Colored Pixels in JPEGs vs RAW

[gmelder]

I'm preping for the eclipse and ran a test shooting the Sun with my 60D and a 100-400 lens. The RAW images appear to have more grain in them vs JPEG which seems smoothed out. The bigger issue is that with JPEGs I get certain pixels showing up in different colors, same place with each picture, but the RAW is pristine with no individual pixels showing. What causes this?

[kvbarkley]

I would guess the JPEG compression.

Can you post an example?

Shooting the eclipse begs for RAW.

[gmelder]

[gmelder]

First image here is JPEG with pixels showing.

[gmelder]

Second image here is RAW. No pixels showing. These are screen shots from Light Room with 2:1 Mag.

[kvbarkley]

Just noise, or hot pixels. You might want to try it with just tle lens cap on and see if they show up in the same spot. Lightroom might be doing more aggressive noise filtering.

[jrhoffman75]

I think your focus might be off as well.

[kvbarkley]

I agree.

[Peter]

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@gmelder wrote:

I'm preping for the eclipse and ran a test shooting the Sun with my 60D and a 100-400 lens. The RAW images appear to have more grain in them vs JPEG which seems smoothed out. The bigger issue is that with JPEGs I get certain pixels showing up in different colors, same place with each picture, but the RAW is pristine with no individual pixels showing. What causes this?

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Your raw converter removes hot/dead/stuck pixels.

[TCampbell]

I agree, these are stuck pixels (and easily removed).

Focus is soft.

John's examplemay be having issues with reflections.  Normally you wont see a glow around the sun.  It'll look more like kvbarkley's image.

Here's a shot from the Oct 23, 2014 eclipse (partial eclipse as seen from where I live) as it was just beginning.  That day also just happened to have what would turn out to be the largest sunspot group of the 11 year solar cycle.