Achromatic Mars - Nov 18th

[Robert_T]

Hi All, dragged out the 6in saxon refractor to image Mars last night. I stacked a Baader IR/UV and a WO Minus Violet filter to cut out the outer spectrum, but RGB misalignment (partially correctable in Registax) really cruels the image clarity and colour balance possible. Planetary imaging through an achromatic refractor is a bit like painting a house with a broom, sure it can be done and you get some colour... but the look leaves a little to be desired

here it is for what it's worth

[davidpretorius]

i see what you mean about the fringing.

there is good detail there in the green and blue when you split them in astra image. So your focussing etc looks pretty good. I am not very experienced with refractors, so am not sure what is causing the fringing???

Asimov may be able to help

Great image scale regardless.

Can you post the registax output without the wavelets???

[asimov (John)]

Hi Robert. Now this is very interesting to see your shot next to mine given were both using the same scope.

You have better image scale than me.

I'm STILL re-running my original AVI in registax to see if the saturation problem can be overcome. I can get excellent details popping out at the expense of natural colour/saturation. I can also get natural colour, apart from the main central planetary details which turns purple...

I think wer'e both on a completely different learning curve than the reflector boys here. IMO The 'default' settings on the toucam for a reflector is different than for a refractor. I've seen visually on the laptop screen what happens to mars if you take it to 80% saturation...no doubt you have too. I may ignore the visual next time & capture anyway, & see what happens in the final result.

Trial & error!! I'll give the fringe killer a go & see what happens. Nice shot anyway!

[Robert_T]

[QUOTE=asimov] Now this is very interesting to see your shot next to mine given were both using the same scope.

You have better image scale than me.
QUOTE]

Hi Asi - image scale is pretty hard to compare really from these posted images. I use a 3x barlow and an extension tube. I also use various amounts of resampling but generally around 1.4x. How much I crop the image in Registax before taking it out to further process also plays a part -

as a result I don't think even I've got two images with exactly the same image scale

cheers,

[asimov (John)]

Hi again Robert, yeah I used to play with resampling etc. but I gave all that up lol. I use a 2X barlow with no extension. Interesting to note though that I could push it even further if I wanted to, very interesting & thanks for that vital bit of info.

I've just re-processed my AVI (again) see what you reckon of it when I post it.