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POLL: What mode, gain and offset do you use?

QHYCCD QHY600PH M CMOS Filters
Stellar NomadsShannon FoyeChris White- Overcast ObservatoryKevin MorefieldJohn Hayes
•42 replies•1.5k views
Stellar Nomads avatar
Stellar Nomads avatar
hello folks

I have the previous version QHY600 and I also have the Astrodon I-series LRGB as well as Antilia Ha 3nm. I would like to know what everyone is using for setting? I am using it with an OOUK AG16 F/3.8 newtonian.

Thanks so much for your input and time.
Robert Lowenthal avatar
Robert Lowenthal avatar
For Narrowband filters: Readout Mode 1 (High Gain Mode), Gain = 56
For Broadband filters: Readout Mode 3 (Extended Full Well  Mode - 2CMS), Gain = 0

I currently have Offset at 20, but from what I’ve been reading I’m considering bringing up to 50 or 60.
Pete Bouras avatar
Pete Bouras avatar
CMS-0 Gain 26 offset 30 for LRGB
CMS-1 Gain 56 offset 30 for SHO
David Koslicki avatar
David Koslicki avatar
2CMS-0 Gain 56 Offset 76 for everything. I'm also using Antlia filters
Paul O’Brien avatar
Paul O’Brien avatar
Very interesting to see the variety of settings people use.  I use one setting for all my NB and broadband imaging with very good success: Mode 0; Gain 27; Offset 10.
Well Written
Stellar Nomads avatar
Stellar Nomads avatar
thank you all. Mind also sharing what F ratio are you using and what exposure times please? I know there have been a LOT of questions around this subject, and I want to sort consolidate it in one place.

Again, you are appreciated.
GalacticRAVE avatar
GalacticRAVE avatar
LRGB: extended full-well 2cms, gain 0, offset 52
narrowband: 2CMS-1, gain 56, offset 52
Christian Koll avatar
Christian Koll avatar
High Gain Mode, Gain 56, Offset 50 for everything. using a refractor f/5.6 and also Antlia LRGB and 3.5nm NB filters.

CS
Chris
Greg McCall avatar
Greg McCall avatar
Mode 5, gain 56, offset 40 for all images. Mostly bin 1x1
i originally used no offset and then a small offset but was wondering why I got black speckles in the stacked image. 

after some research, I learned what it could be so picked a bigger offset. 
40 seemed reasonable but it will be interesting to see what others get
Paul O’Brien avatar
Paul O’Brien avatar
I image everything at f/7.0 using Astrodon LRGB and 3nm Ha filters along with Antlia 3nm OIII and SII filters.  Exposures range from 60-120 sec for LRGB and 300-600 sec for NB.  All unguided.
Stellar Nomads avatar
Stellar Nomads avatar
Thank you so much all, much appreciated.
Stellar Nomads avatar
Stellar Nomads avatar
any thought about binning to get a more acceptable pixel scale ? I am down to 0.51"/pixel with the 16 inch newtonian, so 1"/pixel would be a little better in my estimation. Also, the enormous file size of 1x1 binning will NOT be missed :-D
Paul O’Brien avatar
Paul O’Brien avatar
I've thought about it but have not pulled the trigger so far.  My pixel scale is around .76", which is not ideal for my skies but manageable.  The biggest factor to do it would be the file size issue, as you pointed out.  Full scale pre-processing of nebula can take a long time even with my new fast desktop so I'm now cropping everything to the extent possible before running WBPP, which has helped my processing times.  Still, those smaller file size using binning would be awfully nice to have.  smile
Well Written Insightful Respectful Concise Engaging
AstroShed avatar
AstroShed avatar
High gain mode 1, Gain 56 and offset 25 for all filters, I just alter exposure length between Broadband with only an LP filter, and Narrowband with 3nm filters. No need to use different modes.
Stellar Nomads avatar
Stellar Nomads avatar
Paul O’Brien:
I've thought about it but have not pulled the trigger so far.  My pixel scale is around .76", which is not ideal for my skies but manageable.  The biggest factor to do it would be the file size issue, as you pointed out.  Full scale pre-processing of nebula can take a long time even with my new fast desktop so I'm now cropping everything to the extent possible before running WBPP, which has helped my processing times.  Still, those smaller file size using binning would be awfully nice to have. 

I did a pretty substantial project involving M33, I ended up with 97GB in WBPP !!!!!!..  my 14700K powered desktop took over 2 hours to run WBPP
Paul O’Brien avatar
Paul O’Brien avatar
Paul O’Brien:
I've thought about it but have not pulled the trigger so far.  My pixel scale is around .76", which is not ideal for my skies but manageable.  The biggest factor to do it would be the file size issue, as you pointed out.  Full scale pre-processing of nebula can take a long time even with my new fast desktop so I'm now cropping everything to the extent possible before running WBPP, which has helped my processing times.  Still, those smaller file size using binning would be awfully nice to have. 

I did a pretty substantial project involving M33, I ended up with 97GB in WBPP !!!!!!..  my 14700K powered desktop took over 2 hours to run WBPP

I know what you mean!  Been there, done that.  I did a big project and had almost 100GB and it took a while to run.
Shannon Foye avatar
Shannon Foye avatar
Camera is a QHY268M

Narrowband
   - High Gain Mode
   - Gain 56
   - Offset 25
   - USB Limit 25
   - Minimum ADU of bias sub exposures range from 250 to 280

Broadband
   - High Gain Mode
   - Gain 0
   - Offset 25
​​​​​​​   - USB Limit 25
   - Minimum ADU of bias sub exposures range from 260 to  290
Stellar Nomads avatar
Stellar Nomads avatar
Shannon Foye:
Camera is a QHY268M

Narrowband
   - High Gain Mode
   - Gain 56
   - Offset 25
   - USB Limit 25
   - Minimum ADU of bias sub exposures range from 250 to 280

Broadband
   - High Gain Mode
   - Gain 0
   - Offset 25
  - USB Limit 25
   - Minimum ADU of bias sub exposures range from 260 to  290

Thanks
alistairmac avatar
alistairmac avatar
The setting I use are -

QHY600
BB mode 3, Gain 0, offset 30
NB mode 1, Gain 56, offset 30

QHY268
BB mode 4, Gain 0, offset 50
NB mode 5, Gain 56, offset 50
Stellar Nomads avatar
Stellar Nomads avatar
The setting I use are -

QHY600
BB mode 3, Gain 0, offset 30
NB mode 1, Gain 56, offset 30

QHY268
BB mode 4, Gain 0, offset 50
NB mode 5, Gain 56, offset 50

thanks. Mind sharing the exposure length as well ?
Kevin Morefield avatar
Kevin Morefield avatar
Mode 3, Gain 25, Offset 20.  I use that for all filters. 

F3 DeltaRho: 120 Luminance, 300 RGB, 600 NB
F3 FSQ106: 300 LRGB, 600 NB
John Hayes avatar
John Hayes avatar
Kevin Morefield:
Mode 3, Gain 25, Offset 20.  I use that for all filters. 

F3 DeltaRho: 120 Luminance, 300 RGB, 600 NB
F3 FSQ106: 300 LRGB, 600 NB

Same here Kevin!
Stellar Nomads avatar
Stellar Nomads avatar
Kevin Morefield:
Mode 3, Gain 25, Offset 20.  I use that for all filters. 

F3 DeltaRho: 120 Luminance, 300 RGB, 600 NB
F3 FSQ106: 300 LRGB, 600 NB

Thanks Kevin
Stellar Nomads avatar
Stellar Nomads avatar
John Hayes:
Kevin Morefield:
Mode 3, Gain 25, Offset 20.  I use that for all filters. 

F3 DeltaRho: 120 Luminance, 300 RGB, 600 NB
F3 FSQ106: 300 LRGB, 600 NB

Same here Kevin!

Thanks John
Kevin Morefield avatar
Kevin Morefield avatar
John Hayes:
Kevin Morefield:
Mode 3, Gain 25, Offset 20.  I use that for all filters. 

F3 DeltaRho: 120 Luminance, 300 RGB, 600 NB
F3 FSQ106: 300 LRGB, 600 NB

Same here Kevin!

Well I stole it from you!