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Help with Jupiter


catburglar
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Here's one of my first attempts at Jupiter from last night. I'm reasonably pleased, but wonder if there's a bit more detail to be had. Should I be able to improve on this or do I need to try a 'real' planetary camera?

My equipment list is: Nexstar 6SE, Toucam pro II, 2x Barlow, blue filter .

I used the filter because it seemed to sharpen up the contrast a little without reducing the image brightness too much. The pixel size is 5.6 micron, so I think I need a slight increase in focal length to get the best of it- with my barlow I get F20.The image is a stack of 200 (from a series of 400) with wavelet processing in Registax.

So to the specific questions:

Any advice as to how I might improve upon this image?

Do I need an IR cut with this webcam?

Do normal visual colour filters have an IR cut off effect?

At F30 could I expect any significant improvement in resolution (assuming I can keep S/N the same level)?

Would I be better off getting a planetary camera with smaller pixels- will it show a significant resolution improvement in a 6 inch scope?

Can anybody explain how I should approach wavelet processing in Registax? I've looked at a few tutorials, but they all seem to say 'just fiddle with the sliders and see what happens!'. There must be some clues as to what the values in the 'denoise' and 'sharpen' boxes' mean- do they relate to spatial frequencies, pixel sizes or something else? Why are there 6 controls when I only have a single layer in my image? I can see some of the effects, but I'd like to understand a bit more of what's going on under the hood!

Regards

john

post-5479-0-11777900-1394617623_thumb.jp

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I'm thinking that's pretty good John, some nice detail and colour on the disk and Io, Callisto and Europa.    You could perhaps try a little upscale, levels and perhaps a little unsharp mask - though it's easy to push the data too far!

UV-IR cut are usually recommended for colour webcams/planetary cams - though most have some filtering in place, decent astro filters probably have better transmission and more sharply defined cut offs.

Decent transparancy and seeing are the primary factors, sufficient cool down and good collimation probably next.     These cameras can and still do produce excellent results, though higher frame rates and sensitivity of the 618's and ASI120MC/QHY5L-IIC certainly offer advantages - particularly with dimmer targets and less than ideal seeing.

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Jake

Thanks- I was quite chuffed, the conditions were pretty good, it was the first time I'd been able to detect the GRS visually (it's a lot more difficult than any photos would have you believe).

But...if you look at the images Michael Wilkinson has produced with his 8 inch SCT and an ASI 120MC, there's no comparison. Is it down to his natural talent, his 2 inches of extra aperture, 500mm of focal length or his camera?

I guess what I'm asking, is before Mars comes to opposition should I change my scope, my camera or just practice more??

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Practice helps enormously.  Your focus looks fairly good so I reckon the seeing might have let you down a bit.  I reckon you could easily go to a Revelation 2.5x barlow and possibly even a 40-50mm extension as well to get a larger image.  I would use an IR filter, but not colour filters. f/30 to f/35 is about as high as I think you'd want to go with the Toucam.  Up to there I think you should get better detail, but it's a bit of a balancing act and if the seeing won't play ball then it's never going to work.

I'd stack a lot more frames, too.  Based on what I was doing with the SPC900 (pretty much the same camera?)  I'd say you could easily go for two or three minutes worth of data at 10fps and stack perhaps half of them depending on the quality.  When it comes to Mars you can probably go for five minutes.

I honestly don't know how good the Toucam is compared with the SPC900.  I believe they're supposed to be very similar.  These are some images I captured with a 127 Mak (so smaller than your C6) and SPC900.  From memory in SharpCap I'd set the exposure to maximum, the frame rate to 10fps and then adjust the gain to give a 65%-ish histogram, but I don't know if the same would apply to the Toucam.

europa.png

mars-2012-03-17.png

Given that Mars opposition isn't that far away, I reckon you'd be better off getting in as much practice with capturing data and processing using what you have than changing kit now and having to get everything working nicely and get comfortable with using it before then.

James

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Great first attempt at imaging Jupiter John.  Much better than my first goes.

I like you, use the exact same scope (Nexstar6SE) and SPC900 webcam which is more or less the same as your Toucam.  I previously asked how far I could push my focal length with this scope too, but sadly no one replied then, but James mentioned F30-F35.  He is the expert with these webcams so aim for that.

I have only been able to image Jupiter myself at F20 using a Celestron 2x barlow (purely because that is all I have at present to use) and using a Baader Neodymium and IR Cut Filter as I was told it was important to extract as much detail as possible due to removing the filter that was on the webcam originally before the modification. 

Seeing is a very big factor on how good the image will be as both Jake and James have already mentioned so never give up after your first goes.  Each night is different.  I have only captured 100secs AVI's but I have been advised I can increase this to 180secs.

Here is an example of what I was able to achieve so far using the same equipment as you so you can compare.

Jupiter27thGRSAfterPhotoShopJpeg27_02_20

I used my Celestron Nexstar 6SE, SPC900 webcam with a 2x barlow.

Used Bahtinov Mask for focusing

Recorded 100 seconds of AVI @10FPS

Stacked using AS!2 Used 55% of Frames

Registax for Wavelets

Used Photoshop to adjust brightness, contrast. (Still no idea what else I should do in there)

I have found that keeping gain between 50-60 % is a must.  Using more or less will cause onion rings on the image after processing.  I cannot help you in exactly what each wavelet does, I just adjust them all until Jupiter looks the way I like it.  The more you do the more you will learn. 

I am not an expert like many other members here, but hope this information has been of some use to you. 

Michael

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Jake

Thanks- I was quite chuffed, the conditions were pretty good, it was the first time I'd been able to detect the GRS visually (it's a lot more difficult than any photos would have you believe).

But...if you look at the images Michael Wilkinson has produced with his 8 inch SCT and an ASI 120MC, there's no comparison. Is it down to his natural talent, his 2 inches of extra aperture, 500mm of focal length or his camera?

I guess what I'm asking, is before Mars comes to opposition should I change my scope, my camera or just practice more??

Don't be put off, your's is certainly better than my own first attempts and of many others here.   There's always more money that can be spent on kit, but without practice and developing an understanding/feeling you could end up spending lots of money and still fall a long way short of getting the best out of the investment.   My answer is probably to get out and practice capturing and processing (at least as important).

JamesF's post provides some first class examples of what you can expect to achieve with the 5" mak and SPC900 (although Mars may have had a more favourable opposition and elevation for these shots!), but with the benefit of aperture these are realistic expectations of what can be achieved.      If you don't already have a good barlow, the Revelation x2.5 also gets my thumbs up and is excellent value.

That said I think Mars is going to be a very difficult target for any of us this year and a more sensitive and faster (higher frame rate) camera might be worth considering.    Though you could also spend £300-500 pounds and find that the weather and seeing at opposition were terrible and it didn't much of an outing!

Having a big scope and nice camera is always going to be tempting (and I am frequently tempted!) - in theory I could image like Damien Peach with a C14 and ASI120MM (or Flea 3), but the reality is likely to be a long way short and bring scopes bring there own issues (beside cost); weight/mounting requirements, portability, long cool downs, dew control....  Perhaps one day I will :p

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Wowzer- it's obvious from the images of James and Michael E that there's more to come from my scope and camera combo.

I'll look to get a 2.5 or 3x barlow to increase the scale a bit and try an IR cut filter- if nothing else it'll keep the chip clean!

For my exposures, I kept the gain around 50%, but set the exposure quite low to try and avoid saturating the images. The individual frames seemed very noisy, so perhaps I need to tweak the exposure up a bit.

For now, I'll keep my credit card in it's holster and sharpen up my game.

Thanks to you all.

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Wowzer- it's obvious from the images of James and Michael E that there's more to come from my scope and camera combo.

I'll look to get a 2.5 or 3x barlow to increase the scale a bit and try an IR cut filter- if nothing else it'll keep the chip clean!

For my exposures, I kept the gain around 50%, but set the exposure quite low to try and avoid saturating the images. The individual frames seemed very noisy, so perhaps I need to tweak the exposure up a bit.

For now, I'll keep my credit card in it's holster and sharpen up my game.

Thanks to you all.

Good luck John.

Regarding the exposure, through our scope the image can be very dim so yes up the exposure a bit. When you start imaging Saturn and Mars, you will find you will need to use full exposure and possibly more gain than would be ideal but you should still get a nice image.

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Great first attempt John - I'm in a similar 'boat' - as I use the same Toucam II (aka PCVC840K) webcam, flashed to the SPC900 firmware, but with a smaller Nexstar 4SE scope.  I also use a Baader UV/IR-cut filter on the webcam.

I took the following a couple of nights ago ... took 2x AVIs of 3000 frames each @ 20fps (no idea why 20 rather than 10), and joined them using PIPP with quality sorting enabled, took the best 4000 frames and stacked in AS!2, then used Registax to RGB-align and some small amount of post curve processing in Photoshop.   This was with a Celestron 2x Barlow, giving approx F/26....

Saturn2-2014-03-09.jpg

Sharpcap settings as follows....

[Philips SPC 900NC PC Camera]
Frame Divisor=1
Resolution=640x480
Frame Rate (fps)=20.00
Colour Space / Compression=YUY2
Exposure=-4
Brightness=64
Contrast=54
Saturation=40
Gamma=1
ColorEnable=255
BacklightCompensation=0
Gain=43

I would be interested to see other people's Sharpcap settings for comparrison to see whether there is a common / standard set of values that give the best results.

Cheers,

Mike

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Assuming the Toucam is USB1 just like the SPC900 then at 640x480 the frames have to be compressed quite a bit to fit into the bandwidth available.  That compression is lossy, so you're effectively throwing away data.

There is some compression at 10fps though it's nowhere near as much as far as I recall.  At 5fps I don't think there's any, but 5fps isn't too great if you want lots of data to work with.

As regards settings, I used to turn gamma to 0 and leave brightness, saturation and contrast at their default values for the SPC900.  I don't know if the Toucam values are the same though.

James

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Mike

My sharpcap settings are similar,.

[Philips Toucam Pro Camera; Video]

Frame Divisor=1

Resolution=640x480

Frame Rate (fps)=10.00

Colour Space / Compression=IYUV

Exposure=-6

Brightness=66

Contrast=26

Saturation=0

Gamma=13

ColourEnable=255

BacklightCompensation=0

I was advised to keep below 10fps because the camera doesn't run to USB2 speeds and I don't get an option for YUY2 colourspace.

The gain setting isn't shown in SharpCap, but I control it in the driver and set it to about 50%

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