HaRGB test

[Andy01 (Andy)]

Hi folks,

This is a bit rough and ready, (and there are some gradients, noise and dodgy colours) but it's my first crack at blending Ha and RGB, using a modded DSLR camera. (My SBIG is currently being serviced)

The RGB was shot from the 'burbs through light clouds and no LP filter so it's just a test. But there's so much potential there with the technique! I can see why it's so popular with many of the contributors on this forum.

Can't wait for next new moon, clear skies to try it out properly.

10 x RGB 2min 1600iso, 6x Ha 5min 1600 iso,
darks but no flats - cooled /modded Canon 40da 85mm lens

Anyway, thanks for looking, all tips, advice and suggestions most welcome.

Cheers
Andy

[jsmoraes (Jorge)]

I bought an H alfa 12 nm filter to test with my Canon T3. The camera is standard, with original Canon internal filter.

I found this graphic with information about the performance of Canon and Baader filter.

And as I have Moon-Skyglow-filter, I did a superposition of curves of my set of fiters to be in test: Canon original, Skyglow and H alfa.

And just like you, I am wainting for a clear sky to do it.

I hope to be able to capture more red information without destruction from some iodine street lights in front of my observatory that iluminate the interior of my telescope ! Yes, the light comes inside my telescope.

I built a wall around of my observatory with 2 meters to solve this problem. I finish it this week. But the light create a red fog around, because of the humidity, since I am 500 meters from beach.

I know that the performance will be limited, but any help is a help, right ?

[LewisM]

I bought a 12nm H-a filter to go with my OSC, and it works VERY VERY well. Maybe should have gone 15nm, but 12 seemed like a good compromise on performance vs cost.

[Andy01 (Andy)]

And just like you, I am wainting for a clear sky to do it.

Cool, it will be very interesting to see your results

Originally Posted by LewisM

I bought a 12nm H-a filter to go with my OSC, and it works VERY VERY well. Maybe should have gone 15nm, but 12 seemed like a good compromise on performance vs cost.

Hi Lewis, that's great would you mind posting an image you have created with this technique?

Cheers Andy

[rustigsmed (Russell)]

looks good Andrew, have you got a before Ha version to show the difference it makes? considering a Ha filter for my dslr myself.
also have you captured the Ha under a moon? does it cut out enough moonlight at 12nm?

cheers

rusty

[Andy01 (Andy)]

Originally Posted by rustigsmed

looks good Andrew, have you got a before Ha version to show the difference it makes? considering a Ha filter for my dslr myself.
also have you captured the Ha under a moon? does it cut out enough moonlight at 12nm?

cheers

rusty

Hi Rusty,
Here you go, 10x 2min RGB taken from light pollutionville (with no LP filter), along with the 12nm Ha (6x 5min frames), and the much nicer reprocessed final merged result.

I've had some issues with focusing the Ha and there appears to be a difference in image scale with/without the Ha filter which made the merging interesting! It's still a bit off.

The Ha was shot under a 70% moon, and the RGB was shot after the moon dropped, but then the clouds came over (sigh). There are many useful threads about moonlight and Ha on this forum if you search about.

I used the blending technique mentioned here... http://starizona.com/acb/ccd/software/ps_hargb.aspx????

Note that this is shot under poor seeing conditions, hazy/cloudy and light polluted - so it can only get better from here

Yes, I'm now going to get myself one of these Ha filters for my OSC

Cheers

Andy