Noob M42

[gdheib0430]

Here you go guys a whole lot better than the first two I took...I still need to work on my focus but I was to excited to go shoot that I forgot my laptop to check my images. Also, when I pulled this into PS I noticed the "dark" areas had a random mix of red greens and blues all pixelated...is that my camera goofing off or possible light pollution?

Sony a300 34 x 10" @ 1600iso 70mm (25 darks). First one is the raw stacked image and the second is the PSd version messing with curves and levels.

[Jannis]

Nice widefield of orion!

The random RGB pixels are what's known as high ISO noise, made because of the high amplification of the signal at ISO 1600 (back on the old days, even ISO 100-200 was considerd "extreme". ISO 1600 is amplified 4-5x to that in the sensitivity, and therefor the random pixels are showing up). On the other hand, you don't have too much ISO noise, and you have the potential to do some great shots with that camera, so don't let that chance run away!

ISO noise will always be a big problem with these types of cameras, but we solve it by stacking many frames together to lower the random noise, and therefor be able to drag out more details.

example; ISO 1600 is 4x as sensitive as ISO 200, and also giving more noise.. However, that also means that stacking 8 pics at ISO 1600 shuold give equal noise as 1 taken at ISO 200, and like that, we get rid of the random noise that you noticed with these red, blue and green pixels.

Now that's in theory, but as the ISO noise increasement curve isn't going stright when increasing the ISO, we often hve to add many more frames to get rid of the noise, but the theory remains. Basicallt, there will always be noise/random pixels, but the more frames we stack, the better we'll even it out and ger rid of it.

[gdheib0430]

That is by far the best explination of ISO I have herd yet...it makes way more sense now thank you so much.

[Sierra Golf Mike]

I can't see any images? Anyone else?

[delphinusuk]

I'm afraid I can't see anything either (i'm using tapatalk to browse the forum).

[gdheib0430]

Yeah I took the attachment off the server I can put it back up though if you want to view it again.

[Sierra Golf Mike]

Please do.