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Getting Back Into Planetary Imaging, Need Help Dusting Off the Cobwebs

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#1 Rustler46

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Posted 31 July 2019 - 03:41 AM

Tonight I was able to gather a half dozen videos each for Jupiter and Saturn. While everything worked, there are some issues that I need to deal with. First here's my equipment

  • Celestron-11, between f/10 and f/20 using 2X Barlow
  • Losmandy G-11 mount with Gemini-1 electronics
  • ZWO ASI 290MC
  • ZWO ADC
  • Firecapture 2.6 
  • MacBook Pro 16GB, 500GB SSD, USB 3.0

The 2X Barlow lens set was attached to the camera nosepiece. This was inserted into the ADC and straight into the C-11 rear port (no diagonal). It has been a few years since trying any L/P imaging. So I'm a bit rusty. Using a ROI the frame rate was ~170 fps for Jupiter and ~75 fps for Saturn. USB 3.0 is the way to go! Here are some of the capture settings:

  • RGB and AVI format 
  • Debayer was  not enabled
  • Gain ~350 for Jupiter, ~375 for Saturn
  • Exposure for brightest color at around 70% on the histogram.
  • Gamma off for capture
  • Jupiter videos were either 60 seconds or 120 seconds. Saturn was 120 seconds.

I used the G-11 mount's search function to acquire the planet if go-to didn't put it on the sensor. Focusing was a challenge, especially after the seeing deteriorated. Focus was established on the planet itself. I found Jupiter easier than Saturn, since it had more details. Saturn just had the Cassini division. But the biggest issue was a dirty sensor - lots of dust spots. I had to move the planet to a location on the full sensor that didn't have any dust spots. Then I manually guided the planet to keep it within the ROI. I made a half-hearted attempt to adjust the ADC. While I'm sure there was still some dispersion, the situation was at least improved.

 

So first off I'll need to clean off the dust spots. I have a Pocket Rocket for the loose stuff.

 

Any suggestions for cleaning?? Can I use a lens brush if necessary? What about lens cleaning fluids? Once cleaned, keeping the Barlow lens set attached should keep it clean.

 

I'll be running the videos through AutoStakkert 2 or 3. Is there a Mac OS version? That would be easiest. If not I have an old XP Windows machine with Registax and AutoStakkert 2.

 

I'll likely re-install a JMI EV-1 motorized Crayford focuser, which will make focusing easier. It has numeric index marks that should help determining best focus. It will be something like - Is setting 34 or 35 a better focus? How about 36? The ability to have repeatable focus settings is a big improvement over the stock moving mirror focus with the image shift and all. I'll be able to calculate the f/ratio once I determine number of pixels under each planet. It would be nice if it was around f/15, with my camera's pixel width of 2.9μ.

 

Any comments or suggestions about FireCapture settings and video capture technique would be appreciated.

 

Best Regards,

Russ

 

 



#2 Kokatha man

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Posted 31 July 2019 - 04:23 AM

Dirty sensors are the bane of ZWO Russ, but once cleaned & kept sealed as part of a specific imaging train they should provide endless no-fuss useage! (caps on the end of the complete imaging train when not in the scope, but any slight dust at that end is virtually harmless as it is out of focus as far as the camera is concerned.

 

I use a Pec Pad where I've cut a single pad into strips about 1/4"+ or so wide (wash hands first & also clean, sharp scissors) hold one side & after cutting up half the single Pec Pad into multiple strips without handling these I discard the rest of the pad...a bit obsessive but placing these strips in a ziplock bag gives me way too many! wink.gif )

 

I cut a strip from a soft plastic ice-cream lid a bit narrower than the pad strips I've cut, no more than about 3" long.

 

This plastic, cut this way, has some "spring" in it & if you double one of those cut Pec Pad strips over one end & add a couple of drops of any good cleaning solution (Eclipse, Visible Dust etc) onto that doubled-over end you drag it with a bit of pressure across the actual glass screen on top of the camera sensor one way, flip the stick over & do the same with the other "edge" of this cleaning "wand" you've made.

 

You can then move the doubled-over pad on the plastic "wand" a bit to expose a new bit at the tip/bottom edge, another drop maybe of cleaning solution & do another double wipe...you can buy cleaning "swabs" or "wands" ready-made that only need cleaning solution (eg, Visible Dust etc) but they are horribly expensive & not worth it compared to the cheap ones I've described here.

 

Understand that you can also clean the "AR" window this way, which is a glass covering the sensor & sensor glass.....but that usually isn't an issue - it is that hard glass layer on top of the actual electronic sensor I am talking about cleaning - this is where in-focus dust bunnies etc lay!

 

This is tough glass btw - you won't damage it! wink.gif

 

Test the camera under a light or outdoors by plugging it in & turning the gain/exposure down so that you are not drowning out those dust spots when you view the sensor carefully on the screen of your laptop - you'll know when you're ok!


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#3 happylimpet

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Posted 31 July 2019 - 05:08 AM

Baader optical wonder fluid and a microfibre cloth for me, works every time, though as Darryl says I keep mine safely dust free in a permanent planetary imaging train of adapter-ADC-barlow-flip mirror-filter wheel-camera.


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#4 Rustler46

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Posted 31 July 2019 - 05:32 AM

Dirty sensors are the bane of ZWO Russ, but once cleaned & kept sealed as part of a specific imaging train they should provide endless no-fuss useage! (caps on the end of the complete imaging train when not in the scope, but any slight dust at that end is virtually harmless as it is out of focus as far as the camera is concerned.

 

I use a Pec Pad where I've cut a single pad into strips about 1/4"+ or so wide (wash hands first & also clean, sharp scissors) hold one side & after cutting up half the single Pec Pad into multiple strips without handling these I discard the rest of the pad...a bit obsessive but placing these strips in a ziplock bag gives me way too many! wink.gif )

 

I cut a strip from a soft plastic ice-cream lid a bit narrower than the pad strips I've cut, no more than about 3" long.

 

This plastic, cut this way, has some "spring" in it & if you double one of those cut Pec Pad strips over one end & add a couple of drops of any good cleaning solution (Eclipse, Visible Dust etc) onto that doubled-over end you drag it with a bit of pressure across the actual glass screen on top of the camera sensor one way, flip the stick over & do the same with the other "edge" of this cleaning "wand" you've made.

 

You can then move the doubled-over pad on the plastic "wand" a bit to expose a new bit at the tip/bottom edge, another drop maybe of cleaning solution & do another double wipe...you can buy cleaning "swabs" or "wands" ready-made that only need cleaning solution (eg, Visible Dust etc) but they are horribly expensive & not worth it compared to the cheap ones I've described here.

 

Understand that you can also clean the "AR" window this way, which is a glass covering the sensor & sensor glass.....but that usually isn't an issue - it is that hard glass layer on top of the actual electronic sensor I am talking about cleaning - this is where in-focus dust bunnies etc lay!

 

This is tough glass btw - you won't damage it! wink.gif

 

Test the camera under a light or outdoors by plugging it in & turning the gain/exposure down so that you are not drowning out those dust spots when you view the sensor carefully on the screen of your laptop - you'll know when you're ok!

Thanks so much for the cleaning tips! I'll re-read and put to use in getting my sensor clean. I assume this method is for this particles that are stuck, won't blow or brush off.



#5 Rustler46

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Posted 31 July 2019 - 06:39 PM

I'll be running the videos through AutoStakkert 2 or 3. Is there a Mac OS version? That would be easiest. If not I have an old XP Windows machine with Registax and AutoStakkert 2.

 

I'll likely re-install a JMI EV-1 motorized Crayford focuser, which will make focusing easier. It has numeric index marks that should help determining best focus. It will be something like - Is setting 34 or 35 a better focus? How about 36? The ability to have repeatable focus settings is a big improvement over the stock moving mirror focus with the image shift and all. I'll be able to calculate the f/ratio once I determine number of pixels under each planet. It would be nice if it was around f/15, with my camera's pixel width of 2.9μ.

 

Any comments or suggestions about FireCapture settings and video capture technique would be appreciated.

There isn't any Mac OS version of AutoStakkert!-2 or -3. Neither is any such version being planned. The suggested way to run AS!-3 on a Mac is to run it under a "wineskin". This ports a Windows program to function under Mac OS:

 

Installing WineHQ Packages

 

So that's my task for this evening, to get AutoStakkert!-3 running on my Mac. I just don't want to hassle with moving multiple large files on a flash drive. For Registax on a PC, it's just a single JPG or Tiff file to be moved. I suppose it too could be made to run on my Mac. The problem with the wineskin route is often when the Mac OS upgrades, the wineskin must be re-established.


Edited by Rustler46, 31 July 2019 - 06:40 PM.


#6 Kokatha man

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Posted 31 July 2019 - 07:41 PM

...I omitted to say that I do this sensor cleaning in our bathroom Russ - probably the cleanest, most dust-free room we have! wink.gif

 

Yes, it's for "stuck-on" crud - unfortunately it's the type that usually gives you most trouble, but once given a decent clean & the camera ensconced in the imaging train of barlow etc it should stay very clean. wink.gif

 

That strip of Pec Pad you make by cutting a whole pad into thin strips is wrapped around the plastic ice-cream "wand" you've made...held between a thumb & forefinger & after you've made a wipe on each edge you simply "slide" the strip along a tad to expose a new bit at the end - hope I made that clear! lol.gif

 

Or you could fold an entire pad over carefully I guess & use that, refolding the bit with the cleaning solution applied & re-using...the plastic "wand" emulates the expensive pro ones you can purchase which is why I went that route & it allows you to put some controlled pressure on the wipe. wink.gif



#7 Rustler46

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Posted 01 August 2019 - 07:41 PM

Tonight I was able to gather a half dozen videos each for Jupiter and Saturn. While everything worked, there are some issues that I need to deal with. First here's my equipment

  • Celestron-11, between f/10 and f/20 using 2X Barlow
  • Losmandy G-11 mount with Gemini-1 electronics
  • ZWO ASI 290MC
  • ZWO ADC
  • Firecapture 2.6 
  • MacBook Pro 16GB, 500GB SSD, USB 3.0

The 2X Barlow lens set was attached to the camera nosepiece. This was inserted into the ADC and straight into the C-11 rear port (no diagonal). It has been a few years since trying any L/P imaging. So I'm a bit rusty. Using a ROI the frame rate was ~170 fps for Jupiter and ~75 fps for Saturn. USB 3.0 is the way to go! Here are some of the capture settings:

  • RGB and AVI format 
  • Debayer was  not enabled
  • Gain ~350 for Jupiter, ~375 for Saturn
  • Exposure for brightest color at around 70% on the histogram.
  • Gamma off for capture
  • Jupiter videos were either 60 seconds or 120 seconds. Saturn was 120 seconds.

I used the G-11 mount's search function to acquire the planet if go-to didn't put it on the sensor. Focusing was a challenge, especially after the seeing deteriorated. Focus was established on the planet itself. I found Jupiter easier than Saturn, since it had more details. Saturn just had the Cassini division. But the biggest issue was a dirty sensor - lots of dust spots. I had to move the planet to a location on the full sensor that didn't have any dust spots. Then I manually guided the planet to keep it within the ROI. I made a half-hearted attempt to adjust the ADC. While I'm sure there was still some dispersion, the situation was at least improved.

 

So first off I'll need to clean off the dust spots. I have a Pocket Rocket for the loose stuff.

 

Any suggestions for cleaning?? Can I use a lens brush if necessary? What about lens cleaning fluids? Once cleaned, keeping the Barlow lens set attached should keep it clean.

 

I'll be running the videos through AutoStakkert 2 or 3. Is there a Mac OS version? That would be easiest. If not I have an old XP Windows machine with Registax and AutoStakkert 2.

 

I'll likely re-install a JMI EV-1 motorized Crayford focuser, which will make focusing easier. It has numeric index marks that should help determining best focus. It will be something like - Is setting 34 or 35 a better focus? How about 36? The ability to have repeatable focus settings is a big improvement over the stock moving mirror focus with the image shift and all. I'll be able to calculate the f/ratio once I determine number of pixels under each planet. It would be nice if it was around f/15, with my camera's pixel width of 2.9μ.

 

Any comments or suggestions about FireCapture settings and video capture technique would be appreciated.

Well, my results are sort of garbage compared to what I've seen others produce with similar equipment. In my defense I'm quite rusty in lunar/planetary imaging. Also seeing was poor. Nonetheless here's one of my Jupiter images:

 

Screen Shot 2019-08-01 at 5.28.21 PM.png

 

I'm not happy with the bright rim on the right. But despite the rather blurry image, it was nice to see the color and the number of belts captured. I did reduce the color saturation quite a bit. This is 1160 of 9660 frames (12% of a 60-second video) using AutoStakkert!-3 and Registax-6.

 

Comments and suggestions would be appreciated.

 

Some Pec Pads and Eclipse cleaning fluid are on order to clean the camera's very dusty sensor. Thanks Darryl!

 

Russ


Edited by Rustler46, 02 August 2019 - 01:23 AM.

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#8 Rustler46

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Posted 02 August 2019 - 02:37 AM

This evening I did a quick measure of the number of 2.9μ pixels covered by Saturn's 18.2 arc-second disc. This amounted to 135 pixels. If my calculations are correct, this means the focal length was 4437 mm. Given the native focal length of the C-11 is 2800 mm, this gives the Barlow amplification = 1.58X. This seems about right with the 2X Barlow lens set installed on the camera nosepiece. 

 

I've done another measure on Jupiter. It's 42.5 arc-second equatorial extent occupies 340 of the 2.9μ pixels. This gives the Barlow amplification = 1.71X. The focal length is 4790 mm. At that focal length the image scale is 0.12 arc-sec/pixel.

 

I suspect the Jupiter measure is more accurate than the one for Saturn. The former was measured by cropping the Jupiter image in Lightroom to just encompass the equatorial diameter of its disc. The Saturn image was just measured with a ruler on an old computer monitor.

 

For Saturn it wouldn't hurt to have a bit more focal length to get more pixels under its image. For that I can move the Barlow lens set to the other side of the ADC.

 

Russ


Edited by Rustler46, 02 August 2019 - 02:47 AM.

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#9 Rustler46

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Posted 02 August 2019 - 04:01 PM

This evening I did a quick measure of the number of 2.9μ pixels covered by Saturn's 18.2 arc-second disc. This amounted to 135 pixels. If my calculations are correct, this means the focal length was 4437 mm. Given the native focal length of the C-11 is 2800 mm, this gives the Barlow amplification = 1.58X. This seems about right with the 2X Barlow lens set installed on the camera nosepiece. 

 

I've done another measure on Jupiter. It's 42.5 arc-second equatorial extent occupies 340 of the 2.9μ pixels. This gives the Barlow amplification = 1.71X. The focal length is 4790 mm. At that focal length the image scale is 0.12 arc-sec/pixel.

 

I suspect the Jupiter measure is more accurate than the one for Saturn. The former was measured by cropping the Jupiter image in Lightroom to just encompass the equatorial diameter of its disc. The Saturn image was just measured with a ruler on an old computer monitor.

 

For Saturn it wouldn't hurt to have a bit more focal length to get more pixels under its image. For that I can move the Barlow lens set to the other side of the ADC.

Here is the simple math behind figuring the focal length of a Celestron-11 telescope based on the size of the image on a sensor. There are on-line calculators that do the math. But it’s informative to see what’s behind the calculator.

 

According to SkySafari, Jupiter's equatorial diameter on July 30th 2019 was 42.5 arc-seconds.

 

Using Lightroom-5 on the image, the 448 X 448 pixel region of interest was cropped to 340 X 340 pixels to measure the equatorial diameter in pixels.

 

Screen Shot 2019-08-02 at 12.16.29 PM.jpg

Screen Shot 2019-08-02 at 12.17.09 PM.png

 

The ZWO ASI290MC camera has 2.9μ pixels or 2.9 X 10-6 meters.

So Jupiter’s linear extent on the sensor was 

  • JL= 340 pixels X 2.9 X 10-6 meters/pixel = 340 X 2.9 X 0.000001 meters
    JL= 0.000986 meters

To convert Jupiter’s angular extent to degrees:

  • JA= 42.5 arc-seconds ÷ (60 arc-secs/arc-minute) ÷ (60 arc-minutes/degree)
    JA= 42.5 ÷ 3600 degrees
    JA= 0.0118°

 

To determine focal length we need to convert Jto radians:

  • JA= 0.0118° ÷ 57.3 ° per radian
    JA= 0.000206 radians

    Note: 57.3 is the conversion factor from radians to degrees. Since there are 2π radians per complete circle of 360°, then 360° ÷ 2π = 57.3°. The radian itself is dimensionless (at least as far as having a unit of dimension), since it is the ratio of arc length to radius length.

 

Now bringing in the focal length, F as it relates to linear and angular dimensions of Jupiter’s image: 

  • J÷ F = JA in radians

    or

    F = JL ÷ JA
    F = .000986 meters ÷ 0.000206
    F = 4.79 meters

 

That is focal length = 4790 mm. With the aperture being 279 mm this gives 4790 ÷ 279 = f/17.2.

 

Since the native focal of the Celestron-11 is 2800 mm, the amplification of the Barlow lens placed on the camera’s nosepiece is 4790 ÷ 2800 = 1.71.

 

For your enjoyment on a cloudy night. Let me know if there are any errors in logic or math.

 

Best Regards,

Russ


Edited by Rustler46, 02 August 2019 - 11:12 PM.

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#10 troyt

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Posted 02 August 2019 - 11:26 PM

I use this way to calculate focal length: 

 

F = 206.265 x P x U

    ---------------
           O

P is the size of the object in pixels as captured
U is the pixel size of the camera in microns
O is the true size of the object in arc-seconds
F will be the focal length as calculated from this formula, in mm.

 

Here is the link to explain this further. 

It's really simple this way and I like the fact I'm using the planet size as captured in the image. What you are actually capturing is then being feed into the calculation I really like this feedback. 

 

No offence -  but when I looked at the way you are calculating this I had to take some headache tablets bangbang.gif


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#11 Rustler46

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Posted 03 August 2019 - 01:03 AM

I use this way to calculate focal length: 

 

F = 206.265 x P x U

    ---------------
           O

P is the size of the object in pixels as captured
U is the pixel size of the camera in microns
O is the true size of the object in arc-seconds
F will be the focal length as calculated from this formula, in mm.

 

Here is the link to explain this further. 

It's really simple this way and I like the fact I'm using the planet size as captured in the image. What you are actually capturing is then being feed into the calculation I really like this feedback. 

 

No offence -  but when I looked at the way you are calculating this I had to take some headache tablets bangbang.gif

Yeah, formulas like that are quite useful if one doesn't want to suffer the evil of the math involved. As mentioned some on line references just allow for input of the variables to produce the result. No need to even have a calculator.

 

I usually just resort to the math on a cloudy night, since often I can't remember the formula or where the on line calculator was located. In reality the formula is based on the calculations I presented. It gives essentially the same answer. Such a formula is in a convenient form for those not wanting to punish themselves. 

 

I do that from time to time to keep my math skills from evaporating over time.

Certainly no offense was taken.

 

Best Regards,
Russ



#12 Tulloch

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Posted 03 August 2019 - 02:51 AM

Yeah, formulas like that are quite useful if one doesn't want to suffer the evil of the math involved. As mentioned some on line references just allow for input of the variables to produce the result. No need to even have a calculator.

 

I usually just resort to the math on a cloudy night, since often I can't remember the formula or where the on line calculator was located. In reality the formula is based on the calculations I presented. It gives essentially the same answer. Such a formula is in a convenient form for those not wanting to punish themselves. 

 

I do that from time to time to keep my math skills from evaporating over time.

Certainly no offense was taken.

 

Best Regards,
Russ

FYI, online formula (along with a bunch of other useful calculators) are here

 

http://www.wilmslowa...#ARCSEC_PIXEL_d

 

I know sometimes it's nice to go back to first principles, but online calculators are so easy (assuming you remember where they are scratchhead2.gif ).

 

Andrew


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#13 Rustler46

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Posted 03 August 2019 - 03:13 AM

FYI, online formula (along with a bunch of other useful calculators) are here

 

http://www.wilmslowa...#ARCSEC_PIXEL_d

 

I know sometimes it's nice to go back to first principles, but online calculators are so easy (assuming you remember where they are scratchhead2.gif ).

 

Andrew

Thanks Andrew. That certainly is an extensive set of useful calculators. I'll bookmark that page and hope I can find it in the future.

 

Russ


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#14 RedLionNJ

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Posted 03 August 2019 - 01:30 PM

Well, my results are sort of garbage compared to what I've seen others produce with similar equipment. In my defense I'm quite rusty in lunar/planetary imaging. Also seeing was poor. Nonetheless here's one of my Jupiter images:

 

attachicon.gif Screen Shot 2019-08-01 at 5.28.21 PM.png

 

I'm not happy with the bright rim on the right. But despite the rather blurry image, it was nice to see the color and the number of belts captured. I did reduce the color saturation quite a bit. This is 1160 of 9660 frames (12% of a 60-second video) using AutoStakkert!-3 and Registax-6.

 

Comments and suggestions would be appreciated.

 

Some Pec Pads and Eclipse cleaning fluid are on order to clean the camera's very dusty sensor. Thanks Darryl!

 

Russ

Hi Russ,

 

Seven seconds' of stacked video is likely never going to cut it unless you have first-class seeing.  When the seeing is like you had it, there's really not much you can do about it, either. You either need to cherry-pick the best few THOUSAND frames (so figure on capturing maybe eight times as many as that), or have substantially better seeing and only capture maybe eight or ten thousand to start with, but of better quality.

 

As you ease back into this, you'll likely back off a bit on the registax wavelets, too - the current result is a typically-aggressive attempt to pull detail out of largely mush. We've all (or most of us) been there at some point. Softer is nicer.

 

The need to reduce saturation is also the result of too-aggressive wavelets. With the ASI290MC,  I find i need to increase saturation a little, maybe 2 points in Registax.

 

As far as image scale (or effective focal ratio) goes - measure an image in Winjupos - that will give you the arcsec/pixel, which you can plug into one of those WImslow formulae Andrew referred to.

 

You also have the misfortune of being even further north than most Americans - good seeing is very rare when the planets are so far south. But it's good to get in shape for Mars 2020.

 

Grant


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#15 Rustler46

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Posted 04 August 2019 - 11:29 PM

Hi Russ,

 

Seven seconds' of stacked video is likely never going to cut it unless you have first-class seeing.  When the seeing is like you had it, there's really not much you can do about it, either. You either need to cherry-pick the best few THOUSAND frames (so figure on capturing maybe eight times as many as that), or have substantially better seeing and only capture maybe eight or ten thousand to start with, but of better quality.

 

As you ease back into this, you'll likely back off a bit on the registax wavelets, too - the current result is a typically-aggressive attempt to pull detail out of largely mush. We've all (or most of us) been there at some point. Softer is nicer.

 

The need to reduce saturation is also the result of too-aggressive wavelets. With the ASI290MC,  I find i need to increase saturation a little, maybe 2 points in Registax.

 

As far as image scale (or effective focal ratio) goes - measure an image in Winjupos - that will give you the arcsec/pixel, which you can plug into one of those WImslow formulae Andrew referred to.

 

You also have the misfortune of being even further north than most Americans - good seeing is very rare when the planets are so far south. But it's good to get in shape for Mars 2020.

 

Grant

Thanks for the encouraging comments, Grant. Yeah mushy seeing like I had won't produce good results. While cloudy weather prevails here I might try stacking a far smaller number of frames that are of better quality. Likely that will be much more noisy. But these are the only videos I have to work with a present. I'll slack off on the wavelets - "softer is nicer" for sure. Here's one attempt with 250 of 10,275 frames stacked in AS!-2.

 

Screen Shot 2019-08-05 at 12.57.35 AM.png

 

This last imaging run was intended to gather all the parts and begin reacquiring the skills to capture a video. I've received the Pec pads and Eclipse fluid. So cleaning of the sensor is next. Jupiter is quickly getting past its prime season. Being less than 30° altitude really makes it hard. Next time out I want to do a better job in adjusting the ADC. The Moon being a bit higher in the sky will be less demanding.

 

Yes, Mars in 2020 - much to look forward to. At over 50° elevation and 22 arc-seconds, that will be a worthy target. But then I hope to be more skilled in planetary imaging.

 

Question:

How much am I giving up in resolution with a one shot color camera? I really don't want to use filters and mono. I guess one advantage with the OSC camera (versus mono and 3 filters) is more frames can be captured in the same amount of time. Your thoughts? Have you been satisfied with the results from the ASI290MC?

 

Thanks again for your comments and advice.

 

Russ


Edited by Rustler46, 05 August 2019 - 05:02 AM.

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#16 Rustler46

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Posted 11 August 2019 - 07:40 PM

Dirty sensors are the bane of ZWO Russ, but once cleaned & kept sealed as part of a specific imaging train they should provide endless no-fuss useage! (caps on the end of the complete imaging train when not in the scope, but any slight dust at that end is virtually harmless as it is out of focus as far as the camera is concerned.

 

I use a Pec Pad where I've cut a single pad into strips about 1/4"+ or so wide (wash hands first & also clean, sharp scissors) hold one side & after cutting up half the single Pec Pad into multiple strips without handling these I discard the rest of the pad...a bit obsessive but placing these strips in a ziplock bag gives me way too many! wink.gif )

 

I cut a strip from a soft plastic ice-cream lid a bit narrower than the pad strips I've cut, no more than about 3" long.

 

This plastic, cut this way, has some "spring" in it & if you double one of those cut Pec Pad strips over one end & add a couple of drops of any good cleaning solution (Eclipse, Visible Dust etc) onto that doubled-over end you drag it with a bit of pressure across the actual glass screen on top of the camera sensor one way, flip the stick over & do the same with the other "edge" of this cleaning "wand" you've made.

 

You can then move the doubled-over pad on the plastic "wand" a bit to expose a new bit at the tip/bottom edge, another drop maybe of cleaning solution & do another double wipe...you can buy cleaning "swabs" or "wands" ready-made that only need cleaning solution (eg, Visible Dust etc) but they are horribly expensive & not worth it compared to the cheap ones I've described here.

 

Understand that you can also clean the "AR" window this way, which is a glass covering the sensor & sensor glass.....but that usually isn't an issue - it is that hard glass layer on top of the actual electronic sensor I am talking about cleaning - this is where in-focus dust bunnies etc lay!

 

This is tough glass btw - you won't damage it! wink.gif

 

Test the camera under a light or outdoors by plugging it in & turning the gain/exposure down so that you are not drowning out those dust spots when you view the sensor carefully on the screen of your laptop - you'll know when you're ok!

Thanks for the tutorial, Darryl ! All the sensor dust motes are gone. Now the camera is sealed with its IR-cut window in place on the nosepiece. Only dust that was sealed inside might in the future become mobilized to land on the sensor. But I did blow the insides with a rocket air blaster, which should have expelled the dust.

 

So tonight I hope to have another go at Jupiter, Saturn and maybe even the Moon. If I remember correctly 4 minutes on Jupiter and 5 on Saturn should be OK as far as rotation is concerned. With a small ROI it has been running at around 150-170 FPS on USB 3.0, giving over 40,000 frames. Now if seeing will cooperate ....

 

Best Regards,

Russ



#17 RedLionNJ

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Posted 12 August 2019 - 05:49 AM

 

Question:

How much am I giving up in resolution with a one shot color camera? I really don't want to use filters and mono. I guess one advantage with the OSC camera (versus mono and 3 filters) is more frames can be captured in the same amount of time. Your thoughts? Have you been satisfied with the results from the ASI290MC?

 

Thanks again for your comments and advice.

 

Russ

Hi Russ,

 

Provided you use AutoStakkert for the alignment and stacking, you give up no resolution by using a OSC camera.  AutoStakkert builds a full-resolution result from the alignment frames as it stacks them. No interpolation, no debayering (in the classical sense of the verb).  If Jupiter is, say, 200 pixels across on your OSC sensor, then the resulting Jupiter image will also be 200 pixels across and each pixel will have a non-interpolated red, blue and green component.

 

WIth a OSC cam, the only aspects to watch out for are the desirability to capture maybe 25% more frames (not a biggie, usually) and to use an IR-block filter (as most OSC cams are sensitive in all three colors well into the IR part of the spectrum).

 

For lower elevations, an ADC is pretty much mandatory for use with a OSC cam.

 

Grant


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#18 Rustler46

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Posted 12 August 2019 - 06:51 PM

Hi Russ,

 

Provided you use AutoStakkert for the alignment and stacking, you give up no resolution by using a OSC camera.  AutoStakkert builds a full-resolution result from the alignment frames as it stacks them. No interpolation, no debayering (in the classical sense of the verb).  If Jupiter is, say, 200 pixels across on your OSC sensor, then the resulting Jupiter image will also be 200 pixels across and each pixel will have a non-interpolated red, blue and green component.

 

WIth a OSC cam, the only aspects to watch out for are the desirability to capture maybe 25% more frames (not a biggie, usually) and to use an IR-block filter (as most OSC cams are sensitive in all three colors well into the IR part of the spectrum).

 

For lower elevations, an ADC is pretty much mandatory for use with a OSC cam.

 

Grant

Thanks for the information, Grant. I much appreciate the expertise of those on this forum.

 

Last night I had another go at imaging the Moon and Saturn. Seeing started off terrible or more likely the warm, insulated OTA needed to equalize. But when it settled down, I got around 115 GB of videos on the two bodies. The SSD and USB 3.0 made for frame rates of 80 fps (full frame of ASI290MC on the Moon) and 175 to over 200 fps on Saturn (with tight ROI). I remembered Lunatiki's advice to turn up the gain a bit to enable shorter exposures. So gain was set to around 75% for Saturn, with the resulting high frame rates.

 

I ran into a problem with AutoStakkert!-2 running in a wineskin on my MacBook Pro. While the program fired up looking normal, I couldn't get it to load any AVI videos, either by drag and drop or choosing from file list. I guess I'll just install AS!-3 in a wine wrapper, since that had worked before. File size may be a problem since they ranged from 7 GB (Saturn) to 22 GB (Moon). But the total number of frames was 40,000 to 60,000 for each video, running a 5-minute video.

 

These videos should give me something to work with for the time being. I just need to figure out the AutoStakkert problem.

 

Best Regards,

Russ



#19 Kokatha man

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Posted 12 August 2019 - 07:25 PM

Hi again Russ - the amount of "gain" you set is entirely dependent upon the histogram you wish to capture at...the "exposure" value will set the "FPS" as long as the "height" of the "ROI" you use will allow that FPS.

 

This effectively means if you want a 75% histogram you need more gain than for a 50% histogram - but you do not need a 75% histogram at all! You can go quite a bit lower than 50% actually, but a 50%-55% histo is more than sufficient.....

 

Remember that gain is electronic amplification of the signal from the sensor & the greater the gain, the more noise induced: setting it for a lower but satisfactory histogram is usually a better choice & it is very easy to "blow out" the EZ zones of both Saturn & Jupiter, especially after applying any sharpening wavelets; so keeping the gain/histo within satisfactory limits is beneficial overall. ;)


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#20 Rustler46

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Posted 14 August 2019 - 12:47 AM

Last night I had another go at imaging the Moon and Saturn. Seeing started off terrible or more likely the warm, insulated OTA needed to equalize. But when it settled down, I got around 115 GB of videos on the two bodies. The SSD and USB 3.0 made for frame rates of 80 fps (full frame of ASI290MC on the Moon) and 175 to over 200 fps on Saturn (with tight ROI). I remembered Lunatiki's advice to turn up the gain a bit to enable shorter exposures. So gain was set to around 75% for Saturn, with the resulting high frame rates.

 

I ran into a problem with AutoStakkert!-2 running in a wineskin on my MacBook Pro. While the program fired up looking normal, I couldn't get it to load any AVI videos, either by drag and drop or choosing from file list. I guess I'll just install AS!-3 in a wine wrapper, since that had worked before. File size may be a problem since they ranged from 7 GB (Saturn) to 22 GB (Moon). But the total number of frames was 40,000 to 60,000 for each video, running a 5-minute video.

 

These videos should give me something to work with for the time being. I just need to figure out the AutoStakkert problem.

I haven't had success in getting AutoStakkert!-3 to run in a Wineskin on my Mac. But AS!-2 runs fine. The problem getting files to load is the file size limit. It seems to load a file of 1.28 GB with no problem. But a 6.76 GB AVI video will not load. So the file size may be limited to 2 or 4 GB.

 

Questions:

  • Does anyone know the file size limit for AS!-2?
  • Is there any reason to choose the .ser over the .avi format?
    AutoStakkert!-2 handles either one.

 

I'll send an e-mail to Emil. In the past he has responded quickly. I've tried trimming the avi files to a smaller size. But the hassle isn't worth it. I just need to produce videos no larger than the limit.

 

Russ



#21 Rustler46

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Posted 17 August 2019 - 04:23 AM

Seeing was absolutely terrible tonight. All videos captured ended up being deleted. But I did determine that AutoStakkert!-2 can open files of less than 4 GB. Previously it wouldn't open ones of 6.7 GB. So I'll just be sure to keep file sizes down.



#22 Tulloch

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Posted 17 August 2019 - 05:27 AM

It’s probably because AS!2 is a 32 bit program, the max file size is 4GB in size. AS!3 is a 64 bit program so can take larger files.

Andrew


Edited by Tulloch, 17 August 2019 - 07:46 AM.

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