3 more Astrophotos

[AstroJason]

Hi all,

We finally had a night of clear weather in Sydney last Wednesday night. So took advantage of this to get some more shots.

These are just 17 x 30 second exposures with noise reduction performed in camera. Stacked in DSS. No Bias or Flats applied. Taken with an unmodded Canon 60D and Canon 70-200mm f4L IS lens on my NEQ6Pro mount. Processed in Photoshop.

Still got work on my polar alignment... you can see its out in my Tuc 47 image. Thinking I may have clipped the black a bit too much in this image.

The LMC was the hardest of the 3 to process. With the light pollution I have to battle, it was difficult to bring out its details without amplifying the LP. I think this would benefit from a lot more subs, not to mention longer exposures than just 30 seconds, just that my sky does not allow for this, really need to get out to a dark site!

The other image is of Sirius and M41. I really like how this image turned out.

If anyone would like to have a go at processing my data from DSS let me know. I'm sure people with more experience will be able to do a way better job on these than I did, especially on the LMC image.

Any feedback is always appreciated.

Cheers,

Jason

[E_ri_k]

Nice start. I found when I first imaged the LMC, I was taking 2 minute exposures at ISO1600 to pick up enough data. Put your data up if you like though. Would be fun to have a play with it.
Erik

[AstroJason]

Hey Erik, yeah there is no way I'd be able to get anything apart from a total white frame at that exposure length and that high ISO.

Just on putting my data up here though, anyone know how to do it? Or do I store it somewhere like a file share site?

[E_ri_k]

A fellow user suggested to me to use "Dropbox" for some of my stuff. It works really well. Try that and post the link the file.

Erik

[AstroJason]

Hey Erik,

I just used SkyDrive to share the file. http://sdrv.ms/UHlAF1

Its very large though! 167MB because its still the 32bit tiff file. Anyone else want to have a go at processing this data be my guest!

Cheers

[E_ri_k]

Can you maybe save it as a 16 bit file, or try cut it down to under 100MB? I'm having trouble opening it.
Erik

[AstroJason]

Hey Erik,

I saved and uploaded a 16 bit version. Let me know how that goes. http://sdrv.ms/TaNkE7

Cheers

[E_ri_k]

Thanks Jason, Opened this time :) Had a very quick play in Pixinsight and CS5 with it. Think I pulled out as much as I could. There was alot of skyglow going on in the bottom left hand corner, so I cropped as much out as I could. Think you need loads more data and calibration frames.

I never bothered with noise reduction in camera, it seemed to take ages. I don't know if I'm correct, but you don't need to take bias frames with a DSLR? Correct me if I'm wrong anyone. Dark's and flats are essential though.

Erik

[AstroJason]

Hey Erik, sorry I didnt reply sooner as I was away. Really like your go at my data. You have brought out loads more detail. yeah that skyglow is the stadiums at olympic park :mad2: yeah i figured i needed loads more data for it.

Yeah the noise reduction in the camera takes another exposure for the same length of time as the light exposure. figured it would save me time having to do it myself later. went to my dark site out at heathcote last night and got more detail from a single 30 exposure there than the combined data here! Will post some of the pics up later.

Thats interesting that you say bias frames may not be required for DSLRs. Would lile to know why that is the case

[E_ri_k]

Good stuff! Keep taking images out there. I'm not sure about the BIAS and DSLR, just a topic I read about some time ago. One person had said that CMOS based cameras automatically subtract a BIAS frame after every image? Not 100% sure. May be worth checking out?

Erik