Poor FPS Imaging Planets

[sandconp]

I have been imaging Saturn and Jupiter with a ZWO ASSI178MC OSC camera and I can't see to get a reasonable FPS number. I am only getting 5 or 6 FPS at best using a 640X480 ROI. When I try the same camera with Firecap using the same camera and ROI, I am getting 20 FPS or better.

I have the high speed option enbabled and the turbo option set at 90.

[admin]

Hi,

worth checking the camera settings as a number of them can affect FPS

1) Exposure - if this is set to 150ms then you will only get 5-6 fps as that's as many frames as you can fit in a second
2) capture mode - RAW16 will be slower than RAW8 (but at ROI it shouldn't notice)
3) Turbo USB - there is always a 'best' setting for this, but not always the highest. Sometimes turning it up too high can cause slow rates
4) Save format - if the slowdown only occurs when capturing, check you are saving to SER, which is the fastest file format

I don't personally have the ZWO178, but I have the 174 and can get 150fps or more in full resolution RAW8 on that camera when connected on USB3.

cheers,

Robin

[sandconp]

Robin,

Here were my settings and yes my exposure was set at 150ms. That number seemed to work the best when I looking at the screen. I was also using a 2X Barlow lens. So I am assuming that I need to adjust the exposure setting to a lower number? Is there any way you could add the FPS to this report? I was using RAW8 by the way.

[ZWO ASI178MC]
FrameType=Light
Debayer Preview=On
Pan=1164
Tilt=1040
Output Format=SER file (*.ser)
Binning=1
Capture Area=768x520
Colour Space=RAW8
Temperature=24
Hardware Binning=Off
High Speed Mode=On
Turbo USB=90
Flip=Horiz
Frame Rate Limit=Maximum
Gain=272
Exposure=150.0000ms
Timestamp Frames=Off
White Bal (B)=48
White Bal (R)=70
Brightness=0
Auto Exp Max Gain=247
Auto Exp Max Exp M S=30000
Auto Exp Target Brightness=100
Mono Bin=Off
Background Subtraction=Off
Planet/Disk Stabilization=Off
Banding Threshold=35
Banding Suppression=0
Apply Flat=None
Subtract Dark=None
Display Black Point=0
Display MidTone Point=0.5
Display White Point=1
Notes=
Celestron Telescope Driver=RA=21:45:55,Dec=-14:07:52 (JNOW)
TimeStamp=2022-07-14T06:54:51.7687139Z
SharpCapVersion=4.0.8667.0
StartCapture=2022-07-14T06:54:51.7361985Z
MidCapture=2022-07-14T06:55:51.8871985Z
EndCapture=2022-07-14T06:56:52.0385688Z
Duration=120.302s
FrameCount=802
TimeZone=-5.00

[admin]

Hi,

OK, so that makes sense having about 5-6fps at 150ms exposures. The trick for planetary imaging is to turn *up* the gain and turn *down* the exposure until you get to a point where you get about 20-30fps. Individual frames may look very noisy due to the high gain, but once you stack 1000 or so then that noise will pretty much vanish.

The latest versions of SharpCap 4 do include FPS in that report - ie.

Code: Select all

TimeStamp=2022-07-15T18:26:43.5150747Z
SharpCapVersion=4.0.9160.0
StartCapture=2022-07-15T18:26:42.8944385Z
MidCapture=2022-07-15T18:26:44.4444385Z
EndCapture=2022-07-15T18:26:45.9942018Z
Duration=3.100s
FrameCount=23
ActualFrameRate=7.4199fps
TimeZone=+1.00

cheers,

Robin

[sandconp]

Thanks Robin.

Any plans to add Focal Length into the stats IE when I use a Barlow the (FL would double) like Firecap provides?

[admin]

Hi,

currently no, but there is a 'notes' section at the bottom of the controls on the right, so you can add any notes you want which will then end up in the capturesettings.txt file when you capture.

cheers,

Robin

[sandconp]

Thanks that will be helpful iE seeing conditions too.