Frames are 14 rows low / tilt when sequence with guiding

[Craigar]

Seems that my frames are 14 rows down when sequencing with guiding. This doesn't happen with regular "manual" live view captures or even a simple sequence without guiding (and live view on). So this causes misaligned with my darks and flats. Using DSS to stack, if they had a way to specify a row offset (as well as columns) then I would just use that as a workaround

Shooting full frame so there isn't any place to specify tilt or pan, which is logical cause it's a full frame.
I determined this problem by looking at the sensors "hot/stuck" pixels while overlaying a 50% opacity "sequenced with guiding" light frame and they align if I move the light frame down exactly 14 rows.

QhyIII 485C imx 485
guiding: Qhy II mono > Phd2
mount iOptron Ieq45

Windows 10 64bit ASUS laptop

my sequence:
SEQUENCE
DELAY 1
STILL MODE
STILL MODE
SET COLOUR SPACE TO RAW16
SET OUTPUT FORMAT TO "FITS files (*.fits)"
GUIDING CONNECT ABORT False
LOOP 10 TIMES
#Capture 500 Light frames
PRESERVE CAMERA SETTINGS
FRAMETYPE Light
GUIDING DITHER EVERY 15 FRAMES
CAPTURE 500 FRAMES REQUIREGUIDING True
GUIDING DITHER EVERY STOP
END PRESERVE
END LOOP
END SEQUENCE

Thank You
Craig

[Craigar]

Using Sharp cap pro 4.0.9751 64 bit

Thank you Craig

[admin]

Hi,

for (certain) QHY cameras, there is an underlying problem with the SDK that it captures different areas of the sensor in still mode compared to live mode, even when maximum resolution is selected. In fact, you might notice that for some cameras the maximum resolution is a bit different depending on whether you are in still or live mode. Unfortunately the offsets/differences in size between the two areas are not documented and the SDK doesn't report them to applications like SharpCap, so there is nothing I can do to try to mask or reduce the impact of this issue.

When you are using an affected camera and trying to use darks and/or flats, you need to ensure that all of them are captured with the camera in live mode, or all of them are captured with the camera in still mode for them to line up. Alternatively, you can make sure the 'force still mode' control on the right is switched to on - when that is enabled, the camera will be run in still mode even when SharpCap is in live mode. This is probably the best alternative as long as you don't mind that the maximum frame rate will be reduced quite a lot by having this option switched on.

Sorry that the end user has to deal with this complexity

Robin

[Craigar]

Thank you Robin, that sounds perfectly believable although not logical.. it would sure make more sense if they kept it consistent but as many people are reporting QHY seems to have kind of sketchy code and drivers, like the 2x2 bin never worked right on this camera in 16 bit color, Etc.

Also complete different subject I bought an Altair guiding camera and part of the decision to get it was the free year but then I went back home to California and never finished doing that registration but I went ahead and bought a one-year registration from you so I'm going to go out and read about this and hopefully I could use that one year that I got with all Terror mono guide camera I think it's called it gp-cam or something.. and I also want to know how toset a longer interval after a dither completes, because I have vibration or blur in the first frame after a dither. Also I can't upload an avatar image and I've made a JPEG that is smaller than 60k and smaller than 90 by 90 pixels and try to three different times and just cannot get it to upload it says it's too big.. I'll go try and look these minor issues up through your forums.

Thank you again Craig

[admin]

Hi Craig,

the resolution difference is something I have asked QHY about in the past, but there has never been any change in the SDK to help mitigate the problem, so sadly the situation will continue

You do get an included year of SharpCap Pro with your Altair camera, *but* it's worth noting that the license you get is limited - it will only work on Altair cameras and won't let you use the Pro features on other brands like your QHY. That's just the way the deal between us and Altair regarding the included licenses is laid out...

You can set a longer wait interval after dithering in the SharpCap guiding settings - set the minimum settle time to a higher value as a starting point.

I can't see anything obvious that should block an avatar upload - I did check and it looks like there are a mixture of jpg, gif and png files that have been uploaded as other user avatars. I just did a test and managed to upload a 64x64 avatar image in png format, so it should work.

cheers,

Robin