My Best Jupiters So far - 15 Sep 2012

[SeedyF]

I was out at 4am on a Saturday morning for the second week on the trot today - and well worth it both times to see Jupiter high in the sky

I think I am getting the hang of the 250 dob now and this weeks images are better than last weeks. Even though I thought the seeing last week was better - just shows what I know!!

Here are the best two with Ganymede off to the left. Still some way off Neil Philips and Space Cowboy standards but it's progress

These were taken & processed using the following;

Skywatcher 250px Flextube Goto Dob

Philips SPC900 webcam with IR Filter

TAL 3x Barlow

Captured in SharpCap at 10 fps, 4 min AVIs

Stacked in Registax 5

Tweaked in Photoshop

[Freddie]

Chris, looking very nice. Worth getting up for.

You are maybe a touch over exposed as it looks like some of the fine detail is a little "washed out".

[Pete Presland]

looking very good, certainly getting some very good results from the spc900, well worth the effort.

[SeedyF]

Thanks guys.

I pushed the exposure up one notch on these two which seems to be my problem and may have washed it out a bit in processing.

Using the tips Neil Phillips gives on wavelets I've had another go at the second image above this time using Dyadic wavelets.

[Space Cowboy]

Nice images Chris just a shame the brightness is washing things out a little. If you are using sharpcap to capture I would make sure the histogram is 60-70% and keep saturation at default setting.

How is your Dob tracking? Do you fancy using more fl, maybe f25 range?

[SeedyF]

Stuart - last week it was fantastic, no visible drift, but today there was a little drift. Not enough to need any adjustment in a 4 minute capture though. I think I need to look at the backlash.

I stacked my TAL 3x and my budget 2x barlows together last week and the image was stable in the centre of the picture. The poor quality 2x barlow meant the resulting image was unusable but it was a good experiment!

[JohnC]

Great shots, look forward to future ones.

John

[Space Cowboy]

Stuart - last week it was fantastic, no visible drift, but today there was a little drift. Not enough to need any adjustment in a 4 minute capture though. I think I need to look at the backlash.

I stacked my TAL 3x and my budget 2x barlows together last week and the image was stable in the centre of the picture. The poor quality 2x barlow meant the resulting image was unusable but it was a good experiment!

Blimey Chris if you don't need to make any adjustments during 4 mins your scope is tracking miles better than mine as I have to use the hand control every 30 secs.

Can you unscrew the lens off your 2x barlow to make an extension tube?

[neil phillips]

Hi Chris your getting there. I reckon you could go up a bit in focal length. if you have good tracking perhaps try a long tube extension. at least two inches. with the tal. it will give you a bigger image. just set the exposure so that when gain is at about 85 90% the image is not dim. you need to get the image so that the white clouds do not look burnt out. i dont think the levels here actually look that bad.

i cant see no burn out. I havent used a spc for some time. but the ideal exposure is usually 1/25th secs. 1/23rd whatever. So that it has some speed to beat the seeing. i would be tempted if i was you. to put a two inch tube on that tal. Maybe even more. ( 2.5 or 3" ) put it between the barlow and the camera. focus as best you can. set exposure to what i suggested, around 1/ 25th secs and the settings Stuart suggested. Then wack gain up to full. Hopefully the image will look a little burned out in the middle. if so back off the gain untill you see the white clouds look more under control and not over bright. Its a good way to learn without relying on numbers all the time. Then defocus and refocus watching the detail on the screen from about 2 or 3 feet away ( trust me it works ) you should start to see some very fine detail on screen. when you see that start capture. If all this works out try 3 or 4 mins at 10 fps and capture away. shoot jupiter as high and late as possible. i reckon you could get a lot closer to Stuart. You just need to learn how. Its hard to give advice from afar. But i reckon you can do it. you just need to get the right powers going. and the camera settings working at there best. your focal length here is on the small side. your 10" will surprise you Chris. These are the kind of things i would be doing if your setup was here. Hopefully your collimation is very good. and your optics always cooled

[Ewan]

Nice pictures Chris, i was out at the same time as you doing the same thing but experimenting with HD video, still prefer Toucam really as you just pop it in & go tbh.

Sky seemed a little bright last night for some reasons or my eyes were foggy

[SeedyF]

Thanks For the input Neil & Stuart and the positive comments from everyone.

Now I know I can start picking out detail I'm keen to keep pushing. My rubbish barlow does have a screw off lens and is 5cm once the lens is off so it will give me a bit more size. As soon as I get the chance I'll try that and fiddling with the settings you've both suggested. I need to play with Sharpcap in the daytime because I don't know half of its features. I have no idea how to access the histogram - lol.

Onwards and upwards

[Space Cowboy]

Good points made by Neil there. The histogram option is on the drop down menu next to reticule on the toolbar at top of the display screen. Sometimes the screen brightness of your monitor can make judging the light level tricky by eye so the histo is a fool proof method, its certainly made my images more consistent since I started using it 12 mths ago.

When I first starting imaging with my Dob I too used the 3x Tal which I then combined with a 2x SW barlow tube giving around f24. For sure the 5x Powermate is a great tool but lovely images can be had with the 3x + extension. Simply sliding the webcam nose further out of the focusser adds extra fl too.

[Clayton]

Nice shots Chris!

Exposure looks good to me with no burnout ( histo backs this up)

I remember the histogram in Sharpcap is a bit tricky to find, but don't use it so maybe someone else can help.