issues with first use of sharpcap on new computer

[Moonstruck]

Hi,
I recently bought a new laptop (Acer Nitro 5), and loaded all my astronomy software onto it, including Sharpcap. I just tried imaging last night for the first time (Eagle nebula) with the new software download, and have been having some issues:

1. There are 3 USB ports on the new computer that are type 3. When I initially plugged in my camera (ZWO asi 294 MC), one of the ports didnt work with sharpcap - the tools menu didn't show up. After changing the cable, it appeared to be working- the tools menu then appeared - but as I was imaging, the live view screen went blank, but the camera was still shown as connected. I changed ports to another USB port, and it appeared to be working at first, except the live view then turned off intermittently. It seems like my USB ports on this new laptop don't work well with sharpcap! Any idea why? I spent a fortune on this new laptop and I don't know if it is the laptop or possibly has something to do with the sharpcap settings. I need to know soon, as the 30-day window for return of the laptop is quickly approaching and I need to know if i should return it. I had much better luck using sharpcap with my old HP laptop, but since I upgraded to this one it just doesn't seem to work right.

2. The plate solver worked (I set it to solve and slew to the target), but i kept getting the message that it was significantly off target (i think it said 5 degrees, or maybe 5 minutes off)? I told it to slew anyway and it did, I'm just wondering why it was so far off. I did a good alignment and it should have been pretty much right on target without having to slew much, but it was way off, almost every time.

In spite of these issues, I managed to get 60 1-min subs of the eagle nebula, stacked them in deep sky stacker, and included a link to the autosave file below. Maybe you can look at this and let me know if it looks ok. I tried processing it, and the resulting image looks terrible... much of the Eagle nebula didn't show up well and I got really significant vignetting around the edges:

DSS Autosave file:
https://drive.google.com/file/d/15HnYvm ... sp=sharing

I included my sharpcap camera settings file below. Can you let me know what you think is going on here? Are all my settings correct for my camera? Note that I forgot to turn on the camera cooler - not sure if that mattered. Also should I be using the RAW8 or RAW16 setting? And what is "turbo USB" and is it set correctly? Thanks in advance for any advice!

Camera settings:
[ZWO ASI294MC Pro]
FrameType=Light
Debayer Preview=On
Pan=0
Tilt=0
Output Format=FITS files (*.fits)(Auto)
Binning=1
Capture Area=4144x2822
Colour Space=RAW16
High Speed Mode=On
Turbo USB=80(Auto)
Flip=None
Frame Rate Limit=Maximum
Gain=120
Exposure=60.754s
Timestamp Frames=Off
White Bal (B)=95
White Bal (R)=52
Brightness=17
Cooler Power=0
Temperature=22.1
Target Temperature=-10
Cooler=Off
Auto Exp Max Gain=285
Auto Exp Max Exp M S=30000
Auto Exp Target Brightness=100
Mono Bin=Off
Trail Width=3
Minimum Trail Length=100
Trail Detection Sensitivity=9
Remove Satellite Trails=Off
Background Subtraction=Off
Planet/Disk Stabilization=Off
Banding Threshold=10
Banding Suppression=0
Apply Flat=None
Hot Pixel Sensitivity=5
Subtract Dark=None
NegativeDisplay=0
Display Black Point=0
Display MidTone Point=0.5
Display White Point=1
Notes=
EQMOD ASCOM HEQ5/6=RA=18:20:07,Dec=-13:46:21 (JNOW)
TimeStamp=2022-08-25T01:55:28.2948365Z
SharpCapVersion=4.0.9246.0
StartCapture=2022-08-25T01:55:10.5441343Z
MidCapture=2022-08-25T02:26:14.0571343Z
EndCapture=2022-08-25T02:57:17.5693032Z
Duration=3727.025s
FrameCount=61
ActualFrameRate=0.0164fps
TimeZone=-4.00

[admin]

Hi,

well, first the camera settigns, which all look reasonable. There are always tweaks that can be made, but nothing looks badly wrong (and you certainly got a decent final image with a little stretch showing the nebulosity).

The USB issues are more challenging to work out - I have certainly seen cases where particular cameras just do not seem to work well on certain USB ports (add-in cards that gave USB3 ports to PCs that did not have them used to be an issue, but you see less of those now). I would suggest working through the steps in the USB troubleshooting guide - viewtopic.php?f=18&t=349&p=1556#p1556 - to see if any of the suggestions there help resolve the issues you are seeing. If you can find a configuration that works consistently it is usually relatively simple to work back from that point to your normal configuration one step at a time and work out what change causes the issues.

The plate solve/resync/recenter action does prompt for confirmation if the error in the mount's position appears to be more than 5 degrees. Really this is to protect against false positive plate solve results (which sometimes do happen). If there is such a false positive then the plate solving result may be very distant from the real mount position (10s of degrees or more). In your case it sounds more likely that it was just a case where the pointing offset was a bit over 5 degrees. This can happen for a combination of reasons including polar alignment being off, initial alignment being incorrect, cone error, clutches slipping/moving at some point or even if you have just accidently moved the tripod.

Hope this helps,

Robin

[Moonstruck]

Thanks Robin- yes that is very helpful. Also- what are the turbo usb and high speed mode settings for, and should I try them out? Not sure if that would hurt or help my USB issues.

[admin]

Hi,

Turbo USB controls how hard the ZWO driver tries to push data over USB at high speeds - in general turn it down for stability, turn it up to increase frame rate.

High speed mode is to do with 8 bit imaging and getting the very highest frame rate. I think it does weird things to the gain too on some cameras and is of limited use in my experience - leave it switched off.

cheers,

Robin