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View Full Version here: : My darks don't seem to work?


cybereye
15-02-2011, 07:35 AM
I've been having some issues trying to remove the sensor noise from my images of the Flame and Horsehead nebulae that I took last Friday night using my DSLR.

When I look at my RAW images I can quite clearly see the sensor noise in the top left and right hand corners of my images. I can also see the sensor noise in my darks in the same place as my images. However after stacking in DSS and then subsequent processing in PS I still seem to have noise in the same areas as the sensor noise although it is more diffuse and widespread.

The more I try to process the final image and bring out the faint detail in the nebulae the more this noise becomes apparent. I've attached the image below and although heavily cropped the noise can still be seen at the bottom left and right hand corners (I've flipped the picture to see the horse's head).

I'm in a bit of a quandary as to how to go about solving this problem. It's already been suggested that I try retaking the images but use the in-camera noise reduction option. The other option I thought of was to use IRIS to do my pre-processing but I came across a different problem there so I'll save that for a different thread!

Any ideas as to how to solve this problem would be gratefully accepted!:help:

Mario

PS I know the image is not the best and that's why I've posted it!!
PPS Image consists of:
5x5min lights @ISO800
2x5min darks @ISO800
3 flats

jjjnettie
15-02-2011, 09:23 AM
Sorry Mario, but I've all but given up imaging at this time of year due to noise issues with my dslr.
I'm waiting until Winter before I set up again.

niko
15-02-2011, 09:52 AM
I'm certainly no expert but this looks like amp glow rather than hot pixels etc. I have one corner of my images with that red aura from the amp and have just had to learn to frame my pics accordingly so I can crop it out

cheers

niko

cybereye
15-02-2011, 10:11 AM
Niko and jjj,

Thanks for your advice. Amp glow it is and I've found this thread here on IIS...

http://www.iceinspace.com.au/forum/showthread.php?t=22219

I'll give ICNR a go otherwise I'll follow jjj's lead and shut-up shop till winter!!!

Cheers,
Mario

jjjnettie
15-02-2011, 10:23 AM
aye, and start saving up for a cooled ccd cam.