darks and bias are different size then the lights....please help :(

[tingting44]

hey guys, this is doing my head in a bit!! im playing about with some old data (101 5sec lights of orion neb, 1 master dark and 1 master bias), the size of my lights are 2592x1728 and my master darks are at the size of 5203x3465???

How is this possible? ive tried to change the size of the darks/bias to match the lights but its coming out at 1 less like this... 2592x1727 and when DSS tries to stack them it says something like different pixel sizes so can not stack? its driving me mad any help at all would be great

[frugal]

It looks like you have binned 2x2 your lights but not your darks.

Sent from my GT-N7000 using Tapatalk

[Stephen]

As above, you've either binned or used a lower quality setting on the camera to take the lights

[tingting44]

What the hell is binned mate? lol

and all were taken using large RAW's so i just dont get it, it seems impossible to even change the image size to what i want? any ideas how id change the size? if i change the width the height changes and vice versa.......really frazzing my brain this is lol, right off to work for a lovely day graft see you at 1pm

[ollypenrice]

I'd say that the darks and bias cannot be used because the fixed pattern noise in a different capture mode will be different. Resizing them would be no good. In extremis you could probably resize flats but not not darks or bias. Just shoot some new ones.

Binning means taking blocks of 2x2 or 3x3 pixels and treating them as one super-pixel. With a one shot colour this isn't normally possible because the colour information would be destroyed. Binning is used on dedicated astronomical monochrome CCD cameras to speed things up at the cost of resolution.

Presumably you inadvertently changed capture modes on your camera?

Olly

[sidelight]

If you are using a DSLR did you set the bayer pattern to super pixel in DSS?  That would treat a group of 4 pixels as 1, halving the size of your lights.  I've not used DSS in a while to see if it only applies this to certain image types.

[tingting44]

thanks guys, think ill just scrap these as there over a year old, i just need some time to get out and capture some new data now...... grhhhhh when ever that might be with work and cloud cover

thanks for the help tho guys