Astro imaging of Jupiter and Saturn

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  • Member since
    April, 2012
  • From: North Carolina east coast USA
Astro imaging of Jupiter and Saturn
Posted by stepping beyond on Friday, December 13, 2013 8:58 AM

I'm having all kinds of drama with my SSUEll and these particular objects, I've barlowed 2x and I can't even locate it again . They come in clear as a bell in my 20, 9 and 4mm that I use for focusing in on these targets before putting in the electronic eyepiece. I'm at a road block , I just can't figure out what I'm doing wrong. This cheaper electronic eyepiece should bring these targets to clarity, after all it's our solar system and it's a solar system cam. Maybe I'm just not doing something right, any help out there?

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Posted by chipdatajeffB on Friday, December 13, 2013 9:24 AM

It's likely a combination of exposure and mount problems.

What is your scope and mount, and how are you aiming the mount?

I have a camera that is similar to yours and I have no trouble locating the planets. I use a daylight video exposure and frame rate to locate, then I fiddle with exposure until I can see well enough to nail focus and position. Then I fine-tune exposure, which is generally a matter of finding the right frame rate for the seeing and then making very small incremental changes to focus, coupled with any change in gain or other exposure factor needed to get the best image possible.

If you don't use a focusing mask, you can focus on the satellites (focus until they are as small as possible).

If your seeing is average or worse, nailing exposure and focus are very difficult.

But if you are having trouble with aiming, everything will be very much more tedious. With an equatorial mount, a good polar alignment is a very big help. I don't usually drift-align for planetary imaging, but I do get it as close as possible with a polar scope and then make very small incremental changes while watching a low-magnification image on screen. When I use the software supplied with the camera (IC capture with the DMK and the standard Philips software with the ToUCam or NC), I put the planet in one corner of the field of view to make it easier to tell which way to move the mount. When I use K3CCD, I use the centering reticle cursors.

Start with low mag to make acquisition easier, then move up in mag in increments, checking aiming as needed. Finish with aligning using the same image scale you will use for capture.

I often find that once I insert a barlow (I use Powermates), the focuser sags a bit and I have to realign.

The universe is not only stranger than we imagine, it's stranger than we CAN imagine. --- JBS Haldane

Come visit me at Comanche Springs Astronomy Campus (we're on Google Maps) in Texas.

www.3rf.org

  • Member since
    April, 2012
  • From: North Carolina east coast USA
Posted by stepping beyond on Friday, December 13, 2013 10:32 AM

Celestron eq 80mm powerseeker w/ motor on a cg1 mount. Jeff, For the life of me, it won't come to clarity. It'll be awesome in the oculars but, I'll be darned if it won't with the Starshoot ll. Polar aligned but, no star test as you stated before. Why is it that it'll come to clarity in the 4mm and not the 5mm SSUE ll? I'm not giving up on this electronic ep , even when I get my Mallincam jr . I like this SSUE ll it's  simple and light to use with CPSeq80 except for this drama. Jeff I shot the moon earlier that night and it was great for a lil' ep cam but, this is the second night in a row that I had the object stay in the field of view and I'm getting better every time I go and play with it.I had made a major accomplishment keeping the planet in the center. I even had the motor running but, there is a drift issue that needs to be addressed.

  • Member since
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  • From: North Carolina east coast USA
Posted by stepping beyond on Friday, December 13, 2013 10:57 AM
I had videoed Venus the night before and it did a lot better than Jupiter, I have the OTA removed from the tripod , so it doesn't get jarred during transport into my cave. Jeff I use the AMCAP software and maybe I need to make some adjustments in there, what do you set yours on for planets?
  • Member since
    July, 2003
  • From: Eastern SD.
Posted by johnjohnson on Friday, December 13, 2013 1:11 PM

Sounds to me that your eyepiece and imager are not parfocal. You may have to dedicate an eyepiece to being parfocal to your imager so that when you have the object focused in the eyepiece it will also be focused for the imager. An easy place to start is the Moon. Use the eyepiece of your choice and focus on the Moon. Use a fine tip "Sharpie" and mark your focuser tube right where it comes out of the rear of the scope. Now insert your imager and adjust it untill it comes to focus. Mark the focuser tube again. The difference between the two marks indicates parfocal correction you must make. You will need to use these marks for future reference to get close to focus for each device or put a parfocal ring on one or the other.

Parfocal

Another method is to insert your imager and bring it to focus on the Moon. Without changing the focuser position insert your eyepiece but do not tighten the retaining screw. Slide the eyepiece up and down till you reach focus. If you reach focus by sliding the eyepiece out you will have to put the parfocal ring on the eyepiece. If the eyepiece requires you to move the focuser inward more than the barrel allows, you will have to put the parfocal ring on the imager. Do the reverse and start with the eyepiece and bring it to focus. Now move the imager up and down to determine where you must place the parfocal ring.

Also make sure that your auto gain control for the imager is turned off and manualy set the gain to where it is barely on.

JJ

20" F5 Obsession, OMI mirror .987 Strehl. 10" F4.7 reflector. 6" F5 ST reflector. 120mm F7.5 EON. 80mm F11.3 guide scope. SkyWatcher EQ-6 Hyper Tuned.   Flicker Astro Site   More Astro Images

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Posted by chipdatajeffB on Friday, December 13, 2013 4:56 PM

To add to what JJ said, you also have the problem that with a refractor, when you add the barlow you may not be able to get far enough "out focus" -- outward focuser travel.

The barlow acts to increase the focal length, so your focal point will be farther from the objective. You might need to add an extension tube.

Most of my planetary imaging is done at between 3,600mm and 4,800mm using a 1,200mm apo and barlows. That means I am using one and sometimes two extension tubes.

I don't have general settings that work in every case, but I do have a workflow I can describe. Also, most of my images are in Flickr albums (chipdatajeffb is also my Flickr name) and I have exposure setting info in the description or comments to each photo.

The workflow is basically:

  1. Get a decent polar alignment with the polar scope and an eyepiece in the main scope.
  2. Fine tune the alignment by watching for drift at low or moderate magnification. Tweak alignment using altitude and azimuth adjustments on the mount.
  3. Once I can keep the planet in the field of view for 15 minutes at moderate to high power, I switch to the imager and recheck the alignment onscreen.
  4. Set exposure and gain sufficient to get a bright image of the planet centered in the field of view of the imager.
  5. Decrease gain to the point where the image almost goes away, then double the exposure. This gives a somewhat dim view, but bright enough to just focus.
  6. Work on focus until precise focus is achieved. This involves altering exposure and gain, sometimes (but rarely) gamma adjustments while I work on focus. Once focus is good, I move on to fine tweaking of exposure.
  7. To focus on Saturn, I use Titan to get close (make it as small and sharp as I can), then I switch to the Cassini division. "Surface detail" on Saturn is not sufficiently contrasty to use for focusing my setup. So I tweak focus until the Cassini division is as sharp as possible. Then I shoot several short videos and run them through Registax, then retweak as necessary.
  8. To focus on Jupiter, I use the two broad equatorial belts, or sometimes the Galilean satellites to begin with. Once they are sharp and contrasty, I shoot a couple of short videos and run them through Registax to check fine focus. If seeing is excellent, I sometimes tweak the focus on smaller belt details "live" while capturing video, then I use VDub software to clip out the less-focused part of the video.

With planetary imaging, seeing is everything. If you don't have better-than-average seeing you simply will not capture fine detail. So, using the above workflow, I sometimes pack it in for a few hours if I more than the usual amount of trouble of focus. It is very frustrating to "chase the seeing" early in the workflow ...

The universe is not only stranger than we imagine, it's stranger than we CAN imagine. --- JBS Haldane

Come visit me at Comanche Springs Astronomy Campus (we're on Google Maps) in Texas.

www.3rf.org

  • Member since
    April, 2012
  • From: North Carolina east coast USA
Posted by stepping beyond on Friday, December 13, 2013 5:48 PM

JJ you just may have a point there, I'd forgotten about adjusting my gain control . It's half way and that is ok for lunar but, for Jupiter and Saturn it just may be too much. If these cotton puff clouds would leave, I will attempt again. Thank you for your imput, we'll see if that takes care of clarirty issues. Thank you SB

  • Member since
    April, 2012
  • From: North Carolina east coast USA
Posted by stepping beyond on Friday, December 13, 2013 6:15 PM

Jeff I align everytime I'm out, I do have a lil' drift issue. I've been working on that but, since it's got below freezing I've abandoned the efforts till it warms up above freezing. I tried the moons and festoon bands, I get the moons to a pinpoint but, can't bring the bands out to my satisfaction. Visually they're sharp and crisp in 6 and 5mm in my Nagler zoom , nice in my Z100 9 and 16mm . I'm going to try what you guy's given me and see where that goes, I'll keep trying till I get it. As for these particular planets the gain needs to be down to almost non existant according to JJ , Help me to better understand why?  Or is that just the way it is for AP. Thank you SB

  • Member since
    July, 2003
  • From: Eastern SD.
Posted by johnjohnson on Friday, December 13, 2013 7:47 PM

SB

The sensor in your SSUE may be different than the Logitech webcam I am using. The SSUE looks like and ordinary webcam to me though. I checked it's specs and it is using a 1/4" chip. 640 by 480 pixels. 8 bit A/D conversion. Typical of many webcams.

I have found with my webcam that setting the gain slider into the lowest 1/4 of the scale helps with the focusing. My gain settings are usualy close to almost off. Due to the image scale of planets and low surface contrast gain needs to be low to help bring out the details. Do not expect to see these details on your computer screen while live viewing. Only after taking an AVI or MOV and stacking will you begin to bring out the details.

You mention that when you are viewing through an eyepiece you can see all these details on Jupiter. You must remember that you have an auto iris operating in your eyeball. Your camera dosen't. The gain control handles this function for the camera. Exposure time also affects brightness and details. With only 8 bit depth sensors it is easy to saturate them. Keeping the gain and exposure low helps to avoid saturation and pixel overflow (blooming) into the surrounding pixels. Over saturation of the pixels due to high gain will cause poor focus. An over saturated image will seem focused sharply but this is due to the blooming over into surrounding pixels. Pixels are like a bucket surronded by other buckets. Once a bucket is full it overflows into the surronding buckets that are also filling up, a cascading effect. At the end of an exposure length all the buckets dump and begin filling again. If all the buckets are full at each dump you have no real information from them other than that they were fully on all the time. No contrast, luminace, or RGB differences between them.

Start with your gain and exposure fairly low. Leave the saturation (color in this case) brightness and contrast at their normal settings. Experiment with both to help get as much detail (not brightness or color)on your computer screen as possible with out being to bright. You will find that the image on the computer screen will be fairly dim (dissapointing) as to what you were expecting. Color may also be lacking. Post processing after stacking is the only way to bring up the brightnes and contrast along with color saturation adjustments (as long as the pixels have not been over saturated or luminance).

JJ

20" F5 Obsession, OMI mirror .987 Strehl. 10" F4.7 reflector. 6" F5 ST reflector. 120mm F7.5 EON. 80mm F11.3 guide scope. SkyWatcher EQ-6 Hyper Tuned.   Flicker Astro Site   More Astro Images

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  • Member since
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  • From: Texas
Posted by chipdatajeffB on Saturday, December 14, 2013 8:30 AM

I almost never image with the gain set above minimum. The Moon, Jupiter, Venus, Mars, and Saturn are very bright, so there is no need to increase gain.

Increasing gain adds noise to the image.

The universe is not only stranger than we imagine, it's stranger than we CAN imagine. --- JBS Haldane

Come visit me at Comanche Springs Astronomy Campus (we're on Google Maps) in Texas.

www.3rf.org

  • Member since
    April, 2012
  • From: North Carolina east coast USA
Posted by stepping beyond on Friday, December 20, 2013 6:20 PM

I thank both of you JJ and Jeff, I'm been trying to do it on my own and I don't know what I'm doing . I've found it better to ask and hope for a reply, I'm sticking with the cs astronomy site. At least you take the time to explain it so that I can understand a lil' . Thank you guy's

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