Milky Way with Ioptron

[Fay]

19x220secs, Ioptron, cls, Canon 600D, dks and flats, Sigma @ F3.5 10mm

light pollution at bottom and a tree

[MarkS]

The Ioptron Skytracker has certainly done its work well.

The image scale is really good.  You've done a good job of removing the light pollution but it might be a bit difficult to remove the remaining greenish background.

Did you take flats?

Mark

[Fay]

Yes. It is not amazing but glad I tried the ioptron

[RobertM]

That's certainly a wide field and a tricky one to process with that greenish hue.

Robert

[Fay]

Well I was trying to tame the red and probably went too far

[RobertM]

I blame the CLS but then I tend to do that.

[Fay]

i need a lesson on star colour, yours are nice and blue

[RobertM]

I didn't use a CLS

[Fay]

so is that definitely the problem?

[MarkS]

In my experience a CLS filter will always ruin the colour balance of a Milky Way or constellation shot.

[Fay]

It is ok not to use one with the shorter exposures. But difficult with the long ones. Will try without next time

[RobertM]

The exposures on mine were 180s at ISO 1600 and f/4 so not much different and I didn't use any filter.

I also had a CLS clip filter and found I lost so much signal that I sold it.

[Fay]

so why would the milky way shot look so different to this one, which looks ok? i think this was taken with 50mm lens, normal tripod, cls and a single image.

the milky way was taken with 10-20 sigma, on Ioptron,  and does have a lot of edge problems at 10mm.
I thought colours etc were corrected during stacking

[MarkS]

so why would the milky way shot look so different to this one, which looks ok? i think this was taken with 50mm lens, normal tripod, cls and a single image.

There's no Milky Way in your Orion shot so you can colour balance it without worrying about the Milky Way looking odd.  The problem with the CLS filter is that it literally chops out half the wavelengths in the spectrum. This means it causes problems with the subtle colour variations in the "cloudy" parts of the Milky Way.

The IDAS LPS-P2 gives a better colour balance and the IDAS LPS-D1 which I now use is even better.  But for the Milky Way I would still use no filter at all.  Without a filter there will be big problems with gradients but the end result is better.  I hope to show you an example later tonight  

[The Thing]

That's very nice Fay and no 'greenish hue' visible on my laptop.