SharpCap Forums

Running an ASI2600MC-P on the latest SC Beta. And while the camera's always had a propensity to generate cross hatching it always disappeared when stacked. Last night's work on M101 was just hatch. Both yesterday's flats and yesterday's images. Crud.

Here's what I'm seeing with today's flat field:


And here's today's SC flat screen grab:


Settings: RAW16 FITS 1/60sec -10C full frame no bias 60 flat frames

I've used this combination before successfully.

Starting to get mighty discouraged.

p.s. After browsing the SC forum I tried forcing the RGGB debayer matrix. No joy. So I reset the debayer program to ON - which I've always used with no problem. Log appended

[ZWO ASI2600MC Pro]
FrameType=Light
Debayer Preview=On
Pan=0
Tilt=0
Output Format=FITS files (*.fits)
Binning=1
Capture Area=6248x4176
Colour Space=RAW16
Hardware Binning=Off
High Speed Mode=Off
Turbo USB=40
Flip=Horiz
Frame Rate Limit=Maximum
Gain=120
Exposure=16.6670ms
Timestamp Frames=Off
White Bal (B)=63(Auto)
White Bal (R)=99
Brightness=102
Window Heater Power=On
Temperature=-10.1
Cooler Power=92
Target Temperature=-10
Cooler=On
Auto Exp Max Gain=100
Auto Exp Max Exp M S=25000
Auto Exp Target Brightness=150
Mono Bin=Off
Background Subtraction=Off
Planet/Disk Stabilization=Off
Banding Threshold=35
Banding Suppression=0
Apply Flat=None
Subtract Dark=C:\0 SharpCap Images\DARKS\ZWO ASI2600MC Pro\RAW16@6248x4176\1X -10C 120g darks\3m 1X 120g -10C dark.fits
Display Black Point=0
Display MidTone Point=0.5
Display White Point=1
Notes=
TimeStamp=2021-04-23T21:04:00.9433969Z
SharpCapVersion=4.0.7680.0
FrameCount=60
FrameType=Flat
UsedBias=False

Note that the NONE option wasn't available for darks. And just checking by running a 2 second light the NONE still seems to be crowded out by past darks.

Ah ha! Perhaps because I was set on FLIP????

EUREKA! THAT WAS IT. Never used the FLIP before last night. Just ran a flat without the flip and it was fine. This problem was documented in the forum archive but it should have been corrected.

Hi,

the ZWO camera should behave correctly as you move through the various flip options (if you leave debayer to 'ON'). If you set it manually then you have to adjust the manual value for each of the possible 4 flip combinations.

One thing I did notice is that your settings file shows a dark frame in use when capturing the flat - it's difficult to be sure from the filename, but I suspect that the dark was a long exposure one (3 minutes?). You should not use long exposure darks while capturing flats - if you are using darks then they should always match the exposure, gain and temperature used for the light frames. Another thing to note is that the dark should have the same 'flip' orientation as the light frames, otherwise things like hot pixel correction will go horribly wrong.

The image showing with cross hatches is natural for a RAW image that is viewed without debayering (or one that has been debayered with the wrong settings).

What I am somewhat surprised by is that you were not getting the option to make a monochrome flat frame - that seems wrong. The fact that you cannot select to use bias frames is because you already have a dark frame selected - that's OK.

cheers,

Robin

Hi Robin,

This is an ASI2600MC-P on the latest SC beta.

I've run this lots of software configurations trying to solve this. Including calling and am pretty sure that the problem persists even with debayer preview = 0.

The dark frames box was filled with old darks but the NONE option wasn't present. Maybe the box fills up, but there's no apparent way to delete previous darks. Or to not have a dark selected. This doesn't happen all the time.

Will explore further.

CORRECTION. Just out again and the DARK frame did have a bar next to it. While the various dark frame wouldn't scroll the bar did move the selection to the top and NONE was the top option.

And tonight the flip does work cleanly when set as you described. QUESTION If I flip the image do the darks and flats flip automatically as well? It would seem from your previous response that the answer is no. Confusing enough as things stand. Will just avoid SC flips.

And although I'd not have occasion to use it, the monochrome flat frame option is showing up on last night's screen and on tonight's as well

Hi,

yes, you are correct - the flat/dark do not flip automatically and need to be taken in the same orientation as the light frames. Another thing that is on the to-do list for some time in the future.

I think there was a small bug with the monochrome flat option - if you changed the debayer option while the flat screen was showing then it could be enabled or disabled wrongly - I've fixed that for the next update.

cheers

Robin