not another Eta Carina!

[Robert_T]

Hi All, well with my tree line this may be the last chance I'll have to image it for quite a while. Went a bit deeper with 6 x 300s exposures with the Canon 40D at ISO800 and via IDAS-LPS filter and 0.8reducer in the YO ED80 at F7.

It's a slight improvement noise-wise on my last attempt with the ED80 at least:)

Comments and advice welcome.

[strongmanmike]

Oh no!...Cut down those trees then and let's see even more Eta's!!! :scared: :doh:

Nice work Robbie lovely FOV to capture the whole nebula there.

Mike

[leon]

You have done well Robbie, just keep em coming mate, Eta is such a nice one to capture.

leon

[Hagar]

Nice image Robert.
Lots of the fine detail captured but I think just from a first look you could pull a bit more image out of this shot. Without having a close look at the histogram, the background looks very black. I will have another look when I get home from work.

Nice clean image
Keep at it.
Well done

[renormalised]

That's a much better shot of the neb than last time....great work!!!:D

[renormalised]

The big problem with trying to bring out as much detail as possible in an image is that you risk adding noise and other artifacts from the processing. I think there's plenty there to see and I'd leave it at that.

There's such a thing as doing too much processing:)

[Robert_T]

:DThanks Fellas... but beware I might just take a branch lopper to my tree-line and squeeze a few more weeks of Eta yet:P


it's a great kindergarden for when you're starting out and trying to get the hang of the basics:thumbsup:

[Alchemy]

yep eta is a nice target to start on and get your gear working well:thumbsup:

[gregbradley]

This is a good image Robert. Really good.

There appears to be a slight tilt in your optics train (camera sagging in the focsuer perhaps?) as the bottom left looks slightly out of focus whereas the right hand side is sharp.

Also, you've done a lot of things right here - nice colours, the stars have colours (yeah! DSLR images often show the stars as white when they are not all white).

But dude - why only 30 minutes? You stopped when you were on a roll mate!

There is a culture in the DSLR world where 10 minutes is a long image exposure. I don't get it.

In the CCD world 1.5 hours is a bare minimum and 6-50 hours is really going for it. And CCD cameras are usually more sensitive than DSLRs.

There is one guy I forget his name -who does really long exposure DSLR images at the Yahoo digital astro group. His images with a 20Da rival fine CCD images.

So do exactly what you did (except check for camera sag) and do another 3 hours and you'd have a whammy of an image! You can't process the signal if it isn't there in the first place and you get the signal with lots of exposure time. I have found my best images really required the least processing because it was all there in the first place. We kind of work hard in the processing department when something is deficient in the basics.

Basics done well and long makes the excellent image not Photoshop magic.

Greg.

[Robert_T]

Thanks Greg, appreciate the tip, especially re the possible sag in my optical train...I'll have to look at that, quite a few possibilities including misalignment on the WO reducer.

I'd certainly like to go deeper and longer. Biggest obstacle is I have yet to get my auto-guiding working properly. I'm lucky if I can get a 5 minute exposure without trailing. I've been struggling with this for weeks. I'm about ready to chuck it in with the LXD75 and Phd via Ascom and get an EQ6 with ST4 guide port. Then maybe some deeeeep stuff:D

[gregbradley]

Hi Robert,

Yeah been there with the autoguiding troubles.
Your first investment always has to be in a decent mount.

I had a WO once and I found teh 2 inch visual back was a tad larger than 2 inches causing a little gap. TRhe solution I used was to shove the camera in and lock it up whilst I held it in otheriwse it could sag in the visual back. This causes a tilt and infocus on one side and a bit off in the other.

That's a great image so take heart.

So how did you manage the 5 miunute exposures you already got?

Greg.

[Robert_T]

Hi Greg... by taking about 20 of them and picking out just the ones that didn't trail:D

[skeltz]

good going rob,colours look pretty spot on to me, and yeah like greg said more,more time its worth the effort
Keep it up.