Colour gradients during DBE

[RickS]

Hi Peter,

I'm in Brisbane but live close to the city so I don't do a lot of acquisition from home these days and mostly use remote scopes.  The M83 data is coming from Martin Pugh's observatory at Yass, near Canberra.

I mostly use HT manually.  I use MaskedStretch occasionally, usually as a blend with a HT stretched version.

The sample size I used was the default that DBE picked.  I do bump it up sometimes if it looks too small.

Cheers,
Rick.

[peterbrack]

Oh okay Rick, good you get to use the remote scope. We have a farm out of Perth where I recently built an observatory, so not too much light pollution.

I tried manually using HT last night just by bring in the right marker to the left. But the image didn't seem to have contrast- maybe I am meant to bring the left marker to the right. Was working on a different image and found the auto stretch had much more contrast than me trying to manually use the HT for the stretch. Liike it was a little whited out, if  that makes sense, without darkness

Peter

[RickS]

Hi Peter,

When I retire I'd like to spend more time acquiring data and perhaps set up a permanent obsy under dark skies but in the meantime I'll be mostly be doing remote.  The Queensland Astrofest is coming up soon so hopefully I will get a bit of a dark sky fix then    Having a farm under dark skies would be wonderful!

With HT you stretch by dragging the midtone slider (the middle one) to the left.  The left hand slider is dragged to the right to set the black point. I usually do a few applications of HT in an iterative process.  Make sure you have the real time preview on so you can see what is happening and also click on the track view button (tick at bottom right) so you can see the graphs.

Another option is to use STF but reduce the amount of stretch.  To adjust this, Ctrl-left click on the STF "radioactive" button to get the STF Auto Stretch dialog and reduce the value of the target background.  If you do this and then auto stretch again you'll get a milder screen stretch.

Cheers,
Rick.