Don't Laugh at my Jupiter ;)

[kirkster501]

I want to get into planetary now that Jupiter is starting to get a bit higher.  This meagre effort is only at a very small imaging scale at the moment with my TEC140 and ASI224MC and no barlow so the planet shows very small on the sensor.   I did some preliminary setting up in order to get Jupiter on the sensor with my Telrad and red dot finders so that my C925 is ready for Jupiter next time.  The seeing was rubbish and there was loads of mist and it is obviously quite low in altitude from the UK currently.  Despite that I thought I'd do a quick capture all the same.  So this is best 30% of 2000 frames with a bit of sharpening.  I don't think Damian Peach need worry about this new kid on the block stealing his thunder just yet  🤣

 

Edited September 23, 2021 by kirkster501

[Dark Vader]

Thats better than anything I've managed yet, although I am trying to do it with a smartphone...

Single shot handheld (couldn't set the mount up properly in the dark and gave up with swearing 😄)

Tweaked a bit in PS Express and shot with a lot of luck. Samsung A6, ISO64,1/60sec, Camera FV-5 app. BST 15mm barlowed 2.25x. Jpeg Zoomed a bit and screenshot.

GRS just visible and Io barely visible bottom left.

[ItsmeMaw]

I would never laugh!

I'm still shooting single images with my Canon. Most I get are substandard compared to the exceptional astrophotographers here on the SGL.

But I do this for my own pleasure and I enjoy every image I take. 

Seeing better images here just inspires me to keep trying!

[vlaiv]

Next step would be to add x2 barlow to your setup and tweak capture parameters.

2000 frames is very low count - you want x20 of that - about 40000.

Set your exposure length at about 5-6ms. Set your gain at 379. Use 8bit mode to do capture. Make sure your camera is connected via USB3.0 connection and your computer has SSD to store the video. Use SER video format. 

Don't worry about histogram being "low" or anything like that. It is not important in planetary imaging. Take at least 3 or 4 minutes of video (say you manage 150FPS and you image for 4 minutes - that is 240s - total number of frames should be around 36000). Stack top 5-10% of that.

If you can - take calibration frames as well (well calibration movies). Take something like 100+ dark subs video and do at least that much for flat frames (and flat dark). Use Pipp to pre process your video and keep bayer matrix intact. AS!3 will use bayer drizzle to extract color information.

[kirkster501]

Thanky you Vlaiv for those tips

Edited September 23, 2021 by kirkster501

[morimarty]

Hi Kirkster Your Tec140 would easy handle a 3x barlow which would give you F/Ratio of F21 thats 5x per pixel and a resolution of 0.26 right in the ball park. And as Vlaiv says up your frames captured and use a ROI of 640x480 HTH.

[vlaiv]

36 minutes ago, morimarty said:

Hi Kirkster Your Tec140 would easy handle a 3x barlow which would give you F/Ratio of F21 thats 5x per pixel and a resolution of 0.26 right in the ball park. And as Vlaiv says up your frames captured and use a ROI of 640x480 HTH.

Any scope will easy handle x3 barlow - question is, is there a point.

ASI224 has 3.75µm pixel size and corresponding F/ratio for critical sampling is F/15 (calculated at 510nm). No need to go higher than that - it only spreads light more and reduces SNR for given total imaging time. No additional detail will be captured.

[kirkster501]

I have a 2" x2 Powermate so may try these suggestions tonight if it is clear  

Edited September 23, 2021 by kirkster501

[Neil H]

Well that's loads better than what I got last time I tried , will be trying again soon I hope , well done brilliant 

[kirkster501]

I managed to get 30000 frames with the x2 Powermate with the TEC140/ASI224Mc.  Jupiter was dancing around like a dice in a glass being shaken, the seeing was so bad and clouds kept rolling in obstructing it.  However,  I think I have now got the idea of focus.  I've got the main bands and, I think, the GRS in this, albeit slightly fuzzy and hazy.  Good fun all the same    I will keep working hard to get better whenever I can get the opportunity.

I'm trying to expand my repertoire of AP subjects and themes - I'm also branching out into solar and lunar -  because DSO imaging (especially LRGB) seems to be becoming more and more unsustainable in the UK with each passing year.  Indeed, I have considered flogging all my DSO AP cameras and telescopes and focusing on quality widefield Sigma lenses and OSC imaging for DSO and a C11/C14 for planetary/lunar and maintaining my Dob for visual.  That is how bad it is getting.

Edited September 24, 2021 by kirkster501

[morimarty]

The seeing was horrendous in the east midlands last night so you have done well to capture a jupiter image at all. Thats a very good point you make about Dso lrgb imaging. Planetary imaging dont seem to be as badly effected due to the high magnification thats why I branched out aswell. I think narrowband is the way to go now for Dso imaging from our backyards. Thats what I was doing last night setting up my rig for NB Dso imaging for the coming season. (good look on your ventures).

[vlaiv]

5 hours ago, kirkster501 said:

I managed to get 30000 frames with the x2 Powermate with the TEC140/ASI224Mc. 

What was your exposure length there?

[kirkster501]

About 4ms.  Needed to be longer Vlaiv.

[vlaiv]

1 hour ago, kirkster501 said:

About 4ms.  Needed to be longer Vlaiv.

That is actually about right. Not sure why you have image like you have there. It should be better looking.

It was either exceptionally poor seeing, or something was not quite right. What did you use for stacking? How many frames did you end up using, What is the size of your alignment point (if you used AS!3 - which you should use btw ).

All of those things can make difference on quality of your final image. 

[lukebl]

On 23/09/2021 at 14:34, vlaiv said:

2000 frames is very low count - you want x20 of that - about 40000.

I find with my  ASI 120mc camera and admittedly very low-spec laptop, I can only get about 50 frames per second. So 40000 frames would take over 13 minutes. Way too long for Jupiter’s fast rotation, even using derotation. Is 40000 frames really feasible for a subject like Jupiter? I get a much faster frame rate with my mono cam, but that’s not much use with Jupiter as the planet’s features will have moved after each colour channel capture.
 

I aim to get whatever I can over a period of about a minute, i.e. about 3000 frames. Short of a major hardware upgrade, there’s not much else I can do.

[vlaiv]

12 hours ago, lukebl said:

I find with my  ASI 120mc camera and admittedly very low-spec laptop, I can only get about 50 frames per second. So 40000 frames would take over 13 minutes. Way too long for Jupiter’s fast rotation, even using derotation. Is 40000 frames really feasible for a subject like Jupiter? I get a much faster frame rate with my mono cam, but that’s not much use with Jupiter as the planet’s features will have moved after each colour channel capture.
 

I aim to get whatever I can over a period of about a minute, i.e. about 3000 frames. Short of a major hardware upgrade, there’s not much else I can do.

40000 frames is feasible only with USB 3.0 cameras where you can achieve 150-200fps. You also need SSD, or enough RAM for buffering purposes. I used to image with very low spec laptop - but it had SSD and USB 3.0 and I was able to get very good FPS rates - close to those advertised as max for given camera (ASI185mc / ASI178mc).

I limit my runs to about 4-5minutes. It really depends on aperture size and software that I'm using. AS!3 can deal with quite a bit of rotation of the planet because of the way it works. You can easily calculate largest drift of features, depending on planet rotation speed, distance and working resolution. In most cases - drift over few minutes is order of magnitude of pixel size - so maybe 2-3 pixels. Frame to frame distortion will move features more than that (sometimes even 1"-2", so several pixels) and AS!3 is able to undo distortion by using alignment points and warping back the image (effectively solving issue of tilt component of wavefront aberration over the image - a bit like rudimentary adaptive optics). That also solves any small rotational issue.

Reason this does not work when doing LRGB imaging is because actual feature position is calculated from reference frame. Reference frame is made so that alignment points are placed on their "average position" - rationale being that seeing will move point randomly around its true location. If you image each channel for few minutes - well they will have different reference frame due to planet rotation.

Best way to deal with that is to use WinJupos and derotate color frames to match that of luminance.

By the way, I think that hardware upgrade to be able to exploit USB 3.0 speeds is well worth it. If you keep everything else the same, but you capture x9 more subs with USB 3.0 system (36000 vs 3000 frames) - you'll be effectively improving your SNR by factor of 3. That enables you to sharpen more aggressively and get more detailed image.

[kirkster501]

It was incredibly poor seeing Vlaiv.  Beggars cannot be choosers in the UK of late, clear skies are 1% of the total skies. Less even.

Edited September 25, 2021 by kirkster501

[vlaiv]

6 minutes ago, kirkster501 said:

It was incredibly poor seeing Vlaiv.  Beggars cannot be choosers in the UK of late, clear skies are 1% of the total skies. Less even.

Maybe if you lower number of stacked frames? Try stacking something like 1-5% to see what sort of image you get. Also, if you are using AS!3 - play with size of alignment points. Make them smaller.

I have a feeling that more can be pulled out of that recording.

[lukebl]

1 hour ago, vlaiv said:

40000 frames is feasible only with USB 3.0 cameras where you can achieve 150-200fps. You also need SSD, or enough RAM for buffering purposes.....

Thanks for that vliav. Very useful.

However, until you mentioned it, I'd never heard of SSD. I really know very little about computers! I just switch them on and hope they'll work. The laptop has a USB 3.0, but I guess just not enough RAM.

[Mr Spock]

You have an image - it's a lot better than most of us can manage. Planetary imaging is another one of these dark arts that're a mystery to us 'normal' folk.

[vlaiv]

3 hours ago, lukebl said:

However, until you mentioned it, I'd never heard of SSD.

Yes, solid state disks - much faster data transfer speeds than regular hard drives with spinning platters (which now seem so "stone age" in computer terms - magnetic spinning discs ).

[lukebl]

3 minutes ago, vlaiv said:

Yes, solid state disks - much faster data transfer speeds than regular hard drives with spinning platters (which now seem so "stone age" in computer terms - magnetic spinning discs ).

I've just checked, and mine is an SSD. Not much RAM and very little capacity on the drive, though.

[vlaiv]

2 minutes ago, lukebl said:

I've just checked, and mine is an SSD. Not much RAM and very little capacity on the drive, though.

I guess that you should have no issues with FPS then. You can always try "on bench" speed.

Select smaller ROI - like 640x480, switch to RAW8 format, turn on Turbo USB / High speed and see what sort of FPS you are getting in SharpCap (provided you are using it).

[kirkster501]

Starting to look a bit better, a very quick process on the imaging rig, will look at it more tomorrow.  I grabbed many 4 minute sequences./  I did exactly what Vlaiv said.  The key is focus, focus and focus.  Did I say focus????  And that focus is not at all easy.  This is with TEC140 and ASI224MC with a 2x Powermate.  Want to start simple with my refractor.  Next is the C925.

Edited September 25, 2021 by kirkster501

[jetstream]

1 hour ago, kirkster501 said:

Starting to look a bit better, a very quick process on the imaging rig, will look at it more tomorrow.  I grabbed many 4 minute sequences./  I did exactly what Vlaiv said.  The key is focus, focus and focus.  Did I say focus????  And that focus is not at all easy.  This is with TEC140 and ASI224MC with a 2x Powermate.  Want to start simple with my refractor.  Next is the C925.

Excellent improvement!

Vlaiv has (is) helped me understand much of this and I'm following your progression with much interest. We have the same camera- 224MC but I'll try the moon with the 90mm first then the TSA120. Your right about focus- I was playing around on some trees about 2 km across the lake and many little flaws of mine revealed itself.

Keep posting please!