I have a camera which can pass its ASCOM image array to Voyager as INT32 data. Normally Voyager gets INT16 data from the ASCOM driver, but can Voyager save a 32 bit image?
Hi Craig
Strange, from what I know there are no cameras with A / D converters with resolution greater than 16bit for astrophotography. Voyager will use 32 bits when there are cameras with those characteristics, if you are referring to the sum and average counts on the pixels that some CMOS do, there is no benefit in this regard.
All the best
Leonardo
I am using an FLI KL4040 sCMOS camera which has a 12 bit ADC. But, the ASCOM driver for the camera has the ability to sum images. So I can take say 30 images of 1 second each and sum them to get a 30 second resulting image. The advantage of doing this is the increase in dynamic range. Suppose you have two stars on the image, 1 is faint and 1 is bright. If you take a 30 second single image you will saturate the ADC with the bright star. But if you take 30 images and sum them, then save the image in 32 bit you end up with no stars saturated, provided of course you don’t saturate any star on the sub exposure. The benefit of this is much larger dynamic range and only 1 image written to disk, not 30 subs.
So the driver has the ability to send an ASCOM image to Voyager with 32 bit floating point or integer data. The driver does write the image separate from ASCOM but it does not include some of the FITS header data that I need. One solution is to have Voyager save the 16 bit version of the image, the camera driver to save the 32 bit version then I write a small program to extract the FITS header info I need and add it to the 32 bit image.
Hi Craig,
sorry but actually we are not interested in this kind of development.
We have experiences with this camera and moravian version done 1 year ago … Moravian make things more simple without loosing nothing in 16bit but calibration fo AP are a problem in anycase for this sensor.
All the best
Leonardo
Actually, it is the ASCOM driver that I am more interested in. For me, Voyager connects to the camera through the ASCOM driver. So I am assuming Voyager uses ASCOM calls to start a capture and get the image back from the driver. The default data in the image array is INT16. But ASCOM also supports INT32. But it is whether or not the ASCOM client (Voyager) can write the FITS file using INT32 data.
Sorry Craig,
but this is not time for Voyager to do this kind of add on.
All the best
Leonardo
No problem Leo. I have a work around for it now which involves a few extra steps. But hopefully one day we will see higher dynamic range cameras on the order of 24 bit or 32 bit. Not so much for lower noise but to not saturate on brighter stars in the image. This is for photometric research.
Craig
Hi know,
i’ve another request for this feature. Is on the todo list.
All the best
Leonardo