Atomic

I didn't know that - thanks. However, this is what I get in AS!3..

The camera appears to be detected correctly in SharpCap

..and I can see that colour space is being detected automatically.

I could force greyscale but I don't think that would be the problem

I also don't seem to see the problem if I stack directly in Registax 6.. (I prefer using AS!3 as it seems to stack better and quicker).

I have no problems using my ASI224MC camera.

Any other thoughts please?

Thanks

Martyn

Sorry for the delay..  Hiw do I check the Bayer pagtern? Is this something in. AS!3…?

Hi all

I have recently acquired a ZWO ASI 178MM and am getting a weird artifact when stacking using AS!3.

Visually, it looks like an interlaced image with horizontal lines across the image. At first glance it looks like it needs an unsharp mask

This is a snip from a Ha image taken today. I have had the same problem when imaging the moon. The issue becomes much worse when the image is processed using Registax v6.

Interestingly, stacking using Registax doesn't seem to cause the problem. Post processing, it's less visible (top image) but the lines are definitely there when I initially load the image into Registax. The wavelet and sharpening process really accentuates the problem.

Sorry if that is a bit jumbled, I hope you can see the problem.

Thanks

I have had a very auick response back from SX.

<snip>

These cameras were designed to give minimal readout noise and this requires a relatively slow download speed. Your 7 seconds is pretty typical for the SXVR cameras.

CCDs have a single readout amplifier, unlike CMOS cameras that have severalthousand, and so they cannot be downloaded very quickly. This is not anissue for a deep sky camera, as the exposure times are typically hundreds of seconds, and so a 7 second download is a small part of the time per image.

Problem resolved.. 

Best wishes 

Martyn

Thanks for the response.

However, if you look at the lower config file, I am still getting a very poor frame rate using 1024x768

[H694]
FrameType=Light
Debayer Preview=Off
Capture Area=1024x768

...

Duration=112.474s
FrameCount=26
ActualFrameRate=0.2312fps

To me it looks like the camera is processing very slowly, its not a transfer issue. I am just puzzled about this, I think I'll need to ask Starlight Xpress.

Martyn

Hi all

I wonder if you could help me with a problem. I am fairly new to imaging using dedicated Astro cameras. Up to now, I have only used modified webcams and recently a Zwo 224mc planetary camera SharpCap v4. I am still learning.

I have recently purchased a second hand SXVR-H694 camera from one of the esteemed members of this forum to try some deep sky imaging. 

To practice setting up, I have been imaging the moon in daylight so I can see what I am doing

The problem I have is that the frame rate appears to be (apparently) very slow and I can't fathom out what the problem is. Using the 224mc, I have no problems with a reasonably fast frame rate (using USB2). With the H694, I can only capture one frame every 7 or so seconds, even when I set the capture area  smaller than the 224mc and 8bit.

Starlight express have a 'universal' app called Starlight Vision which uses an elderly version of OpenGL (v3) which is not compatible with the laptop hardware.

Camera settings below. Note the Duration and Frame Count. Although the frame rate is 0.15frames/sec, there is no sign of trailing on the image which suggests that the real frame rate is very much faster. To me it looks like the camera is running slowly processing the data but I can't see why.  Is this normal?

Any suggestions?

Thanks 

Martyn

[H694]
FrameType=Light
Debayer Preview=Off
Capture Area=2750x2200
Binning=1x1
Colour Space=MONO8
Output Format=SER file (*.ser)
Pan=0
Tilt=0
Frame Rate Limit=Maximum
Exposure=2.0000ms
Target Temperature=0
Cooler=On
Temperature=1.20000004768372
Timestamp Frames=Off
Black Level=0
Digital Gain=15.4911138101208
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=
TimeStamp=2023-05-27T19:56:40.8530406Z
SharpCapVersion=4.0.9478.0
StartCapture=2023-05-27T19:56:45.0012779Z
MidCapture=2023-05-27T19:57:17.7932779Z
EndCapture=2023-05-27T19:57:50.5860291Z
Duration=65.585s
FrameCount=10
ActualFrameRate=0.1525fps
TimeZone=+1.00

and with reduced frame size:

[H694]
FrameType=Light
Debayer Preview=Off
Capture Area=1024x768
Binning=1x1
Colour Space=MONO8
Output Format=SER file (*.ser)
Pan=862
Tilt=716
Frame Rate Limit=Maximum
Exposure=2.0000ms
Target Temperature=0
Cooler=On
Temperature=0.200000002980232
Timestamp Frames=Off
Black Level=0
Digital Gain=15.4911138101208
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=
TimeStamp=2023-05-27T20:09:33.1832153Z
SharpCapVersion=4.0.9478.0
StartCapture=2023-05-27T20:09:35.3503394Z
MidCapture=2023-05-27T20:10:31.5873394Z
EndCapture=2023-05-27T20:11:27.8247724Z
Duration=112.474s
FrameCount=26
ActualFrameRate=0.2312fps
TimeZone=+1.00

Thanks for that link. 

The calculator at the end gave me the assurances that I need. 

Really very helpful and bookmarked

Thank you both for your comprehensive responses.  I think that I am starting to understand the limitations of the sensor and telescope combination. I'll need to read a bit more, I have ordered a copy of every pixel counts and I am sure that will help fill the gaps.  In the meantime, i need to get a camera.. It won't be state if the art, but it will get me started. 

Best wishes 

Thanks for that.  I think that i need to try and understand the pixel imaging scale vs resolving scale. I understand over and under sampling but puzzled why this would have an effect when the sensor is simply collecting photons.. I appreciate i may have oversimplified that last sentence

Hi all

Total newbie at guided imaging. 

I intend to purchase a second hand mono ccd or cmos camera and guide camera to have a go at longer exposure tracked imaging. I have been reading reviews on some cameras and am puzzled about a cameras suitability for different focal length/ratio of telescopes.  I note that many refer to short to moderate focal ratios, say f4 to f6.

Firstly, I dont understand why this is significant except that a telescope with a focal ratio of f10 would have a slightly dimmer image projected onto the sensor than say a F5 instrument. 

Why is this important?

Secondly what would be the effect of using a telescope with a focal ratio outside the recommended guidelines?

i have a 200mm f5 newt and  285mm f10 SCT here. EQ6 goto mount

Thanks

Martyn

Perfect. A great review. 

I was looking for a decent barlow lens. I have just ordered one of these 

Thank you