Jupiter 18th Nov - better seeing after midnight here in London

[jimness]

Amazing! I think this one is even better!

Can I ask, how much time do you spend with collimation? Do you check it often and do you have a special method?

I'm just trying to workout how you're getting such superb images!

Thanks! Yeah, collimation is pretty painful - in fact a few days earlier I thought I'd really nailed it; the seeing was excellent and I actually had nice concentric rings rather than some crazy ring-of-fire arrangement - so I got it collimated as well as I could using the same camera and x3 barlow, on Aldebaran (I think, anyway it was close to Jupiter). There was me thinking I'd finally nailed collimation; pointed the scope at Jupiter, and then the fog descended.

This weekend I couldn't collimate at all; the seeing was rubbish earlier on. But I kept it going as I'd set things up to capture remotely, and when the seeing improved I guess it showed that the collimation had held well.

I'd always at least check collimation before any session, if possible - I've seen occasions where I'd collimated just a few days before and then it had gone right out, probably cos of the old mirror shift problem on these SCTs. It's not exactly fun; on the other hand, the process itself gives you a good idea if what the seeing's like, so it works out that collimation is a much easier process on those nights when it's really worth doing...

Jim

[Space Cowboy]

Hats off to you Jim thats a world class image you have there! Detail inside the GRS is something special. Sub 10" scope in the UK....awesome!

[neil phillips]

Thanks again.

Yes, exactly the same process. I wasn't certain the AVIs needed derotating with just 2 mins but I thought I'd do it anyway as it wouldn't do any harm. Then the same RGB derotating too.

This one was a slightly 'cleaner' set - with the 3 min ones, SharpCap crashed on the Green (I think?) channel, so I ended up doing it again some minutes later - meaning the whole set of captures covered a good 12 minutes or so. But these 2 min ones were all done in quick succession so less derotation was needed, which I think has improved the limbs slightly.

13fps by the way, I think (Exposure -4 in Sharpcap) and a cheapo 3x Barlow. I have a Televue x2.5 but find the larger image size of the x3 outweighs the brighter exposure of the x2.5.

Jim

Hi again Jim im a little confused. could you tell me what the total capture time was for all 3 rgbs. And or each channel ? Your seeing must have been good at 13 fps. why such a slow frame rate Jim ?

I dont shoot any lower than 30fps. was it very bad transparency that forced you at this frame rate ? I am guessing thats a yes, especialy as the calmest air often happens with bad mist and dew. ( though not always )

I noticed you used sharpcap. Why not IC capture ? I cant remember the focal length of the C9.25 but its 3x that, so about 8000mm Focal length is that about right. ?

For most seeing in the uk 8000 mm FL is pretty optimum for sharpness, with smaller scopes. Jupiter does look like its got bigger and brighter. I havent managed to image for weeks now. Hopeing to get some of this misty calm air over Essex in the next 3 weeks blow some this way Jim please.

The image is so good i feel odd saying this, but with better trans, i reckon you could improve on this at 30 fps. This is the 618 dmk isnt it ?

Hope you dont mind these discussions, youve created a buzz on here. Its about time we got a image like this from smaller scopes in the uk. its been a long time.

The good thing is it aint over yet. I am sure Freddie will be getting a killer shot too soon. Hes images have looked very good. And of course Stuart hasnt nailed one yet. And dare i say myself. But its great shots like this that will inspire everyone im sure.

I know i keep saying it. but just love this shot. its got beautiful colour rendition. Is very soft and natural. But has sharp non rotated features. meaning no rotation blur seems to be showing at all.

Just a class capture, and class processing. I am actually quite excited seeing this. so far the uk has just dealt most of us averagely good images. Not great ones like this. Just hope the weather changes quite soon. you cant underestimate how much better the images come out when Jupiter is prime time under good seeing. As youve snatched here. Great job.

[jimness]

Hi Neil,

For the first image, the total capture time was 9 minutes - though due to the software crashing in the middle the start of the red to the end of the blue would have ended up being more like 12-13 minutes, I think. I could confirm this more accurately later if need be.

The second image is from a total of 6 minutes, 2 minutes for each channel. No crashes so no more than 7 minutes to cover the lot I'd say.

Now I mentioned 13fps, which is what I calculated from what SharpCap told me ('captured 2340 frames in 180s' or whatever it was). I probably ought to verify that in Registax or something to be sure! Also, I failed to mention that the second image was actually 21fps. These values equate to exposure -4 (13fps) and -5 (21fps) in Sharpcap - I guess that might vary depending on the camera used. I don't think I've ever managed 30fps with a 3x barlow, unless I used maximum gain....remember the C925 has a nice big obstruction in the middle and is F10, so your scope will be passing a lot more light through than mine. Focal length of the 9.25 is 2350mm - so 7050mm with a 3x Barlow, then whatever the DMK turns that into...

I typically use low gamma (one step up from the bottom), high but well shy of maximum gain, and set the exposure to the fastest I can get away with at those settings. I reckon there might have been some dew forming hence going down to 13fps; last night I applied the missus' hairdryer and got comfortable brightness at 21fps, though the seeing was rotten. I was indoors throughout Sunday night's session, pretty much, having got the filter wheel software finally working and my wireless network extended to the bottom of the garden, so I didn't have much visual feedback of what was actually going on out there; only got the nice surprise on the wavelets page the next day! The reason I want to do this remotely is because my set up is on ultra-wobbly wooden decking; I reckon even breathing whilst sitting in there affects the steadiness. Of course when my cats start clambering all over the shed then it's game over.

I've tried IC Cpature, in fact I gave it another go that night, at 27fps - but I really like the simplicity of Sharpcap, and particularly how it auto-names files in a way that's actually useful. After all if you set the software up with the same settings using the same camera you'll end up with exactly the same AVI, I'm pretty sure.

The camera was actually originally a DBK21, I believe, but the chip replaced with the mono ICX618. I bought it already modded; I assume it's effectively identical to a DMK21AU618.

One tiny note on the colour rendering; I guess this is mostly due to getting the correct exposures with each channel, but I also have an action in Photoshop I made which auto-balances the colour channels, which usually helps with these images. Unfortunately I can't remember exactly how it works as I nicked it from a book (a photography book rather than astrophotography) - but basically it adjusts the curves individually on each of the R,G,B channels so that each one has the exact same brightness levels. You might be able to find this with some googling (as long as you have Photoshop of course)

I've gotta say Neil, your images last year were a real inspiration to me and surely many others on here; I'm delighted to be able to build on that and am really looking forward to what you come up with soon! 60 degrees is what it's all about mate...

Cheers

Jim

[jimness]

Seems like the original Flickr link has barfed up for some reason...how do I edit a post?? Anyway here's the new link (dunno why it changed)

[AztecastroMcJ]

Excellent results and nice process Jim, some great details there,

and done remotely aswell, well done

James

[bus_ter]

I've just been looking at all the recent Jupiter images and then came back here.. WOW all over again! It's leaps and bounds above the average standard. Even with a mainstream scope and camera (If you ever get a hold of a C14 Damian Peach will need to watch out!).

Do you have a list of tips, or advice, or whatever it is that enabled you to take it to the next level?

[neil phillips]

Thanks for the reply Jim, that tells me a lot. The first image is good, Still loaded with detail, but the second looks better to me. 12 ? 13 mins for a rgb run is amazingly long time for jupiter, i think this shows the power of Winjupos de rotate rarther well. Not sure if its the faster frame rate or the time being easier on winjupos but the second image looks better for it. certainly less artifacts

I think if anything this shows there maybe a limit to time spans and any advantage in using long ones with winjupos. I am personally going to experiment with 9 min captures all 1 min sequences first by de rotating the single 1 min images into combined RGBs and then combinging again on winjupos. And also 2 min runs ) so 6 mins in total ) for some quicker processing.

I havent tried de rotate avis yet, if i get any good data after seeing this i will likely try that too. ( but will have to get advice as ive not done that before ) I think de rotating images is fine if the data is good. But i am undecided at the moment if its worse than avi de rotation ?

As for your colour comments i dont have PS but i belive registax auto colour balance does a similar job. Which is what i use. The thing i personally like about IC capture is the colour histogram grapths which makes it easier to balance the colour channel histograms. Ive not tried sharpcap.

Thanks for your comments about last years shots. I actually did better last year than this year so far. which is nuts considering how much higher Jupiter is. But ive had lots of equipment issues.

and havent imaged anything for weeks. I now have a new focusser sitting on my newt. Though i have to work on it again tomorrow, as it hasnt all lined up as good as i want. Hoping to nail that collimation problem soon. When the next clear night happens i should be back in action. Though if seeing is rubbish it will be more average images likely. But at least i will be ready for any other good nights that hopefully will come before Jupiters size decreases.

I looked at your earller imaging session post on here Jim. And the leap in processing quality, and seeing quality was very dramatic. Dont think ive seen anyone jump so fast in quality between

nights Before. Its amazing to see. The second image does it for me. I will be watching everything you post from now on thats for sure. Hope you dont mind astro stalkers

Thanks again for all the info. Keep up the amazing work.