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Old 29-03-2013, 04:01 PM
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OzEclipse (Joe Cali)
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Join Date: Jun 2012
Location: '34 South' Young Hilltops LGA, Australia
Posts: 1,483
Gav,
Can you explain what you mean by harder than it looks? What went wrong when you tried?

Liz,
I couldn't remember or reproduce the Photoshop processing. I've been teaching a variety of photography courses here in Canberra for almost 20 years including courses on Photoshop and Lightroom. I sometimes forget I know a little more than the average person.

o instead I've posted the unprocessed image and a reprocessed image done entirely in Lightroom 3.2 which uses Adobe Camera Raw 6.2 using a raw processing workflow only. No bitmap processing in Photoshop.

You can see the development settings in the reprocessed image. The last two attachments show the setting panels that were hidden in the first screen dump.


My image was taken from the NW suburbs of Canberra with no Moon where the sky is pretty reasonable but not true dark sky. Single exposure of 4s @ ISO 12500 with a 300mmf4 lens and unmodded DSLR. Processed in Lightroom and Photoshop after.

I'll set it all out in case there is something that is obvious camera technique to me but not to you.

Pre-exposure
  • Solid tripod - not a floppy one
  • 300mm f4 lens set to f4
  • cable release
  • careful focusing using live-view.

During exposure

  • ISO 12500 RAW capture
  • Make 4s exposure using cable release and mirror lock up
  • In-camera noise subtraction


Post exposure

  • Import to Lightroom
  • Lightroom Processing as shown
Attached images
1. Raw image converted to jpeg without processing
Lightroom screendump



2. Raw image processed ACR6.2 Lightroom screen dump


3. Screen dump of luminosity setting

4. Screen dump of sharpening and noise reduction settings. The image window also shows what a mess the sharpening and noise reduction has made of 100% scale star images. This method is based on capture and processing for a particular maximum output size.


Note : there are some jpeg aliasing artifacts not present in my version introduced because of the compression required to meet the IIS 200kB file limit.


Joe
Attached Thumbnails
Click for full-size image (Eta Carina unprocessed.jpg)
176.1 KB29 views
Click for full-size image (Eta Carina raw processed.jpg)
175.1 KB31 views
Click for full-size image (Luminance.png)
19.8 KB26 views
Click for full-size image (Detail.png)
59.9 KB25 views

Last edited by OzEclipse; 29-03-2013 at 08:56 PM. Reason: Edited comment re: image 4
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