Post by admin »

Hi Keith,

normally the keys to making this work are

1) use the latest update of SharpCap 3.2 (downloads page is newer than auto-update). At the beginning it should tell you to aim for an exposure in a certain range (ie 0.1s to 1.0s).
2) make sure the brightness doesn't change during the run
3) if the camera is disturbed when covering/removing the sensor for dark measurements, you can move the selection area to put it back over the area that it was on for the initial measurements before pressing 'proceed' after uncovering the sensor.

If you still have problems, please post a screenshot showing the failure message and also the SharpCap log (collected from Help->ShowLog after the failure happens).

thanks,
Robin
KeithT
Posts: 6
Joined: Mon May 13, 2019 11:30 am

Re: 269c sensor analysis

Post by KeithT »

Thanks Robin
I downloaded the latest version, but crucially discovered that my Aurora Flat Panel cane be dimmed using variable power output of my Pegasus Ultimate Powerbox 2. This managed to get the constant light to a suitable level for the sensor analysis to complete.
It also enabled me to simply switch the power off for the black level, meaning the test area was also exactly constant.

So, it has analysed the sensor and given Unity Gain between 501 & 630, which I gather is consistent with norms for this camera.
At least now I can use the tool to judge sky conditions properly, never having imaged with a CMOS camera before (always CCD)
Thanks for the response and the great programme.
Keith
User avatar
admin
Site Admin
Posts: 6667
Joined: Sat Feb 11, 2017 3:52 pm
Location: Vale of the White Horse, UK
Contact:

Re: 269c sensor analysis

Post by admin »

Hi Keith,

all you need to hope for now some clear skies :) – unfortunately the weather forecast isn't looking promising (round here anyway).

Cheers, Robin
Post Reply