Double Exposure RAW Files Poorly Processed

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Level 1

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Double Exposure RAW Files Poorly Processed

I have an Olympus OMD-EM5. I'm shooting double exposures and when I import the RAW files into Aperture, once the Aperture preview is generated the picture becomes horribly over processed. Saturation seems maxed out on things like leaves, but also colors shift: a pale blue flower turns deep purple. I tried shooting RAW + JPEGs and the JPEGs of course look fine in Aperture as they do in camera and are not reprocessed in any apparent way. So the glitch seems to be in processing RAW double exposures.

Is anyone else working with double exposures seeing the same problem with their RAW files? Any ideas and what is happening?

Thanks

MacBook Pro, Mac OS X (10.6), 15" MBP; OSX 10.6; 2.66GHz; 4GB memory; 500GB HDD; AEBS & AX

Posted on Sep 23, 2013 12:33 PM

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Answer 1

Best reply

Kirby Krieger

Level 6

12,542 points

Sep 23, 2013 12:44 PM in response to atnbirdie

How are you creating a double-exposure RAW file? RAW is, by definition, sensor data for one exposure. (It might be possible -- I'm ignorant of how.) Does Olympus state that double-exposures creating in-camera can be exported in a RAW format? If so, you will likely have to convert them using Olympus' converter. Once converted (to 16-bit TIFF, for example) you would be able to import them into Aperture.

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Answer 2

atnbirdie Author

Level 1

10 points

Sep 23, 2013 12:51 PM in response to Kirby Krieger

The camera manual says "a RAW image recorded on a card can be overlaid with multiple exposures and stored as a separate image. The number of pictures taken is one." I've never used the Olympus converter as Aperture has always worked. I'll have to install it and give it a try.

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Answer 3

Sep 23, 2013 12:58 PM in response to atnbirdie

How do you have the Auto Gain set?

Sounds like you will want that on but you might want to take some test shots with it in both settings, on and off.

You probably also want to try it tieh the Overlay off.

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Answer 4

atnbirdie Author

Level 1

10 points

Sep 23, 2013 1:05 PM in response to Frank Caggiano

Actually, I've tried all options: auto gain on & off and the overlay method. Seem to get the same result with every one. I'll take some more and see how Olympus Viewer processes them.

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Answer 5

Sep 23, 2013 3:34 PM in response to atnbirdie

atnbirdie wrote:

The camera manual says "a RAW image recorded on a card can be overlaid with multiple exposures and stored as a separate image.

It might be -- iirc, this is how Canon does it -- that the resulting "separate image" is a JPG (or can be viewed correctly only as a JPG).

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Answer 6

atnbirdie Author

Level 1

10 points

Sep 23, 2013 6:32 PM in response to Kirby Krieger

In my camera, all types of double exposures still come out as ORF RAW files. Turns out Olympus Viewer can process the images correctly. I imported to Viewer and the ORF files looked fine. I exported as 16 bit TIFF and imported to Aperture. Still looked fine. Imported the same ORF directly to Aperture and got an overprocessed image.

So with my camera, if I want to play with RAW images, I'll have to run them through the Oly Viewer softward to get a TIFF I can play with in Aperture. JPGs direct to Aperture is of course my other optioin.

Thanks for input from all.

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