Morning Saturn - Jan 5

[Sebbie (Sebastian)]

Got up in the early dawn hours and was amazed how steady the atmosphere was. Saturn looked sharp and steady at f20 so I finally gave TV 3x Barlow a go.

Sequence of three images taken 15 minutes before sunrise.. higher elevation makes a big difference!

[MGTechDVP (Mariusz)]

Fantastic... What scope are you using?

[EricB (Eric)]

Fantastic pictures Seb. Well done


Eric

[asimov (John)]

Yes, good seeing is the key but when it gets to be almost overhead later, any ordinary or bad seeing will be very forgiving. Nice work.

[Saturn%5 (Graeme)]

Nice work

[Shiraz (Ray)]

excellent Sebastian - top quality.

[Jen]

Dam how do you do that scope? Camera? Processing?
Nice pics

[Larryp (Laurie)]

Great pics, Sebastian!

[Sebbie (Sebastian)]

Thanks everyone, I've created a signature block listing my equipment.

For Saturn images DFK21AU618 CCD was used in Y800 (640x480) 60fps IC Capture mode. Meade 12'' LX200 @ F30 (employing TeleVue 3x barlow), exposure set to 1/60 sec. 600 frames double stacked in AS!2 followed by RGB correction, gamma & wavelets in Registax. Final touches (including colour balancing) in ACDSee Pro.

To summarise.. a lot of image processing work!!! I'm attaching one of the raw stacks for reference.

Recent good seeing allowed me to accurately collimate my scope which has helped a lot. One problem I'm currently faced with concerns dust particles in the optical train; they are severely enlarged at F30 causing detail smearing during stacking. I have checked both barlow and the camera and even moved them around while watching the preview but the specks did not move..

Does anyone know if there's some way of removing these pre-stack? See attached Jupiter avi frame..

Thanks,
Seb

[asimov (John)]

The dust motes are on the covergass that covers the chip. Camera blower brush to start with & if they don't shift, a cotton bud & distilled water. The glass cover is very resilient to scratching however a LIGHT TOUCH is required. Ive been doing it this way for 6 years. After saying that, I had one Imaging Source camera that was faulty - The motes were on the chip underneath the coverplate..It's non removable without knowing what your doing, not to mention warranty voiding.

[Sebbie (Sebastian)]

Originally Posted by asimov

The dust motes are on the covergass that covers the chip

Thanks John, I had a quick look and it's really difficult to identify anything visually - see attached pic. Used the dust blower but stopped short from camel brushing glass cover for now.. will check if it's made any difference next time I'm imaging.

I have Maxim DL software and remember seeing something about removing circular noise patterns.. Do you know if raw avis can be fed through some cleansing routine? I have quite a lot of Jupiter data from last week in need of processing.

[asimov (John)]

Yes. They are unbelievably small & near impossible to detect with the eye though Sebastion..

I published a short article for cleaning chips, & inspection with a barlow at the computer, in a brightly lit room. I'll see if I can find it rather than type it out again..

[asimov (John)]

Ok I wrote this before I found out about the barlow technique. http://oortcloud.org/index.php?topic...79090#msg79090

What I do now is similar, only I leave the nose cone off, hold the 2X barlow in front of the chip, slowly pan around a room with a light on (with the camera working & hooked to the laptop of course!) & eventually with the right lighting circumstance, you'll see the motes. Clean & repeat. 10X if U have to lol. If they don't shift...you might have what I had (motes under coverplate) which is bad.

The idea of using the barlow is simple; a bigger magnification makes them way easier to see. The other possibility is motes on the barlow elements but unlikely..The barlow is too far away from the imaging plane..

[Sebbie (Sebastian)]

Thanks, sounds like fun..

I hope I don't have these 'built in'.

[Poita (Peter)]

Thanks so much for the raw images as well, it is so helpful to know how much of the image is in the processing.

Cleaning the sensor will usually get rid of the dust specs, I use a microscope to inspect the ccd window.