Posting an image... - Hello, I'm a NEWBIE - HELP!! (Newbies assistance, User Guides and thank you notes) - CHDK Forum supplierdeeply

Posting an image...

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Posting an image...
« on: 22 / August / 2012, 01:56:26 »
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Hello here is an image i shot with my G-12 loaded with CHDK. It is the "summer triangle" that is overhead right now in the northern hemi. It nicely frames the milky way. I piggybacked it on my telescope mount with go-to capability. My G-12 would normally have max exp of 15secs.

Approx 400 secs, iso 800, f/4.0, cam lens at approx 10mm. Covering approx 40 degrees of the sky. I was about 20 miles outside of my city and it is a bit washed out, but i like it.


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Offline lapser

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Re: Posting an image...
« Reply #1 on: 01 / September / 2012, 15:13:49 »
That looks great, and is an example of why I'm so excited about CHDK.

Starting with a raw file will help some. I use Photoshop Lightroom to process the raw files. But it will also help to use regular Photoshop to change the "levels" of the photo using the histogram. You see 3 sliders in the levels option. Slide the lower and upper sliders to the points where the histogram starts to go up. Then slide the center slider until you get the best looking picture. Auto-contrast does something similar,  I think.

I've attached your photo processed this way. Keep shooting!

Bill
EOS-M3_120f / SX50_100b / SX260_101a / G1X_100g / D20_100b
https://www.youtube.com/user/DrLapser/videos

Re: Posting an image...
« Reply #2 on: 01 / September / 2012, 16:46:11 »
Holy C**p you made that look good. Ty. 

i am going to post it on my astronomy email list and give you credit for editing.

Can i do the same in GIMP?   i cant afford PS or lightroom

take care,

Dave

Re: Posting an image...
« Reply #3 on: 01 / September / 2012, 17:02:09 »
Sure you can use gimp. I did it with your original photo. Just use the tool:
Colors -> Brightness/Contrast

I set brightness to -70 and contrast to 80 or 90 (not remember). Here you have:
if (2*b || !2*b) {
    cout<<question
}

Compile error: poor Yorick


Re: Posting an image...
« Reply #4 on: 01 / September / 2012, 17:12:42 »
thanks outslider

Re: Posting an image...
« Reply #5 on: 05 / September / 2012, 23:43:01 »
For very long exposures, you may want to think about using a "darkframe" as well.  You should be able to google plenty of info on the subject.  But basically what you want to do is take a picture with the same settings (ISO, exposure, etc.) as your picture but with the lens cap on.  Optimally, it should also be taken at the same air temperature and camera temperature as your original. 

You can then subtract the noise from your darkframe from the original.  In Gimp load both pictures as a separate layer.  Put the darkframe above the original in the layer list.  Then set the layer mode to "Subtract".

On both my SX20 and a530 I get a patch of reddish noise bleeding down from the top left corner on long exposures.  It looks like you may have the same problem. Subtracting a darkframe gets rid of that nicely.

If you plan on doing a lot of astrophotography, you may want to look into Registax and DeepSkyStacker.  They're both free.

Re: Posting an image...
« Reply #6 on: 05 / October / 2012, 21:02:00 »
Thanks xeju. I now have Gimp, DSS, and photoshop elements. So i will try the layering options. Heres a timelapse i took two weeks ago. I used interval.bas. I shot  through my G-12 at f/4.0, 400 or so frames, ISO 800, 20 sec exposures , noise reduction on which gave me my interval. Its noisy, so i'll need to address that next shoot. At the end you will see my friend with his astronomy set-up.


St Rita Timelapse se23/2012
« Last Edit: 05 / October / 2012, 21:41:16 by spark802 »

Re: Posting an image...
« Reply #7 on: 11 / October / 2012, 20:48:47 »
Heres a shot of Orion with my G-12 loaded with CHDK at 10,000 iso.15 secs, f/4.0 or so.


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Online blackhole

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Re: Posting an image...
« Reply #8 on: 12 / October / 2012, 10:04:31 »
It looks good.
 I tried to process your previous picture and got a lot of details.


Re: Posting an image...
« Reply #9 on: 12 / October / 2012, 19:39:28 »
That looks great, and is an example of why I'm so excited about CHDK.

Starting with a raw file will help some. I use Photoshop Lightroom to process the raw files. But it will also help to use regular Photoshop to change the "levels" of the photo using the histogram. You see 3 sliders in the levels option. Slide the lower and upper sliders to the points where the histogram starts to go up. Then slide the center slider until you get the best looking picture.

Ok so now i have photoshop elements.I will look for the histogram color options there.

 

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