Narrowband (HA) imaging in Moonlight

[Alveprinsen]

So...

Lets say you have a modified DSLR... It is not debayered though, so its still a one-shot color camera...

How about slapping one of those narrow HA band filters in that thing? Would you still be able to capture data (although no where near as efficiently as with a mono CCD camera) during moonlight?

I dont mind letting the scope work for me all night... So if I could image even just a little while the moon is up, it would be totally worth it.

Sincerely, Alveprinsen.

[Luke]

Yes, you can use a H-a filter on a modded DSLR with strong moonlight (though these days I prefer to image the moon on those nights as I am more into webcam imaging now and I love the moon ).

Only the red pixels (1 in every 4 pixels) will be picking up the H-a, but that's not as bad as it sounds. To keep it simple, suppose your camera was 4,000 x 4,000 pixels. You should get about 2,000 x 2,000 pixels with H-a signal, NOT 1,000 x 1,000 (which is what I first thought).

A lovely movie here from Mark Hellweg (though with my 450D I found OIII is not so good in strong moonlight and have had no luck so far with SII, the signal was so weak - so I only used H-a on moony nights):

How to make narrowband filter deep sky images with a DSLR and clip filter for astrophotography

[Alveprinsen]

Yes, you can use a H-a filter on a modded DSLR with strong moonlight (though these days I prefer to image the moon on those nights as I am more into webcam imaging now and I love the moon ).

Only the red pixels (1 in every 4 pixels) will be picking up the H-a, but that's not as bad as it sounds. To keep it simple, suppose your camera was 4,000 x 4,000 pixels. You should get about 2,000 x 2,000 pixels with H-a signal, NOT 1,000 x 1,000 (which is what I first thought).

I am glad to hear that.

I've done imaging without filter at all in strong moonlight, but it washes out pretty much everything but the absolutely brightest targets.

If I get my hands on a EOS clip in filter from Astronomik or something, I should be able to spend those moonlight evenings gathering data as well, instead of simply wasting all that time on my couch in front of the idiot-box.

Gonna check out that movie of yours...

Sincerely, Alveprinsen.

[Alveprinsen]

Oh, btw...

Do you just stack the Ha images with the rest of the RGB images, or do you stack the Ha images alone, and then do some voodoo ritual in Photoshop of somekind?

[Zakalwe]

You combine the data in PS:

http://stargazerslounge.com/topic/113323-adding-ha-to-rgb/