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Finally another break in weather - Jupiter, Saturn and Mars - 7-10-20

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#1 dcaponeii

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Posted 11 July 2020 - 08:22 AM

Seeing only average but made a little progress.  This shot of Jupiter is the best of numerous captures.  My focus is still not sharp and easy to define in the camera.  I've not take to bracketing exposures around what I think is the right focus but may have to resort to that.  I have been successful (thanks to everyone who's been helping me) with greatly increasing the total number of frames from what I had been achieving and the improvement is beginning to show.  I thought the linear features to the east of the GRS was some digital artifact but this morning I see on other's pictures that they are real.  Still resolution challenged for a 12" scope.  Starting to play with WinJuPos but it's not giving me much in the way of improvement yet.  Jupiter is 25% of 38000 frames shot at 300 G and 3 ms exposure.  About a 333 fps capture rate.  120 s total capture

 

2020-07-10-0552_3-DC-L-JupAS_256110w.jpg

 

Still getting digital artifacts around the Cassini division.  This is a 5% of 60,000 frames shot at 375 Gain and 4 ms.  About a 256 fps capture rate. 240s total capture.  Note:  If I stack much more than the 5% serious double ring sections appear around the Cassini division.  I've not yet tried using smaller AP's in AS!3 to try and improve things.  These are using an AP=64.

 

2020-07-10-0819_5-DC-L-SatAS_5671wp.jpg

 

I'm not sure why my Mars images on average tend to be higher resolution than either my Saturn or Jupiter images.  I suspect I'm still relying too much on focusing on the limb which works better for Mars than the others.  Seeing has not been great (5 or 6/10).  This is shot at 275 Gain with 3.5 ms exposure.  About 285 fps.  This is a 1% stack of the 68000 frames.

 

2020-07-10-0828_6-DC-L-MarsAS_1627wp.jpg


Edited by dcaponeii, 11 July 2020 - 08:32 AM.

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#2 sunnyday

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Posted 11 July 2020 - 08:34 AM

very nice photos , thanks .



#3 jesco_t

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Posted 11 July 2020 - 02:21 PM

I think your images will benefit greatly from an ADC. That one will eliminate the color fringing and boost your resolution. I suppose you’re on the northern hemisphere and Jupiter/Saturn are quite low in the sky? Your Saturn is nice already as it is already smile.gif

 

Even with my puny 5“ Mak the atmospheric dispersion severely limits my resolution with Jupiter and Saturn. Mars is higher in the sky, so you that may be why you’re getting better results on it. I am at 54 degrees north, btw.

There’s also a minimum elevation below it’s not worth to image. For me it’s 10 degrees, if Jupiter is below it all I get is - erm - not satisfactory at all. But that my be different for different locations.

 

for focusing Jupiter I try to find the spot where turning the focus does not change my image on screen. If you are at focus, there’s a plateau where there is no change, like a local minimum in a graph. Live view itself shows too little details for me to properly judge focus on the disc. Maybe that helps you?



#4 dcaponeii

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Posted 11 July 2020 - 04:47 PM

I think your images will benefit greatly from an ADC. That one will eliminate the color fringing and boost your resolution. I suppose you’re on the northern hemisphere and Jupiter/Saturn are quite low in the sky? Your Saturn is nice already as it is already smile.gif

 

Even with my puny 5“ Mak the atmospheric dispersion severely limits my resolution with Jupiter and Saturn. Mars is higher in the sky, so you that may be why you’re getting better results on it. I am at 54 degrees north, btw.

There’s also a minimum elevation below it’s not worth to image. For me it’s 10 degrees, if Jupiter is below it all I get is - erm - not satisfactory at all. But that my be different for different locations.

 

for focusing Jupiter I try to find the spot where turning the focus does not change my image on screen. If you are at focus, there’s a plateau where there is no change, like a local minimum in a graph. Live view itself shows too little details for me to properly judge focus on the disc. Maybe that helps you?

I appreciate your comments.  I'm outside Dallas, TX and when on the meridian Jupiter and Saturn are abut 35 degree above the horizon.  I picked up an ADC a couple of weeks ago but have not taken a serious attempt to use it just yet.  Maybe this evening if I have time to work with it before things get busy.  However, the lack of the ADC might explain why Mars is a bit better than the other two.  Saturn is still well below the resolution I should be able to achieve with a well collimated 12" diameter scope as I'm not resolving ringlets nor the Encke division at all.  I get conflicting feedback with regard to focusing.  About half say work on camera and the other half seem to view through an eyepiece or perhaps with a flip mirror for focusing.   Getting better is most of the fun in any case so as long as the weather holds I'll be improving.



#5 Tulloch

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Posted 11 July 2020 - 07:12 PM

Well, you certainly seem to have your fps issue solved! On my 9.25" system, I've found a good balance between noise and frame rate is about 150fps for Jupiter, 100 fps for Saturn. Darryl on his 14" tends to image Jupiter at 250 fps and Saturn a little less. Your 12" will capture more light than mine, but less than Darryl's.

 

The only advice on focusing that I've seen on this forum is to focus using the camera with the image on the screen, never with an eyepiece and switch back. Personally I've found that focusing on one of Jupiter's moons usually gets me as close as I can, or getting the Cassini Division as sharp/black as possible for Saturn. Sometimes I play with the gamma function on FC to try and help focus on a cloud pattern on Jupiter, but it's usually similar to the moon method for me. I don't know how you actually focus, but I've found that attaching a piece of foam rubber pipe lagging and a hair clip to the focus knob really helps me get focus without inducing vibrations.

 

"Lucky imaging" requires just that - you need to be lucky with the frames you capture. Sometimes you can get very lucky, when the atmosphere cooperates - other times, you are just plain unlucky, and there's not much you can do about that. However, the more times you go out, and the more frames you take, the luckier you get ...

 

Andrew


Edited by Tulloch, 11 July 2020 - 07:16 PM.


#6 dcaponeii

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Posted 12 July 2020 - 07:40 AM

Well, you certainly seem to have your fps issue solved! On my 9.25" system, I've found a good balance between noise and frame rate is about 150fps for Jupiter, 100 fps for Saturn. Darryl on his 14" tends to image Jupiter at 250 fps and Saturn a little less. Your 12" will capture more light than mine, but less than Darryl's.

 

The only advice on focusing that I've seen on this forum is to focus using the camera with the image on the screen, never with an eyepiece and switch back. Personally I've found that focusing on one of Jupiter's moons usually gets me as close as I can, or getting the Cassini Division as sharp/black as possible for Saturn. Sometimes I play with the gamma function on FC to try and help focus on a cloud pattern on Jupiter, but it's usually similar to the moon method for me. I don't know how you actually focus, but I've found that attaching a piece of foam rubber pipe lagging and a hair clip to the focus knob really helps me get focus without inducing vibrations.

 

"Lucky imaging" requires just that - you need to be lucky with the frames you capture. Sometimes you can get very lucky, when the atmosphere cooperates - other times, you are just plain unlucky, and there's not much you can do about that. However, the more times you go out, and the more frames you take, the luckier you get ...

 

Andrew

I've got a JMI motorized Crayford focuser on the scope so I get focus close with the Crayford focuser on the Meade and then tweak the focus with the JMI at the computer.  I too am using the moons to focus Jupiter and the Cassini Division to focus Saturn.  Seeing has not been good lately am I'm still concerned about the possibility of astigmatism in the optical train somewhere.  When I go through focus small "wings" appear around the moons, aligned vertically in one case and horizontally when I come out the other side of focus.  It's driving me nuts but I can't seem to collimate it away.  It's the smallest I've seen after my collimation on the 10th.


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