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first go at imaging saturn

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20 years 5 months ago #1939 by michaeloconnell
Replied by michaeloconnell on topic Re: first go at imaging saturn
Dave G:
That's a good idea you have with the sheet. It'd be good if we could come up with a standard method for taking images. Next time I try it, I'll make sure to have a few of those printed off and make a note of my settings. Good idea! :idea:

Dave L:
The more frames u run the better the image. Each image will always be very noisy/grainy looking but the noise tends to cancel itself out with the more images u take. If I were doing it again, I'd go for at leat 1,500 or mabey even 2,000. I reckon Saturn can take that.
However, Jupiter and, to a lesser extent, Mars are a different story. As they have surface detail, too long an exposure will smear the detail. How long is too long?? - no idea! Will find out in due course. This was my first night recording a video clip as long as that.
Apparently the webcam is electronically designed with a max exposure time of 5fps, so recording a video clip at 3fps "may" not actually be improving the situation. I wonder, is it grabbing a single 0.2sec frame and digitally multiplying to create an image of exposure similar to 0.333 sec??? Don't know for sure but it is a thought.
When I get home this evening, I'll post a snapshot of what a still frame looks like.

Michael

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20 years 5 months ago #1946 by michaeloconnell
Replied by michaeloconnell on topic Re: first go at imaging saturn
Here's a print-screen of one of the better frames from my avi file.

In this frame the cassini division is apparent. However, this wasn't the case for all the frames due to the atmospheric turbulence.

Michael

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20 years 5 months ago #1964 by
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Michael,
If it were manipulating 2 frames to give an apparent fps of 3.3, I dont think that would be a good thing, in that you might end up smearing good frames with not so good frames and never getting "perfect" frames???

Using astrosnap, each frame for me ends up been approx in size, 225k , 2k of these frames would amount to about half a gig of harddrive space, does it take registax2 along time to process? did you do an all nighter.

BTW, either the image of saturn is extremely faint on the image in the previous post (and I'm too tired to see it properly) or the wrong pic is there ??????

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20 years 5 months ago #1965 by dave_lillis
Replied by dave_lillis on topic Re: first go at imaging saturn
That last post was from me, I didnt mean to log in as a guest.

Anyway, what I'm really asking is that can you get the same image from 150 frames or must you go so high, do you have an equivilant image from just 100-200 frames. ?

Dave L. on facebook , See my images in flickr
Chairman. Shannonside Astronomy Club (Limerick)

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but what a way to go. :)
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20 years 5 months ago #1967 by daveg
Replied by daveg on topic Re: first go at imaging saturn
DaveL

Yeah, each frame is 225k and 1500 @ 5fps is approx 650MB. The image on the webcam data page is from 150 frames and isn't asa clear as michaels 1500 frame image. It takes Regi about 30mins on my laptop (pentium 2.5GHz 128 MB RAM) to do the 1500 fames.

DaveG

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20 years 5 months ago #1969 by michaeloconnell
Replied by michaeloconnell on topic Re: first go at imaging saturn
My understanding is that the image of Saturn should be fairly faint on the screen before u start recording. You should only be barely able to make out all of the rings. If you have 1,500 frames and then add the best 15% say, that's still adding over 200 images together. If the original image is too bright, then the detail becomes washed out when all the frames are added together - or at least that's my understanding of it anyway.
If I were doing it again, I would have the brightness a TINY bit higher but that's all. The reason why I would adjust it a small amount is just to get the bit of the A ring behind the pole.
BTW, the image in my previous post is correct. Perhaps if you re-calibrate your monitor you might see it better or try it on the PC rather than the laptop.
Michael
P.S. I simply recorded my avi files and then processed them the following day. It takes about the 30mins (rough estimate) for my PC to process each. (1.7GHz 512mb RAM)

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