RAW and sRAW conversions different in Lightroom

I've been shooting lots of timelapses recently. I typically shoot them with a Canon 5D Mark II in sRAW (small RAW: a lower resolution RAW file) because otherwise I end up with thousands of 21-megapixel images to store. My timelapse workflow involves bringing all of the images into Adobe Lightroom, setting white-balance and 16:9 crop on all images, and exporting as JPG to be opened as an image sequence in Quicktime 7 Pro. I noticed yesterday that one of my timelapses had a jump exposure in the middle of the movie. Upon close inspection, I discovered that the change in exposure was due to Lightroom treating RAW files differently than sRAW files! I had forgotten to set my camera to record sRAW images and ended up switching to sRAW in the middle of the sequence.

Below is an example of the difference between RAW and sRAW conversion. Images were exported from Lightroom with identical settings.


Lightroom conversion: RAW on left, sRAW on right. sRAW has brighter conversion.

However, when I extract JPG thumbnails from the RAW images, the exposures look identical:


Successive frames of the timelapse when bypassing Lightroom

If you're a die-hard Lightroom user, be aware that it processes RAW and sRAW differently! The frames are sufficiently different that it makes mixing RAW and sRAW in a timelapse sequence impossible in Lightroom.

Tonight's timelapse is below. I wanted to use the Recovery tool to pull back some of the blown-out area around the sun, but the Lightroom issue prevented me from doing so (and I was too lazy to use DPP).

Until tomorrow!