dissapoited m31

[Daniel-K]

34x200 secs

iso800

modded 550D

30 darks

39flats

SW LP filter

about 1.4 hours worth

quite disappointing in this really after the other night i was expecting more color. i processed 32min worth of data i managed the other night and seem to have more color in that then the 1.4 hours from last night.here's the two images ones 32mins and the other is 1.4 hours. i prefer the 32min it has more color bot processed the same and im struggling with vignetting!

the one on the left is 1.4 hours and the right is 32min

[nmoushon]

The one on the left actually is over proccessed which is why it has "more color" The one on the right is more like the actual color of M31. It looks good too. How are you taking your flats?

[Daniel-K]

well its the first time i have taken flats so not sure how i use my laptop screen on a blank page iso 800 and 1/40 secs i have no idea if its right though ?

[nmoushon]

You can use notepad laptop screen. Put camera on same iso and switch to AV mode and let the camera auto detect the correct settings. Works the best that way. I've found anyways.

[Daniel-K]

ahh okies thanks

[ollypenrice]

Even the best flats will not give you immunity from gradients. If you ran these images through Dynamic Background Extraction in Pixinsight you'd be amazed by how much easier it would be to stretch and cut back using the familiar 'levels and curves' routine. You have more galaxy in the long image but you also have more LP and gradient. If working in poorish skies DBE would be an incredible boon. Even for me at a thoroughly dark site it's a Godsend. A cheaper alternative would be Gradient Xterminator, a Ps plug in, but it is not as sophisticated. Pixinsight would also lose the greens that are upsetting your colour balance but the Deep Sky Colors website has a freebie called Hasta La Vista Green...

Olly

[Daniel-K]

the sky was a bit dewy last night but what i cant get my head around is the short one has no darks or flats its just simply 32min of data and it looks far better, im going to restack and see what happens, just took 40 new flats with the method mentioned above, thanks olly for the tips

[Daniel-K]

in DSS should i use RGB calibration or per channel calibration in the settings?

[Daniel-K]

could some one please tell me if this histogram is ok to start with it ? im not sure on the peaks on the right side?? this is the image straight out of DSS cropped of the overlapping frames.

[MickyWay]

Hi Daniel,

The histogram looks typical.

Try moving the left hand slider (black pixels) up to the start of the curve. You can try moving the centre slider (grey pixels) a little to the left. This will improve the contrast of the image.

Press 'cancel' to start again.

Always crop your image to get rid of any black borders that may be present after stacking. Otherwise you'll have a distorted histogram to start with.

Regards, Colin

[Gina]

Very good