Colour deep M42 with Bert's 300mm lens

[tornado33]

Hi all
After surviving yesterdays massive hail storm, I got up in the wee hours just after moonset to get M42 with Berts 300mm f2.8 flourite lens.
I took 4x10 mins ISO 200, IDAS uv/ir and Baader UHCS filters, modded 350D, masked with a 2x 1 min ISO 200 image for the bright parts, dynamic and colour stretching in IRIS used, masked in Photoshop, noiseware used to finish off. I was after the faint Ha regions around M42 itself.
Larger version here
http://www.iceinspace.com.au/uploads/m42%204x10%20mins%20iso200%20uhcs%2 0300mmmasked_filteredmed.jpg
Scott

[RB]

I love it Scott !
It's refreshing to see M42 this way.

Well done on capturing all that Ha region.

[PhotonCollector]

That's totally awesome, Scott. :eyepop:

Very impressed.

[Striker]

So much nebula we dont see very often...its huge.

Very well done Scott

[strongmanmike]

Yeh nice work :thumbsup:

Have you tried stopping it down as it has some aberations visible there but still rather nice huh?

Mike

[CometGuy]

Lovely deep image Scott. I have to agree with Mike regarding the stars, but then your eye so drawn to the nebula you don't seem to notice as much.

Terry

[iceman]

Wow, great wide image Scott.

[[1ponders]]

Wow! Pretty special Scott :cool2:

[tornado33]

Thanks everyone :)
It might be the filters causing the abberations in the bright stars as normally the UHCS is in scopes F4 or slower, not F2.8 so I might try stopping down to F4 next time.
Scott

[tornado33]

Heres a version processed without colour stretching just dynamic stretching in Iris , and masking in photoshop
Larger version here
http://www.iceinspace.com.au/uploads/m42%20masked_filteredmed.jpg
This shows the background faint cloud better.
Scott
PS, Octanes method of doing flats works well too, I emulated that here, after finishing imaging I took the lens with camera still on to my PC with paintshop pro showing just white on the monitor , pointed lens at that for a flat field

[RB]

Great work Scott.

Just wondering if it would be better to use a grey screen on the PC instead of pure white for flats, or won't that make any difference?

[Ric]

Hi Scott, thats a top image that you have captured.

great stuff

[CometGuy]

Scott,

I am intrigued by the star aberation in the star images, they do not seem to appear in some of your previous images with the same lens. For example the NGC253 image. Do you know what is different as I have same star problem with the Sigma lens I just purchased. I am wondering if it is tied up with the filter inside the camera (mines a Baader UV/IR) and am considering removing it totally.

Terry

[Octane]

Scott,

Lovely work.

I love the extended nebulosity you've picked up here.

And yes, the method I use for flat frames appears to work quite well. You just have to make sure you've got no aberrations on your LCD screen first and that it is evenly-illuminated. I've seen non-even illumination on some cheap notebooks.

Regards,
Humayun

[TidaLpHasE]

:eyepop:What an awsome image of this regular and extensively imaged area.

I love all the neb stuff showing in your image.

Fantastic:thumbsup:

[spacezebra]

Beautiful, absolutely beautiful.

Cheers Petra

[tornado33]

Thanks all.
Andrew, I set the exposure to "auto" when taking the flats, that way correct exposure will happen, and I guess the brighter the screen the faster the shutter speed for the flats, as long as screen is evenly illuminated it should be okay. The actual flats look greenish, thats because of the UHCS filter.

Terry, I have two 2 inch filters, an IDAS uv/ir filter, and a Baader UHCS filter
screwed together. They sit inside the canon mount that in turn screws onto the back of the lens. There is a slight amount of play, I can hear the filters rattle slightly when I pick up the lens, Im thinking that this may cause them to not be completely flat, causing the abberations around the bright stars. If I use no filters at all I get star bloat in bright stars but nice even round ones, as my 350D has no internal filter at all, just clear AR coated glass, because I wanted to experiment with IR photography.

The above is what I think is happening anyway.
Scott

[CometGuy]

Scott,

Very interesting.

I noticed the aberations are symetrical about the centre so I don't think it is because of tilt or looseness of the filters. The really are remarkeably like the aberations I get and I have a cut Baader filter in my camera (in addition to the sensor coverglass) so there are 2 optical windows between the imagiing surface and the lens.

I am half tempted to go back into the camera and completely remove the filter but am not sure if I would be able to reach infinity focus with the lenses I have (although most do focus a little past infinity).

The more modern lenses seem to be optimised to take into account the extra optical surfaces in a DSLR sensor.

Terry

[tornado33]

Im tempted to try an image with my unmodded 350D and see what happens, or even put the uv/ir filter ahead of the uhcs rather then behind it, though I cant imaging changing the filter order would affect anything?
Scott