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Star trails;)

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Offline outslider

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Re: Star trails;)
« Reply #10 on: 04 / March / 2012, 09:16:12 »
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Comparing with yours my photo is rather modest, but I still like to share it :)
It was around 200 photos from my window. This huge trail is from moon (there were some clouds there). Looks catastrophic...
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Offline imtheguy

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Re: Star trails;)
« Reply #11 on: 05 / March / 2012, 00:24:24 »
Quote from: outslider on 04 / March / 2012, 09:16:12
Comparing with yours my photo is rather modest, but I still like to share it :)
It was around 200 photos from my window. This huge trail is from moon (there were some clouds there). Looks catastrophic...

Cool effect!   I had considered but not shot the moon yet.  Definitly looks like a pile of space rubble should be on the ground somewhere over the horizon.  Also looks like you have DFS still on (like my Elph300) and could use the StarTracer program to fill in all the gaps if you wished.
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Offline outslider

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Re: Star trails;)
« Reply #12 on: 05 / March / 2012, 05:37:52 »
A... StarTracer? I'll test it tonight! Looks cool.

I was also thinking of adding a CHDK function for raws for star trails (just like we have raw-sum and raw-average, I could add raw-sum-lighten). This shouldn't be defficult to do, the raw-sum code should be just taken and a simple if() statement have to be used. This would work almost as fast as raw-sum we have now (which is not very fast, but this way you'd have stars-trail photo directly in RAW format!).

This would be usefull not only for star trails, but also for car trails and so on.
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Offline imtheguy

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Re: Star trails;)
« Reply #13 on: 05 / March / 2012, 12:06:16 »
Quote from: outslider on 05 / March / 2012, 05:37:52
A... StarTracer? I'll test it tonight! Looks cool.

I was also thinking of adding a CHDK function for raws for star trails (just like we have raw-sum and raw-average, I could add raw-sum-lighten). This shouldn't be defficult to do, the raw-sum code should be just taken and a simple if() statement have to be used. This would work almost as fast as raw-sum we have now (which is not very fast, but this way you'd have stars-trail photo directly in RAW format!).

This would be usefull not only for star trails, but also for car trails and so on.

Sorry, should have included a link to StarTracer and his other related stuff here --> http://www.tawbaware.com

As far as RAW format for stars....I will be happy just to get the DFS working so I can use that 24mm wide lens on the sky.  Other than possible oversharpening by the camera during jpg processing that would enhance noise, I have yet to find a reason to shoot star trails in RAW just because in my one test did not find enough difference to justify the extra work.  Its not like there is any real tonality that is enhanced with more bits per pixel.   But I am open to learn.

If I ever get DFS working I will shoot a trail in RAW and post the jpg vs raw results.
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Offline outslider

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Re: Star trails;)
« Reply #14 on: 05 / March / 2012, 14:37:07 »
I had DFS off on these photos. But these photos were taken not exactly to do star trails but timelapse video. However, it was not very interesting, so I made star trails instead. Since the delay between photos was ~ 60 sec and exposure time was around 20-30 sec. there are gaps on trails. The other reason for gaps are clouds (especially visible on moon's trail).

I wonder how would sun trail look like taken on sunrise...
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Offline imtheguy

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Re: Star trails;)
« Reply #15 on: 05 / March / 2012, 15:00:16 »
Quote from: outslider on 05 / March / 2012, 14:37:07
I had DFS off on these photos. But these photos were taken not exactly to do star trails but timelapse video. However, it was not very interesting, so I made star trails instead. Since the delay between photos was ~ 60 sec and exposure time was around 20-30 sec. there are gaps on trails. The other reason for gaps are clouds (especially visible on moon's trail).

I wonder how would sun trail look like taken on sunrise...

Yikes...you are the man.  I am so far unable to either expose beyond the 15sec camera max or turn off DFS in the Elph300.  I have tried both Interval.LUA as well as just taking manual shots with overrides set to 25sec exposure but so far no joy.   Anything you might be doing that is not obvious to me to obtain >15sec and no DFS?   

Many thanks.
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Offline imtheguy

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Re: Star trails;)
« Reply #16 on: 05 / March / 2012, 15:25:25 »
Quote from: outslider on 05 / March / 2012, 14:37:07
I wonder how would sun trail look like taken on sunrise...

I was fortunate to have access to a lighthouse to shoot the sunrise but i made a timelapse instead of a trail.  once all the wonderful color and highlights fade it quickly becomes pretty dull.  If I were to shoot a sun trail I would definitly use one of my wide lenses on a dslr that provide sharply defined starburst.  Probably my Pentax da15mm Ltd. lens is the best I know of.  You have given me something to try.
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Offline outslider

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Re: Star trails;)
« Reply #17 on: 05 / March / 2012, 16:24:07 »
I'm waiting for the results;) Unfortunately I own only sx130, so this cheap camera has some limitations, especially according to lens... But it's enough to learn more and do some experiments.

Currently my camera stays in a university laboratory and takes shoots - I like to see, how does light change in the lab during the sunrise ;)
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Offline mikeworth

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Re: Star trails;)
« Reply #18 on: 31 / May / 2012, 08:14:34 »
This is something I've had a quick go at; light pollution is washing out most of the visible stars, although on a night with no moon and maybe pointed away from lights might give me a better chance of lots of trails. Unfortunately most of the pretty buildings are lit at night which causes problems getting both a nice foreground and nice sky. I've avoided the battery issue by building an AC adaptor which allows the camera to keep shooting until the card is full. The camera is a powershot A800

Here is what I managed to get first try:

There was too long between each exposure and some cloud which caused the dotted trails and smoke effect.

Mike
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Offline outslider

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Re: Star trails;)
« Reply #19 on: 01 / June / 2012, 00:52:36 »
Seems like you have used high ISO (noises). Try to use lower ISO but longer shutter time. This also helps with less gaps.

The background is in fact very pretty!
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