geoflewis

1 hour ago, yelsac said:

Thanks Geof 👍

Just out of interest what settings do you guys use for ir? I used basically the same for colour images around 5ms but upped the gain to 310 in sharpcap. 

I'm using the same capture speed for IR as colour. I have auto histogram set at 85% for both, so gain will be a little different, but otherwise it's the same.

1 hour ago, neiil phillips said:

Thanks again Geoff. Was nice to be back in the saddle so to speak. Having to set up such a monster Newtonian from scratch. Is never easy. Everything just flowed. No hassles. Its like I had never been away. usually something becomes difficult. Or goes wrong. But no. Everything went well. I was surprised how well

That's great to hear Neil, but I'm not surprised, as you're such an accomplished imager with bags of experience, so as you say, just like getting back in the saddle as if nothing changed...

3 hours ago, neiil phillips said:

Thanks Guys much appreciated

Heres a 5 min capture. video de rotation 

23:37 UT

That's excellent Neil 👏

1 hour ago, Kon said:

Regarding CH4, Geof @geoflewisand I have been comparing notes. I have tried around 50ms with a histogram of 70% but recently I am working at 95% for my IR so I want to try again. Geof can comment on his settings. I am at 8" and with a very narrow band ch4 of 890 at 10nm. My last attempt I combined 4x2min in Winjupos.

I’m still finding my feet with the CH4. Currently experimenting with 2m at 100ms, which capture speed was suggested to me by one of the Aussie planetary imagers. I’ll try derogating and stacking the TIFFs from a fee SERs and take it from there. I’d like to go faster, maybe  70ms-80ms, but will wait to see how 100ms turns out before changing anything.

46 minutes ago, neiil phillips said:

Still only 3 mins will try 5 de rotated  soon 

 

Looking good Neil

2 minutes ago, orion25 said:

Thanks, Geof. It actually was Io; left-right orientation was flipped.

Ah yes, I can see now that the GRS wake is in front of the GRS....

Nicely done Reggie.

It must be an illusion with a bright spot in the SEB to the left of Io's shadow, making it look like Io following the shadow as it was prior to opposition.

Nice images and processing as ever Neil and as others said, it's great to see you back imaging and posting.

Some good detail in those images Tom, but as others have commented they are noisy / oversharpened. As @Space Cowboy demonstrated, I too am finding Image Analyser frequency domain and colour noise filters) in conjunction with Astrosurface are useful tools and easier to control for final processing than Registax.

Excellent images and presentation

That looks good. I never realised that the ASIair had planetary capture capability.

That's a very nice image - the original that is, not sure what happened with the png version, but that looks over processed almost like you accidently reapplied the wavelets to the original....

Very nice results and yes, IR can help cut through poor seeing.

2 minutes ago, Astroscot2 said:

Hello Geof

Keeping the capture duration to 90 seconds max.

I'm using AS3 to analyse and stack, typically I aim for the top 10% quality frames which can be around 1000 frames total .

Taking the stacked file into PIPP to align frames.

Registax 6 for wavelets, sharpening and De-noise

Winjupos to de-rotate and stack final images

Pixinsight for final adjustments.

 

During the Mars opposition last year, I was getting fairly good results with the above excluding Winjupos and Mars was only 18" ,  I sort of expected good results on Jupiter also with more detail. Not seeing the wow effect of wavelets at all..

 

Mark

Hi Mark,

Apart from using PIPP those steps all seem fine to me. I only question use of PIPP as AS3! should have aligned everything fine before stacking, so are you using PIPP before or after AS3!.

If you'r confident about  collimation and have 'cooled' the scope sufficiently, then I suspect it's just poor seeing - it's the main killer for us in the UK. I had several nights of good seeing recently under a persisting 'high', but I think that you're much further north than me where there was lingering low pressure which generally is less favourable. WinJupos won't help if the source images aren't good enough. Believe me I've had weeks and months where I could get nothing usable.....

27 minutes ago, Barv said:

Fantastic job on those Geof! You've really nailed focus too. That C14 is clearly performing well for you. Do you have any cooling issues with it?

Cheers

Harvey

Thanks Harvey,

I have the C14 pretty well dialing in I think, but do get lazy sometimes, by not checking collimation as often as maybe I should. Cooling can be an issue in summer or after a hot day, so I'm reluctant to open the RoR too early when the Sun is still shining, maybe open a crack with the door open to allow some airflow in the obs. This time of year temperature is less of an issue, plus I have aftermarket fans fitted, so will usually run those onopening up to help stabalise air inside the tube with conditions outside. I sometimes run the fans during imaging, but generally I'm good to go without them after running them for 20-30 mins, or so this time of year.

34 minutes ago, inFINNity Deck said:

One way to arrive at a factor of 5, is to calculate the optimal focal ratio using the spatial cut-off frequency for the shortest observable wavelength. If we consider that we record in our images wavelengths between 400nm (blue) and 700nm (red) and assume that the shortest wavelength would in theory be able to show the finest details, then the optimal focal ratio would become 2 x [pixel size] / 0.400 = 5 x [pixel size]. @vlaiv for instance uses 400nm in his calculations (as he wants to be properly sampling over the whole visible spectrum) and so arrives at 5 x [pixel size]. The issue I see with this approach is that blue light is most scattered by our atmosphere, so it is less likely that we will actually achieve the highest resolution at that wavelength, even in lucky-imaging. At the other end of the spectrum we have red light of 700nm, which would result in an optimal focal ratio of 2 x [pixel size] / 0.700 = 2.9 x [pixel size], but that of course would be the lower limit (provided we image under an ideal atmosphere, using an ideal scope). I always used green light of 540nm in my calculations (as can be seen in my papers), which results in the 3.7 x [pixel size] as a maximum useful focal ratio for planetary imaging mentioned before (one can now easily imagine that this is not entirely correct for a reddish planet like Mars). The reasons for using that wavelength in my calculations were that the Sun's continuum reaches its maximum around it, that the Baader Continuum filter has a bandpass around it (for obvious reasons), that the green filter is more or less centred around it, and that ZWO colour cameras have their maximum quantum efficiency around it (actually slightly before it).

For the article on the effect of seeing on the visibility of sunspots we simulated various telescopes under various seeing. From those simulations I later deduced the relationship between seeing and oversampling factor as roughly 1.6 x [seeing]^0.74. If we create a set-up with a C11 or an 180mm aperture Maksutov that samples optimal at zero arc-seconds seeing (regardless how we define it) and use it at a best seeing of 0.6 arc-seconds, the oversampling-factor will only be about 1.1 (so 10% oversampling), while at 0.7 arc-seconds this is about 1.2, so the ideal focal ratio will only have to be adjusted by a few tens of percent. But if the best seeing during an imaging session is 2 arc-seconds, the image will be oversampled by almost a factor of two.

Weather permitting I observe, sketch and image the Sun on a daily basis for two scientific programs and also measure the seeing during those sessions using a Solar Scintillation Seeing Monitor:

I do not measure seeing at nighttime, but can imagine that it can be a bit better than at daytime due to the absence of the Sun. Still I do not expect to image diffraction limited very often (if ever) with the C11 here in the Netherlands (due to its aperture the C11 is seeing limited above a seeing of about 0.4-0.5 arc-seconds).

I therefore firmly believe that it is for above reasons that I have yet to find a planetary image that was not oversampled (or at least not more than by 10% or 20%). But again: please post an image here that is not oversampled as I would be very interested to see it.

Nicolàs

 

Nicolàs,

This is a very interesting discussion, which I've enjoyed following, but given the OP's opening phrase, 'I’m dipping my toe in the water with planetary imaging....' maybe it's a little too deep for this thread.....

17 minutes ago, bosun21 said:

Do I need to have the frames captured in the Winjupos time format during capture?

It's not essential, but highly desirable as makes it image measurement in WinJupos so much easier.

18 minutes ago, bosun21 said:

I think I’ll just carry on with my method including the addition of Astrosurface, and as I become efficient I’ll then add Winjupos and Image Analyser. Otherwise I feel I will get slightly overwhelmed.

In my experience, it's definitely worth beoming comfortable with each step / tool, before plunging in, though some people get to grips with this stuff faster than others (I'm slow 🙂 ). WinJupos is a fairly straightford, though somewhat tedious process, but can really help extract those last fine details when seeing has been good. Have a try once you're ready, we're here to help if you need it. Image Analyser is very new to me and really only adds very subtle benefits/improvements, that most people won't detect, so I'd say last on your list of things to learn - others may disagree with me of course.

1 hour ago, bosun21 said:

Winjupos is next on the list for me to learn, at what stage do you de rotate? I initially thought that you had to do it before stacking with a SER file or am i way off the mark? Thanks.

You have a choice. You can derotate the SERs then grade and stack the best frames, or grade and stack the best frames in AS3!, then derotate the resulting TIFFs, which is my preferred method. The advantage of derotating the SER is that you can capture much longer video files, however, they can become huge and in my experience will roughly double in size after derotation.

My method goes like this.

1. Capture a number of short (typically 1m) SER files, which if using a mono camera will be for each RGB filter, or IR, CH4 etc. I'm now using a colour camera ASI462MC, so just capture 1m colour SERs and since this camera is very sensitive in IR, can also capture IR and CH4 data with it.
2. Take each SER through AS3! and typically stack best 15%-25%. Check analysis graph for % frames above 50% line. You want to have enough frames for a stack that isn't too noisy, without including poor quality frames. Export as TIFF.
3. Open the TIFF from 2 above in Registax (could use Astrosurface, but I still use Registax at this stage). Apply a mild wavelets, just enough to reveal features without sharpening. The idea here is to give enough detail for WinJupos to lock onto features during the measurement stage. I also use Registax RGB balance tool here and if you've not RGB aligned in AS3!, then do that here. I also check the histogram tool and lower the white point to brighten the image, but not too much to avoid clipping. Export file as TIFF (renaming to not overwrite original - I usually add R6 and wavelet settings, eg _R6(1-1-1-10-20-30). Long file name I know, but I find it useful when reviewing later.
4. Open the TIFFs from stage 3 in WinJupos. Select the correct planet, then use the measurement tool to accurately align the reference frame to the image. Take time to get this accurate and if available use any moons in your image for alignment.
5. Load the measurement files into the derotation of images (or RGB frames if shooting mono). Adjust the LD (limb darkening factor - I use between 65-85, but is trial and error). Set details for observer, file name, orientation (north/south up), file type (eg TIFF), etc., select folder for image to be saved, then compile image.
6. Open the derotated and stacked TIFF from WinJupos in Astrosurface (or Registax if you prefer) and apply final wavelets, denoise, etc.

Hope this helps.

John Rogers always wanted south up in the past, so I kept submittingbthem that way until lst year when he said most were now submitting north up so I switched everything. Then Richard McKim told me he still prefers south up, but I'd already sent everything north up. I'm not cahnging back again as most non astronomers thought my south up views of Jupiter looked weird....

On 07/11/2023 at 19:03, CraigD1986 said:

What’s the best way to focus if there is no moon? I have the ZWO EAF. Just manually by eye or focus on a star?

As others said, I always focus on the planet. It takes time, so best to make small adjustments and observe for a few seconds, then tweak back and forth until you're confident you have the best for the conditions. Of course it is impossible in poor seeing.

Also as others have said, aim for x5 pixel size and if anything, err on being slightly over sampled than undersampled, though for my recent images I have been slightly unsampled and using ADC, so it's not a killer.

These are both excellent and not a lot between them, but I think 1m SERs will likely give sharper results in good seeing, 2m is quite long for Jupiter's fast rotation.

That's lovely Pete and good to see a traditional south up view again

Excellent first capture. As @Kon says, I'm increasingly relying on Astrosurface for wavelets, though I do still hit the initial stack out of AS3! with a light wavelets and colour balace in Registax, before derotation in WinJupos. After that it's Astrosurface and Image Analyser (IA) though IA isn't really necessary until you've got a handle on Regisatx and/or Astrosurface.

I've used both linear and gaussian in Registax in the past, but in the last couple of years have settled on linear without any sharpen or denoise. These are fairly typical settings prior to WinJupos derotation.

If I was just processing a single stack to conclusion, then I'd hit it a bit harder, say something like this...

Every session requires something different and I find that I have better control with wavelets and denoise in Astrosurface after I've derotated and stacked the TIFFs from a few SERs. Something like this...

Good luck, keep trying and keep asking....

20 hours ago, Astroscot2 said:

Hello.

Ive been trying to get a decent image of Jupiter for over 1 month now, seeing conditions have not been great here and so far ive been disappointed with my results.

Im using a 10" newtonian which is well collimated, QHY462C camera with good frame rates, TV barlow.

Last night 1 took 4 videos with the hope of stacking them and hopefully get an improvement with de-rotation in Winjupos,  Im not sure what im doing wrong but the final image looks smeared.

Watched a few tutorials and not getting good results, Ive shown below single stacked SER file and combination of 4 stacked SERs in Winjupos.

Any pointers appreciated.

 

Mark

 

Hi Mark,

Sorry, but initially I have more questions than answers...

1. What duration is each SER
2. What % of each SER are you stacking
3. What other software apart from WinJupos are you using, e.g. AS3!, Registax, Astrosurface, etc.

As @Kon says, it's important to only include good data into WinJupos derotation.

If the seeing is bad, then unfortunately you will not get good results, as planetary imaging is very intolerant of poor seeing. Your equipment is well suited to high res planetary imaging, so one just has to keep trying....

Thanks Kostas, I know very well about a laughing wife, though I get more eye rolls than laughs from mine when I'm having a hissy fit about the weather ruining my hobby....😳