Tarantula Test Image

[JohnH]

I have been out of the country for work so could not do any imaging for about 6 weeks including the Mercury transit.

The last image I posted was a test of the Tranatula nebula with my new NBP filter - it came out very green...which I expected. For comparison I shot the same target again - without the filter and it came out very green - which I did not expect. This is with an unmodded Canon 20D so the Ha response is poor I have not done much to the colours apart from trying to make white stars white...the image was taken in hazy conditions with patchy cloud and an almost full moon rising (10x3min @ ISO 800) so not good conditions but I was keen to get something due to the long lay off....

Is this object really so strong in OIII ?

Do you have any tips to get the colour balance right?

[rat156]

Hi John,

Yes the colour balance is out, way too blue. The problem may be in the white balance setting for the Canon, try shooting something big and bright, like Tuc47 ATM, then just play with the white balance settings until you get it "right". Getting colours "right" is very subjective, but there are plenty of pics of the big bright stuff around for you to compare.

Also the Tarantula is very big, most of the surrounding sky shows some nebulosity. Take a look at Brad Moore's image @ http://www.southern-astro.com.au/gallery.php?PhotoID=8 of the tarantula, although he used Ha, so the stars look funny, I suspect he got the RGB balance pretty right.

Cheers
Stuart

[spearo (Frank)]

Yep
I agre a bit too blue
but the focus and tracking seem spot on
good work, you'll get a nice image once the color balance is achieved.
cheers
frank

[Doug]

Oh well John, just to be different, I can't say the colour balance is off by much at all.
Why?
Well, I see reddish stars in there, I see Yellowish , blue and white ones too.
Who is to say that the spider is red anyway?
The image below is a false colour image derived from yours, but it is 'false colour'.
The only thing I do agree on is that the image is a beauty, I like it; well done.
cheers,
Doug

[Ric]

Hi John, considering the conditions you described I think it is a great image.
I agree with Doug, I dont think the colour is off by much.

cheers

[tornado33]

Howdy
Yes it is strong on o3, though modded cameras do show more red. Fiddling with red Curves in Photoshop can bring out more red too, heres your image so processed. Theres plenty of detail in there, it is well focussed and tracked.
Scott