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View Full Version here: : Another great saturn night last night (30/1)


bird
31-01-2007, 08:57 PM
Last night was my last night of imaging on this trip, and probably the last night of imaging for saturn this year as I'll be focussing on Jupiter when I get home on Friday.

It's been a fairly long trip - Lostock, then Pt MacQuarie, then Glen Innes, and finally home again in a couple of days with lots and lots of data, probably about 200Gb of stuff all up.

The seeing hasn't been that good here in Glen the last few days, until last night :-) when I found the best seeing of the whole trip, and it lasted a good couple of hours around 2am when Saturn was at its highest.

I already had lots of RGB saturn data from Lostock, so I focussed purely on capturing luminance data last night. Lots and lots of Luminance. 45Gb of Luminance data to be precise :-) I plan on combining this with the RGB data from Lostock.

For the time being it can sit on the laptop until I get home, but then the great Reprocessing Of Data will begin, and hopefully something nice will pop out the other end...

I also think I've solved a long-standing mystery that has prevented me from using luminance data in the past - I use a 5x powermate + extension tubes that put the camera about 12cm from the top surface of the powermate, giving me more than the 5x nominal power, more like 6.5x. But I think this extension has an unfortunate side effect of introducing a slight amount of chromatic abberation, not enough to be visible in an eyepiece, but enough to blur a luminance image in teh camera taken with no filters.

So last night I removed the extension and used the powermate as a 5x, the way it was intended, and the focus and clarity in the luminance data was
much better. The image was a bit smaller as well, so I could use lower gain which is also nice.

Other people using a 5x powermate - Iceman - might want to try this as well and see if it makes the luminance data clearer.

cheers, Bird

matt
31-01-2007, 09:04 PM
Good stuff, Bird.

Can't wait to see the resulting images.

All this RGB and Luminance talk is foreign territory to me, but something I'm keen to learn as I look to take a step up from the beloved ToUcam.

I nearly placed an order for a DMK21AF04 today. Nearly;)

I wouldn't mind practicing with a firewire mono ccd cam before shelling out the coin.

iceman
01-02-2007, 08:12 AM
Sounds great, Anthony! Can't wait to see the data.. I can see the "real work" backlog piling up already :)

I don't use an extension with my 5x powermate unless the seeing is REALLY good, however there's a natural extension with the filter wheel, giving me about 6-6.5x as well. For luminance in future I might try putting the camera directly in the 5x powermate, and remove the filter wheel (and therefore the extension) from the equatino.

davidpretorius
01-02-2007, 08:45 AM
thanks for the heads up, looking forward to the finished product.

I always use the extension tube with the 5x, cos i am stubborn, too lazy to take it out and only image in colour......but once I have a new camera, i will give what you say a rip! - thanks