Hi guys,
Saw people posting on photomalaysia regarding this problem so i used my GX1 to test around, as im planning to take star photography at my upcoming bali trip, I found that even at iso 160 I can see problem during long exposure shot, you will notice speckles in the photo which is caused by hot pixel noise, as I don't have other friends with GX1, I'm not sure if this is just the general problem with this camera or only this particular unit, therefore I would like to ask for some helps here to check together.
Turn off long exposure noise reduction, turn off shutter AF in custom menu, set to manual focus, exposure wise iso 160, shutter speed 60s, aperture F8, then put it on the table, then shoot with lens cap on. After that try to examine the image by zooming in, or transfer to computer to zoom in 1:1 ratio, you will find speckle(red/blue dot) which is fixed pattern in all the test images.
I have tried this with long exposure noise reduction on in the camera, and still the speckle is visible after dark frame subtraction in the camera, therefore that makes this camera almost not usable for long exposure stuffs while it supports 60s exposure natively.
If you guys have G3, do try it out too since GX1 and G3 both share same sensor, I do wish you guys don't see the hot pixel noise issue because I do wish GX1 is capable of producing usable long exposure image.
Says you guys don't have that problem, then i should send this camera for warranty, thank you!
This problem also apparent with the PEN series [my EP3 is also susceptible to long exposure noise] so I don't think your camera is at fault.
for some of the suggestion and better understanding on the reason why it happened.