M57 Ring Nebula, 2015-08-03,01:30 CEST, Manche

[The Thing]

Hi All,

This is a bit of an experiment. I wanted to see if this camera could be used for long exposure RGB deep sky images.

I used a QHY5L-II Colour on the back of my LX90 8" UHTC at f10. This is 24x120s subs at 50% gain, offset 10, LX mode enabled, 8 bit mode. Ambient temperature last night was 23c. Lovely for me but rubbish for the camera. 8 Darks were used and were vital, the noise was bonkers. No flats or bias applied. Seeing was all over the place and there was plenty of moonlight }-[, guiding was around 3asec/pixel.

But not a bad result for a first go, better than I expected. As a result I am going to add some passive cooling, here is the mod I'm going to do, quite straighforward, very cheap and easily removable. the fan and heatsink are already on order from China.

[MarkS]

An interesting demonstration and not a bad result!

Mark

[JohnP]

good result Duncan - up-close & personal.. Like it - John

[Carole]

Great result and good idea and project.

Carole

[The Thing]

Thanks all.

FYI I had to use QHY EZPlanetary to capture (for technical reasons, see the APT Yahoo group!) and ended up with colour TIFFs to process rather than RAW FITS, hence this is able to be the Autosave.tif with no further processing. I'll try to set EZP for RAW capture if I can next time. It would also be nice if QHY wrote the driver to retrieve the CCD temperature which I am sure would have been impressive as the body was warm even when the ambient was 23c...

This is a 640x480 crop from the full 1280x960 of the chip, no binning, sharpening or anything - this is what DSS produced. It's a bit soft as I had to set DSS to use strong hot and cold pixel removal so a lot of pixels are median replacements.