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Saturn with Mak 127 and SPC900


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Hi everyone,

These are hardly comparable with some of the incredible Saturn pics we've seen on here over the last few days, but thought I'd show what I managed to get out of the set up mentioned in the title, and a standard kit 2x barlow back at the start of April. No real beauties yet with the 3x barlow, it's so dim the only way to get a reasonable image is to slam all the camera settings up so far that registax can't make out the planet from the noise! That barlow did only cost a tenner though, so I guess I shouldn't expect miracles!

5 min avi, captured through Sharpcap and run through Registax. I'm working on learning to use other software, but until I can be sure I'm getting better results from that, I'll still with what I know!

Tons of room for improvement on the processing, and although a part of me wants to rush out and upgrade my kit, there's a part of me that says "hey, you see that little dot in the sky up there, I took a picture of that with some pretty basic kit from my back garden and it came out like this!"

Curious to know how long other people are running their captures for on Saturn - it seems to me there's less surface detail to suffer from rotational blur as there is on Jupiter, so I'm wondering whether there'd be any gain from running a 10 - 15 minute capture to maximise frames, so that you can be really picky about stacking only the best?

As always, any advice welcomed.

D.

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Nice images. Winjupos de-rotation of images works best for using up to 30 mins of data producing a smoother image. Say you stack 3 or 4 images from a 25 min period and then combine them into one image in winjupos.

Edited by Space Cowboy
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Thanks all, certainly a huge improvement from the days of pointing an average digital camera down the eye-piece!

Stuart, are you noticing a considerable effect on your images by doing that? I have wondered before if there was a way to stack strong individual images instead of the standard avi frames - it sounds like that might be it!

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Thanks for that Stuart, I'll look into that. Sounds like very interesting software.

Thanks James, I have seen plenty better taken with the mak, but most are using an extension tube I think, so that is an experiment I must try soon too. The weather hasn't been great has it - I've had 2 good nights at the start of April and one aborted attempt due to mist and haze back in March. It's frustrating as I know there's still improvement to be made just by getting the basic camera settings right (I feel the SPC900 can make planets look a bit like something out of a kids cartoon if you don't nail the settings!) but when you can get out with the scope it always seems like a wasted opportunity to be tinkering with settings and running tests!

Maybe I should bite the bullet and take advantage of the next reasonable night to do exactly that. I'd hate for that one magic night of great seeing to come around and I waste it trying to figure out what settings are best for the camera!

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With the 127 Mak (with any Mak or SCT probably), adding an extension either before or after the barlow effectively gives you a bit more focal length because focusing "further out" with this design of telescope means moving the focal plane outwards which means in turn that the focal length is increased. This has the benefit of giving a larger image with the downside of reducing the amount of light available per pixel.

I use a 2.5x barlow with a 40mm extension behind it for imaging Jupiter with the SPC900, but I might drop the extension for imaging Saturn if it turns out I can't get enough light on the sensor for a good image, or even drop down to a 2x barlow.

James

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With the 127 Mak (with any Mak or SCT probably), adding an extension either before or after the barlow effectively gives you a bit more focal length because focusing "further out" with this design of telescope means moving the focal plane outwards which means in turn that the focal length is increased. This has the benefit of giving a larger image with the downside of reducing the amount of light available per pixel.

I use a 2.5x barlow with a 40mm extension behind it for imaging Jupiter with the SPC900, but I might drop the extension for imaging Saturn if it turns out I can't get enough light on the sensor for a good image, or even drop down to a 2x barlow.

James

Pushing the focal plane further out with extension tubes (or flip-mirror) increases the focal length of those SCTs and Maks that focus by moving the main mirror (not all do). Adding a tube after the barlow only has an effect on classical barlows, but not on telecentric lenses such as TV PowerMates and Meade TeleXtenders (except for the 5x PowerMate). In telecentric lenses the distance from lens to the sensor or field stop has little or no effect,

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Pushing the focal plane further out with extension tubes (or flip-mirror) increases the focal length of those SCTs and Maks that focus by moving the main mirror (not all do). Adding a tube after the barlow only has an effect on classical barlows, but not on telecentric lenses such as TV PowerMates and Meade TeleXtenders (except for the 5x PowerMate). In telecentric lenses the distance from lens to the sensor or field stop has little or no effect,

Yes, I didn't intend to include powermates and telextenders in my definition of "barlow" (I don't personally consider them to be one). I should have made that clear.

I've never seen a Mak or SCT that didn't focus by moving the primary. Do you know of an example I can google for?

James

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Some rare beasts have a separate focuser:

Officina Stellare Supremo 250

I have seen one weird SCT (not sure if produced commercially) which had a fixed primary. The OMC300 (modfied Cassegrain really, more of a Klevtzov-like design) also has a fixed mirror.

Anybody using a Crayford or R&P focuser on and SCT should be aware that the extension tube effect only works if you use the built-in mirror shifting focuser.

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Good point about using a secondary focuser. I can't look at OS telescopes unfortunately. It takes too long to dry the drool out of my keyboard.

James

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Thanks folks, you're very kind! And thanks to everyone who's offered advice in my first year as an SGL member, it's helped massively!

As a relative newbie to imaging, I've found the SPC900 to be a little beauty. I was lucky enough to pick mine up for £20, but it's worth so much more to me! My finger hovered over the "purchase now" button for an ASI120 camera the other day, but a combination of having to save for a house deposit, a "don't you dare" glance from the Mrs and an interesting debate in another thread about the ASI vs Flea vs DMK battle (among others) stopped me from going through with it. I'm approaching those crossroads of wanting better images, and having to decide whether I head down the route of a better camera or a bigger scope! Or both, of course, but that will never get signed off by the Mrs, however many fancy scarves and pairs of shoes she might have!! :rolleyes:

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Derek

I too have pondered getting a bigger scope due to wanting bigger images. I have come to the conclusion that working with a smaller scope forces you to work harder at honing your techniques, so I am going to stay with my 6 inch kit for a while. I have been getting some cracking images of Saturn lately and its a real joy. I also like the fact that I can set up and pack up pretty quickly after a session, and my scope doubles as a wildlife spotter in the day time. There is a lot to be said for smaller, lighter kit!

regards

Dan

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I think you're right Dan - I've become so attached to my little setup for so many reasons that I think I'd rather go down the camera route. I think if I do get another scope it would be something geared more towards dso imaging, as I'd like that variety around what I can image. Plus I'd like not to fall into the trap of always wanting a bigger scope, however large I go, and seeing the amazing results of the C11s and C14s here on SGL, I could see that I would never be truly satisfied until I've got something equally huge in my back garden!!

You have been getting some great Saturn shots! I'm hoping to get out again soon as Saturn's a wee bit brighter now than when I last got out, so fingers crossed, though the forecast isn't great.

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