Jupiter with Fullerscope - decent seeing

[CraigT82]

Last nights Jupiter (6th August 2020 ignore the wrong date in the image!). Seeing was fairly good for my urban street location (I saw the reports of good visuals posted by John and others).

8.75" Fullerscope with Altair 224C, APM 2.7x barlow and ZWO ADC. Baader L filter.

I captured 20 x 1 minute runs and discarded 3 of them. Stacked best 30% of the rest and derotated the lot. PS for final tweaks.

Cheers

Edited August 7, 2020 by CraigT82

[sputniksteve]

Very very nice

[vlaiv]

Very nice.

Out of interest, did you go for 0.14"/pp on purpose or is it just consequence of gear used (APM barlow and ASI224 combined with your scope).

Another question - did you measure distance from barlow element to sensor to be precise about x2.7 magnification?

I have the same barlow, but only as an element and I use it with extensions - but never actually measured to get exact magnification. I wonder how much CC properties of this barlow change with change in distance to sensor?

[si@nite]

A cracking shot of Jupiter Craig, seeing was mush here on Jupiter, but faired better on Saturn!

[vlaiv]

@CraigT82

I have another question, I hope you don't mind. It is about processing - do you use wavelet sharpening?

In fact, I hope you don't mind me having a bit of tweak of the image you posted? Data is exceptional and if one takes care to present it at optimum sampling rate for this gear (0.24"/pp) and does a bit of tweaking with sharpening, this is the result:

I personally like it like that - it might be smaller in size but it is much sharper / more detailed, what do you think?

 

[CraigT82]

14 minutes ago, vlaiv said:

Very nice.

Out of interest, did you go for 0.14"/pp on purpose or is it just consequence of gear used (APM barlow and ASI224 combined with your scope).

Another question - did you measure distance from barlow element to sensor to be precise about x2.7 magnification?

I have the same barlow, but only as an element and I use it with extensions - but never actually measured to get exact magnification. I wonder how much CC properties of this barlow change with change in distance to sensor?

Hi Vlaiv,

It's just a consequence of the gear used really. The Jupiter image I posted from the 30th I measured from the image to be exactly 2.7x amplification of the native FL, and last night It was a bit more than that as I had to add in a small T extension between barlow nosepiece and filter wheel to prevent the filter wheel fouling the securing screw of my HD parallizer (because I had the tube at a different orientation to the session on the 30th session where it didn't foul - it was easier to add in the extension than to rotate the tube!).

I also never use the barlow with it's body, I have various nosepiece extensions so that I can tune the distance to give me more or less power if needed but in my usual configuration it does actually give me approx 2.7x.  I might not be the best barlow for me as this long FL newt doesn't have that much coma and so I wonder if I'm introducing some anti-coma to the edges of the image? I've never tested it. Well, I thought I always keep the target in the centre of the view so probably not an issue.

[CraigT82]

14 minutes ago, vlaiv said:

@CraigT82

I have another question, I hope you don't mind. It is about processing - do you use wavelet sharpening?

In fact, I hope you don't mind me having a bit of tweak of the image you posted? Data is exceptional and if one takes care to present it at optimum sampling rate for this gear (0.24"/pp) and does a bit of tweaking with sharpening, this is the result:

I personally like it like that - it might be smaller in size but it is much sharper / more detailed, what do you think?

 

Yes that looks great! Your processing skills far outstrip mine

I did use wavelets but fairly gently.  Did you nudge the No.2 slider for that image?  By what factor did you downscale to get the 0.24" scale? (Edit: nevermind just checked the image size on the one you posted 294x294)

Edited August 7, 2020 by CraigT82

[geoflewis]

1 hour ago, CraigT82 said:

Last nights Jupiter (8th August 2020). Seeing was fairly good for my urban street location (I saw the reports of good visuals posted by John and others).

8.75" Fullerscope with Altair 224C, APM 2.7x barlow and ZWO ADC. Baader L filter.

I captured 20 x 1 minute runs and discarded 3 of them. Stacked best 30% of the rest and derotated the lot. PS for final tweaks.

Cheers

That's a cracking image for the altitude Craig. I had my first go at it this year, last night with my C14 and got nowhere near the detail you've captured.

[CraigT82]

8 minutes ago, geoflewis said:

That's a cracking image for the altitude Craig. I had my first go at it this year, last night with my C14 and got nowhere near the detail you've captured.

Thanks Geof we must have had all the good seeing over in the West, sorry!

[MarkAR]

Excellent image Craig and a really good reprocess by @vlaiv.

[vlaiv]

14 minutes ago, CraigT82 said:

I also never use the barlow with it's body, I have various nosepiece extensions so that I can tune the distance to give me more or less power if needed but in my usual configuration it does actually give me approx 2.7x.  I might not be the best barlow for me as this long FL newt doesn't have that much coma and so I wonder if I'm introducing some anti-coma to the edges of the image? I've never tested it. Well, I thought I always keep the target in the centre of the view so probably not an issue.

Yes, it certainly won't have much impact on Jupiter image if you place the planet on optical axis - it is only about 45" wide - so 22.5" to each side? Even on fast scope there will be no difference.

There might be some difference for lunar shots with larger sensor?

My reasoning is that regular CCs need exact spacing, but are flexible in terms of F/ratio of scope. I guess that this barlow works pretty much the same - you can use it both on F/5 and on F/8 scope and it won't change much but it should be at about x2.7 for best CC performance.

I'm just asking this because suitable magnification depends on wanted sampling rate and with any barlow one can dial that in by changing distance, but this particular barlow might have side effects in CC performance if there is large change in magnification (distance).

16 minutes ago, CraigT82 said:

I did use wavelets but fairly gently.  Did you nudge the No.2 slider for that image?  By what factor did you downscale to get the 0.24" scale?

Although you mentioned that you sampled at 0.14"/px I did a quick check to make sure image was not resized afterwards - measured diameter of ~312px which for 45" diameter gives about ~0.144"/px - so I figured that image was not scaled. Then I just took ratio of 0.14 and 0.24 being 0.58333 and then I scaled it to 58% using IrfanView and Lanczos resampling.

Image is in 8bit format - so not really suitable for wavelet sharpening and I was surprised that it actually worked.

I usually start with first slider and use higher as needed. This time I boosted by very small amount even fifth one. Not overly scientific about it - I just went by what looks the best. I did reset sliders a few times because I in first few rounds I just asses how much I can push things and then I go for finding balance.

[Stu]

That’s an excellent image again Craig.

I was observing with my similar scope last night (8” f8) and had some great views; the seeing seemed pretty good! I was picking up the white separation between GRS an SEB which was excellent, not seen that for a while. Crazy thing is I’ve still had clearer views through my Tak when Jupiter was higher! Can’t wait until then, should be fab.

[morimarty]

Thats a great image with lots of detail on show.

[astroman001]

An excellent image from the UK this year. Well done. Better than I have managed with my C14!

Peter

[Pete Presland]

Really nice end result, some really pleasing detail in the GRS especially.