New to SGPro and the ASI1600 and enjoying both. Trying to build up my dark library but I have noticed a difference in the files when using the Native driver vs Ascom:
Linked folder contains a single 30s dark frame using the ascom driver vs native. Gain/Offset were 200/50 in both cases. There is also an integrated dark master of 20 darks which I integrated in PI.
I like the idea of being able to change gain/offset per event (so use the native driver) but it looks like the native driver is producing a black line at the top of my frames? This happens across gain/offset (i matched the ascom setting) and exposure length.
James, when taking darks it is best to match them in as many ways as possible to the lights. That would include the driver used as well, if possible. With the ASI1600, depending on which version you are using, there may be a USB Limit setting in the ASCOM driver that can have an impact on the DFPN (dark fixed pattern noise, the banding notably) as well, and you will want to make sure that setting is the same between the lights and darks. Further, you will want to avoid changing that setting as much as you can, as changing it will often change the DFPN.
I am not sure if the SGP integrated support has a USB Limit setting, and if you are using the ASI1600 Pro you would not need to worry about it.
As for the dark line, I am not sure what might cause that…however, if you acquire lights with the native SGP support for the camera, then you would want to acquire your calibration frames (all of them, darks, biases, flats, flat darks) the same way.
My intention was always to do as you recommended and use the same driver/settings, but when I tested each driver I was surprised to see a difference (the black line). I will probably revert to the ascom driver which doesn’t show this…
James, I found two interesting things recently about the two drivers. when I click the settings next to connecting the camera the driver settings come up for the preset settings or of course enter gain and offset manually. Above that though you can select RAW8 or RAW16. I’ve noticed those don’t stay set between sessions. I have to go in and verify/change to RAW16.
The other thing is the event uses the native driver i believe. It offers only gain and offset. Does anyone know if this driver is mapped to RAW16?
I don’t believe the SDK we’re using has access to the USB limit (and even if it did we would choose not to expose it because it seems to be the root of most ASI instability). Probably need to look at updating the SDK anyways.
Actually, USB Limit is there to allow the end user to manage instability, not introduce it. It depends a lot on the system and the way it’s USB works, but the same USB Limit is not going to be stable on every system. Some systems may require a lower limit, some a higher limit. In my case, a very low limit causes problems with the ASI1600, but a limit around 80 is very very stable.
If there is a way to expose it in the native ASI support, I think it would be useful. I think it would be ok to hid it behind an advanced settings button or something, but it is a useful tool to improve stability if stability becomes an issue.
I think this is an issue for the ASI 183 also. I use the ASCOM drivers because they allow the feature to be adjusted. I found I was able to get my ASI183 to work with USB2 only and with a low USB transfer rate if that is what the slider to the left means.
It looks like it could be ASI_CONTROL_TYPE::ASI_BANDWIDTHOVERLOAD, with comment “The total data transfer rate percentage”.
Native driver support for ZWO is pretty much useless to me with my ASI1600MM-Cool if I’m not able to tune the “USB Limit” parameter. It has a huge impact on amp glow when using USB 3.
While the ASI ASCOM driver allows me to set “USB Limit”, I’m not able to use different gain/offset settings in the same sequence with that driver.