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Jupiter April 3rd IR 742+Colour repro.

Space Cowboy

By Space Cowboy
in Imaging - Planetary

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theo

theo

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Like the set up Stuart. Should make things a lot more user friendly.

I've done the deed by the way. Placed an order for ASI120 mono cam. Looking forward to getting to grips with it and hopefully some decent seeing :-)

Pete

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neil phillips

neil phillips

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Like the set up Stuart. Should make things a lot more user friendly.

I've done the deed by the way. Placed an order for ASI120 mono cam. Looking forward to getting to grips with it and hopefully some decent seeing :-)

Pete

Your red channels will rock Pete. I assume you have a red filter ? if not worth getting as they settle the seeing a bit. Not as much as IR but then with a much less light loss. so you could under good seeing go for a nice healthy focal length shot. And still be relatively smooth.

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theo

theo

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Your red channels will rock Pete. I assume you have a red filter ? if not worth getting as they settle the seeing a bit. Not as much as IR but then with a much less light loss. so you could under good seeing go for a nice healthy focal length shot. And still be relatively smooth.

Cheers Neil. Thats something I am going to get for sure. I would like to get the full filter set and wheel, but budget may not stretch that far at the moment...will need to do the sums.

If not I may get the filter set first and just use the red for the time being and combine with DFK data. This is new territory for me so there will be plenty of experimenting.

Im sure I will have plenty of qestions along the way!!! Your experience and advice is and will be very appreciated.

Regards

Pete

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cgarry

cgarry

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Posted

I went through a phase of using IR as a luminance layer because the IR data was obviously sharper. I think you need to be careful doing this though, because while it produces more visually striking images they look unnatural (in my opinion), and I would even extend this comment to using red as a luminance layer.

There are lots of Saturn images which use red used as a luminance layer and while it results in more detail, the pole becomes unnaturally dark.

On Mars, clouds seem to dissapear when IR is used for luminance. I thought my IR-RGB Mars images looked good until I compared them to true RGB images taken at the same time which showed clouds that was missing from the IR version.

My IR filter never seems to find itself in front of the camera these days and I would say there is unfortunately no substitute for good seeing!

What I did find worked well on Saturn last opposition was using an ADC and getting a true luminace layer using an IR/UV blocking filter. I was able to use a very short exposure because the L was so bright and this seemed to get around the seeing problems. Though I have only managed to do try this on one ocassion so I don't know if it is a reliable method or I just got lucky.

Cheers,

Chris

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neil phillips

neil phillips

Posted
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I went through a phase of using IR as a luminance layer because the IR data was obviously sharper. I think you need to be careful doing this though, because while it produces more visually striking images they look unnatural (in my opinion), and I would even extend this comment to using red as a luminance layer.

There are lots of Saturn images which use red used as a luminance layer and while it results in more detail, the pole becomes unnaturally dark.

On Mars, clouds seem to dissapear when IR is used for luminance. I thought my IR-RGB Mars images looked good until I compared them to true RGB images taken at the same time which showed clouds that was missing from the IR version.

My IR filter never seems to find itself in front of the camera these days and I would say there is unfortunately no substitute for good seeing!

What I did find worked well on Saturn last opposition was using an ADC and getting a true luminace layer using an IR/UV blocking filter. I was able to use a very short exposure because the L was so bright and this seemed to get around the seeing problems. Though I have only managed to do try this on one ocassion so I don't know if it is a reliable method or I just got lucky.

Cheers,

Chris

I couldnt agree more, its one reason i never obsessed with IR in the mix. Or red as a lum, prefering to use either IR or red as seperate images fo a alternate look. My fav technique is try and produce slightly higher focal length shots with the red channel. As a aside to the RGBs. its just personal preferances. But mostly for the reasons you give Chris. I also think the standard LRGB has the most natural approach other the RGB, but even here i am sure ive read the man himself mr D has reservations about the LRGB tech. But of course as Stuart pointed out with low staturn nothing wrong in extracting more detail. And i am sure when he does this, we will see a standard colour shot for comparisons. so its a added benefit. Not a take over technique im sure he will agree. Its all good

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cgarry

cgarry

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Neil your comments about LRGB got me to thinking as to how it could be less 'natural' than RGB. I guess that the standard L channel will be dominated by the red and green end of the spectrum with the blue end not contributing as much. The different exposures/gains required for standard RGB imaging proves this point I think.

But I am not sure which approach is more 'natural'... LRGB feels more natural as you are just 'colouring in' a simple monochrome image as seen from the surface of earth. With RGB you effectively create an luminance channel, including the use of a B channel that has had much more 'gain' applied to it than the other channels. If the clouds ever clear I feel some experiments coming on.

Chris

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Alan

Alan

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This an interesting thread guys ... I'm learning a lot. Thanks Stuart I never realised that WINJPOS corrected for differing image scales which had put me off trying to combine previous IR and colour images ! I have a dbk21/618 and a SPC900/618 mono chipped + 680nm IR filter (slow frame rate but good sensitivity) so if the skies ever clear again I'll have a go with that very practical eyepiece wheel. More tools and tricks to try and beat our seeing and all for only £26!

Cheers

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Alan

Alan

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Not tried the wheel yet Alan but there may be a collimation issue judging by how far off centre my laser was when I tried it on the wheel the today. :embarassed:

Mine should arrive tomorrow Stuart but thanks for the heads up. I'll check it and let you know if my sample is OK or not.

Cheers,

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  • 3 years later...
Space Cowboy

Space Cowboy

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Wow this is rolling back the years lol 

The turret was cheap and needed tightening up to reduce the slop Lee. Unfortunately this made it very stiff to turn and my DOB OTA is easily moved with the slightest knock so it caused much gnashing of teeth and I decided to just swap the cams manually.

A higher quality turret would work great.

The slop did come in handy as I now use the turret as a tilt adapter for my PST to remove the Newton rings produced by the qhy mono cam.

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