The Lagoon in HAlpha with a Canon 300d/ED80

[seeker372011]

Imaged over two nights-Saturday 14 July and last night..

20 x 10 minutes at ISO 800 and 14 x 3 minutes also at ISO 800-conditions-poorish, first quarter and near full moon
details:
Astronomik 13 nm H Alpha Filter
CG 5 mount autoguided (PHD)
ED 80
Canon 300D
Processed in Deep Sky Stacker and Photoshop

For a larger image -

http://www.flickr.com/photo_zoom.gne?id=938271841&size=l

for a crop from the same image showing the nebula itself more clearly

http://www.flickr.com/photo_zoom.gne?id=939266314&size=l

[seeker372011]

just for fun I combined this H alpha image with OIII data I acquired last year.

This OIII data was only 50 minutes of total exposure and of poor quality -star trailing and noisy-but still, here is my first colour mapped image (OIII data contributed to blue and green channels, H alpha data to red and 20 % to blue-to simulate synthetic H beta )

comments and critique most welcome, thanks for looking

[Radar]

G'day Seeker, that is an awesome image mate. I have never seen line filters used with a DSLR before.

I have to ask this next question - Is your DSLR a monochrome ccd? Otherwise how do you use a O3 filter with it?

Cheers

Ray

[AstroTasmania]

Hi Seeker,

Great shot and good to see a DSLR being used to tap into the narrow band, I also think you may have grabbed Ray's interest!!! digital and all that!

I am heading in this direction as soon as time permits with my modified 350D & filterless Nikon D50, on a Tak 180ED & SN-10

Keep posting your results please.

Clear skies...

Shevill

[seeker372011]

G'day Seeker, that is an awesome image mate. I have never seen line filters used with a DSLR before.

I have to ask this next question - Is your DSLR a monochrome ccd? Otherwise how do you use a O3 filter with it?

Cheers

Ray

Thanks Ray and Shevill.

Ray, I use a Canon 300D -I used a modified 300D for the H Alpha and a stock 300D for the OIII..probably could have used the modded camera for both.

I capture in colour and then -in the case of H Alpha-discard the blue and green channels as noise and in the case of OIII, I discard the red channel as noise and use the blue and green data.

Its not the most efficient approach obviously as you are using only a portion of the Bayer Matrix (only 1 in 4 pixels for H Alpha and 3 out of 4 for OIII-but since I don't have a cooled mono CCD camera and the only clear nights seem to be around first quarter or full moon, I have no option!

Narayan

[Radar]

That's the first time I've ever heard of this being done. Needless to say, I'm impressed with this technique (disregarding colour channels as noise).

On a slightly differet note, are you able to post an image that was taken with the modified 300d and then one that was taken with the stock one? I'm interested to see how effective these mods are.

Cheers Narayan.

Ray

[AstroTasmania]

Hi Ray,

If you look in a back back issue (?last year? in Sky & Space magazine, you will see an article that I wrote on "Taking Sharper Lunar Images" in which I describe separating the channels and discarding the red & blue as noise and blue unfocused in a refractor. Keeping the Luminence and green channel which has very little noise etc.

Once you go digital, a whole new world is opened up to you!

Clear skies...

Shevill

[seeker372011]

On a slightly differet note, are you able to post an image that was taken with the modified 300d and then one that was taken with the stock one? I'm interested to see how effective these mods are.

Cheers Narayan.

Ray
Hi Ray
I dont have two images of the same object handy but will find some old images on CD somewhere and post them ..there is huge difference to the H alpha response! simply no comparison.

You couldn't image with an unmodded Canon through a H Alpha filter with any sort of decent results

[wakaleo]

Ah me, so much to learn. Just love it!

Jim

[Radar]

Hi Ray
I dont have two images of the same object handy but will find some old images on CD somewhere and post them ..there is huge difference to the H alpha response! simply no comparison.

You couldn't image with an unmodded Canon through a H Alpha filter with any sort of decent results

Intreresting. The difference must be huge. Can a modified DSLR still be used for normal photography?

Cheers

Ray

[AstroTasmania]

Hi Ray,

Tha long answer is "Yes".

Clear skies...

Shevill

[phoenix]

Hey Seeker very nice photos.:thumbsupmate:







Cheers Jason:pipethinker:

[seeker372011]

Intreresting. The difference must be huge. Can a modified DSLR still be used for normal photography?

Cheers

Ray


Yes, as Shevill said..but you need an external (or internal) IR filter to replace the original filter..even for shooting in RGB -that is when I am not using a narrow band filter I need to use a Baader uv/ir filter

without any filter the white balance gets all stuffed up..here's a picture without a uv/ir filter with a modified Canon 300d that shows what I mean
narayan

[Radar]

Okay, thanks guys.

I like the idea of narrow band imaging with a DSLR.

Do you have a filter ring that goes between the scope and the camera? Or can the camera be fitted with the line filter?

Regards

Ray

[AstroTasmania]

Hi Ray and Seeker,

Also check out the X-nite cc1 filter that can be used in front of a modded DSLR, do a Google search.

I bought one some time back from the USA - not cheap in a large size, I got the largest and a set of step rings to suit my range of lenses, no good on fisheye lenses though!!

Clear skies...

[seeker372011]

I simply screw the UV/IR filter or H alpha filter into a camera adapter which connects to the usual T adapter

one other thing to keep in mind-the removal of the IR filter means auto focus wont work;also the viewfinder and LCD screen are not too useful for focusing..you need "DSLR focus" software to be sure of focus as you can't do it visually
fortunately it only costs about $60

[AstroTasmania]

Hi Seeker,

My modded Nikon D50 has filter removed and replaced with clear glass of right thickness, so auto focus works OK. I use it for daylight and other Infra-Red imaging, but will eventually use it for astro with a Baader UV/IR Cut filter.

Clear skies...

Shevill

[Radar]

Thanks guys. DSLR's sound awesome.

Ray