Help Please, DSO's and DSS

[JKB]

This is my first proper attempt at DSO. It should be the Flame Neb but I just cant get anything out of it. Not sure I like DSS but new to it!

145x 15s subs (Not enough?)

10 Darks

10 Flats

I once took a 60s of same area and got loads of detail. DSS stacked 142 of the 145 so assumed results would be better. The pic is after PS and curves etc.

Any advice? Canon 30d ISO 1000

Cheers

[pook]

Just doesn't seem to be enough data there. There also appears to be some severe streaking... I suspect thin high altitude cloud has streaked across some of your subs.

You've also got the same weird diffraction pattern on Alnitak as I get.. interesting.

[JKB]

Yes I was wondering about the diffraction pattern. Something the SW150 has a problem with?

[Jannis]

Looks like you used very little the saturation fungtion in DSS?

after stacking, and aligning the RGB channels, set saturation to +20-25%, and save as TIF 16 bit after roughly adjusting teh levels to have same brightness as the pic you attached already here.

Then, if possible, upload that uncompressed TIF somewhere for us to download, and it will be a lot easier to give it a try.

Edit: but i can clearly see the flame nebula in your pic, so the date Is there, just very hard to extract from a compresset 8-bit jpg...

[Zakalwe]

Try this tutorial, especially the bit about aligning the RGB channels.

15s subs are fairly short......you might need a lot more of that length, or some longer subs.

[JKB]

Thanks all for your replies.

I will try again later tonight and save Image for anyone to have a play with too!

Cheers

[Sparrow]

A useful tutorial reference from Zakalwi there and a good starting point for image processing.

The one thing I would point out is that there is an option in the DSS settings for aligning the RGB so it does it for you, rather than having to do it manually after stacking.

Regards

John

[Zakalwe]

I have stretched it to hell and back in back in PS. It looks like there is some sort of "smearing" on the image, which would explain the weird diffraction pattern.

Was the front objective dewed up, by any chance?

[JKB]

It was taken through the Reflector so no dewing probs, unless Primary got any on it? Is that possible?

I will upload decent picture later after running it through DSS again with aforementioned tutorial now read and understood.

Thanks

[Jannis]

Dew can still be a problem on both promary and 2nd mirror. I've had them both already...

Even had on the sensor on the DSLR once, but then it was very very bad conditions.

[JKB]

Ah never thought about secondary! Interesting. Is there much you can do to prevent it? It was below freezing the night of shots but only just.

Thanks

[pook]

Yes I was wondering about the diffraction pattern. Something the SW150 has a problem with?

It may well seem to be, yes. I have exactly the same problem. See this thread.

http://stargazerslounge.com/imaging-image-processing-help-techniques/133245-weird-diffraction-spikes.html

[adamsp123]

I really think your sub length is too short. 15 secs is not very long I would do 4 mins at ISO 800 or equivalent on that target at F5.3 - my scope.

[Jannis]

I did a quick try in PS, not much success for me neither.