SharpCap Forums

Thanks Robin, didn’t realize how complicated that change would be. Probably why I’m not a programmer

Anyway your 4.2 is great it’s going to be a real hit.

Robin,
I noticed a change with 4.2. With 4.1 the best fwhm I would get would be about 4. With 4.2 I get down to 2.9. I also noticed when auto focus runs the first couple of marks are low then go up then back down to the bottom of the curve then back up. With 4.1 the start of the auto focus would start with the left point of curve was the highest value. Visually at the start of auto focus I can see the shadow of secondary but fwhm is still quite low.

Hi,

my guess is that this is a side-effect of me changing some of the details of star detection to try to make more faint stars detectable. The change in best value isn't a big concern, as really things only depend on how FWHM changes, not the precise values, but the detection problems when out-of-focus are more concerning. It sounds as if the new code is giving a small FWHM result in the case of seeing 'donut' stars, so I will have to dig into that.

cheers,

Robin

A new, updated build is now available from https://www.sharpcap.co.uk/sharpcap/sha ... p-4-2-beta

This introduces a new 'satellite forecast' feature (see viewtopic.php?f=38&t=9513&p=53006) as well as many tweaks, bug fixes, small improvents, etc.

cheers,

Robin

admin wrote: Fri May 15, 2026 12:33 pm Hi,

my guess is that this is a side-effect of me changing some of the details of star detection to try to make more faint stars detectable. The change in best value isn't a big concern, as really things only depend on how FWHM changes, not the precise values, but the detection problems when out-of-focus are more concerning. It sounds as if the new code is giving a small FWHM result in the case of seeing 'donut' stars, so I will have to dig into that.

cheers,

Robin

I would think HFD/HFR would be more robust when you have donuts for out-of-focus stars. Supposedly HFD is also more robust against poor seeing than FWHM is.

Hi,

strictly speaking, SharpCap does measure the HFD/HFR, but the UI talks about FWHM as it's more familiar/commonly used. It may be something like the measurement box for what area to measure over is poorly estimated for donut stars - I will have to check.

cheers,

Robin

Hello Robin,

Do you change something to the Plate Solve or stars detection ?

With the last version 4.2 ... the Plate Solve works with the Ultra-Hi-Res, but no more with the Hi-Res or Default stars index.

with the following "setup" ...
- ASCOM Sky Simulator with camera: 1920x1200 pixel, 5.86 µm und 754 mm focal
- in addition G18 star database and "F/2" focal ratio
- in SharpCap camera control: exposure 1000 ms with gain 900

With the Default or the Hi-Res SharpCap star index ... no Plate Solve.

If I test the same "setup" with the SharpCap version 4.1 ... then I can found a Plate Solve with each 3 index.
I used the GSServer simulator mount and it was pointing at M65.


Regards,
Jean-Francois

Hello Robin,

One additional point for the GPS camera.
With a QHY174GPS ... it works fine, the "GPS" settings are available and all seems OK.
But for my ToupTek ATR585GPS ... no GPS activated. No setting in the Camera Controls and no information on the lower line.

Regards,
Jean-Francois

I have found the bug report for Dave's crash and it looks like something that I should be able to resolve for the next update - perhaps related to changes I made to allow the window layout of SharpCap to be reset to the default.

cheers,

Robin
[/quote]

Was able to use the latest beta version last night and didn’t have any issues with switching or opening new windows. Was able to pause my live stack and run the multi star focus tool, then back to live stacking.

Hi,

@Jean-Francois - I will look into both of those, star detection is my suspect for the first one, as the plate solving is unchanged. The second is odd because I don't think I have changed the ToupTek code at all in the new version - not even the SDK...

@davemartin88 - glad to hear all working well for you at the moment

cheers,

Robin