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First attempt at dithering


MikeCM

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Had a go at dithering in APT. First time I have used dithering as well as APT.Usually use canon utilities with my DSLR but often got colour blotching +++ and for some reason canon software was playing up.. Took 18 x 180 of M27 and was quite amazed how much of a difference dithering makes. The stars are not too good but I think I will have to look at my autoguiding and dithering settings. Any advise here?

All in all quite pleased but typically there is always some problem when imaging. On this occasion the battery of my camera ran out so I was unable to take darks(hence the noise) and flats.

M27.jpg

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Looks great, and the stars look good until you zoom in quite close - I'd be pretty pleased if I'd taken this image. I've only tried dithering once, and I ended up with APT fighting with PHD2, so I still need to figure out the settings. I'll be interested to see what people say :happy7:

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2 hours ago, MikeCM said:

I was unable to take darks

Hi. That's good! I find dark frames introduce more noise. So: light, bias and flat frames, yea. Dark frames, no. With the former combination and dither you should find a big improvement in noise.

** Why not just use APT dither to begin with? It's just 2 clicks. Make sure you have set the correct imaging focal length and your camera model number in APT, hit 15 for APT dither and that's it. To get it super precise with PHD2 in charge, you need to do a few simple calculations. I made some examples for my canon 700d -I think you have a similar if not the same sensor-. HTH.

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On 11/6/2016 at 13:25, MikeCM said:

Thanks John  

I just used the default settings in APT along with PHD2 although I did think the dithering was knocking off my guiding

Thanks, I'll have a look at that as I also use APT and PHD2.  

John

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Very nice image. But: what noise?? The background looks unusually even and flat. I tend to get this effect (also with the stars) when I use too much noise reduction in PixInisght. Some noise gives a more pleasing look than a completely even background. I usually apply a 50% gray mask when doing noise reduction. This reduces noise enough to make further processing easy, but not so much as to give a plastic-looking background.

Just an idea ...

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