Elephants Trunk Nebula- My next "little Project"

[pyrasanth]

I saw some work other people had been doing in the forum capturing the Elephant's trunk nebula & thought this would be a good target for my RASA. I started the HA capture last night & obtained 27 reasonable subs. The conditions were a bit hazy so I know detail is lost & the light skies don't help but I think the result is encoraging. Let me know what you think. I only have the HA at present. This is 27 4 minutes subs using the 2" Baader fast HA filter & the RASA (Astrodon) LPR Filter. Guiding is done using direct guide on the Paramount/SkyX & the processing is done in Ccdstack & Photoshop. The image looks much better if you open it up full size.

I've presented the full field as captured with no cropping.

[ollypenrice]

Clean as a whistle and in less than 2 hours. Nice stars, deep. The RASA has to impress. Maybe it's a shame not to use more of its (expensive) flat field but you're getting superb results here. I suspect a lot of UK imagers short of clear nights will be thinking, 'Hmmmm, F2.2...'

Olly

[wxsatuser]

Clean as a whistle and in less than 2 hours. Nice stars, deep. The RASA has to impress. Maybe it's a shame not to use more of its (expensive) flat field but you're getting superb results here. I suspect a lot of UK imagers short of clear nights will be thinking, 'Hmmmm, F2.2...'

Olly

Needs a dslr.

[pyrasanth]

Clean as a whistle and in less than 2 hours. Nice stars, deep. The RASA has to impress. Maybe it's a shame not to use more of its (expensive) flat field but you're getting superb results here. I suspect a lot of UK imagers short of clear nights will be thinking, 'Hmmmm, F2.2...'

Olly

Thanks for the kind words. I'm planning a new camera in the next couple of months. I'm looking at the Atik 11000. This has a field big enough to fit the entire M33 galaxy & more in one frame. However I need to get special adapters made so It's a work in progress. The Atik 11000 will fit the front of the RASA fairly well & won't significantly increase the central obstructive. The pixel size is quite large on the 11000 & people have pointed out sampling issues but that would be a good compromise as lets face it- my location- 4 miles from Birmingham Airport is not Atacama!

[pyrasanth]

I managed to capture some SII & OIII data to build the image below. However the full moon played havoc wih the OIII data so I will redo the whole project in August/September when the skies are darker but I am encouraged with the results as this is only a total of 4 hours. Click the image to see the full size picture.

[ollypenrice]

Thanks for the kind words. I'm planning a new camera in the next couple of months. I'm looking at the Atik 11000. This has a field big enough to fit the entire M33 galaxy & more in one frame. However I need to get special adapters made so It's a work in progress. The Atik 11000 will fit the front of the RASA fairly well & won't significantly increase the central obstructive. The pixel size is quite large on the 11000 & people have pointed out sampling issues but that would be a good compromise as lets face it- my location- 4 miles from Birmingham Airport is not Atacama!

The RASA's focal length is a little longer than that of the Tak FSQ106 which is commonly used wth the 11 meg chip and has more APODS as a combination than you can shake a stick at. It's what Tom and I use on our projects and is also used by our guests. I wouldn't overestimate the issues involved in this kind of sampling rate.

Eg http://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/i-3D2Hw7s/0/X3/M31%20Outer%20Halo-X3.jpg or http://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/i-ZBmVMGT/0/X3/M45%20final-X3.jpg

Sure, it would be nice to have a full format camera with smaller pixels but you still get results with the 11 meg. You'd need to watch the vignetting, though. The standard RASA adapters do vignette on large chips. They taper when they need to stay full aperture right back to the camera.

Olly

[pyrasanth]

Thanks Olly. I'm having the adapter specially made by Starizona which will combine the filter slide & adapter to fit the RASA made at the correct back focus. This should minimise the vignetting. The example of M31 is a real cracker of a picture. I would be happy to get anything even approaching that.