Qhy 600 and readout mode

Hi
I am trying to get my qhy 600 set up and see how to input the gain and offset , but how do I select a readout mode as I would need to use a few for different types of image capture
any ideas
Thanks
Harry

Currently readout mode can be set in SGPro through use of the camera’s ASCOM settings dialog, but SGPro does not currently support in-sequence readout mode changes (because it has never been considered something that needs to vary during execution of a sequence… at least nobody has ever asked for it in 10+ years). Do you have such a use case?

Hi
with the qhy you use different readout modes for narrowband / LRGB etc
so often I would capture LRGB and Ha in the same night this means automation is not possible and I would need to manualy alter readout modes as required - also different gains and offsets are required as well- so quite a lot of messing about and remembering to do so as well .
I know different profiles could be set up for each though ( gain and offset ) but of course not readout modes - qhy has at least 4
Thanks for the reply
Harry

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ok, that’s good to know. I have added this to our list… we don’t mind supporting it, just didn’t know it was needed. Unfortunately, it will need to wait until after 4.3 though.

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Hi Ken
Thanks for considering it - much appreciated

Harry

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Harry,

I’d be curious to know which readout modes you use for wide band (LRGB) vs. narrow band (NB) imaging. I almost exclusively use the “High Gain” mode and vary the gain and offset settings as desired. It sounds like you have come up with a different scheme using different readout modes. I’d appreciate learning what you do and why you make this choice.

Thank you very much!

Ben

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Ken.

  • 1 for this.

I often run RGB and NB in the same session so it would be useful. Usually when no moon I capture OIII alongside RGB.

Hi
I am newish to cmos cameras and there seems to be lots of settings for these cameras and with a lot off reading and trial and error I have settled on

  1. Narrow band - Mode1 gain 56 offset 50 - very low read noise 0f 1.68 e with full well of 21657 but unlikley to exceed this with narrow band
  2. LRGB – mode3 -gain10-offset 50 - readnoise about 6.5e , but with full well depth about 70000 more usefull for brighter objects

But what works for you is best and there seems to be no bad options !

Regards

Harry

Thank you for your explanation, Harry. Those are sound choices.

I make my camera mode and gain selection based even more so on the comparative dynamic ranges instead of just the full well depths. The dynamic range value indicates the number of distinct steps available to use in collecting data. You may be interested in looking at a post I made showing my measurements of the QHY600M sensor. I find the most useful plot of the dynamic range to be the one in terms of steps. This quantity is the full well depth divided by the read noise, both being dependent upon mode and gain.

You can see that both of your choices have high dynamic range and are indeed comparable to each other in value. The other consideration, which you stated, is that your narrow band imaging is unlikely to utilize the entire dynamic range under normal circumstances, although you may have some stars in the field of view that are quite bright even at the narrow band wavelengths.

In SGP, I would certainly welcome the ability to change the camera mode in-sequence, of course, should I wish to expand my use of the parameters.

Ben

Hi
Thats good information thanks - CCD was easy plugin and go :slight_smile:
Thanks
Harry

Hi Gents
If you are watching I intend to try some lucky imaging , this being on brighter smaller objects , prob mainley galaxys .
so many frames required and to reduce download times sub frames would be good ( dont need all the qhy600 chip ) - cant see you can do this , in frame and focus yes but not in capture , Is it possible to add please
Thanks
Harry

I am also interested in a function to set the gain, offset and readout mode within a sequence for each target. I also use the QHY600 and currently it is not possible to capture both narrowband and LRGB within a sequence. You mention that it will take until after 4.3. What does this mean in terms of time?
Thanks for your reply
Klaus