M83 cdk17

[gregbradley]

I took this image of M83 with 2 different cameras at different times using the same scope.

I used a FLI Proline 16803 and a Microline 8300. Interestingly the Microline requires twice as much exposure time to match the Proline.
Both cameras have the same sensitivity (60% QE) but the Microline has smaller pixels (5.4microns verus 9microns of the Proline). I am not 100% sure what my seeing is but it seems the Microline is oversampling and thus losing sensitivity and is better suited to a faster refractor.

This one has 2 hours of Ha (8 x 15minutes) 240 minutes of luminance and 80 minutes red, 90 minutes of green and 90 minutes of blue for a total of 11:40 hours.

Taken at my home observatory.

http://www.pbase.com/gregbradley/image/134016715/large

Greg.

[mill (Martin)]

Looks good but it looks very soft to me.
For the time you have spend it didn't pay off.
A reprocess maybe??
The data is there

[TrevorW]

I'd have to agree with Martin on this, not the finer detail that one would expect from the exposure time involved

Cheers

Trevor

[Peter Ward]

Very soft.....sorry... not what I'd expect from a 17"

Perhaps bad seeing??

[strongmanmike (Michael)]

Man, the Ha exposure has brought out the HII regions nicely.

I agree with the others though, it does look pretty soft and given the exposure time and apperture the faint fuzzies in the background seem to be missing


Mike

[Enrique]

Greg: is that imaged cropped and zoomed in?

Enrique

[Bassnut (Fred)]

Well...., no.

[gregbradley]

Originally Posted by mill

Looks good but it looks very soft to me.
For the time you have spend it didn't pay off.
A reprocess maybe??
The data is there

Yes it is a bit soft. Perhaps an AO unit may help there. As far as the seeing goes perhaps it was poor.
I think focus was fine. I did notice the Microline's smaller pixels are not as well suited to the CDK as the Prolines
larger pixels. I can post an example and you'll immediately see the Proline gives quite a bit more detail. Looks like I
stick to the Proline with this scope.

Originally Posted by TrevorW

I'd have to agree with Martin on this, not the finer detail that one would expect from the exposure time involved

Cheers

Trevor

I thought so too but its as sharp as I can get that data set.
Probably better off to use the Proline rather than the Microline on this camera on most objects. Brighter objects probably won't make as much difference.

Originally Posted by Peter Ward

Very soft.....sorry... not what I'd expect from a 17"

Perhaps bad seeing??

Not 100% sure. May well be.

Originally Posted by strongmanmike

Man, the Ha exposure has brought out the HII regions nicely.

I agree with the others though, it does look pretty soft and given the exposure time and apperture the faint fuzzies in the background seem to be missing

Mike

Perhaps I should also check my collimation in case its gone out.

Originally Posted by Enrique

Greg: is that imaged cropped and zoomed in?

Enrique

No that is the FOV of the Microline.

Greg.

[Leonardo70 (Leonardo Orazi)]

Greg, color and H-Alpha is wonderful .... for the details i think you are mega-oversampled

[gregbradley]

Thanks Leonardo.

Its gonna need some major redo of luminance with the Proline and
some decent seeing. Consider it a work in progress then.

Greg.